Joseph F McGuire, M.A., Ph.D.

• Assistant Professor of Psychiatry and Behavioral Sciences

https://www.hopkinsmedicine.org/profiles/results/directory/profile/10004044/joseph-mcguire

Telencephalon and diencepahlon enlarge zever herbals buy npxl 30 caps with mastercard, the olfactory bulb develops in the telencephalon herbals that increase bleeding purchase npxl with amex, the hypophysis (pituitary) anlage appears in the diencephalon herbals usa cheap npxl online visa. Neurons herbals for blood pressure purchase npxl 30 caps line, which originate in the basal plate of the spinal cord anlage are e erent (m otor) neurons; neurons herbs uses order npxl 30 caps on-line, which originate in the alar plate, are a erent (sensory) neurons. In bet ween- the eventual thoracic, lum in bar and sacral regions- an additional zone, from which the autonolies m ic neurons originate. Like any other tissue or organ, the nervous system, is built into the overall structure of the hum an body. The connective tissue responsible for their integration into the body are the m eninges. These m em branes completely cover the brain and spinal cord and can be divided into 3 di erent layers (see B). Meninges of the brain and spinal cord de ne a space which is lled with a watery (cerebrospinal) uid. The outer layer of connective tissue (epineurium), com m unicates with the structures of the body also enveloped by connective tissue. Superior view of the m eninges; a and b brain in situ; c view of the dural folds after brain has been rem oved; d layers of m eninges. The m eninges of the brain and spinal cord - from outer to inner layer - are divided into · Dura mater (pachymeninx), outermost layer surrounding the brain and spinal cord consists of tough, collagenous connective tissue. The dura mater participates in the formation of specialized venous sinuses, the intracranial venous sinuses. In addition, one of its inward-directed folds (dural fold), the falx cerebri, connects to the tentorium cerebelli and separates the t wo cerebral hemispheres incompletely dividing the cranial cavit y into compartments (see illustration B, p. The dura mater does not form similar structures in the spinal cord where it forms only the outermost layer. The leptom enix it self divides into t wo layers: ­ arachnoid m ater: It lies bet ween the dura m ater and the ­ pia m ater: It is the innerm ost layer, intim ately at tached to the surface of the brain or spinal cord and is separated from the arachnoid m ater by the subarachnoid space. However, the com m unication bet ween the dura m ater (outerm ost m eningeal layer) and it s environm ent in the cranial cavit y di ers characteristically (and in clinically signi cant ways) when com pared to the vertebral canal. In the cranial cav- it y, the endosteal (inner) layer of the dura m ater also form s the inner periosteum of the cranial bone whereas in the vertebral canal, a real space- the epidural space- separates the dura m ater from the vertebral periosteum (for m ore details, see D, p. The subarachnoid space, which surrounds both the brain and the spinal cord, lies bet ween the arachnoid m ater and pia m ater. Topographically, it represent s the extraneural liquor space which is connected with the intraneural liquor space- the ventricular system com posed of four ventricles and aqueduct (in the brain) and the central canal (in the spinal cord). Due to the pressure gradient, cerebrospinal uid exit s the fourth ventricle, located in the brain stem, through specialized openings and ows into the subarachnoid space. The red-colored areas in (b) m ark the junction/continuit y of the ventricular system with the subarachnoid space. The cavit y of the neural tube and it s folding form s the ventricular system and gives it it s distinct shape (see A, p. It s distinct shape is derived from the form of the brain and spinal cord and how they are surrounded by the m eninges. The convex surface of the brain does not conform everywhere to the internal concave surface of the cranium which leads to the creation of topographically characteristic "enlargem ent s" of the subarachnoid spaces, the cisterns. They do not serve a particular function but are the inevitable result of t wo shapes that are not wholly congruent. Fascicle Epidural space Dura m ater Epineurium Spinal cord Vertebral body a Spinal ganglion, dural sheath has been opened Spinal nerve b Perineurium Endoneurium Nerve fiber D the peripheral nerve and surrounding structures: the epineurium a cut through the vertebral canal with spinal cord; b peripheral nerve, "pulled out like a telescope". The spinal cord (a) is surrounded by m eninges in the sam e way as the brain (see B). It is clearly visible that · the dura m ater (red in a) m erges with the epineurium of the peripheral nerve, · the dura m ater spinalis (unlike the cranial dura m ater) is not rm ly attached to the bone or the inner periosteum. The nerve is com prised of fascicles (nerve ber bundles) which are covered by their own connective tissue sheath- the perineurium. The connective tissue sheath that surrounds the peripheral ganglion corresponds to the epineurium. All complex m otor functions, all perceptions as well as the em ergence of consciousness, are tied to the functional integrit y of the brain. With regard to m orphology, the telencephalon is divided into t wo alm ost sym m etric hem ispheres which are incompletely separated by a longitudinal ssure. Each of the t wo hem ipheres consist s of six lobes, the anterior ends of three of these are called poles. The surface of each lobe is m ade up of folds or gyri, which in part are nam ed for the lobe in which they are located. It can only be viewed from the external aspect once the surrounding brain sections have been pushed aside (see p. A m edial view of the hem isphere shows gyri which are collectively referred to as the lim bic lobe. Within the temporal lobe lies a part of the cortex called the hippocam pus which is only visible after resection of surrounding part s of the brain (see D, p. B Telencepahlon: internal structure a horizontal cut, superior view; b coronal cut, anterior view. An exam ple would be the basal nuclei (nucleus caudatus, putam en, globus pallidus). Portions of the ventricular system - the lateral ventricles- also visiare ble in a horziontal cut. The white m at ter, the m acrosopic appearance of which is largely hom ogeneous, can be functionally divided into tracts, which depending on their course can be further di erentiated. The internal capsule is a white m at ter structure in which num erous tracts concerned with carrying sensory and m otor infom ation are closely grouped together. Phylogenetically, the cortex can be divided into paleocortex (the oldest part of the cerebral cortex), archicortex and neocortex (the most recent part of the cerebral cortex). All part s of the cerebral cortex consist of m ultiple layers of neurons but there are m icroscopic di erences bet ween paleocortex, archicortex and neocortex. Topographically, the diencephalon consist s of structures surrounding the third ventricle found in the m idline of the brain. During em bryonic developm ent, the diencephalon is covered by the fast growing cerebral hem ispheres and sit s above the brainstem. A m id-sagit tal, coronal or horizontal cut through the brain provides a good overview of the diencepahlon using the third ventricle as a reference point. Due to the location of the individual part s of the diencepahlon related to the third ventricle, none of the views allows for a complete overview where all the sections listed below are visible: · In it s upper section, the lateral wall of the third ventricle is form ed by a large paired structure, the thalamus (a ­ d). Both halves of the thalam us lie very closely together and occasionally touch in the region of the interthalam ic adhesion (a). The hypothalam us can be considered the prim ary autonom ic control center for a num ber of body functions (blood pressure, water balance, temperature, food intake, horm one secretion). Lateral to the posterior part of hypothalam us, beneath the thalam us but not involved in form ing the ventricle, lies the subthalamus (b) a group of nuclei concerned with m otor function. A sm all nuclear group- epithalam us- located superior and posthe is terior to the thalam us (d). Looking at the intact diencephalon from below, at the base of the hypothalam us the hypophysis as well as a group of nuclei, the mammillary bodies are visible. Also visible from below are the optic nerve, optic chiasm and the optic tract- portion of the visual pathway. The roof of the third ventricle is form ed by the body of the fornix, a pair of crura form ing a pathway that extends on each side from the hippocampus (a part of the tem poral lobe of the cerebral cortex) to the hypothalam us. Note: the internal capsule delineates the topographical border bet ween the diencephalon and telencephalon. In an intact brain, the brainstem is visible only from basal aspect since laterally and posteriorly it is surrounded by the cerebellum and the tem poral lobes. It has an elongated shape which in situ has a cranial-caudal orientation that is ventrally slanted. The axis of the brain stem is described using the sam e term s of location and direction used for the longitudinal body axis. The brainstem consist s of three brain sections, which from cranial to caudal are the m esencephalon, pons, and m edulla oblongata. The cerebellum, which is not part of the brainstem, is located dorsal to the brainstem and at tached to it by the cerebellar peduncles. Inside the skull, the brainstem lies close to the clivus, a region of the occipital bone. Visible from the out side in a ventral view (a) are · the cerebral peduncles (crura cerebri), composed of tracts descending to the pons, m edulla oblongata and spinal cord, · the basilar pons, containing a large tract that enters the cerebellum, · the pyram id (form ed by the pyram idal tract), and · the olive (a group of nuclei). In dorsal view (b, visible only after the cerebellum has been rem oved): · the quadrigem inal plate (tectum), with t wo paired nuclear groups for auditory and visual function, form ing the roof plate of the m esencepahlon, · the m edulla oblongata with t wo paired tubercula form ed by the posterior funiculus nuclei, · intersection of the three paired cerebellar peduncles which border the brainstem and bet ween which lies the diam ond-shaped base of the fourth ventricle (rhom boid fossa). The rhom boid fossa is form ed partially by the pons and partially by the m edulla which is form ed by the m edulla oblongata. Note: the brainstem is the point of entry and em ergence for all true cranial nerves (for classi cation see p. C Brainstem: compartmental organization and internal structure Cross section of brainstem, superior view. Although they can be found in all segm ents of the brainstem to a greater or lesser degree, they are m ost prom inent in the m esencephalon. The base of the brainstem usually contains large motor tracts descending to the brainstem and the cerebellum. A continuous band of gray mat ter, the substantia nigra, is located directly above the cerebral peduncles. Large groups of nuclei are found here that serve di erent functions (particularly prom inent is the red nucleus). Multiple ascending (sensory) tracts to the telencephalon (over the thalm aus in the diencephalon) and the cerebellum and a few descending tracts to the spinal also occupy the tegm entum. Depending on it s location in the m esencephalon it is either called roof plate or due to its distinct shape (see Bb) the quadrigem inal plate. This roof region contains t wo superior collicular and t wo inferior collicular nuclei which play an important role in the visual and auditory pathways. Sim ilar to the telencepahlon, the cerebellar verm is and hemispheres contain centrally located white m at ter (or m edulla), surrounded by gray mat ter in the form of the cortex. The m orphological appearance of medulla and cortex in a midsagit tal section is called the abor vitae (tree of life). Em bedded within the white m at ter are four paired deep cerebellar nuclei, composed of gray m at ter. The cerebellum is concerned with multiple functions including the unconscious control of balance and ne motor skills. The cerebellum is located dorsal to the brainstem and form s the roof of the fourth ventricle (a). It lies beneath the occipital lobe of the telencephalon from which it is separated by a dural fold- tentorium cethe rebelli, (not shown here, see p. Bet ween the brainstem and cerebellum on both sides is a recess- cerebellopontine angle (b) which is the of clinical signi cance. Like the telencephalon, the cerebellum consists of t wo hem ispheres, which are separated by an unpaired verm is (c). The surface of hem ispheres and verm is shows furrow-like depressions, the ssures, which separate the very thin folia from one another. Fissures and folia of the cerebellum correspond to the sulci and gyri of the telencephalon. The occulonodular lobe (b) one of the m ain subdivisions of the cerebellum, is located inferiorly and consists of the paired occuli, their peduncles, and the nodule of the vermis. All tract s to and from the cerebellum pass through the three paired cerebellar peduncles. Mesencephalon Metencephalon Brainstem Pons Cerebellum Medulla oblongata Rhom bencephalon F Cerebellum and brainstem: Terminolog ical peculiarities Topographically, the cerebellum is not part of the brainstem, yet phylogenetically is derived from it. The com bination of pons, cerebellum and m edulla oblongata, the structures which surround the diam ondshaped fourth ventricle, is called the hindbrain or rhom bencephalon. The three-dim ensional representation (b) shows that the term "horn" is used to describe the threedim ensional nature of the anterior, posterior, and lateral colum ns of gray m at ter. At the central core of gray m at ter lies part of the ventricular system, the central canal of the spinal cord. The gray m at ter of the spinal cord is surrounded by · w hite matter, which is composed of tract s (funiculi) clearly visible in the three-dim ensional representation (c) which are analogous to the colum ns of gray m at ter and are called the anterior, posterior, and lateral funiculi. Occasionally, anterior and lateral funiculi are collectively called the anterolateral funiculus. The spinal cord lies within the vertebral canal, which is form ed by the vertebral foram en of all the vertebrae stacked on top of one another and the ligam ents of the vertebral colum n traversing the vertebrae. From there, only certain parts of the spinal cord, the root s, extend further caudally. The spinal nerve prim arily divides into a posterior ram us (B) and an anterior ram us (D). From this motor neuron originates the motor root of a nerve, which extends to the skeletal muscle; b displays a sensory pathway, which runs within the anterolateral system of the spinal cord. It com es from the skin and extends to the (som atosensory) cerebral cortex passing through interm ediate regions (m ainly the thalam us in the diencephalon). The rst neuron of this tract lies in the spinal ganglion and is therefore a neuron of the peripheral nervous system. For this purpose, the spinal cord contains intersegm ental bers (lateral proper fasciculi, not shown here) located in the white m at ter, which are responsible for relaying inform ation within the spinal cord without exiting it. These are intersegm ental bers which arise from cells in the gray m at ter, and, after a longer or shorter course, reenter the gray m at ter and ram ify in it. In term s of their function, the tract s running through the spinal cord are called extrinsic apparatus and the intersegm ental bers intrinsic apparatus. Knowledge of location, course and function of tract s of the spinal cord is essential for understanding clinical symptom s in case of injuries to , or diseases of, the spinal cord. The necessary blood supply is ensured by t wo paired arteries (a): the larger internal carotid a.

Note: Dysfunction of the upper m otor neurons leads to a central t ype of palsy and dysfunction of the lower m otor neurons to a peripheral palsy (sim ilar to a lesion to the m otor bers in the cranial nerve) herbs pregnancy buy genuine npxl on-line. Since only one part of the facial nucleus is innervated ipsi- and contralaterally herbals usa order npxl 30 caps overnight delivery, a distinction can be m ade bet ween a nuclear or infranuclear lesion palsy (lower m otor neuron or peripheral nerve is a ected) vs herbals images discount 30 caps npxl fast delivery. Synopsis De nition a nd function the control of eye m ovem ent s is extrem ely complex herbals for hair loss discount npxl 30 caps with mastercard. In order to guarantee an unam biguous visual impression herbals interaction with antihistamines npxl 30 caps buy with mastercard, im ages fall on corresponding areas of the retina. The ocular m otor control is m ainly a re exive response m ediated by subcortical centers (see "projections of the retina," p. However, they are not initiated by the precentral gyrus (som atom otor function) but are controlled by a specialized com m and center in the frontal lobe (as opposed to the precentral gyrus), called the frontal eye eld (part of Brodm ann area 8). Neura l wiring a nd topogra phy of pa thwa y the originating neurons are located in the frontal eye eld (in this case, neurons are usually not num bered, thus the term "originating neuron"). Their axons travel along with axons of neurons of the precentral gyrus in the internal capsule as corticonuclear bers. The neurons from area 8 project ipsi- and contralaterally to neurons in the pretectal area (at the diencephalic-m esencephalic junction) and to the reticular form ation and nucleus prepositus. The connections bet ween the cerebellum and the vestibular nuclei, especially the nucleus prepositus, coordinate the m ovem ent s that m aintain balance with the help of eye m ovem ent s. In the brainstem, the m edial longitudinal fasciculus contains bers responsible for interconnecting the nuclei responsible for eye m uscles with the com m and centers and with the vestibular system (see also "brainstem pathways", p. Clinica l correla tions · Only dysfunction of a single m otor nucleus that controls eye m uscles leads to dysfunction of a single m uscle or m uscle group in one eye. Synopsis Essentially, brainstem pathways can be divided into t wo groups: · Longitudinal pathways that exclusively or m ainly pass through the brainstem · Pahways that interconnect nuclei of the brainstem the four m ajor brainstem interconnections are explained below. Longitudina l pa thwa ys (not shown here) Either descending, thus m ainly som atom otor or viscerom otor, or ascending, thus m ainly sensory: · Descending pathways ­ Pyramidal tract (with it s di erent part s, see p. Form ed by several pathways: bers originate from the telencephalon (pallidum), diencepahlon (thalam us), cerebellum and- from the brainstem it self- the red nucleus. These individual pathways com bine to form the central tegm ental tract that ends in the inferior olivary nucleus. The inferior olivary nucleus is therefore a central relay nucleus of the extra-pyram idal m otor system. The hypothalam us as the m ain autonom ic control center interconnect s with parasympathetic nuclei and the gustatory nucleus. At the sam e tim e, there are collaterals reaching the m otor nuclei of cranial nerves involved in chewing, swallowing, sucking, and gagging. Neuron Corticopretectal loop Pretectal area Periaqueductal gray Tegm entum of midbrain Accessory oculom otor nucleus (Edinger-Westphal) Interm ediolateral nucleus (Th 1­ 5) Vestibular nuclei Ciliary ganglion Superior cervical ganglion Ciliary m. This includes not only the conscious perception of visual impressions but encompasses ve di erent functions with the retina (a diencephalic derivative) as the com m on starting point. Visua l pa thwa y Mediates conscious perception and processing of visual impression (color, shape, size, position, m ovem ent, etc. Retinopretecta l pa thwa y · Through control of the visceral m otor innervation m ediates the pupillary light re ex for which sm ooth m uscles are responsible. The EdingerWestphal nucleus m ediates pupil constriction (m iosis) and lens accom odation and the sympathetic neurons are responsbile for contraction of pupillary dilator m uscle (mydriasis). In the rst case, the inform ation is related to the am ount of light that enters the eye, which causes the pupil to dilate or constrict. Since the cerebral visual cortex is not involved, this response can also be triggered in an unconscious patient. In the second case, inform ation about im age sharpness is transm it ted which causes the lens to adjust to shift focus bet ween near and far object s (and thus leads to focusing of the im age). This requires a perception of the actual sharpness by the visual cortex, which m eans that only fully conscious people can respond adequately. Retinotecta l system · Responsible for re ex tracking eye m ovem ents and accom odation. This way, the head and eyes autom atically "follow" the m oving object so that the im age always falls on the site of the sharpest vision in both eyes. Accessory optic system Transm its visual inform ation via the m esencephalon to the vestibular system (to analyze head m otion). Inform ation relayed to the hypothalam us Note: Axons from the nasal retina cross in the optic chiasm (approx. Thus, for all above m entioned system s, axons from both eyes enter the respective relay stations, m eaning bilateral processing of inform ation. For a general overview, the passes through several relay stations to reach the epiphysis (m elatonin production and release). Palatine salivary glands Internal carotid plexus External carotid plexus Facial a. Inferior salivatory nucleus Jugular foram en Subm andibular gland Middle m eningeal a. Red = sym pathetic Blue = parasympathetic Green = carrier Y ellow = canal or foram en A Autonomic ganglia of the head Autonom ic and sensory ganglia of the head can be easily confused. This is why both t ypes are depicted here along with the direction in which the ganglia relay impulses (see arrows). Inside the ganglia, bers of preganglionic neurons from the brainstem term inate at the perikaryon of the postganglionic neurons, which project their axons to the target organs. On their way to the target, the very thin and thus m echanically very sensitive bers use other structures by trav-eling along them, including blood vessels or other nerves running to the sam e region as the autonom ic bers although they serve di erent functions. This is initially confusing which is why the autonom ic bers are represented here in green (parasympathetic) or red (sympathetic) and the "m ain bers" which have nothing to do with the autonom ic bers are represented in blue. All structures m entioned here exit the skull through speci c openings (canals and foram inae) which are represented in yellow. Tubal branch Root of tongue Palatine tonsil Pharynx Tympanic cavit y Auditory tube Ear Dura m ater Pharynx Larynx Bronchi Trachea Esophagus Auricular branch Meningeal branch N. Petrot ympanic fissure Internal branch Bronchial branches Tracheal branches Esophageal branches Solitary nucleus 2. Orange = general som atosensory; proprioception Red = special viscerosensory Purple = special som atosensory Anterior ampullar n. Vestibular labyrinth Saccule Turquoise = general som atosensory; epicritic and protopathic Y ellow = canal or foram en B Sensory gang lia of the head Unlike the autonom ic ganglia, the sensory ganglia contain no synapses. The sensory ganglia contain the bodies of the pseudounipolar or bipolar (in case of the vestibulocochlear n. It s bers pass through the superior ganglion and end in the spinal nucleus of the trigem inal n. Note: the cerebral cortex is the starting and ending point for t wo loops, the basal-ganglia loop and the cerebellar loop. It picks up signals from the basal ganglia and the cerebellum and relays the integrated impulse pat tern to the m otor cortex. At the sam e tim e, the thalam us receives input from the sensory organs ("sensory thalam us"). If these signals are relevant for m ovem ent, the thalam us feeds them into the impulse pat tern as above. Thus, the thalam us is the m ajor integration center for both loops as well as for sensory input. The thalam ic im pulses eventually generate a "complete" detailed m ovem ent program. It is relayed to brainstem centers (red nucleus, reticular form ation, inferior olivary nucleus) for ne tuning. The inferior olivary nucleus represents a particularly signi cant connection of the cerebellar loop toward the spinal cord. The m ovem ent is ultim ately initiated by im pulses from the m otor cortex (m ostly precentral gyrus), which reach the spinal cord via the pyram idal tract (here corticospinal tract) (for voluntary m ovem ent). The spinal cord it self executes the m ovem ent and sends the impulse via the spinal nerves to the corresponding m uscles. Inform ation about the execution of m ovem ent is sent via spinocerebellar tract s from the spinal cord to the cerebellum, which uses this inform ation for constantly m aking postural adjustm ents in order to m aintain balance. The cerebellum does not have direct e erent connections to the spinal cord but can indirectly in uence the spinal cord via the inferior olivary nucleus. The inferior olivary nucleus of the brainstem plays a signi cant role (c): It projects both to the cerebellum and to the spinal cord and receives a erent s from both regions. Additionally, the inferior olive receives a erents from other brainstem nuclei (red nucleus and reticular form ation). All a erents end in the cortex with collaterals ending in cerebellar nuclei (not shown here). Histologically, the olivocerebellar tract is the only one that provides clim bing bers (they directly end on the Purkinje cells in the cortex). All other a erent s end as m ossy bers on the granule cells in the cerebellar cortex. The cerebellar e erent s largely originate from the nuclei (see left side, b) and run either to the thala- m us (feedback loop to the telencephalon (see left side, a) or to brainstem nu-clei, which in turn project to the spinal cord via extrapyram idal tracts and thus control m otor functions (cf. The projection from the vestibular nuclei to the nuclei that control eye m ovem ents help with com pensatory eye m ovem ent s during head m ovem ent. Note: A direct projection of the cerebellum to the spinal cord has not been so far proven in hum ans. There, association pathways connect di erent cortical areas of the sam e hem isphere (they never cross). There are three distinct t ype of association bers: · Arcuate bers (not shown here) connect adjcent gyri. Note: the bers of the vertical occipital fasciculi connect lateral temporal and parietal lobes and cross the occipital lobe. Motor im pulses from the cerebral cortex thus travel to contralateral subcortical centers and in uence m otor activit y of the contralateral side of the body. Y the thalam us itself, is reached by pathways of subordinate et, centers, m ost of which are located contralaterally. Subsequently, sensory impulses to the cerebral cortex originate m ainly from the contralateral side of the body. Exceptions to this basic principle: · Motor function: cortical projections to individual m otor nuclei of cranial nerves (see p. Neuron Superior olivary nucleus Right Lateral lem niscus Red nucleus Cerebellum Pallidum c Inferior olivary nucleus Pyram id (with corticospinal fibers) Rubroolivary tract Olivocerebellar tract Cerebelloolivary fibers Thalam us Inferior olivary nucleus Spinoolivary fibers Olivospinal tract Anuloolivary fibers 2. Neuron Posterior cochlear nucleus Spinal cord A De nition of the terms "olive," "inferior," and "superior olive" and connections of both olives a Brainstem, ventral view; b Cross-section of the m edulla oblongata near the pons- superior view; c Cross-section of m edulla oblongata- inferior view. It is located inside the m edulla oblongata, mediodorsal and largely cranial to the inferior olive and is thus clearly visible on cross-sections directly caudal to the pons (b). Due to the partial overlap of the inferior and superior olive, both nuclear complexes are sometim es visible on sam e cross-sections. Similar term s are used for the superior and inferior olive, which are adjacent topographically. It receives a erent s from the anterior cochlear nucleus (both ipsi-and contralateral); both superior olives are connected and project via the lateral lem niscus to ipsi- and contralateral hierarchically upper nuclei of the auditory pathway. It consists of several nuclei; this is why it is also often referred to as "inferior olivary complex. Connections of the inferior olive: the inferior olive is involved in the coordination of m otor activties and thus extensively connected to other neural regions concerned with m otor functions: · Olivocerebellar and cerebello-olivary tracts: connections with the cerebellum · Olivospinal tract: pathway to the the anterior horn of the spinal cord · Spino-olivary Spinoolivary bers: pathway originating in the spinal cord · Anulo-olivary bers: pathway from the basal ganglia and diencephalon (for more details see p. A lem niscus is not a "new" pathway but rather the nam e of a portion of a pathway. The speci c nam es of the individual lem nisci is based on · their location relative to each other in the brainstem (m edial and lateral lem niscus), · their origin in the spinal cord (spinal lem niscus), or · their origin in a cranial nerve nucleus (trigem inal lem niscus). It starts with the course of the second axon in the brainstem and ends at the entry into the thalamic nucleus (diencephalon). Details follow: · Medial lemniscus (c): Continuation of the fasciculus gracilis or cuneatus. Second neurons (with the bodies in nucleus gracilis or cuneatus) are already in the brainstem. The entire lem niscus is form ed by bers that crossed in the decussation of the m edial lem nisci and ends in the contralateral ventral posterolateral nucleus of the thalam us. The bodies of the second neurons are located in the posterior horn of the spinal cord and all of them decussate while still in the spinal cord; therefore the spinal lem niscus itself does not cross. The spinal lem niscus runs very close to the m edial lem niscus in som e parts of the brainstem; therefore an "individual" course is rarely described. Note: Unlike the other three term s, "spinal lem niscus" is not frequently used; occasionally it is used as a synonym for the lateral spinothalam ic tract. The second neurons (with the bodies in the principal nucleus or spinal nucleus) cross only partially and end in the contra- and ipsilateral ventral posterom edial nuclei of the thalam us. It conveys the epicritic and protopathic sensation from the head (not including the back of the head). Distinctive feature: it divides into an anterior trigem inothalam ic tract (uncrossed bers) and posterior (crossed bers). Due to a particular role of the m esencephalic nucleus, which is discussed in a di erent chapter, this illustration depicts only a part of the trigem inal pathways. Second neurons (with the bodies in the anterior cochlear nucleus) in the brainstem; som e cross and som e rem ain ipsilateral; therefore they end in the contra- and ipsilateral m edial geniculate nucleus (m edial geniculate body) of the thalam us. Distinctive feature: the lem niscus contains "its own nuclei" (nuclei of the lateral lem niscus), which serve as relay stations for the auditory pathway. Superior colliculi Inferior colliculi Anterior cochlear nucleus Commissure of the superior colliculus Com missure of the inferior colliculi Pontine cochlear comm issure Midbrain, tectum Midbrain, tectum Tegm entum of pons (Trapezoid body) Cerebellum; m edulla; close to fastigial nucleus Com missura cerebelli Pathw ays of the spinal cord (Medulla spinalis) Hem isphären des Cerebellum Anterior/posterior white comm issure In each case bet ween the anterior and posterior horns Connection bet ween sym metrical halves of the spinal cord; part of the fasciculi proprii (propriospinal bers) Layer of gray mat ter; Not a real functional comm issure. Synopsis B Decussations Note: the term "decussationes" refers to the crossover of tracts, not to analogous sites on the opposite side but to topographically di erent regions. For instance, the pyram idal tract runs from one cerebral hem isphere to contralateral half of the spinal cord.

As a result herbs uses 30 caps npxl buy amex, blood is "stolen" from the vertebral artery circulation and there is a reversal of blood ow in the vertebral artery on the a ected side (arrows) herbs menopause generic npxl 30 caps without a prescription. This leads to de cient blood ow in the basilar artery and m ay deprive the brain of blood queen herbals purchase npxl 30 caps line, producing a feeling of lightheadedness herbals summit 2015 cheap npxl 30 caps online. This view was selected because m ost of the arteries that supply the brain enter the cerebrum from it s basal aspect herbals for arthritis cheap npxl 30 caps buy online. Note: the three principal arteries of the cerebrum, the anterior, m iddle, and posterior cerebral arteries, arise from di erent sources. The anterior and m iddle cerebral arteries are branches of the internal carotid ar- tery, while the posterior cerebral arteries are term inal branches of the basilar artery (see p. The vertebral arteries, which fuse to form the basilar artery, distribute branches to the spinal cord, brainstem, and cerebellum (anterior spinal artery, posterior spinal arteries, superior cerebellar artery, and anterior and posterior inferior cerebellar arteries). Note: If one of the m ain vessels of the arterial circle rupture due to a defect in the vascular wall (aneurism, see B, p. Blood Vessels of the Bra in Artery of precentral sulcus Artery of central sulcus Artery of postcentral sulcus Posterior parietal artery Prefrontal artery Parietooccipital branch Posterior temporal branch Middle temporal branch C Terminal branches of the middle cerebral artery on the lateral cerebral hemisphere Left lateral view. They can be subdivided into t wo m ain groups: · Inferior term inal (cortical) branches: supply the temporal lobe cortex · Superior term inal (cortical) branches: supply the frontal and parietal lobe cortex. Lateral frontobasal artery Anterior temporal branch Artery of precentral sulcus Artery of central sulcus Artery of postcentral sulcus Posterior parietal artery Prefrontal artery Angular gyral branch Parietooccipital branch Lateral frontobasal artery Anterior tem poral branch Middle temporal branch Posterior tem poral branch D Course of the middle cerebral artery in the interior of the lateral sulcus Left lateral view. It then continues through the lateral sulcus along the insula, which is the sunken portion of the cerebral cortex. When the temporal and parietal lobes are spread apart with a retractor, as shown here, we can see the arteries of the insula (which receive their blood from the insular part of the m iddle cerebral artery; see A). Pericallosal artery Interm ediom edial frontal branch Callosom arginal artery Anterom edial frontal branch Polar frontal artery Medial frontobasal artery Anterior cerebral artery Posterior cerebral artery Anterior temporal branches Posterom edial frontal branch Cingular branch Paracentral branches Precuneal branches Dorsal callosal branch Parietooccipital branch Parietal branch Calcarine branch Posterior temporal branches E Branches of the anterior and posterior cerebral arteries on the medial surface of the cerebrum Right cerebral hem isphere viewed from the m edial side, with the left cerebral hem isphere and brainstem rem oved. The m edial surface of the brain is supplied by branches of the anterior and posterior cerebral arteries. While the anterior cerebral artery arises from the internal carotid artery, the posterior cerebral artery arises from the basilar artery (which is form ed by the junction of the left and right vertebral arteries). Lateral occipital artery, segm ent P3 Interm ediate (m iddle) temporal branches Medial occipital artery, segm ent P4 367 Neuroanatomy 17. Most of the lateral surface of the brain is supplied by the middle cerebral artery (green), whose branches ascend to the cortex from the depths of the insula. The branches of the anterior cerebral artery supply the frontal pole of the brain and the corti- cal areas near the cortical m argin (red and pink). The posterior cerebral artery supplies the occipital pole and lower portions of the temporal lobe (blue). The central gray and white m at ter have a complex blood supply (yellow) that includes the anterior choroidal artery. The anterior and posterior cerebral arteries supply m ost of the m edial surface of the brain. Blood Vessels of the Bra in Anterior cerebral artery Branches to thalam ic nuclei Branch to globus pallidus Posterom edial central arteries Basilar artery Posterior cerebral artery a Anterior cerebral artery Anterolateral central arteries (lenticulostriate arteries) Middle cerebral artery, insular part (M2) Middle cerebral artery, sphenoidal part (M1) b Anterior choroidal artery Middle cerebral artery Anterior choroidal artery Posterior cerebral artery B Distribution of the three main cerebral arteries in transverse and coronal sections a, b Coronal sections at the level of the m am m illary bodies. The internal capsule, basal ganglia, and thalam us derive m ost of their blood supply from perforating branches of the following vessels at the base of the brain: · Anterior choroidal artery (from the internal carotid artery) · Anterolateral central arteries (lenticulostriate arteries and striate branches) with their term inal branches (from the m iddle cerebral artery) · Posterom edial central arteries (from the posterior cerebral artery) · Perforating branches (from the posterior com m unicating artery) the internal capsule, which is traversed by the pyram idal tract and other structures, receives m ost of it s blood supply from the m iddle cerebral artery (anterior lim b and genu) and from the anterior choroidal artery (posterior lim b). If these vessels becom e occluded, the pyram idal tract and other structures will be interrupted, causing paralysis on the contralateral side of the body (stroke: central paralysis, see C on p. These areas are supplied by branches of the three m ain cerebral arteries: · the sensorim otor cortex. Certain disorders or de cit s are indicative of arterial occlusion in a certain territory. A failure, de cit, or outage of the speech center suggest s an occlusion of the m iddle cerebral a. The brainstem and cerebellum are supplied by the basilar and cerebellar arteries (see below). Because the basilar artery is form ed by the union of the t wo vertebral arteries, blood supplied by the basilar artery is said to com e from the vertebrobasilar complex (or system). The vessels that supply the brainstem (m esencephalon, pons, and m edulla oblongata) arise either directly from the basilar artery. The branches are classi ed by their sites of entry and distribution as m edial, mediolateral, or lateral (param edian branches; short and long circum ferential branches). Decreased perfusion in or occlusion of these vessels leads to transient or perm anent impairment of blood ow (brainstem syndrom e) and may produce a great variet y of clinical symptom s, given the m any nuclei and tract system s that exist in the brainstem. The spinal cord, receives a portion of it s blood supply from the anterior spinal artery (see b), which arises from the vertebral artery (see p. Im paired blood ow in the labyrinthine artery leads to an acute loss of hearing (sudden sensorineural hearing loss), frequently accompanied by tinnitus (see D, p. Blood Vessels of the Bra in B Distribution of the arteries of the brainstem and cerebellum in midsagittal section (after Bähr and Frot scher) All of the brain sections shown here and below are supplied by the vertebrobasilar complex. The transverse sections are presented in a caudalto-cranial series corresponding to the direction of the vertebrobasilar blood supply. Superior cerebellar artery Basilar artery Anterior spinal artery and param edian branches of the vertebral artery Inferior colliculi Superior cerebellar artery Red nucleus Posterior cerebral artery Posterior cerebral artery, interpeduncular branches Cerebral peduncle Posterior com m unicating artery Posterior choroidal artery Cerebral aqueduct Anterior inferior cerebellar artery Posterior inferior cerebellar artery Substantia nigra C Distribution of the arteries of the mesencephalon in transverse section Besides branches from the superior cerebellar artery, the m esencephalon is supplied chie y by branches of the posterior cerebral artery and posterior com m unicating artery. Oculom otor nerve Superior m edullary velum Superior cerebellar peduncle Fourth ventricle Basilar artery, long circum ferential branches Basilar artery, short circum ferential branches Basilar artery, pontine and param edian branches Choroid plexus Trigem inal nerve Middle cerebellar peduncle D Distribution of the arteries of the pons in transverse section the pons derives it s blood supply from short and long branches of the basilar artery. Fourth ventricle Posterior inferior cerebellar artery Vagus nerve Anterior inferior cerebellar artery Olive Anterior spinal artery and param edian branches of vertebral artery Hypoglossal nerve E Distribution of the arteries of the medulla oblongata in transverse section the m edulla oblongata is supplied by branches of the anterior spinal artery, posterior inferior cerebellar artery (both arising from the vertebral artery), as well as the anterior inferior cerebellar artery (rst large branch of the basilar artery). Dural venous sinuses are located either in the at tached or free m argins of the dural folds. The larger venous sinuses are those at tached to the inside to the cranial bone. The wall of the venous sinus is sti, consisting only of dura and an endothelial lining. Since sinuses do not have valves, the direction of blood ow depends on the position of the head. When lying down or holding the head upright, the sinuses convey blood to the internal jugular vv. The system of dural sinuses is divided into an upper group and a lower group: · Upper group: superior and inferior sagit tal sinuses, straight sinus, occipital sinus, transverse sinus, sigm oid sinus, and the con uence of the sinuses · Low er group: cavernous sinus with anterior and posterior intercavernous sinuses, sphenoparietal sinus, superior and inferior petrosal sinuses the upper and lower groups of dural sinuses com m unicate with the venous plexuses of the vertebral canal through the m arginal sinus at the inlet to the foramen m agnum and through the basilar plexus on the clivus (see C). Dura m ater, periosteal layer Superior sagit tal sinus Superior sagit tal sinus See detail in B Falx cerebri Inferior sagit tal sinus Cavernous sinus Sphenoparietal sinus Inferior petrosal sinus Straight sinus Transverse sinus Superior petrosal sinus Tentorium cerebelli Internal jugular vein Sigm oid sinus Em issary vein Galea aponeurotica Scalp Extracranial scalp veins Outer table Diploe Inner table Lateral lacuna with arachnoid villi (Pacchionian granulations) Diploic veins Granular foveola Arachnoid septa Dura m ater, m eningeal layer Sinus endothelium Falx cerebri Bridging vein Superior cerebral veins B Structure of a dural sinus, show n here for the superior sag ittal sinus Transverse section, occipital view (detail from A). The sinus wall is com posed of endothelium and tough, collagenous dural connective tissue with a periosteal and m eningeal layer. The sinus also receives em issary veins - valveless veins that establish connections am ong the sinuses, the diploic veins, and the extracranial veins of the scalp. Blood Vessels of the Bra in Superior ophthalm ic vein Anterior intercavernous sinus Venous plexus of foram en ovale Posterior intercavernous sinus Basilar plexus Inferior petrosal sinus Marginal sinus Sphenoparietal sinus Cavernous sinus Petrosquam ous sinus Middle m eningeal vein Superior petrosal sinus Jugular foram en Sigm oid sinus Great cerebral vein Inferior cerebral veins Occipital sinus Tentorium cerebelli Transverse sinus Straight sinus Superior sagit tal sinus Confluence of the sinuses C Dural sinuses at the skull base Transverse section at the level of the tentorium cerebelli, viewed from above (brain rem oved, orbital roof and tentorium windowed on the right side). Venous blood collected deep within the brain drains to the dural sinuses through superf cial and deep cerebral veins (see p. The red arrows in the diagram show the principal directions of venous blood ow in the m ajor sinuses. Because of the num erous anastom oses, the isolated occlusion of even a complete sinus segm ent m ay produce no clinical symptom s. Internal cerebral vein Great cerebral vein Straight sinus Confluence of the sinuses Inferior anastom otic vein (of Labbé) Inferior petrosal sinus Transverse sinus Superior jugular bulb Superficial m iddle cerebral vein Anterior intercavernous sinus Cavernous sinus Parietal em issary vein Superior sagit tal sinus Straight sinus Superior petrosal sinus Occipital em issary vein Occipital vein Confluence of the sinuses Posterior auricular vein Sigm oid sinus Mastoid em issary vein Condylar em issary vein Deep cervical vein Inferior sagit tal sinus Basilar vein Frontal vein Superior ophthalm ic vein Angular vein Inferior ophthalm ic vein Cavernous sinus Venous plexus of foram en ovale Pterygoid plexus Inferior petrosal sinus Retrom andibular vein Facial vein Vertebral vein External jugular vein Internal jugular vein B Accessory drainage pathw ays of the dural sinuses Right lateral view. The dural sinuses have many accessory drainage pathways besides their principal drainage into the t wo internal jugular veins. The connections bet ween the dural sinuses and extracranial veins mainly serve to equalize pressure and regulate temperature. These anastom oses are of clinical interest because their norm al direction of blood ow may reverse (no venous valves), allowing blood from extracranial veins to re ux into the dural sinuses. This m echanism m ay give rise to sinus infections that lead, in turn, to vascular occlusion (venous si- nus thrombosis). The m ost important accessory drainage vessels include the following: · Em issary veins (diploic and superior scalp veins), see C · Superior ophthalm ic vein (angular and facial veins) · Venous plexus of foram en ovale (pterygoid plexus, retrom andibular vein) · Marginal sinus and basilar plexus (internal and external vertebral venous plexus), see C 374 Neuroa natomy 17. Blood Vessels of the Bra in Sagit tal suture Parietal foram en Parietal em issary vein Superior sagit tal sinus Lam bdoid suture Confluence of the sinuses Transverse sinus External occipital protuberance Sigm oid sinus Mastoid em issary vein Condylar canal Parietom astoid suture Occipital foram en Occipital em issary vein Mastoid foram en Venous plexus around the foram en m agnum (m arginal sinus) Mastoid process Venous plexus of hypoglossal nerve canal External vertebral venous plexus Condylar em issary vein Occipital condyle Internal jugular vein Occipital vein C Occipital emissary veins Em issary veins establish a direct connection bet ween the intracranial dural sinuses and extracranial veins. They run through sm all cranial openings such as the parietal and m astoid foram ina. Em issary veins are of clinical interest because they create a potential route by which bacteria from the scalp m ay spread to the dura m ater and dural venous sinuses. The deep veins drain blood from the deeper portions of the white m at ter, basal ganglia, corpus callosum, and diencephalon into the great cerebral vein, which enters the straight sinus. The t wo venous regions (those of the super cial and deep veins) are interconnected by num erous intracerebral anastom oses (see D). Because the veins of the brain do not run parallel to the arteries, m arked di erences are noted bet ween the regions of arterial supply and venous drainage. While all of the cerebral arteries enter the brain at it s base, venous blood is drained from the entire surface of the brain, including the base, and also from the interior of the brain by t wo groups of veins: the superf cial cerebral veins and the deep cerebral veins. The super cial veins drain blood from the cerebral cortex (via cortical veins) and white m at- Superior cerebral veins Superior anastom otic vein (of Trolard) Superior sagit tal sinus Superficial m iddle cerebral vein a Inferior anastom otic vein (of Labbé) Anterior vein of septum pellucidum Thalam ostriate vein Superior cerebral veins Inferior sagit tal sinus Choroid plexus of fourth ventricle Superior sagit tal sinus Great cerebral vein Internal occipital vein Inferior cerebral vein Anterior cerebral vein Internal cerebral vein Basilar vein b Occipital sinus Straight sinus Transverse sinus A Super cial veins of the brain (super cial cerebral veins) Left lateral view (a) and m edial view (b). Just before term inating in the dural sinuses, the veins leave the subarachnoid space and run a short subdural course bet ween the dura m ater and arachnoid. The bridging veins have great clinical importance because they m ay be ruptured by head traum a, resulting in a subdural hem atom a (see p. The veins on the lateral surface of the brain are classi ed by their direction of drainage as ascending (draining into the superior sagit tal sinus) or descending (draining into the transverse sinus). The super cial m iddle cerebral vein drains into both the cavernous and transverse sinuses (see A, p. Olfactory nerve Anterior com m unicating vein Optic tract Interpeduncular vein Inferior choroidal vein Basilar vein Superficial m iddle cerebral vein Anterior cerebral vein Deep m iddle cerebral vein Cerebral peduncle Internal cerebral vein Great cerebral vein Posterior venous confluence C Basal cerebral venous system the basal cerebral venous system drains blood from both super cial and deep cerebral veins. A venous circle form ed by the basilar veins (of Rosenthal, see below) exist s at the base of the brain, analogous to the arterial circle of Willis. The basilar vein is form ed in the anterior perforate substance by the union of the anterior cerebral and deep m iddle cerebral veins. Following the course of the optic tract, the basilar vein runs posteriorly around the cerebral peduncle and unites with the basilar vein from the opposite side on the dorsal aspect of the mesencephalon. The t wo internal cerebral veins also term inate at this venous junction, the posterior venous con uence. This junction gives rise to the m idline great cerebral vein, which enters the straight sinus. The t wo anterior cerebral veins are interconnected by the anterior com m unicating vein, creating a closed, ringshaped drainage system. Superior sagit tal sinus Superficial cerebral veins Medullary anastom otic vein Superficial cerebral veins Medullary vein Longitudinal vein of caudate nucleus Transverse veins of caudate nucleus Choroidal vein Internal cerebral vein Term inal vein Deep m iddle cerebral vein Inferior lenticular veins Vein of centrum sem iovale Superficial m iddle cerebral vein Lateral superior lenticular veins Medial superior lenticular veins D Anastomoses betw een the super cial and deep cerebral veins Transverse section through the left hem isphere, anterior view. The super cial cerebral veins com m unicate with the deep cerebral veins through the anastom oses shown here (see p. Flow reversal (double arrows) may occur in the boundary zones bet ween t wo territories. The temporal and occipital lobes and tentorium cerebelli have been rem oved on the left side to dem onstrate the upper surface of the cerebellum and the superior cerebellar veins. On the lateral walls of the anterior horns of both lateral ventricles, the superior thalam ostriate vein runs toward the interventricular foram en in the groove bet ween the thalam us and caudate nucleus. After receiving the anterior vein of the septum pellucidum and the superior choroidal vein, it form s the internal cerebral vein and passes through the interventricular foram en along the roof of the diencephalon toward the quadrigem inal plate, which contains the superior and inferior colliculi. There it unites with the internal cerebral vein of the opposite side, and the basal veins to form the posterior venous con uence, which gives rise to the great cerebral vein. Veins of caudate nucleus Anterior vein of septum pellucidum Internal cerebral vein Basal vein Posterior vein of corpus callosum Interventricular foram en Superior thalam ostriate vein Superior choroidal vein Lateral vein of lateral ventricle Great cerebral vein Medial vein of lateral ventricle Straight sinus Superior cerebellar veins Confluence of the sinuses Quadrigem inal plate Inferior petrosal sinus Petrosal vein Sigm oid sinus Great cerebral vein Superior vein of verm is Superior petrosal sinus Verm is (Lateral) inferior cerebellar vein (Lateral) superior cerebellar vein (Medial) superior cerebellar vein Transverse sinus Straight sinus (Medial) inferior cerebellar vein Confluence of the sinuses Inferior vein of verm is B Cerebellar veins Posterior view. Like the other veins of the brain, the cerebellar veins are distributed independently of the cerebellar arteries. Larger trunks cross over gyri and sulci, running m ainly in the sagit tal direction. A medial and a lateral group can be distinguished based on their gross topographical anatomy. The m edial group of cerebellar veins drains the verm is and adjacent portions of the cerebellar hem ispheres (precentral vein, superior and inferior veins of the verm is) and the m edial portions of the superior and inferior cerebellar veins. The lateral group (petrosal vein and lateral portions of the superior and inferior cerebellar veins) drains m ost of the t wo cerebellar hem ispheres. All of the cerebellar veins anastom ose with one another; their out ow is exclusively infratentorial. Blood Vessels of the Bra in Internal cerebral vein Inferior sagit tal sinus Thalam ostriate vein Anterom edial anastom osis Anterolateral anastom osis Trigem inal nerve Anterom edian pontine vein Transverse pontine veins Interpeduncular veins Pontom esencephalic vein Superior verm ian vein Superior cerebellar veins Anterolateral pontine vein Basal vein C Reg ion drained by the deep cerebral veins Coronal section. Three principal venous segm ents can be identi ed in each hem isphere: · Thalam ostriate vein · Internal cerebral vein · Basal vein the region drained by the deep cerebral veins encompasses large portions of the base of the cerebrum, the basal ganglia, the internal capsule, the choroid plexuses of the lateral and third ventricles, the corpus callosum, and portions of the diencephalon and m esencephalon. Transverse m edullary veins a Posterom edian m edullary vein Posterior choroidal vein Internal cerebral veins D Veins of the brainstem a Anterior view of the brainstem in situ (the cerebellum and part of the occipital lobe have been rem oved on the left side). The veins of the brainstem are a continuation of the veins of the spinal cord and connect them with the basal veins of the brain. The veins of the m edulla oblongata, pons, and cerebellum m ake up the infratentorial venous system. Great cerebral vein Superior cerebellar vein Trigem inal nerve Superior petrosal vein Accessory basal vein Trochlear nerve Variant of basal vein Lateral m esencephalic vein Lateral m edullary vein Posterolateral medullary vein Dorsal transverse m edullary veins b Posterom edian m edullary vein Caudal cerebellar peduncular vein Vein of cerebellom edullary cistern 379 Neuroanatomy 17. A Extracerebral hemorrhages Extracerebral hem orrhages are de ned as bleeding bet ween the calvaria and brain. Because the bony calvaria is im m obile, the developing hem atom a exert s pressure on the soft brain.

He is to be referred to the fracture clinic sathuragiri herbals generic npxl 30 caps without prescription, but what is the most appropriate initial treatment A 38-year-old car mechanic has sustained an open fracture of the shaft of the fifth metacarpal of his dominant hand herbs denver npxl 30 caps purchase without a prescription. He has an angulation of 50° on a lateral view but you decide to manage it non-operatively bajaj herbals purchase npxl discount. Which of the following statements best describes the rationale behind this approach Malunion will be compensated by the relatively mobile fifth carpometacarpal joint B herbals india chennai buy 30 caps npxl with amex. Which of the following is an indication for removal of the nail for nail bed injuries Facing the ulna the radial tuberosity should face the ulna on the anteroposterior projection of the forearm zip herbals mumbai order discount npxl line. While not exclusive it tends to be true that fractures more proximal than the distal 7. The stabilizing effect of soft-tissue constraints in artificial Galeazzi fractures. Central band of the interosseous ligament the intraosseous membrane controls motion between the radius and the ulna. Median nerve dysfunction All these complications can occur, but median nerve dysfunction is extremely common. Immobilization in a simple forearm cast Stable undisplaced fractures are suitable for non-operative treatment. The scapholunate is normally widened on radiographs as the scapholunate ligament is torn as the bones separate. Failure to debride adequately the risk of infection following open fractures with simple wounds is 1. Several of the factors mentioned are related to an increased risk of infection but the most important factor is the failure to debride adequately. Middle Because the middle finger is the longest it has the highest incidence of nail tip injuries. Haematoma of 50% of the nail bed the indication for removal of a nail for nail bed injuries is a broken nail with disrupted edges or a haematoma affecting over 50% of the nail bed. Disruption of the iliopectineal line on an anteroposterior radiograph suggests a fracture of which of the following structures of the acetabulum Which of the following would be the preferred approach for a posterior column acetabular fracture A 45-year-old woman suffering from schizophrenia jumps from a motorway bridge approximately 20 m high. Open reduction and internal fixation of the injuries on the next available list C. An 80-year-old woman who lives independently and walks with a stick falls and sustains a minimally displaced intracapsular fracture to the neck of her femur. Closed reduction and internal fixation on the next available trauma list (>6 hours) B. A 45-year-old woman was knocked over whilst shopping, sustaining a displaced intracapsular fracture to the neck of her femur. Which of the following is not true for reamed femoral nails compared with unreamed nails Which of the following statements about the treatment of distal femoral fractures is accurate Locked plates may improve construct stability in the presence of osteoporotic bone C. Restoration of the distal femoral anatomical axis to 5­7° of varus leads to improved longterm outcomes E. A patient sustains a fracture around a stable, previously well fixed femoral component of a total hip arthroplasty. A 73-year-old woman falls and sustains a supracondylar fracture of her distal femur. Lewis and Rorabeck described a classification system for periprosthetic fractures of the knee: assuming this woman has a displaced periprosthetic fracture around a well-fixed, well-functioning arthroplasty how would her fracture be classified The anterior cruciate ligament has two bundles: an anteromedial bundle that is tight in extension and a posterolateral bundle that is tight in flexion B. The posterolateral corner consists of the lateral collateral ligament, the popliteal tendon complex, the popliteofibular ligament, and the posterolateral capsule E. The superficial medial collateral ligament provides the primary restraint to a valgus force in 30° of knee flexion 13. Anterior column the iliopectineal line represents the anterior column and the ilioischial line the posterior column. The medial aspect of the acetabulum is represented by the teardrop and the weightbearing dome by the sourcil. Modified Moore (Southern) the modified Moore (Southern) approach is also known as the Kocher­Langenbach approach and allows access to the posterior wall and posterior column of the acetabulum. Whilst in theory the extended iliofemoral and triradiate approaches would also allow access, they are much larger, with significant morbidity and complications. The traction pin through the distal femur is preferred to avoid ligamentotaxis on the knee ligaments. The position of the screw within the head is recommended to be inferior and central. Awareness of tip-apex distance reduces failure of fixation of trochanteric fractures of the hip. Hemiarthroplasty this woman should be treated with a hip hemiarthroplasty with a proven implant other than an Austin Moore or Thompsons. Total hip replacement should be reserved for patients who are younger than 75 years of age, who walk independently outside with no more than a stick, who are not cognitively impaired, and who are medically fit for anaesthesia and the procedure. Delayed time from injury to surgery Loizou and Parker prospectively studied 1023 patients who were treated for an intracapsular fractured neck of the femur with some form of internal fixation. Avascular necrosis after internal fixation of intracapsular hip fractures; a study of the outcome for 1023 patients. The mortality of younger women with hip fracture was 46 times that of the background mortality of the female population. This study also found that a female patient under 65 was almost five times more likely to sustain a hip fracture if she was a smoker. Epidemiology and outcome of fracture of the hip in women aged 65 years and under: a cohort study. Higher rates of pulmonary complications There are no clinical studies demonstrating that reamed nailing results in an increase in pulmonary complications, but the other statements have been clinically demonstrated. Locked plates may improve construct stability in the presence of osteoporotic bone Despite the availability of multiple fixation techniques, union rates are only moderate. The pull-out strength of locked constructs in osteoporotic bone has been shown to be superior to non-locked ones. Comparison of the 95-degree angled blade plate and the locking condylar plate for the treatment of distal femoral fractures. The Vancouver classification of periprosthetic fractures of the hip was described in order to help with management decisions on the treatment of these fractures. Fractures around the stem or extending slightly distal to it are classified as Vancouver B. This group is further divided according to whether the implant is solidly fixed (B1) or loose (B2). If the femoral component is loose and there is severe bone stock loss, whether caused by generalized osteopenia, osteolysis, or severe comminution, the fracture is classified as type B3. Fractures of the femur, tibia, and patella after total knee arthroplasty: decision making and principles of management. The functions of the fibre bundles of the anterior cruciate ligament in anterior drawer, rotational laxity and the pivot shift. In the Lauge-Hansen classification system which of the following accounts for the majority of fracture types A Weber C-type fibula fracture, most commonly seen as part of an ankle injury, is classified in the Lauge-Hansen system as what What is the classical radiographic feature of a supination­adduction injury to the ankle Which of the following is not a feature of a pronation­abduction fracture pattern She sustains an injury to her right foot by trapping it in a rabbit hole and twisting it. Anteroposterior and lateral radiographs of the foot show no obvious fractures or dislocation except for a small fleck of bone avulsion at the base of the second metatarsal. Which of the following is the most common orientation for fractures of the navicular A 43-year-old man presents to the fracture clinic after a minor twisting injury to his right foot whilst dancing at a party. Radiographs suggest a simple fracture of the base of the fifth metatarsal, at the junction of metaphysis and diaphysis. A 34-year-old man who enjoys running and cycling presents with a 3-week history of mild ache over the lateral border of his left foot. His symptoms are getting worse and he has had to stop running in the last few days. Y type Coronal splits occurred in 60 out of 96 pilon fractures, with sagittal split in the remainder. Of the coronal fractures, a V-type fracture occurred in 15/60, Y-type in 23/60, anterior split in 8/60, and posterior split in 6/60. Supination­external rotation Approximately 85% of ankle fractures are of the supination­external rotation type. Pronation­external rotation Stage 4 Pronation­external rotation injuries classically have a high fibula fracture as their final stage. Vertical medial fracture Supination­adduction injuries start on lateral side with rupture of ligaments or fibular failing in tension (below the syndesmosis). Infracollicular fractures or transverse fractures represent traction injuries that do not occur in supination­adduction. The classical feature is the vertical or oblique fracture line of the medial malleolus as this is pushed off by the talus driven into adduction. Distal anterior­proximal posterior fibular fracture Pronation­abduction injuries start with medial side first, either medial malleolar fracture or deltoid rupture. They progress posteriorly then to the lateral side with abduction force producing a medial distal­proximal lateral pattern or bending wedge pattern (transverse with wedge) of the fibula. Distal anterior and proximal posterior oblique-spiral fractures planes are classic signs of supination­ external rotation injuries and are most clearly seen on lateral view. Simplified diagnostic algorithm for Lauge-Hansen classification of ankle injuries. Reduction of dislocated fragments should be carried out emergently if possible to reduce risk of skin necrosis and further complications. Anatomical reduction has a significant impact on functional outcome and should be the aim wherever possible. Medial Medial dislocation is found in the majority of cases (80%), with lateral dislocation accounting for 15% and posterior and anterior dislocation occurring rarely (1%). These primary fracture lines resulted in the fracture patterns with which we are familiar, including the joint depression and tongue type. The tongue type represents the superolateral portion attached to the Achilles tendon, as described by Essex-Lopresti. Experimental intra-articular calcaneal fractures: anatomic basis for a new classification. Standing weight-bearing views of both feet as well as oblique radiographs the suspicion is that this woman has a subtle Lisfranc injury to her midfoot, unless proven otherwise. The next investigation should be weight-bearing radiographs of both feet, including proper lateral views. Often, the mild diastasis between the first and second metatarsal base is better appreciated on weight-bearing views. There may be a small step at the medial cuneiform­second metatarsal base, which should be carefully compared with the contralateral side. Additionally, you should look for any dorsal subluxation of the second metatarsal base and the classic bruise at the base of the second metatarsal (plantar aspect). The diagnostic accuracy of radiographs in Lisfranc injury and the potential value of a craniocaudal projection. Plantar ecchymosis sign: a clinical aid to diagnosis of occult Lisfranc tarsometatarsal injuries. Dorsolateral­medial plantar the navicula typically fractures along a predictable plane due to the often forceful pull of the tibialis posterior tendon attachment. Jones fracture this fits the classic description by Sir Robert Jones, who suffered this type of injury himself while dancing. This should be differentiated from a simple avulsion fracture of the base of the fifth metatarsal. Jones fractures occur at the metaphyseal­diaphyseal junction and are prone for delayed/non-union. The traditional recommendation is for a non-weight-bearing cast for 6 weeks, although internal fixation with a screw can be considered based on the needs of the individual patient. Acute fractures to the proximal fifth metatarsal bone: development of classification and treatment recommendations based on the current evidence. Stress fracture Some fractures of the fifth metatarsal occur in diaphysis, often as a result of repetitive stress in runners and athletes. They range from an undisplaced fracture to established fracture with sclerosis at the fracture site and in the cortex.

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References

• Farthing MJ. Diarrhoeal disease: current concepts and future challenges. Pathogenesis of giardiasis. Trans R Soc Trop Med Hyg 1993;87(suppl 3):17.
• Giesbrecht GG: Cold, stress, near drowning, and accidental hypothermia: a review. Aviat Space Environ Med 71:733, 2000.
• Zhang W, Doherty M, Leeb BF, et al. EULAR evidence- based recommendations for the diagnosis of hand osteoarthritis: report of a task force of ESCISIT. Ann Rheum Dis 2009; 68(1):8-17.
• Boysen G, Barbieri CE, Prandi D, et al: SPOP mutation leads to genomic instability in prostate cancer, Elife 4:e09207, 2015.
• Bentley RB, Sgouros S, Natarajan K, et al. Changes in orbital volume during childhood cases of craniosynostosis. J Neurosurg 2002;96:747-754.
• Stockman JA, Graeber JE, Clark DA, et al. Anemia of prematurity: Determinants of the erythropoietin response. J Pediatr. 1984;105:786.