Justin M. Sacks, MD

  • Assistant Professor
  • Department of Plastic Surgery
  • Division of Surgery
  • University of Texas
  • MD Anderson Cancer Center
  • Houston, Texas

Its collateral ligaments are inextensible; the cruciate ligaments limit gliding and distraction of the bones; quadriceps anteriorly and gastrocnemius and hamstrings posteriorly stabilize the joint anxiety 30001 discount asendin 50mg with visa. Quadriceps tends to pull the patella laterally because of the obliquity of the femur existential depression definition cheap asendin express, but the displacement is limited by the projection of the lateral condyle of the femur and by the resistance provided by the horizontally attached fibres of vastus medialis into the medial border of the patella postnatal depression definition medical buy asendin 50 mg overnight delivery. When standing on the extended knee the centre of gravity passes in front of the axis around which the femoral condyles roll; the posterior cruciate ligaments thus take the strain depression for dummies buy 50 mg asendin mastercard. It is often due to a flat lateral femoral condyle or weakness in the lower fibres of vastus medialis anxiety x blood and bone mp3 discount 50 mg asendin visa. Nerve supply this is by branches of the tibial depression symptoms head pressure order cheap asendin online, common peroneal (fibular), obturator and femoral nerves. Relations the joint is mainly subcutaneous, being separated from the skin by quadriceps, the patella and patellar ligament anteriorly, the biceps tendon laterally and semimembranosus and semitendinosus medially. To its posterior lie the popliteal vessels and, more superficially, the tibial and common peroneal (fibular) nerves in the popliteal fossa. Anteriorly are the suprapatellar, which extends into the thigh deep to quadriceps and communicates with the knee joint, and the prepatellar, superficial and deep infrapatellar, which are related to the patellar ligament. Posteriorly lie the popliteal bursa, deep to its muscle, and one associated with the gastrocnemius deep to its medial head. Both communicate with the knee joint and the semimembranosus bursa, which lies between the muscle and the medial head of gastrocnemius. This can be detected by the patellar tap: pushing the patella towards the femoral condyle results in a palpable contact between the two bones, which is caused by fluid separating the patella and the femoral condyles, and indicates excessive fluid in the knee joint. The superior tibiofibular joint is a plane synovial joint between the undersurface of the lateral tibial condyle and the articular facet of the head of the fibula. The inferior tibiofibular joint is a fibrous joint between the adjacent inferior surfaces of the two bones. The interosseous membrane unites the interosseous borders of the two bones and gives attachment to the deep flexor and the extensor muscles of the leg. Its floor is the posterior surface of the femur, the knee joint capsule and the popliteus muscle, and it is roofed by thickened fascia lata that is pierced here by the small saphenous vein. It contains the popliteal vessels and branches, the tibial nerve, the common peroneal (fibular) nerve and branches and a few lymph nodes. Any swelling within the fascial compartment as a result of bleeding, infection or venous obstruction produces a rise in the intracompartmental pressure that will hinder its blood supply and produce tender, swollen muscles (compartment syndrome). A fasciotomy incision the length of the compartment is necessary to reduce the pressure within the fascial compartment. The anterior (dorsiflexor) group of muscles Only tibialis anterior is attached to the tibia; the others are each attached to the fibula (Table 16. During walking these muscles pull the leg forwards over the grounded foot; when the foot is not bearing weight they dorsiflex the foot and toes. In the foot is the extensor digitorum brevis, attached proximally to the anterior part of the upper surface of the calcaneus and distally by four small tendons to the medial four toes. The two extensor retinacula lie across the extensor tendons in the lower leg and in front of the ankle joint. The superior extensor retinaculum is a thickening of deep fascia, about 3 cm wide, stretching between the anterior border of the tibia and fibula over the extensor tendons, the anterior tibial vessels and the deep peroneal (fibular) nerve. The inferior extensor retinaculum is thicker and bifurcates, extending medially from the upper surface of the calcaneus and then splitting into two parts in front of the ankle joint; the upper part is attached to the medial malleolus and the lower blends with the plantar aponeurosis. The posterior (plantar flexor) group of muscles these help in propelling the body forwards during walking by plantar-flexing the grounded foot (Table 16. Both gastrocnemius and soleus are powerful plantar flexors of the foot and are thus important in posture and locomotion. Between and within the muscles are extensive deep plexuses of veins; contraction of these calf muscles pumps the blood within them towards the heart against gravity. Rupture may be partial or complete; conservative treatment is adequate for partial tears but complete tears may require surgical treatment. The ankle reflex is demonstrated by tapping the tendon with a tendon hammer, easiest shown with the patient in the kneeling position. Each tendon is enclosed in a separate synovial sheath, those of flexor hallucis longus and flexor digitorum longus passing into the sole of the foot. It descends from the adductor hiatus to the lower border of popliteus, where it divides into the anterior and posterior tibial arteries. The popliteal pulse is not easy to feel because the artery lies deep in the popliteal fossa. Beyond the ankle it continues as the dorsalis pedis artery, which, in the foot, anastomoses with the lateral plantar artery. The dorsalis pedis artery can be palpated over the tarsal bones, just lateral to the extensor hallucis longus tendon. The posterior tibial artery descends through the flexor compartment of the leg alongside the tibial nerve. Its largest branch, the peroneal (fibular) artery, descends in the lateral (peroneal [fibular]) compartment. Medial head of gastrocnemius Popliteus Popliteal artery continuous with femoral at the adductor hiatus Sciatic nerve Common peroneal (bular) nerve Lateral head of gastrocnemius Tibial nerve Divided attachment of soleus Divided peroneus (bularis) longus Flexor hallucis longus Tibial nerve the popliteal vein the popliteal vein is formed by the union of the anterior and posterior tibial veins, crosses the popliteal fossa and passes through the adductor hiatus. It descends along the lateral margin of the fossa and enters peroneus (fibularis) longus, where it divides into superficial and deep peroneal (fibular) nerves. In the calf it descends deep to soleus, on tibialis posterior at first and the ankle joint later. Branches It supplies all the muscles of the posterior compartment and sensation to the knee joint and lower leg. The sural nerve, a cutaneous branch, descends on gastrocnemius and unites with a branch of the common peroneal (fibular) nerve halfway down the calf to run alongside the small saphenous vein behind the lateral malleolus to the lateral side of the foot. It supplies the skin over the posterior calf, the ankle joint and the lateral surface of the foot. It supplies peroneus (fibularis) longus and brevis, and provides cutaneous branches to the lower lateral leg and, by its dorsal cutaneous branches, which descend over the extensor retinacula, the dorsum of the foot. It passes under the extensor retinacula to divide into medial and lateral terminal branches. This is also a useful landmark for the level of the 2nd sacral vertebra and the termination of the thecal sac. A 50-year-old carpet fitter is complaining of a painful swelling close to his knee. The tendon of which muscle is stretched during the execution of the patellar reflex Answer b the patellar ligament provides the insertion of quadriceps femoris into the patella. The stretch reflex caused by the patella hammer is elicited by the femoral nerve carrying fibres from the L3 nerve roots. Tibialis posterior Match the following statements with the muscle(s) in the above list. Tibialis posterior Match the following nerves and statements with the muscle(s) in the above list. The superior extension of the knee joint, known as the suprapatellar bursa, may sustain an anterior penetrating wound which, because of its connection with the knee joint, may cause a septic arthritis. Any effusion in the knee, whether caused by trauma, inflammation or infection, is clinically evident by detectable swelling of the suprapatellar bursa. The popliteal pulse is difficult to palpate in most people because it is the deepest lying structure in the popliteal fossa. Having pierced the adductor magnus at the adductor hiatus, it lies deep to its vein, which is in turn deep to the tibial nerve in the popliteal fossa. All these structures are embedded in fat, and both the artery and the vein are additionally surrounded by a tough fibrous sheath. Flexion of the knee, which allows relaxation of nerve and sheath, often facilitates palpation. At this site the common peroneal (fibular) nerve winds into the lateral, and later the anterior, compartment of the lower leg and is easily damaged. The branches of the common peroneal (fibular) nerve are the superficial and deep peroneal (fibular) nerves. The deep nerve runs with the anterior tibial artery to supply the extensor group of muscles, including tibialis anterior, whereas the superficial peroneal (fibular) nerve supplies the peroneal muscles, which are the major evertors of the foot. Damage to the deep peroneal (fibular) nerve therefore results in an inability to dorsiflex the foot, whereas an injured superficial peroneal (fibular) nerve results in an inverted foot. On his arrival at hospital it is noticed that he has a very swollen lateral side of the knee and lower leg, and that he cannot dorsiflex his foot. The foot is also important as a source of proprioceptive information essential to the maintenance of balance during both standing and walking. This broad articular facet is continuous with a facet on each side of the bone for articulation with the medial and lateral malleoli; the three articular surfaces are known as the trochlear surface of the talus. The concave inferior surface of the body articulates with the posterior facet on the calcaneus. The posterior margin bears a posterior tubercle that gives attachment to the posterior talofibular ligament. Its upper surface has posterior, middle and anterior articular facets for the talus. The middle facet lies medially on the prominent sustentaculum tali, which gives attachment to the calcaneonavicular ligament (spring ligament). Behind the facet is a deep groove, the sulcus calcanei, which, with the sulcus tali, forms a tunnel, the sinus tarsi, which houses the strong talocalcaneal ligament. The inferior surface has an anterior tubercle to which is attached the short plantar ligament and, posteriorly, the medial and lateral processes on the weight-bearing tuberosity, to which are attached the long plantar ligament, the short muscles of the sole and the plantar aponeurosis. On the lateral surface is the peroneal (fibular) tubercle, separating the tendons of peroneus (fibularis) longus and brevis. The posterior surface gives attachment to the tendo calcaneus and the anterior surface articulates with the cuboid bone. The navicular bone lies on the medial side of the foot and articulates with the talus posteriorly and the three wedged-shaped cuneiform bones anteriorly. Its medial surface extends down to form the prominent and palpable navicular tuberosity, to which are attached tibialis posterior and the calcaneonavicular ligament. It articulates with the calcaneus posteriorly, the bases of the 4th and 5th metatarsals anteriorly and the lateral cuneiform medially. Its inferior surface gives attachment to the long plantar ligament, and it has a marked groove for the tendon of peroneus (fibularis) longus. The three wedge-shaped cuneiforms articulate posteriorly with the navicular and anteriorly with the bases of the three medial metatarsals. To the medial cuneiform are attached the tendons of tibialis anterior and posterior and peroneus (fibularis) longus. The metatarsals and phalanges of the foot resemble those of the hand, but the metatarsals are longer and more slender. An accessory ligament, the inferior transverse tibiofibular ligament, a thick band between the two malleoli across the back of the talus, is covered with hyaline cartilage and deepens the articular surface between it and the talus. The tarsal joints the most important tarsal joints are: Stability this is a stable joint maintained by the mortise arrangement of its bones and strong ligaments. The centre of gravity passes anterior to the joint, and as the foot is dorsiflexed on the grounded foot the tibiofibular mortise firmly grips the wider anterior talar surface, i. Anteriorly it is crossed, medial to lateral, by the tendons of tibialis anterior and extensor hallucis longus, the anterior tibial vessels and deep peroneal (fibular) nerve, and the tendons of extensor digitorum longus. Posteromedially, from medial to lateral, it is crossed by tendons of tibialis posterior and flexor digitorum longus, the posterior tibial vessels and tibial nerve, and the tendon of flexor hallucis longus. The tendons of peroneus (fibularis) longus and brevis cross the joint posterolaterally. The collateral ligaments of the ankle, the deltoid and the lateral ligament can be partially or completely torn by forcible eversion or inversion injuries. Inversion injuries are the most common and result in sprains or tears to the lateral ligament, especially its calcaneofibular and anterior talofibular components. The capsule is partly thickened by talocalcaneal bands, but the strongest union is provided by the interosseous talocalcaneal ligament in the sinus tarsi, which is taut in eversion. The capsule is reinforced by the spring ligament, the deltoid ligament and the bifurcate ligament (see below). The bifurcate ligament is attached proximally to the upper surface of the calcaneus and distally to the upper cuboid and navicular. The long plantar ligament passes between the posterior calcaneal processes to the ridges on the inferior surface of the cuboid and the bases of the lateral metatarsals.

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Comparison with a random mix is made because this is theoretically likely to be the best mix that is practically achievable mood disorder nos criteria generic asendin 50mg. There would therefore be practical difficulties in making this product land depression definition order 50mg asendin overnight delivery, as particles of this size tend to become very cohesive depression symptoms singapore order asendin 50 mg without a prescription, flow poorly (see Chapter 12) and are difficult to mix bipolar depression dsm code order asendin 50 mg with amex. In order to appreciate the effect of changing the scale of scrutiny mood disorder dsm 4 code buy asendin 50 mg fast delivery, it is suggested that the reader calculate in a similar manner what particle size would be required if the tablet weight was increased to 250 mg gun depression definition discount generic asendin canada. It should be remembered that the tablet weight or scale of scrutiny will affect both the number of particles present and the proportion of active component. Other more complicated equations for calculating the mixing index have been used but they all tend to rely on similar principles to those described. In order to evaluate a mixing process in this way, there are two basic requirements. First, a sufficient number of samples which are representative of the mix as a whole must be analysed. A minimum of 10 samples is usually analysed, these being removed from different depths into the mixer and from the middle and sides. Areas where blending may potentially be poor should also be included in the sampling. Venables & Wells (2001) have discussed some of the problems associated with removing representative samples and analysing powder blends. When mixing formulations where the proportion of active component is high, it is possible to achieve an acceptably low variation in content without obtaining a random mix. Thus it may be possible to stop the mixing process before a random mix is achieved and therefore reduce manufacturing costs. The quality of a mixture may be assessed by its ability to meet predefined specification limits. Other potential advantages include the speed and nondestructive nature of the analysis. The reader is referred to texts by Bakeev (2010) and Ciurczak & Igne (2014) for further information. Mechanisms of mixing and demixing Powders In order that powders may be mixed, the powder particles need to move relative to each other. There are three main mechanisms by which powder mixing occurs: namely, convection, shear and diffusion. Convective mixing arises when there is the transfer of relatively large groups of particles from one part of the powder bed to another. Mixing does not, however, occur within the group of particles moving together as a unit, and thus in order to achieve a random mix, an extended mixing time is required. In order to achieve a true random mix, movement of individual particles is required. This arises because the powder particles become less tightly packed and there is an increase in the air spaces or voids between them. Under these circumstances there is the potential for the powder particles to pass through the void spaces created either under gravitational forces. Which mechanism predominates and the extent to which each occurs will depend on the mixer type, mixing process conditions (mixer load, speed, etc. Bulk transport is analogous to the convective mixing of powders and involves the movement of a relatively large amount of material from one position in the mix to another. It too tends to produce a large degree of mixing fairly quickly, but leaves the liquid within the moving material unmixed. Turbulent mixing arises from the haphazard movement of molecules when forced to move in a turbulent manner. The constant changes in speed and direction of movement mean that induced turbulence is a highly effective mechanism for mixing. Within a turbulent fluid there are, however, small groups of molecules moving together as a unit, referred to as eddies. These eddies tend to reduce in size and eventually break up, being replaced by new eddies. Turbulent mixing alone may therefore leave small unmixed areas within the eddies and in areas near the container surface, which will exhibit streamlined flow (see Chapter 6). Mixing of individual molecules in these regions will occur by the third mechanism, which is molecular diffusion (analogous to diffusive mixing in powders). This will occur with miscible fluids wherever a concentration gradient exists, and will eventually produce a well-mixed product, although considerable time may be required if this is the only mixing mechanism. In most mixers all three mechanisms will occur, bulk transport and turbulence arising from the movement of a stirrer or mixer paddle set at a suitable speed. If segregation of granules occurs in the hopper of a filling machine, an unacceptable variation in weight may result. Segregation arises because powder mixes encountered in practice are not composed of monosized spherical particles but contain particles that differ in size, shape, density and surface properties. These variations in particle properties mean that the particles will tend to behave differently when forced to move and hence tend to separate. Particles exhibiting similar properties tend to congregate together, giving regions in the powder bed which have a higher concentration of a particular component. Segregation is more likely to occur, or may occur to a greater extent, if the powder bed is subjected to vibration and when the particles have greater flowability. Particle size effects Differences in the particle sizes of components of a formulation are the main cause of segregation in powder mixes in practice. Smaller particles tend to fall through the voids between larger particles and thus move to the bottom of the mass. Percolation can occur whenever a powder bed containing particles of different sizes is disturbed in such a way that particle rearrangement occurs. During mixing, larger particles will tend to have greater kinetic energy imparted to them (owing to their larger mass) and therefore move greater distances than smaller particles before they come to rest. This may result in separation of particles of different size, an effect referred to as trajectory segregation. This effect, along with percolation segregation, accounts for the occurrence of the larger particles at the edge of a powder heap when it is poured from a container. When the mixer is stopped or material discharge is complete, these particles will Powder segregation (demixing) Segregation is the opposite effect to mixing, i. This is very important in the preparation of pharmaceutical products because if it occurs, an already formed random mix may change to a nonrandom mix, or a random mix may never be achieved. Care must be taken to avoid segregation occurring during handling after powders have been satisfactorily mixed. Segregation will cause an increase in content variation in samples taken from the mix, i. This is called elutriation segregation and is also referred to as dusting out or fluidization segregation. Trajectory segregation may also occur with particles of the same size but different densities due to their difference in mass. The effect of density on percolation segregation may be potentiated if the denser particles are also smaller. Often materials used in pharmaceutical formulations have similar densities and density effects are not generally too important. An exception to this is in fluidized beds, where density differences often have a greater adverse effect on the quality of the mix than particle size differences. Particle shape effects Spherical particles exhibit the greatest flowability and therefore are more easily mixed, but they also segregate more easily than nonspherical particles. Irregular or needle-shaped particles may become interlocked, decreasing the tendency to segregate once mixing has occurred. It should be remembered that the particle size distribution and particle shape may change during processing (due to attrition, aggregation, etc. This may not, however, occur for segregating mixes, where there is often an optimum mixing time. This arises because the factors causing segregation generally require a longer time to take effect than the time needed to produce a reasonable degree of mixing. During the initial stages of the process, the rate of mixing is greater than the rate of demixing. After a period of time, however, the rate of demixing may predominate, until eventually an equilibrium situation will be reached where the two effects are balanced. Approaches to minimize segregation If segregation is a problem with a formulation, there are a number of approaches that may be attempted to rectify the situation. Pharmaceutical powder mixes are therefore likely to be partly ordered and partly random, the extent of each depending on the component properties. With an ordered mix, it may be possible to achieve a degree of mixing which is superior to that of a random mix, which may be beneficial for potent drugs. Ordered mixing has been shown to be important in direct-compression tablet formulations (see Chapter 30) in preventing segregation of the drug from direct compression bases. Dry powder inhaler formulations also utilize ordered mixing to deliver drugs to the lungs (see Chapter 37). In this case the drug needs to be in a micronized form in order to reach its site of action. By adsorbing the drug onto larger carrier particles (usually lactose), it is possible to manufacture a product which will provide an even dosage on each inhalation. Ordered mixing It would be expected that a mix composed of very small and much larger particles would segregate because of the size differences. This has the effect of minimizing segregation while maintaining good flow properties. It was first noticed by Travers & White (1971) during the mixing of micronized sodium bicarbonate with sucrose crystals when the mixture was found to exhibit minimal segregation. The phenomenon is referred to as ordered mixing, as the particles are not independent of each other and there is a degree of order to the mix. If a carrier particle is removed, then some of the adsorbed smaller particles will automatically be removed with it. Ordered mixing has also been used in the production of dry antibiotic formulations to which water is added before use to form a liquid or syrup product. In these cases, the antibiotic in fine powder form is blended with, and adsorbed onto the surface of, larger sucrose or sorbitol particles (Nikolakakis & Newton, 1989). Ordered mixing probably occurs to a certain extent in every pharmaceutical powder mix due to interactions and cohesive/adhesive forces between constituents. If there is any excess small-sized material that is not adsorbed onto the carrier particles, this may quickly separate. This is referred to as saturation segregation and may limit the proportion of the active component that can be used in the formulation. The extent to which this occurs depends on the forces of attraction between the components and therefore on how tightly the adsorbed particles are attached to the surface. The orientation of the particles is also important, particles protruding out from the surface being more likely to be dislodged than those lying parallel to the surface. Mixing of powders Practical considerations When mixing formulations in which there is a relatively low proportion of active ingredient(s), a more even distribution may be obtained by sequentially building up the amount of material in the mixer. This may be achieved by initially mixing the active component(s) with an approximately equal volume of diluent(s). Further amounts of diluents, equal to the amount of material in the mixer, can then be added and mixed, the process being continued until all material has been added. It may be more appropriate to preblend the active component with a diluent in a smaller mixer prior to transferring it to the main mixer in cases where the amount of active ingredient is very low. Care must be taken to ensure that the volume of powder in the mixer is appropriate, as both over and underfilling may significantly reduce mixing efficiency. In the case of overfilling, for example, sufficient bed dilation may not take place for diffusive mixing to occur to the required extent or the material may not be able to flow in a way that enables shear mixing to occur satisfactorily. Underfilling may mean the powder bed does not move in the required manner in the mixer or that an increased number of mixing operations may be needed for a batch of material. The mixer used should produce the mixing mechanisms appropriate for the formulation. For example, diffusive mixing is generally preferable if potent drugs are to be mixed, and high shear is needed to break up aggregates of cohered material and ensure mixing at a particulate level. The impact or attrition forces generated if too-high shear forces are used may, however, damage fragile material and thus produce fines. The mixer design should be such that it is dust tight, it can be easily cleaned and the product can be fully discharged. These features reduce the risk of cross-contamination between batches and protect the operator from the product. In order to determine the appropriate mixing time, the process should be checked by removing and analysing representative samples after different mixing intervals. This may also indicate if segregation is occurring within the mixer and whether problems could occur if the mixing time is extended. When particles rub past each other as they move within the mixer, static charges will be produced. To avoid this, mixers should be suitably earthed to dissipate the static charge and the process should be carried out at a relative humidity greater (although not excessively) than approximately 40%. Powder-mixing equipment Tumbling mixers/blenders Tumbling mixers are commonly used for mixing/ blending granules or free-flowing powders. Mixing containers are generally mounted so that they can be rotated about an axis.

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It enters the middle ear and runs forwards in close relation to the tympanic membrane bipolar depression quizzes trusted 50 mg asendin. It then passes medial to the spine of the sphenoid and enters the infratemporal fossa depression vegetative symptoms generic asendin 50mg with mastercard. Here it joins the lingual nerve through which chorda tympani nerve is distributed depression mayo clinic buy asendin 50mg free shipping. Preganglionic secretomotor fibres to the submandibular ganglion for supply of the submandibular and sublingual salivary glands depression keeps coming back purchase asendin with visa. Taste fibres from the anterior two-thirds of the tongue except circumvallate papillae depression symptoms body aches purchase 50mg asendin with visa. The stylohyoid branch arises with the digastric branch anxiety urinary problems buy 50mg asendin with amex, is long and supplies the stylohyoid muscle. The zygomatic branches run across the zygomatic bone and supply the lower part of orbicularis oculi. The upper buccal branch runs above the parotid duct and the lower buccal branch below the duct. The marginal mandibular branch runs below the angle of the mandible deep to the platysma. It crosses the body of the mandible and supplies muscles of the lower lip and chin. The cervical branch emerges from the apex of the parotid gland, and runs downwards and forwards in the neck to supply the platysma. Communicating branches: For effective coordination between the movements of the muscles of the first, second and third branchial arches, the motor nerves of the three arches communicate with each other. The facial nerve also communicates with the sensory nerves distributed over its motor territory. The taste fibres present in the nerve are peripheral processes of pseudounipolar neurons present in the geniculate ganglion. This leads to paralysis of facial muscles especially the buccinator, required for sucking the milk. Pathway of Hearing 1 the first neurons of the pathway are located in the spiral ganglion. Most of the axons arising in these nuclei cross to the opposite side (in the trapezoid body) and terminate in the superior olivary nucleus. Their axons pass through the inferior brachium to reach the medial geniculate body. Fibres from cristae of anterior and lateral semicircular canals and some fibres from the two maculae lie in superior vestibular area of internal acoustic meatus. These three nerve divisions are peripheral processes of bipolar neurons of the vestibular ganglion. The central processes arising from the neurons of the ganglion form the vestibular nerve which ends in the vestibular nuclei. To the archicerebellum through the inferior cerebellar peduncle (vestibulocerebellar tract). Through the vestibular pathway, the impulses arising in the labyrinth can influence the movements of the eyes, the head, the neck and the trunk. It is secretomotor to the parotid gland and gustatory to the posterior onethird of the tongue including the circumvallate papillae. It is sensory to the pharynx, the tonsil, soft palate, the posterior one-third of the tongue, carotid body and carotid sinus. Sensorineural deafness is the failure of production or transmission of action potential due to cochlear disease, cochlear nerve disease or defects in cochlear nerve central connections. It results in a failure to understand spoken language even though hearing is preserved. Vertigo: this is an illusion of rotatory movement due to disturbed orientation of the body in space. Tinnitus may be unilateral or bilateral; high or low pitch; continuous or intermittent. Postganglionic fibres arising in the ganglion to supply the parotid gland (Table 4. These carry general sensations from the pharynx, palate, posterior one-third of tongue, tonsil, carotid body and carotid sinus to the ganglion. The central processes convey these sensations to lower part of the nucleus of the solitary tract. They carry sensations of taste from the posterior one-third of the tongue including circumvallate papillae to the inferior ganglion. The central processes convey these sensations to the upper part of the nucleus of the solitary tract. These carry general sensations from the middle ear, proprioceptive fibres from stylopharyngeus. The central processes carry these sensations to nucleus of spinal tract of trigeminal nerve. Nuclei Course and Relations 1 In their intraneural course, the fibres of the nerve pass forwards and laterally, between the olivary nucleus and the inferior cerebellar peduncle, through the reticular formation of the medulla. Between the internal jugular vein and the internal carotid artery, deep to the styloid process and the muscles attached to it. The three nuclei in the upper part of medulla are: 1 Nucleus ambiguus (branchiomotor) 2 Inferior salivatory nucleus (parasympathetic) 3 Nucleus of tractus solitarius (gustatory). It enters the submandibular region by passing deep to the hyoglossus, where it breaks up into tonsillar and lingual branches. Superior ganglion is a detached part of the inferior ganglion, and gives no branches. The inferior ganglion is larger, occupies notch on the lower border of petrous temporal, and gives out communicating and tympanic branches. It enters the middle ear through the tympanic canaliculus, takes part in the formation of the tympanic plexus in the middle ear and distributes its fibres to the middle ear, the auditory tube, the mastoid antrum and air cells. It contains preganglionic secretomotor fibres for the parotid gland and relays in the otic ganglion. The pharyngeal branches take part in the formation of the pharyngeal plexus, along with vagal and sympathetic fibres. The glossopharyngeal fibres are distributed to the mucous membrane of the pharynx and palate. The tonsillar branches supply the tonsil and join the lesser palatine nerves to form a plexus from which fibres are distributed to the soft palate and to the palatoglossal arches. The lingual branches carry taste and general sensations from the posterior one-third of the tongue including the circumvallate papillae. Absence of taste from posterior one-third of tongue and the circumvallate papillae. On tickling the posterior wall of the pharynx, there is reflex contraction of the pharyngeal muscles. They bring sensations from the pharynx, larynx, trachea, oesophagus and from the abdominal and thoracic viscera. These are conveyed by the central processes of the ganglion cells to the lower part of nucleus of tractus solitarius. They carry sensations of taste from the posteriormost part of the tongue and from the epiglottis. The central processes of the cells concerned terminate in the upper part of the nucleus of the tractus solitarius. The upper part of the nucleus of tractus solitarius comprises superior, middle and inferior parts. The postganglionic neurons are situated in ganglia lying close to (within) the viscera to be supplied. The fibres of the cranial root of the accessory nerve are also distributed through it. The left vagus enters the thorax by passing between the left common carotid and left subclavian arteries, behind the internal jugular and brachiocephalic veins. It gives meningeal and auricular branches of vagus, and is connected to glossopharyngeal and accessory nerves and to superior cervical ganglion of sympathetic chain. It gives pharyngeal, carotid, superior laryngeal branches and is connected to hypoglossal nerve, superior cervical ganglion and the loop between first and second cervical nerves. The ganglion also gives off communicating branches to the glossopharyngeal and cranial root of accessory nerves and to the superior cervical sympathetic ganglion. It passes behind the internal jugular vein, and enters the mastoid canaliculus (within the petrous temporal bone). It crosses the facial canal 4 mm above the stylomastoid foramen, emerges through the tympanomastoid fissure, and ends by supplying the concha and root of the auricle, the posterior half of the external auditory meatus, and the tympanic membrane (outer surface). The pharyngeal branch arises from the lower part of the inferior ganglion of the vagus, and contains chiefly the fibres of the cranial root of accessory nerve. It passes between the external and internal carotid arteries, and reaches the upper border of the middle constrictor of the pharynx where it takes part in forming the pharyngeal plexus. Its fibres are ultimately distributed to the muscles of the pharynx and soft palate (except the tensor veli palatini which is supplied by the mandibular nerve). The superior laryngeal nerve arises from the inferior ganglion of the vagus, runs downwards and forwards on the superior constrictor deep to the internal carotid artery, and reaches the middle constrictor where it divides into the external and internal laryngeal nerves. It accompanies the superior thyroid artery, pierces the inferior constrictor and ends by supplying the cricothyroid muscle. The left recurrent laryngeal nerve arises from the vagus in the thorax, as the latter crosses the left side of the arch of the aorta. It loops around the ligamentum arteriosum and reaches the tracheo-oesophageal groove. It does not have to pass behind the subclavian and carotid arteries; and usually, it is posterior to the inferior thyroid artery. Out of the four cardiac branches of the vagi (two on each side), the left inferior branch goes to the superficial cardiac plexus. It passes downwards and forwards, pierces the thyrohyoid membrane with the superior laryngeal vessels and enters the larynx. In the upper part of the groove, it is intimately related to the inferior thyroid artery. On the paralysed side, there is no arching, and the uvula is pulled to the normal side. Sometimes a sensory ganglion may have a viral infection (called herpes zoster) and vesicles appear on the area of skin supplied by the ganglion. In herpes zoster of the geniculate ganglion, vesicles appear on the skin of auricle. Paralysis of muscles of soft palate results in nasal regurgitation of fluids and nasal tone of voice. Lesions of superior laryngeal nerve produces anaesthesia in the upper part of larynx and paralysis of cricothyroid muscle. The cranial root is assisting the vagus, and is distributed through its branches as vagoaccesory complex. Functional Components 1 the cranial root is special visceral (branchial) efferent. It arises from a long spinal nucleus situated in the lateral part of the anterior grey column of the spinal cord extending between segments C1 to C5. The spinal root arises from a long spinal nucleus situated on the lateral part of anterior grey column of spinal cord, extending from C1 to C5 segments. Course and Distribution of the Cranial Root 1 the cranial root emerges in the form of 4 to 5 rootlets which are attached to the posterolateral sulcus of the medulla. Then it runs downwards and backwards superficial to the internal jugular vein and is surrounded by lymph nodes. The nerve pierces the anterior border of the sternocleidomastoid at the junction of its upper onefourth with the lower three-fourths, and communicates with second and third cervical nerves within the muscle. The nerve enters the posterior triangle of the neck by emerging through the posterior border of the sternocleidomastoid a little above its middle. In the triangle, it runs downwards and backwards embedded in the fascial roof of the triangle. The nerve leaves the posterior triangle by passing deep to the anterior border of the trapezius 5 cm above the clavicle. On the deep surface of the trapezius, the nerve communicates with spinal nerves C3 and C4, and ends by supplying the trapezius. By asking the patient to shrug his shoulders (trapezius) against resistance and comparing the power on the two sides. By asking the patient to turn the chin to the opposite side (sternocleidomastoid) against resistance and again comparing the power on the two sides. Nucleus the hypoglossal nucleus, 2 cm long, lies in the floor of fourth ventricle beneath the hypoglossal triangle. Nucleus for genioglossus muscle receives only contralateral corticonuclear fibres. The rootlets run laterally behind the vertebral artery, and join to form two bundles which pierce the dura mater separately near the hypoglossal canal. Branches and Distribution Branches containing fibres of the hypoglossal nerve proper. Extrinsic muscles are styloglossus, genioglossus, hyoglossus and intrinsic muscles are superior longitudinal, inferior longitudinal, transverse and vertical muscles. Only extrinsic muscle, the palatoglossus, is supplied by fibres of the cranial accessory nerve through the vagus and the pharyngeal plexus.

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In addition anxiety vs depression symptoms discount asendin 50 mg on line, the shape depression chinese definition order asendin without prescription, curvatures depression era glass purchase genuine asendin line, peristaltic waves depression definition in sport order 50 mg asendin, and the rate of emptying of the stomach can also be studied depression symptoms and treatment in hindi quality 50mg asendin. Duodenum the beginning of the first part of duodenum shows a well-formed duodenal cap produced by poorly developed circular folds of mucous membrane and protruding pylorus into it depression test at the doctors asendin 50 mg visa. The rest of the duodenum has a characteristic feathery or floccular appearance due to the presence of well-developed circular folds. However, the terminal part of the ileum is comparatively narrow and shows a homogeneous shadow of barium. Large Intestine in which the barium is evacuated and air is injected through the anus to distend the colon. In the background of air, the barium still lining the mucosa makes it clearly visible. Diseases of the large intestine are better examined by barium enema which gives a better filling. Pyelography (urography) is a radiological method by which the urinary tract is visualized. It can be done in two ways depending on the route of administration of the radiopaque dye. When the dye is injected intravenously, it is called the excretory (intravenous or descending) pyelography. When the dye is injected directly into the ureter, through a ureteric catheterguided through a cystoscope, the technique is called retrograde (instrumental or ascending) pyelography. Excretory (Intravenous or Descending) Pyelography Preparation Abdomen and Pelvis Barium Enema Preparation 1 A mild laxative is given on two nights before the examination. Contrast Medium 2 About 2 litres of barium sulphate suspension are slowly introduced through the anus, from a can kept at a height of 2 to 4 feet. The enema is stopped when the barium starts flowing into the terminal ileum through the ileocaecal valve (as seen under the fluoroscopic screen). Appearance In addition to routine abdomen preparation: 1 For 8 hours before pyelography, the patient is not given anything orally, all fluids are withheld, and diuretics are discontinued. Care is taken not to push any dye outside the vein because it is an irritant and may cause sloughing. Exposures Serial skiagram (excretory pyelograms) are taken at 5, 15 and 30 minutes after the injection of the dye. Then the ureteric catheter is guided into the ureteric opening and passed up to the renal pelvis. As the renal pelvis is filled to its capacity, the patient begins to complain of pain, when further injection must be stopped. General anaesthesia is, therefore, contraindicated because of the risk of overdistension of the pelvis. If the renal pelvis admits more than 10 ml of the dye, hydronephrosis is suspected. An ascending pyelogram can be distinguished from a descending pyelogram because: a. Normally: 1 Minor calices are cup-shaped due to the renal papillae projecting into them. Gallbladder is seen as a cystic oval shadow with a narrow neck in the right upper quadrant along with visualisation of the bile duct and portal vein. Oral cholecystography is an outdated method for visualising the gallbladder by taking radio-opaque dye which is exclusively excreted by the liver and concentrated by the gallbladder. The investigation is done preferably within the first 5 to 10 days of the menstrual cycle. The cannula is connected to a syringe through which 5 to 10 ml of an iodized oil (lipiodol) are injected, and the skiagram taken. However, it is also of value in the diagnosis of anomalies of the female genital tract. Dynamic Radiology of the Abdomen: Normal and Pathologic Anatomy, New York: Springer. Section 2 Nerves, Arteries and Clinical Terms -Wilhan Errest Henley 2 And lo, the Hospital, grey, quiet, old where Life and Death like friendly chafferes meet. At the back of chest, they lie between the pleura and posterior intercostal membrane but in most of their course they lie between internal intercostal and intercostalis intimi. As they reach the anterior ends of their respective spaces, the 7th and 8th nerves curve upwards and medially across the deep surface of costal margin, passing between digitations of transversus abdominis then piercing the posterior layer of internal oblique, to enter the rectus sheath, and continue to run upwards and medially parallel to the costal margin. After supplying rectus abdominis, they pierce the anterior wall of the rectus sheath to reach the skin. At the anterior ends of 9th, 10th and 11th intercostal spaces, the 9th, 10th and 11th intercostal nerves pass between digitations of transversus abdominis to lie between it and the internal oblique and run in this plane. When they reach the lateral margin of rectus abdominis, they pierce the posterior layer of rectus sheath, enter it, pierce the muscle and its anterior sheath to supply the skin. It accompanies the subcostal artery along the lower border of 12th rib and passes behind the lateral arcuate ligament. It lies behind the kidney, anterior to quadratus lumborum, pierces the aponeurosis of 511 the intercostal and subcostal nerves and their collateral branches supply intercostal muscles and muscles of anterolateral abdominal wall. T10 supplying the skin around umbilicus; T7, the skin of epigastrium and T8, T9, the intervening skin between epigastrium and the umbilicus. T11, T12 and iliohypogastric (L1) supply the skin between umbilicus and pubic symphysis. The lateral cutaneous branch of T12 supplies the skin of upper anterior part of the gluteal region. The dorsal divisions of these rami give rise to lateral cutaneous nerve of thigh (L2, 3), and femoral nerve (L2, 3, 4) (Appendix 1). Branches arising from ventral divisions are: 1 Nerve to quadratus femoris (L4, 5, S1): Supplies quadratus femoris, inferior gemellus and hip joint. Branches from dorsal divisions are: 1 Superior gluteal nerve (L4, 5, S1): Supplies gluteus medius, gluteus minimus and tensor fascia latae. Muscular branches to deep transversus perinei, compressor urethrae, sphincter urethrovaginalis, ischiocavernosus, bulbospongiosus, external anal sphincter, levator ani, corpus spongiosum, penis and urethra, lower 2. Only upper two ganglia receive white ramus communicans from the ventral primary rami of first and second lumbar nerves. Branches Abdomen and Pelvis Pudendal Nerve Pudendal nerve supplies the skin, external genital organs and muscles of perineum. It is concerned with micturition, defaecation, erection, ejaculation and in females, with parturition. These pass along the spinal nerves to be distributed to the sweat glands, cutaneous blood vessels and arrector pili muscles (sudomotor, vasomotor and pilomotor). Course It starts in the pelvis, enters the gluteal region through greater sciatic notch, lies on the sacrospinous ligament, leaves the gluteal region through lesser sciatic notch. Section Aortic plexus is formed by preganglionic sympathetic, postganglionic sympathetic, preganglionic parasympathetic and visceral afferent fibres around the abdominal aorta. The plexus is concentrated around the origin of ventral and lateral branches of abdominal aorta. The lower part of the ganglion receives lesser splanchnic nerve and is also called aorticorenal ganglion. The aorticorenal ganglion gives off the renal plexus which accompanies the renal vessels. Secondary plexuses arising from coeliac and aorticorenal plexuses are distributed along the branches of the aorta, namely phrenic, splenic, left gastric, hepatic, intermesenteric, suprarenal, renal, gonadal, superior and inferior mesenteric plexuses, and abdominal aortic plexus. Superior Hypogastric Plexus Thoracic part gets branches from vagal trunks and oesophageal plexus as well as from sympathetic trunks and greater splanchnic nerves. Stomach Sympathetic supply reaches from coeliac plexus along gastric and gastroepiploic arteries. The left vagus forms anterior gastric nerve, while right vagus comprises posterior gastric nerve. The anterior gastric nerve supplies cardiac orifice, anterior surface of body as well as fundus of stomach, pylorus and liver. Cervical part of oesophagus receives branches from recurrent laryngeal nerve of vagus and middle cervical ganglion of sympathetic trunk. Large intestine except the lower half of anal canal is supplied by both components of autonomic nervous system. Left one-third of transverse colon, descending colon, sigmoid colon, rectum and upper half of anal canal (developed from hindgut and anorectal canal) receive their sympathetic nerve supply from lumbar part of sympathetic trunk and superior hypogastric plexus Section 2 Abdomen and Pelvis this plexus lies between the two common iliac arteries and is formed by: 1 Aortic plexus. It divides into right and left inferior hypogastric plexus (pelvic plexus); which runs on the medial side of internal iliac artery and is supplemented by pelvic splanchnic nerves (parasympathetic nerves). Thus, inferior hypogastric plexus contains both sympathetic and parasympathetic nerves. These are for the supply of the pelvic viscera along the branches of the arteries. The nerves of this part of the gut are derived from coeliac ganglia formed by posterior gastric nerve (parasympathetic) and the plexus around superior mesenteric artery. Sympathetic system inhibits the peristaltic movements of intestine but stimulates the sphincters. Some fibres of inferior hypogastric plexus pass up through superior hypogastric plexus and get distributed along the branches of inferior mesenteric artery to the left one-third of transverse colon, descending and sigmoid colon. Rectum and Anal Canal Genitourinary Tract Kidneys the kidneys are supplied by renal plexus formed from coeliac ganglion, coeliac plexus, lowest thoracic splanchnic nerve, and first lumbar splanchnic nerve. Ureter is supplied in its upper part from renal and aortic plexues, middle part from superior hypogastric plexus and lower part from hypogastric nerve and inferior hypogastric plexus. Vesical Plexus Sympathetic fibres pass along inferior mesenteric and superior rectal arteries also via superior and inferior hypogastric plexuses. Parasympathetic supply is from pelvic splanchnic nerve, which joins inferior hypogastric plexus. The external anal sphincter is supplied by inferior rectal branch of pudendal nerve. Afferent impulses of physiological distension of rectum and sigmoid colon are carried by parasympathetic, whereas pain impulses are conveyed both by sympathetic and parasympathetic nerves. Parasympathetic fibres arise from sacral S2, 3, 4 segments of spinal cord, which relay in the neurons present in and near the wall of urinary bladder. Emptying and filling of bladder is normally controlled by parasympathetic system only. The nerve fibres make synaptic system contact with acinar cells before innervating the islets. The parasympathetic ganglia lies in sparse connective tissue of the gland and in the islet cells. Abdomen and Pelvis Liver Testicular plexus accompanies the testicular artery to reach the testis. Prostatic plexus is formed from inferior hypogastric plexus and branches are distributed to prostate, seminal vesicle, prostatic urethra, ejaculatory ducts, erectile tissue of penis, penile part of urethra and bulbourethral glands. Female Reproductive Organs Nerves of the liver are derived from hepatic plexus which contain both sympathetic and parasympathetic fibres. Gallbladder Parasympathetic and sympathetic nerves of gallbladder are derived from coeliac plexus, along the hepatic artery (hepatic plexus) and its branches. The reason of pain in the right shoulder (from where impulses are carried by lateral supraclavicular nerve C4) in cholecystitis is the stimulation of phrenic nerve fibres (C4) due to the communication of phrenic plexus and hepatic plexus via coeliac plexus. Ovary and uterine tube receive their nerve supply from plexus around the ovarian vessels. This plexus is derived from renal, aortic plexuses and also superior and inferior hypogastric plexuses. Sympathetic fibres derived from T10 and T11 segments of spinal cord are vasomotor in nature whereas parasympathetic fibres are probably vasodilator in function. Sympathetic nerve causes uterine contraction and vasoconstriction, while parasympathetic nerves produce vasodilatation and uterine inhibition. In tuberculosis of thoracic vertebrae, the pain is referred to abdomen either as constricting pain when one nerve is involved or general diffuse pain when more nerves are involved. Any blow to the abdominal wall will do no harm to the viscera if the muscles are firmly contracted. From these ganglia arise greater splanchnic nerves which supply abdominal viscera. Gives gastric branches to both surfaces of stomach Gastroduodenal artery supplies the stomach and 1st part of duodenum Right gastric artery supplies stomach. First it courses upward till the cardiac end of stomach, then it enters lesser omentum to run along lesser curvature of stomach.


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