Vice Chair, Sam Houston State University College of Osteopathic Medicine
The median nerve is occasionally damaged in supracondylar fractures antibiotic ointment for boils purchase zibramax once a day, but it is in greatest danger in lacerations of the wrist antibiotics for dogs at tractor supply zibramax 500mg free shipping. If divided at the wrist antimicrobial silver gel discount zibramax 250mg line, only the thenar muscles (excluding adductor pollicis) and the radial two lumbricals are paralysed and wasting of the thenar muscles occurs antibiotic given for strep throat order 250 mg zibramax mastercard. The best clinical test for this is to ask the patient, with his hand resting palm upwards on the table, to touch a pencil held above the thumb. Failure to be able to do this (abduction) is diagnostic of paralysis of abductor pollicis brevis. It might be thought that such a lesion is relatively trivial since the only motor defect is loss of accurate opposition movement of the thumb to other fingers. Pronation of the forearm is lost and is replaced by a trick movement of rotation of the upper arm. Wrist flexion is weak and accompanied by ulnar deviation, since this now depends on the flexor carpi ulnaris and the ulnar half of flexor digitorum profundus. The deformities are readily explained as follows: 1 Since the flexors of the wrist are bulkier than the extensors, their fibrous contraction is greater and the wrist is therefore flexed. There is, therefore, flexion at the wrist, extension at the metacarpophalangeal and flexion at the interphalangeal joints. If the wrist is passively further flexed by the examiner, the tight flexor tendons are somewhat relaxed and therefore the fingers become a little less clawed. Contracture of this fascia results in a longitudinal thickening in the palm together with flexion of the metacarpophalangeal and proximal interphalangeal joints. However, the distal interphalangeal joints are not involved and, in fact, in an advanced case, are actually extended by the distal phalanx being pushed backwards against the palm of the hand. The spaces of the hand the spaces of the hand are of practical significance because they may become infected and, in consequence, become distended with pus. The important spaces are: 1 the superficial pulp spaces of the fingers; 2 the synovial tendon sheaths of the 2nd, 3rd and 4th fingers; 3 the ulnar bursa; 4 the radial bursa; 5 the mid-palmar space; 6 the thenar space. The blood vessels to the shaft of the distal phalanx must traverse this space and may become thrombosed in a severe pulp infection with resulting necrosis of the diaphysis of the bone. The base of the distal phalanx receives its blood supply more proximally from a branch of the digital. The spaces of the hand 219 artery in the middle segment of the finger and therefore survives. At each of the skin creases of the fingers, the skin is bound down to the underlying flexor sheath so that the pulp over each phalanx is in a separate compartment cut off from its neighbours. Infection may, however, track from one space to another along the neurovascular digital bundles. Over the palm of the hand there is very little subcutaneous tissue, the skin adhering to the underlying palmar aponeurosis; in contrast, the skin of the dorsum of the fingers and hand is loose and fluid can, therefore, readily collect beneath it. Unless this is remembered, the marked dorsal oedema which may accompany sepsis of the palmar aspect of the fingers or hand may result in the primary site of the infection being overlooked. This tunnel is made up posteriorly by the metacarpal head, the phalanges and the fronts of the intervening joints. The anterior fibrous part consists of condensed deep fascia attached to the sharp anterolateral margin of each phalanx and is termed the fibrous flexor sheath. Distally, the fibrous sheath ends at the insertion of the profundus tendon (or flexor pollicis longus tendon in the case of the thumb) at the base of the distal phalanx. These fibrous sheaths are lined by synovial membrane, which is reflected around each tendon. The tendons of the 2nd, 3rd and 4th fingers have synovial sheaths which are closed off proximally at the metacarpal head, but the synovial sheaths of the thumb and little finger extend proximally into the palm. That of the long flexor tendon of the thumb extends through the palm, deep to the flexor retinaculum, to approximately 1 in (2. The synovial sheath of the 5th finger continues as the ulnar bursa, an expanded synovial sheath which encloses all the finger tendons in the palm and which also extends proximally below the flexor retinaculum for 1 in (2. Infections of the 2nd, 3rd and 4th sheaths are confined to the finger concerned, but sepsis in the 1st and 5th sheaths may spread proximally into the palm through the radial and ulnar bursa, respectively, and may pass from one bursa to the other via the frequent cross-communication between the two. Since these bursae both extend proximally beyond the wrist, infection may, on occasion, spread into the forearm. Two spaces deep in the palm of the hand may rarely become distended with pus; these are the mid-palmar and thenar spaces. The mid-palmar space lies behind the flexor tendons and ulnar bursa in the palm and in front of the 3rd, 4th and 5th metacarpals with their attached interossei. The 1st and 2nd metacarpals are curtained off from this space by the adductor pollicis, which arises from the shaft of the 3rd metacarpal and passes as a triangular sheet to the base of the proximal phalanx of the thumb. The thenar space is the space superficial to the 2nd and 3rd metacarpals and the adductor pollicis. Infection of these two spaces sometimes results from penetrating wounds or may be due to secondary involvement from a long-neglected tendon sheath infection. Nowadays, they are fortunately extremely rare, thanks to antibiotic treatment and the early surgical drainage of pus collections. Part 4 the Lower Limb Clinical Anatomy: Applied Anatomy for Students and Junior Doctors, Thirteenth Edition. The surface anatomy and surface markings of the lower limb Anatomically the upper and lower limbs are comparable to each other as regards the arrangement of the bones, joints, main muscle groups, vessels and nerves.
An oblique incision is usually favoured midway between the 12th rib and the iliac crest antibiotics for dogs harmful zibramax 100mg, extending laterally from the lateral border of erector spinae antibiotics dairy cheap zibramax online amex. Latissimus dorsi and serratus posterior inferior are divided and the free posterior border of external oblique is identified bacteria questions and answers 100 mg zibramax with mastercard, enabling this muscle to be split along its fibres infection jsscriptpe-inf trj order zibramax 500mg otc. Internal oblique and transversus abdominis are then divided, revealing peritoneum anteriorly, which is pushed forwards. The subcostal nerve and vessels are usually encountered in the upper part of the incision and are preserved. If more room is required, the lateral edge of quadratus lumborum may be divided and also the 12th rib excised, care being taken to push up, but not to open, the pleura, which crosses the medial half of the rib. Anteriorly, the right ureter is covered at its origin by the second part of the duodenum and then lies lateral to the inferior vena cava and behind the posterior peritoneum. The left ureter is crossed by the testicular (or ovarian) and left colic vessels and then passes above the pelvic brim, behind the mesosigmoid and sigmoid colon to cross the common iliac artery immediately above its bifurcation. The pelvic ureter runs on the lateral wall of the pelvis in front of the internal iliac artery to just in front of the ischial spine; it then turns forwards and medially to enter the bladder. In the male, it lies above the seminal vesicle near its termination and is crossed superficially by the vas deferens. Blood supply the ureter receives a rich segmental blood supply from all available arteries along its course: the aorta, and the renal, testicular (or ovarian), internal iliac and inferior vesical arteries. It lies along the tips of the transverse processes, crosses in front of the sacro-iliac joint, swings out to the ischial spine and then passes medially to the bladder. This course of the ureter is readily studied by examining a radiograph showing a radio-opaque ureteric catheter in situ. The pronephros, of importance in the lower vertebrates, is transient in humans, but the distal part of its duct receives the tubules of the next renal organ to develop, the mesonephros, and now becomes the mesonephric or Wolffian duct. The mesonephros itself then disappears except for some of its ducts, which form the efferent tubules of the testis. For further details of the fates of the mesonephros and mesonephric duct, see page 159. A diverticulum then appears at the lower end of the mesonephric duct which develops into the metanephric duct; on top of the latter a cap of tissue differentiates to form the definitive kidney or metanephros. The metanephric duct develops into the ureter, pelvis, calyces and collecting tubules; the metanephros into the glomeruli and the proximal part of the renal duct system. Its blood supply is first obtained from the common iliac artery but, during migration, a series of vessels form to supply it, only to involute again when the renal artery takes over this duty. This theory of origin does not explain their occasional association with multiple cysts of the liver, pancreas, lung and ovary. These ureters may fuse into a single duct anywhere along their course or open separately into the bladder (where the upper ureter enters below the lower ureter). Rarely, the extra ureter may open ectopically into the vagina or urethra resulting in urinary incontinence. The bladder (Figs 60, 61, 85) the bladder capacity in the normal adult is variable, the average being approximately 300 ml. In cases of retention of urine, the adult bladder distends from the pelvic cavity into the abdomen, stripping the peritoneum upwards from the anterior abdominal wall. The surgeon utilizes this fact in carrying out an extraperitoneal incision or suprapubic puncture into the bladder. In children up to the age of approximately 3 years, the pelvis is relatively small and the bladder is, in fact, intra-abdominal although still extraperitoneal. The neck of the bladder fuses with the prostate in the male; in the female it lies directly on the pelvic fascia surrounding the short urethra. The circular component of the muscle coat condenses as an (involuntary) internal urethral sphincter around the internal orifice. This can be destroyed without incontinence providing the external sphincter remains intact (as occurs in prostatectomy). Cystoscopy the interior of the bladder and its three orifices (the internal meatus and the two ureters) are easily inspected by means of a cystoscope. The submucosa and mucosa of most of the bladder are only loosely adherent to the underlying muscle and are thrown into folds when the bladder is empty, smoothing out during distension of the organ. Over the trigone, the triangular area bounded by the ureteric orifices and the internal meatus, the mucosa is adherent and remains smooth even in the empty bladder. Between the ureters, a raised fold of mucosa can be seen that is called the interureteric ridge, which is produced by an underlying bar of muscle. Blood supply Blood is supplied from the superior and inferior vesical branches of the internal iliac artery. Lymph drainage Lymphatics drain alongside the vesical blood vessels to the iliac and then para-aortic nodes. Nerve supply Efferent parasympathetic fibres from S2 to S4 accompany the vesical arteries to the bladder. They convey motor fibres to the muscles of the bladder wall and inhibitory fibres to its internal sphincter. Sympathetic efferent fibres are said to be inhibitory to the bladder muscles and motor to its sphincter, although they may be mainly vasomotor in function, so that normal filling and emptying of the bladder are probably controlled exclusively by its parasympathetic innervation. It is also concerned in the control of micturition and is supplied by the pudendal nerve (S2, S3, S4). Sensory fibres from the bladder, which are stimulated by distension, are conveyed in both the 124 the abdomen and pelvis sympathetic and parasympathetic nerves, the latter pathway being the more important.
Buy 250mg zibramax otc. Antimicrobial Meaning.
Lumbar sympathetic chain the lumbar part of the sympathetic trunk commences deep to the medial arcuate ligament of the diaphragm as a continuation of the thoracic sympathetic chain antimicrobial yoga mats purchase zibramax 100 mg. On each side it lies against the bodies of the lumbar vertebrae bacteria biology purchase zibramax american express, overlapped infection x private server purchase 250 mg zibramax with amex, on the right side antibiotic resistance otolaryngology cheap 500 mg zibramax with amex, by the inferior vena cava and, on the left, by the aorta. Computed axial tomography 167 the lumbar arteries lie deep to the chain but the lumbar veins may cross superficial to it and are of importance because they may be damaged in performing a sympathectomy. Below, the lumbar trunk passes deep to the iliac vessels to continue as the sacral trunk in front of the sacrum. Inferiorly, the chains converge and unite in front of the coccyx as the small ganglion impar. Usually the lumbar trunk carries four ganglia, although sometimes these are condensed to three. All four send grey rami communicantes to the lumbar spinal nerves; in addition, the upper two ganglia receive white rami. Branches from the chain pass to plexuses around the abdominal aorta and its branches, which also receive fibres from the splanchnic nerves and the vagus. The parasympathetic supply to the pelvic viscera arises from the anterior primary rami of S2, S3 and S4 and is distributed with the pelvic plexuses (see page 429). It is now necessary for clinicians to possess a detailed knowledge of the cross-sectional relationships of the body in health so that pathological abnormalities can be appreciated. Clinical students should take every opportunity of studying normal scans with the help of a skilled radiologist. Part 3 the Upper Limb Clinical Anatomy: Applied Anatomy for Students and Junior Doctors, Thirteenth Edition. Surface anatomy and surface markings of the upper limb Much of the anatomy of the limbs can be revised on oneself; otherwise, choose a thin colleague. Bones and joints (see Figs 117, 119, 120, 122) the subcutaneous border of the clavicle can be palpated along its entire length; the supraclavicular nerves crossing it can be rolled against the bone. The acromion process forms a sharp bony edge at the lateral extremity of the scapular spine. It lies immediately above the smooth bulge of the deltoid muscle, which itself covers the greater tubercle of the humerus. Less easily identified is the coracoid process of the scapula, lying immediately below the clavicle at the junction of the middle and outer thirds, and covered by the anterior fibres of the deltoid. Abduction of the arm is a complex affair made up of abduction at the shoulder joint, depression at the sternoclavicular joint and rotation of the scapula; the last two are readily confirmed on self-palpation. With the shoulder abducted, the head of the humerus can be felt in the axilla; note its movement with rotation of the arm. At the elbow, the three bony landmarks are the olecranon process and the medial and lateral epicondyles. A supracondylar fracture lies above these points, which therefore remain in their triangular relationship to each other; in dislocation of the elbow, however, the olecranon comes more or less in line with the epicondyles. Note a hollow in the posterolateral aspect of the extended elbow distal to the lateral epicondyle; this lies over the head of the radius, which can be felt to rotate during pronation and supination. The posterior border of the ulna is completely subcutaneous and crossed by no named vessels or nerve; it can therefore be exposed surgically from end to end without danger. At the wrist, the styloid processes of the radius and ulna can be felt; the former extends more distally. The dorsal tubercle of Lister is palpable on the posterior aspect of the distal end of the radius. In the palm of the hand, palpate the pisiform at the base of the hypothenar eminence. Flexor carpi ulnaris is inserted into it and when this tendon is relaxed by flexing the wrist the pisiform can be moved a little from side to side. The scaphoid is felt at the base of the thenar eminence and also within the anatomical snuffbox, where there is characteristic tenderness when this bone is fractured. In a thin subject, the pisiform and the tubercle of the scaphoid can be seen as bulges when the wrist is extended. Muscles and tendons the anterior fold of the axilla is formed by the pectoralis major, and its posterior fold by the teres major and latissimus dorsi. The digitations of serratus anterior can be seen in a muscular subject on the medial axillary wall. The biceps and brachialis constitute the bulk of the anterior aspect of the arm, and the triceps its posterior aspect. The tendon of biceps is easily felt, and often seen, at the elbow when this is flexed to a right angle. Firm pressure immediately medial to this will, in turn, produce paraesthesiae in the hand as the median nerve is palpated. When the forearm is flexed against resistance, the brachioradialis presents prominently along its radial border. The tendon medial to this is that of the flexor carpi radialis, then palmaris longus (which may be absent), then the cluster of tendons of flexor digitorum superficialis. The tendon of flexor carpi ulnaris lies most medially, inserting into the pisiform; the ulnar pulse can be felt just to the radial side of this tendon. On the dorsal aspect of the wrist (Figs 114, 115) the anatomical snuffbox is bordered by the tendons of abductor pollicis longus and extensor pollicis brevis laterally and that of extensor pollicis longus medially. The tendons of extensor digitorum are seen in the extended hand passing over the dorsal aspects of the proximal phalanges of the fingers. Vessels Feel the pulsations of the subclavian artery against the first rib, the brachial artery against the humerus, the radial and ulnar arteries at the wrist and the radial artery again in the anatomical snuffbox. Surface anatomy and surface markings of the upper limb 173 Flexor carpi radialis Radial artery Median nerve Palmaris longus Flexor digitorum superficialis Flexor carpi ulnaris Ulnar artery and nerve Thenar muscles Flexor retinaculum Recurrent motor branch of median nerve Hypothenar muscles. Extensor digiti minimi Extensor carpi ulnaris Extensor digitorum Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Radial artery Extensor carpi radialis longus and brevis Extensor indicis.
Posteriorly it is pierced by the optic nerve and anteriorly it is connected to the iris by the ciliary body antibiotics for uti chlamydia purchase 250 mg zibramax free shipping. The neural coat the retina is formed by an outer pigmented and an inner nervous layer bacterial chromosome discount zibramax amex, and is interposed between the choroid and the hyaloid membrane of the vitreous antibiotic mouthwash containing chlorhexidine buy zibramax 500mg low price. Anteriorly antibiotics for uti in cats buy zibramax australia, it presents an irregular edge, the ora serrata, while posteriorly the nerve fibres on its surface collect to form the optic nerve. The central artery of the retina emerges from the disc and then divides into upper and lower branches; each of these in turn divides into a nasal and temporal branch. Contents of the eyeball Within the eyeball are found the lens, the aqueous humour and the vitreous body. The lens is biconvex and is placed between the vitreous and the aqueous humour, just behind the iris. The aqueous humour is a filtrate of plasma secreted by the vessels of the iris and ciliary body into the posterior chamber of the eye. From here it passes through the pupillary aperture into the anterior chamber (between the cornea and the iris) and is re-absorbed into the ciliary veins by way of the sinus venosus sclerae (or canal of Schlemm). The anterior part of the hyaloid membrane is thickened, receives attachments from the ciliary processes and gives rise to the suspensory ligament of the lens. This ligament is attached to the capsule of the lens in front of its equator and serves to retain it in position. It is relaxed by contraction of the radial fibres of the ciliary muscle and so allows the lens to assume a more convex form in accommodation (close reading). The four recti arise from a tendinous ring around the optic foramen and the medial part of the superior orbital fissure and are inserted into the sclera anterior to the equator of the eyeball. The superior oblique arises just above the tendinous ring and is inserted by means of a long tendon that loops around a fibrous pulley on the medial part of the roof of the orbit into the sclera just lateral to the insertion of the superior rectus. The eyeball is capable of elevation, depression, adduction, abduction and rotation. Superior oblique Inferior rectus the special senses 427 Levator palpebrae superioris Superior rectus Intraconal fat Eyeball Optic nerve Dural sheath Inferior rectus Extraconal fat Fascial sheath of eyeball. Inferior oblique Orbicularis oculi Superior tarsal plate Conjunctival sac Inferior tarsal plate Orbital septum front. It is pierced by the vessels and nerves of the eye and by the tendons of the extra-ocular muscles. Each consists of the following layers, from without inwards: skin, loose connective tissue, fibres of the orbicularis oculi muscle, the tarsal plates, of very dense fibrous tissue, tarsal glands and conjunctiva. The eyelashes arise along the mucocutaneous junction and immediately behind the lashes there are the openings of the tarsal (Meibomian) glands. These are large sebaceous glands whose secretion helps to seal the palpebral fissure when the eyelids are closed and forms a thin layer over the exposed surface of the open eye; if blocked, they distend into Meibomian cysts. The conjunctiva is the delicate mucous membrane lining the inner surface of the lids from which it is reflected over the anterior part of the sclera to the cornea. Over the lids it is thick and highly vascular, but over the sclera it is much thinner and over the cornea it is reduced to a single layer of epithelium. The line of reflection from the lid to the sclera is known as the conjunctival fornix; the superior fornix receives the openings of the lacrimal glands. Movements of the eyelids are brought about by the contraction of the orbicularis oculi and levator palpebrae superioris muscles. The width of the palpebral fissure at any one time depends on the tone of these muscles and the degree of protrusion of the eyeball. The main part of the gland is about the size and shape of an almond, but it is connected to a small terminal process that extends into the posterolateral part of the upper lid. The tears are drained by way of the lacrimal canaliculi, whose openings, the lacrimal puncta, can be seen on the small elevation near the medial margin of each eyelid known as the lacrimal papilla. The two canaliculi, superior and inferior, open into the lacrimal sac, which is situated in a small depression on the medial surface of the orbit. This in turn drains through the nasolacrimal duct into the anterior part of the inferior meatus of the nose. The autonomic nervous system the nervous system is divided into two great subgroups: the cerebrospinal system, made up of the brain, spinal cord and the peripheral cranial and the autonomic nervous system 429 spinal nerves, and the autonomic system (also termed the vegetative, visceral or involuntary system), comprising the autonomic ganglia and nerves. Broadly speaking, the cerebrospinal system is concerned with the responses of the body to the external environment. In contrast, the autonomic system is concerned with the control of the internal environment, exercised through the innervation of the non-skeletal muscle of the heart, blood vessels, bronchial tree, gut and the pupils and the secretomotor supply of many glands, including those of the alimentary tract and its outgrowths, the sweat glands and, as a rather special example, the suprarenal medulla.
