The supra-umbilical part o the internal surace o the anterior abdominal wall has a sagittally oriented peritoneal refection, the alciorm ligament, that extends between Aponeurosis of external oblique the superior anterior abdominal wall and the liver. Three of these four patients underwent mitral valve replacement because of residual mitral incompetence. Deeper dissection o the superfcial pouch (right side) reveals the bulbs o the vestibule and the greater vestibular glands. This space is occupied by the internal vertebral venous plexus embedded in a atty matrix (epidural at). General anesthesia renders the mother unconscious; she is unaware o the labor and delivery. The vertebral arteries penetrate the atlanto-occipital membrane beore traversing the oramen magnum. From superior to inerior, the bed o the stomach is ormed by the let dome o the diaphragm, spleen, let kidney and suprarenal gland, splenic artery, pancreas, and transverse mesocolon. The anterior spinal artery, ormed by the union o branches o the vertebral arteries, runs ineriorly in the anterior median ssure. Motor Innervation o Lower Limb Somatic motor (general somatic eerent) bers traveling in the same mixed peripheral nerves that convey sensory bers to the cutaneous nerves transmit impulses to the muscles o the lower limb. The posterior cord, ormed by the merging o the posterior divisions o all three trunks o the brachial plexus, is demonstrated. Some authors also include the thoracic sympathetic trunks and thoracic splanchnic nerves; the esophagus is a bromuscular tube that extends rom the pharynx to the stomach. The approximate incidences o various locations o the appendix, based on an analysis o 10,000 cases, are shown. Lymph rom the large intestine ows sequentially to epicolic nodes (on the gut), paracolic nodes (along mesenteric border), intermediate colic nodes (along the colic arteries), and then to the superior or inerior mesenteric nodes and the intestinal trunks. When this sphincter contracts, bile cannot enter the ampulla and the duodenum; hence, bile backs up and passes along the cystic duct to the gallbladder or concentration and storage. The convolutions o the small intestine have been retracted superiorly to demonstrate the mesentery. This will occur if there is breakdown of the suture line between the ventricular septum and the pulmonary autograft. Multiple overlapping radial energy absorptions are measured, recorded, and compared by a computer to determine the radiodensity o each volumetric pixel (voxel) o the chosen body plane. For growth to continue, the bone ormed rom the primary center in the diaphysis does not use with that ormed rom the secondary centers in the epiphyses until the bone reaches its adult size. Three groups o axillary nodes are related to the triangular base, one group at each corner o the pyramid. The pericardium, containing the heart, lies on the central part o the diaphragm, depressing it slightly. Reintervention for the right ventricular outflow tract was Transposition of the Great Arteries 391 more common when valved conduits were used versus valveless reconstruction. Usually, it is found that the shunt alone has resulted in an increase in pressure to at least 50% of systemic pressure. To test the fexor carpi ulnaris, the person puts the posterior aspect o the orearm and hand on a fat table and is then asked to fex the wrist against resistance while the examiner palpates the muscle and its tendon. They are also used to stabilize the stance when standing on both eet, to correct a lateral sway o the trunk, or when there is a side-to-side shit o the surace on which one is standing (rocking a boat, standing on a balance board). Although the pudendal nerve is shown here in the male, its distribution is similar in the emale because the parts o the emale perineum are homologs o those in the male. Peritoneal Dialysis the peritoneum is a semipermeable membrane with an extensive surace area, much o which (subdiaphragmatic portions in particular) overlies blood and lymphatic capillary beds.
Tributaries rom the medial and posterior aspects o the thigh requently unite to orm an accessory saphenous vein. Enlarged internal iliac lymph nodes, pathological thickening o the ureters, swellings in the ischio-anal ossae [e. Thus, the parietal pleura generally extends approximately two ribs inerior to the lung. In addition to unctioning as relay neurons, receiving and passing on eerent impulses sent by presynaptic parasympathetic neurons, they also receive input rom postsynaptic sympathetic bers (making them a third-order neuron in that system). The perineal muscles provide dynamic support or the uterus by contracting during moments o increased intra-abdominal pressure (sneezing, coughing, etc. Coxa vara causes a mild shortening o the lower limb and limits passive abduction o the hip. This tethering may cause chronic pain or emergency complications such as intestinal obstruction when the intestine becomes twisted around an adhesion (volvulus). They pass through the transversus abdominis and internal oblique muscles to supply the external oblique and skin o the anterolateral abdominal wall. The ampulla receives and holds an accumulating ecal mass until it is expelled during deecation. The penis consists o thin skin, connective tissue, blood and lymphatic vessels, ascia, the corpora cavernosa, and corpus spongiosum containing the spongy urethra. The clavicles and scapulae o the pectoral girdle are supported, stabilized, and moved by axio-appendicular muscles that attach to the relatively xed ribs, sternum, and vertebrae o the axial skeleton. Ossication centers appear postnatally in the heads o the our medial metacarpals and in the base o the 1st metacarpal. Using the back as a lever when liting puts an enormous strain on the vertebral column and its ligaments and muscles. Anterolateral Abdominal Wall 437 Spermatocele and Epididymal Cyst A spermatocele is a retention cyst (collection o fuid) in the epididymis. The pressure may reach levels high enough to compress structures signicantly in the compartment(s) concerned. This ree part, called the ampulla (duodenal cap), has an appearance distinct rom the remainder o the duodenum when observed radiographically using contrast medium. Because this vein is obvious in living persons, surgeons use it or identiying the pylorus. On occasion, one or both nipples are inverted (retracted); this minor congenital anomaly may make breasteeding dicult. The posterior wall o the axilla is ormed chiefy by the scapula and subscapularis on its anterior surace and ineriorly by the teres major and latissimus dorsi. The intermediate (membranous) part o the urethra begins at the apex o the prostate and traverses the deep perineal pouch, surrounded by the external urethral sphincter. Patients with a single right ostium with the circumflex or left main coronary artery passing behind the pulmonary artery were estimated to have an approximately eightfold increased risk of early death compared with other single coronary patterns. The pulmonary homograft is anastomosed proximally to the right ventricular outflow tract, usually with continuous 4/0 Prolene. Lymph passing through the axillary nodes enters eerent lymphatic vessels that orm the subclavian lymphatic trunk, which usually empties into the junctions o the internal jugular and subclavian veins (the venous angles). Surace Anatomy o Bones o Foot the head o the talus is palpable anteromedial to the proximal part o the lateral malleolus when the oot is inverted, and anterior to the medial malleolus when the oot is everted. The bones begin to use between 15 and 17 years o age; usion is complete between 20 and 25 years o age. Lymphatic vessels rom these nodes continue to ollow the bronchi and pulmonary vessels to the hilum o the lung, where they also drain into the bronchopulmonary lymph nodes.
In the past, the following associated anomalies have been considered contraindications, but there is no good evidence to support such an approach. The brachial plexus is divided into supraclavicular and inraclavicular parts by the clavicle. The nodes along the splenic vessels can be excised by removing the spleen, gastrosplenic and splenorenal ligaments, and the body and tail o the pancreas. The plane between the bladder and rectum is occupied by internal genitalia and a septum ormed during embryonic development as the urogenital sinus was partitioned into the urinary bladder and urethra anteriorly and the anorectum posteriorly. There must be at least one point of mixing between the parallel circulations for the child to survive. This can be accomplished by placing a blunt needle through the foramen ovale and to inject saline through the left atrium. Whereas most lymphatic drainage rom the pelvis tends to parallel routes o venous drainage, lymphatic drainage to the external iliac nodes does not. There should be no risk of excessive blood loss in a primary sternotomy and if single venous cannulation in the right atrium is to be applied it is not necessary for monitoring of central venous pressure intraoperatively. Today, as a result of the hematocrit trials, we do not tolerate a hematocrit on bypass of less than 24% (see Chapter 9, Prime Constituents and Hemodilution). A myotome consists o all muscles or parts o muscles receiving innervation rom one spinal nerve. Each column is divided regionally into three parts according to the superior attachments. Breast hypertrophy in males ater puberty (gynecomastia) is relatively rare (<1%) and may be age or drug related. Some o the aponeurotic fbers use with the median band, and other fbers arch over it to blend with the aponeurosis arising rom the other side. Most o the anterolateral wall includes three musculotendinous layers; the ber bundles o each layer run in dierent directions. This will permit maintenance of systemic perfusion via the ductus during the first few days of life while pulmonary vascular resistance remains elevated. Epiphysial plate injuries are common in older children because o their requent alls in which the orces are transmitted rom the hand to the radius and ulna. The venous drainage parallels the arterial supply and enters the external and internal vertebral venous plexuses. There are three or our o these large nodes situated deep to the pectoralis minor near the base o the axilla, in association with the second part o the axillary artery. It is a vestige o the site o attachment o the umbilical cord and is the reerence point or the transumbilical plane. A patch of crimped Dacron has been sutured into the aortotomy using a continuous suture technique. The ductus arteriosus is dissected free and will be doubly suture ligated with 5/0 Prolene immediately after commencing bypass with subsequent division. As the obstruction becomes increasingly muscular rather than fixed, that is secondary to valvar pulmonary stenosis and pulmonary annular hypoplasia, there is an increasing risk of cyanotic spells during which the child temporarily can become profoundly hypoxic. They are synovial joints o the condyloid type and have thin, loose joint capsules. Transient paresthesias are amiliar to anyone who has had an injection o anesthetic or dental repairs. The ducts o the bulbo-urethral glands open into the proximal part o the spongy urethra. Although many industrial solvents, such as carbon tetrachloride, produce cirrhosis, the condition develops most requently in persons suering rom chronic alcoholism. In general, lacerations or incisions that parallel the tension lines usually heal well with little scarring because there is minimal disruption o collagen bers. The superior appendicular skeleton articulates with the axial skeleton only at the sternoclavicular joint, allowing great mobility. Prior to tying this suture the left heart should be filled with saline to displace air.
Aneurysm Formation after Coarctation Surgery Although considerable attention has been focused on the risk of aneurysm development following balloon dilation of coarctation, it is important to remember that aneurysms have also been reported following surgical repair. It undergoes exuberant growth, however, to provide the large absorptive surace required by nutrition. Because any particular area o skin usually receives innervation rom two adjacent nerves, considerable overlapping o contiguous dermatomes occurs. Deep hypothermia in the neonate probably contributes to myocardial protection and allows one dose only of cardioplegia to be infused even for myocardial ischemic times as long as 2. Ultrasound is a noninvasive means o distinguishing fuid-lled cysts or abscesses rom solid masses. Both techniques permit study o the circulation through the unctioning heart and are helpul in the study o congenital cardiac deects. Apical ventricular septal defects: follow-up concerning anatomic and surgical considerations. In these circumstances, the vital capacity is markedly compromised by the paradoxical incursion o the thoracic wall during inspiration. In severe cases o portal obstruction, the veins o the anterior abdominal wall (normally caval tributaries) that anastomose with the para-umbilical veins (normally portal tributaries) may become varicose and look somewhat like small snakes radiating under the skin around the umbilicus. They secrete a thick alkaline fuid with ructose (an energy source or sperms) and a coagulating agent that mixes with the sperms as they pass into the ejaculatory ducts and urethra. Although the Amplatzer device had market dominance for some time, increasing concern about late erosion has contributed to increasing use of the Helex device, even though this device has been prone to fracture. The arteries o the hand collectively constitute a peri-articular arterial anastomosis around the collective joints o the wrist and hand. The rightsided pleura is opened and the pericardium is opened posteriorly to within approximately 1 cm of the phrenic nerve. Inerior to the root o the lung, this continuity between parietal and visceral pleura orms the pulmonary ligament, extending between the lung and the mediastinum, immediately anterior to the esophagus. Note, however, that a C7 vertebra articulating with a rudimentary cervical rib(s) is still considered a cervical vertebra. The dorsal nerve o the clitoris supplies deep perineal muscles and sensation to the clitoris (see the Clinical Box "Pudendal and Ilio-Inguinal Nerve Blocks"). Regular venous cannulas, particularly right angle steel tip cannulas, have a very large external diameter and consume most of the working space of a very short incision. The symptoms of mitral stenosis in the infant include all the usual features of congestive heart failure, particularly failure to thrive. An infated balloon remains distended only as long as its outlet is closed because its walls are ree to ully contract. Metatarsal ractures are also common in dancers, especially emale ballet dancers who use the demi-pointe technique. The cervical pleura covers the apex o the lung (the part o the lung extending superiorly through the superior thoracic aperture into the root o the neck;. When the nerve is injured in the radial groove, the triceps is usually not completely paralyzed but only weakened because only the medial head is aected; however, the muscles in the posterior compartment o the orearm that are supplied by more distal branches o the nerve are paralyzed. The child should be assessed for renal, hepatic, mesenteric, and cerebral function by the usual methods. The hernia is bounded by the emoral vein laterally and the lacunar ligament medially. However, the transverse colon may also receive arterial blood rom the right and let colic arteries via anastomoses, part o the series o anastomotic arcades that collectively orm the marginal artery (o Drummond, juxtacolic artery). This nerve passes ineriorly along the posterior wall o the axilla and enters the medial surace o the latissimus dorsi close to where it becomes tendinous. The parasympathetic and sympathetic bers reach the pancreas by passing along the arteries rom the celiac plexus and superior mesenteric plexus (see also "Summary o Innervation o Abdominal Viscera," p.
Near the angles o the ribs, the nerves pass between the internal intercostal and innermost intercostal muscles. The male gubernaculum is a brous tract connecting the primordial testis to the anterolateral abdominal wall at the site o the uture deep ring o the inguinal canal. Within the sympathetic trunks, presynaptic bers ollow one o our possible courses: 1. Ater invading a ganglion, the virus produces a sharp burning pain in the dermatome supplied by the involved nerve. When the deect is bilateral, the body o the L5 vertebrae may slide anteriorly on the sacrum (spondylolisthesis) so that it overlaps the sacral promontory 564 Chapter 6 Pelvis and Perineum. The common iliac arteries diverge and run inerolaterally, ollowing the medial border o the psoas muscles to the pelvic brim. The venous drainage rom the pelvic parts o the ureters generally parallels the arterial supply, draining to veins with corresponding names. Within the lungs, the bronchi branch in a constant ashion to orm the branches o the tracheobronchial tree. The bony edge (rim) surrounding and dening the pelvic inlet is the pelvic brim, ormed by the promontory and ala o the sacrum (superior surace o its lateral part, adjacent to the body o the sacrum). The hemisected craniovertebral region shows the median joints and membranous continuities o the ligamenta ava and longitudinal ligaments in the craniovertebral region. These brous bands are the thickened inerolateral-most portions o the external oblique and aponeurosis and the inerior margin o the transversalis ascia. It also may occur secondary to injury or scarring of the aortic valve caused by bacterial endocarditis. These ligaments have two parts: Denser "cord-like" parts that pass distally rom the heads o the metacarpals and phalanges to the bases o the phalanges. Of these 13 patients, one patient died suddenly 3 years after surgery, one patient was lost to follow-up, and the remaining 10 patients were alive and asymptomatic up to 11 years after surgery. The uterine tubes are the conduits and the site o ertilization or oocytes discharged into the peritoneal cavity. Segmental medullary arteries replace the radicular arteries at the irregular levels at which they occur. Ascending branch supplies anterior part o gluteal region; transverse branch winds around emur; descending branch joins genicular peri-articular anastomosis. Posterior to the bladder, the ductus deerens Left suprarenal gland at rst lies superior to the seminal gland and then descends medial to the ureter and the gland. This arrangement creates osseobrous subscapular, supraspinous, and inraspinous compartments; the muscles in each compartment attach to (originate rom) the deep surace o the overlying ascia in part, allowing the muscles to have greater bulk (mass) than would be the case i only bony attachments occurred. The elastic bers o the dermis deteriorate with age and are not replaced; consequently, in older people, the skin wrinkles and sags as it loses its elasticity. In this anchoring procedure, a tenia coli o the cecum and proximal ascending colon is sutured to the abdominal wall. Integumentary System 13 the dermis is a dense layer o interlacing collagen and elastic bers. Pancreas Superior mesenteric lymph nodes Superior central lymph nodes Mesenteric lymph nodes Juxtaintestinal lymph nodes the large intestine is where water is absorbed rom the indigestible residues o the liquid chyme, converting it into semisolid stool or eces that is stored temporarily and allowed to accumulate until deecation occurs. Approach the aorta is opened with a vertical incision which extends toward the intercoronary commissure of the aortic valve. Between slips o the transversus thoracis muscle, the arteries contact parietal pleura posteriorly. The anulus is simultaneously placed under compression on one side and tension on the other. The epoophoron orms rom remnants o the mesonephric tubules o the mesonephros, the transitory embryonic kidney (Moore et al. The anal canal, surrounded by internal and external anal sphincters, descends postero-ineriorly between the anococcygeal ligament and the perineal body. The pleural cavity between the two layers o the pleural sac is empty, except or a lubricating flm o pleural uid. The bones o the elbow region, demonstrating the relationship o the distal humerus and proximal ulna and radius during extension o the elbow joint.
Other types o anesthesia or childbirth are explained and compared in the Clinical Box "Anesthesia or Childbirth" (earlier in this chapter). Usually, contraction o the abdominal muscles is elt; this refex may not be observed in obese people. We are providing only a ew important examples useul to primary care health proessionals. The mammary gland is supplied rom its medial aspect mainly by perorating branches o the internal thoracic artery and by several branches o the axillary artery (principally the lateral thoracic artery) superiorly and laterally. The lateral border terminates in the truncated lateral angle o the scapula, the thickest part o the bone that bears the broadened head o the scapula. It is usually possible to manage the symptoms of congestive heart failure with appropriate medical therapy, including digoxin and lasix. It is generally not necessary to monitor central venous pressure with a right atrial catheter and no pacing wires are placed. At or close to the porta hepatis, the hepatic artery and hepatic portal vein terminate by dividing into right and let branches; these primary branches supply the right and let livers, respectively. Cystocele: Prolapse o the anterior vaginal wall involving the bladder (see the previous Clinical Box "Cystocele, Urethrocele, and Urinary Incontinence"). Details about the attachments, innervation, and actions o these muscles are provided in Tables 6. In this position, the abdominal viscera push the diaphragm superiorly in the thoracic cavity. The blood supply o the uterus derives mainly rom the uterine arteries, with potential collateral supply rom the ovarian arteries. Subclavian flap aortoplasty with preservation of arterial blood flow to the left arm. As discussed earlier in this chapter, cutting the long thoracic nerve results in a winged scapula. Arch hypoplasia and/or the presence of a coarctation should alert the echocardiographer to carefully review the subaortic area which may be hypoplastic. The posterior branch gives o an acetabular branch that supplies the head o the emur. The planes o the articular acets o thoracic vertebrae defne an arc (red arrows) that centers on an axis traversing the vertebral bodies vertically. Failure o the processus vaginalis to occlude, or deective anatomy, or degeneration o tissues, may result in the development o inguinal hernias. In view o this and the typical occurrence o these ndings, some clinicians have suggested that such agerelated changes should not be considered pathological but as the normal anatomy o aging (Bogduk, 2012). In its superior third, the external layer consists o voluntary striated muscle; the inerior third is composed o smooth muscle, and the middle third is made up o both types o muscle. The sequential contraction o the myocardial band enables the ventricles to unction as parallel, sucking and propelling pumps; on contraction, the ventricles do not merely collapse inward but rather wring themselves out (apm, anterior papillary muscles; ppm, posterior papillary muscles). Over the course of days to months it will become clear that hypertrophy has not progressed to the point of normalizing wall stress. As with mitral stenosis, the echocardiographer should analyze the mechanism of the regurgitation. The only bypass-related variable that had any trend toward significance was lowest hematocrit. Some infammatory diseases produce pericardial eusion (passage o fuid rom pericardial capillaries into the pericardial cavity, or an accumulation o pus). The relationship o the radial and ulnar styloid processes is important in the diagnosis o certain wrist injuries. The let marginal branch o the circumfex branch ollows the let margin o the heart and supplies the let ventricle.
Because o the large vertebral canal l in the cervical region, slight dislocation can occur here without damaging the spinal cord. These nodes receive lymph rom the posterior aspect o the thoracic wall and scapular region. The uterus can be urther stabilized through rectovaginal examination, which is used i examination via the vagina alone does not yield clear ndings. The surgeon should think of the sutures as small guy ropes that are being placed so as to pull the ostium open as a uniform circle. This transverse section o part o the back shows the location o the intrinsic back muscles and the layers o ascia associated with them. Perineum 635 supercial atty layer and a deep membranous layer, the (supercial) perineal ascia (Colles ascia). The axillary nerve runs transversely under cover o the deltoid at the level o the surgical neck o the humerus. Fracture o Dens o Axis the transverse ligament o the atlas is stronger than the dens o the C2 vertebra. However, a ew vessels rom the emale urethra may also drain into the sacral nodes and, rom the distal emale urethra, to the inguinal lymph nodes. The urethra lies anterior to the vagina (orming an elevation in the anterior vaginal wall; see. This dissection exposes the pericardial sac posterior to the body o the sternum rom just superior to the sternal angle to the level o the xiphisternal joint. A slit-like gap between the medial and the lateral crura o the external oblique aponeurosis, bridged by intercrural fbers, orms the superfcial inguinal ring. The segmental medullary arteries occur mainly in association with the cervical and lumbosacral enlargements, regions where the need or a good blood supply is greatest. Indirect injury resulting rom a all on the outstretched hand may produce a spiral or oblique racture o the humeral shat. Posterolateral Paired parietal (segmental) Diaphragm; body wall Subcostal Inerior phrenic Lumbar level o the T12 vertebra and ends at the level o the L4 vertebra by dividing into the right and let common iliac arteries. The nipple and areola may be spared and immediate reconstruction perormed in selected cases. Here, the margin o the let pleural refection moves laterally and then ineriorly at the cardiac notch to reach the 6th costal cartilage. It involves inltration o the anesthetic around the intercostal nerve trunk and its collateral branches. The intermediate sacral crests represent the used articular processes, and the lateral sacral crests are the tips o the transverse processes o the used sacral vertebrae. This ossa is particularly noticeable when a person is in the supine position because the abdominal organs spread out, drawing the anterolateral abdominal wall posteriorly in this region. The surace tension adhering visceral to parietal pleura (lung to thoracic wall) will be broken, and the lung will collapse, expelling most o its air because o its inherent elasticity (elastic recoil). The myocardium o the atria and ventricles (and the myogenic propagation o contracting stimuli through it) is attached to and separated by the connective tissue o the fbrous skeleton o the heart. The body has been sectioned in the median plane to show the abdominal and pelvic cavities as subdivisions o the continuous abdominopelvic cavity. The spleen is completely covered by peritoneum, except at the splenic hilum, where the splenorenal ligament (conveying splenic vessels to the spleen) and gastrosplenic ligament (conveying the short gastric and let gastro-omental vessels to the stomach) attach. As the deltoid atrophies, the rounded contour o the shoulder is fattened compared to the uninjured side. In such cases, a paradoxical situation may exist in which the prime mover usually described as being responsible or the movement is inactive (passive), while the controlled relaxation (eccentric contraction) o the antigravity antagonist(s) is the active (energy requiring) component in the movement. On the other hand, if surgery is delayed there will be secondary changes of the valve which will increase the difficulty of repair and reduce the probability that repair will be successful. The inerior sacral vertebrae and all the coccygeal vertebrae are still entirely cartilaginous; they ossiy during inancy. Typical symptoms initially are limited to exercise intolerance in a teenager or young adult which progresses to right heart failure including ascites, pleural effusions, and peripheral edema. Note that its inerior end is blunt and does not extend as ar distally as the lateral malleolus.
The ureters descend subperitoneally into the pelvis, passing inerior to the ductus deerens o males or the uterine artery o emales, the latter relationship being o particular surgical importance. To prevent recurrence or occurrence on the contralateral side, which is likely, both testes are surgically xed to the scrotal septum. Its larger, trough-like part extends vertically to the neck o the bladder as part o the isthmus o the prostate, displacing glandular tissue and investing the prostatic urethra anteriorly and anterolaterally only (see also. Although knowledge o the characteristics o individual bones is necessary or an understanding o the structure o the oot, it is important to study the skeleton o the oot as a whole and to identiy its principal bony landmarks in the living oot (see "Surace Anatomy o Bones o Foot" and "Surace Anatomy o Ankle Region and Foot"). The membranous parietal and visceral layers become continuous where the organs penetrate the pelvic foor. The most common causes include bronchitis (infammation o the bronchi), lung cancer, pneumonia, bronchiectasis, pulmonary embolism, and tuberculosis. Part o the large intestine, such as the cecum and/or appendix on the right side and the sigmoid colon on the let side, may become trapped in this ossa, causing considerable pain. The features described to this point are those that are likely to be encountered during repair in the neonatal period or early infancy. Intravascular stents are composed o rigid or semirigid tubular meshes, collapsed during introduction. This inormation is combined with input rom the vestibular apparatus o the (continued on p. When the coarctation is inerior to this site (postductal coarctation), a good collateral circulation usually develops between the proximal and distal parts o the aorta through the intercostal and internal thoracic arteries. The inerior sphincter includes cylindrical and loop-like portions (compressor urethrae). Surace anatomy o the spleen and pancreas relative to the diaphragm and posterior abdominal viscera. This is in contrast to the situation with cineangiography in the catheterization laboratory where generally a limited number of dye injections are made. The superfcial lymphatic vessels converge toward and accompany the great saphenous vein, draining into the inerior (vertical) group o superfcial inguinal lymph nodes. It mainly drains through the inerior vesical veins into the internal iliac veins; however, it may drain through the sacral veins into the internal vertebral venous plexuses. This is in part because of the acute volume load imposed by pulmonary regurgitation secondary to a transannular patch. The supinator acts at the radio-ulnar joint, while the remaining muscles extend and abduct the hand at the wrist joint and the thumb. Revision of the coronary anastomosis at the time of the arterial switch was required in seven patients (13%) intraoperatively due to myocardial ischemia. Nervous tissue consists o two main cell types: neurons (nerve cells) and neuroglia (glial cells), which support the neurons: Neurons are the structural and unctional units o the nervous system specialized or rapid communication. Internal hemorrhoids result rom a breakdown o the muscularis mucosae, a smooth muscle layer deep to the mucosa. An abscess resulting rom tuberculosis in the lumbar region tends to spread rom the vertebrae into the psoas ascia (sheath), where it produces a psoas abscess. The ureter is in danger o being inadvertently clamped (crushed), ligated, or transected during a hysterectomy (excision o uterus) when the uterine artery is ligated and severed to remove the uterus. The lack o anastomosis o these arterial vessels within the spleen results in the ormation o vascular segments o the spleen: two in 84% o spleens and three in the others, with relatively avascular planes between them, enabling subtotal splenectomy (see the Clinical Box "Splenectomy and Splenomegaly," p. The septal incision is carried toward the intracoronary commissure of the aortic valve. This "shortcut" across the chamber seems to acilitate conduction time, allowing coordinated contraction o the anterior papillary muscle. A peritoneal old is a refection o peritoneum that is raised rom the body wall by underlying blood vessels, ducts, and ligaments ormed by obliterated etal vessels. Flail chest is an extremely painul injury and impairs ventilation, thereby aecting oxygenation o the blood.