Ischioanal Triangle

The ischioanal triangle contains a horseshoe-shaped fossa filled with fat and is known as the ischioanal fossa. The anal canal and its associated sphincters are in the center of the triangle. The boundaries of the ischioanal fossa are as follows Anterior. Posterior border of the urogenital triangle. Posterior. Gluteus maximus muscle and the sacrotuberous ligament. Lateral. Deep fascia of the obturator internus muscle, which condenses around the pudendal nerve (S2-S4) and the internal pudendal...

Vessels And Lymphatics Of The Thoracic Wall

The nerve and blood supply of the thoracic wall consists largely of the neurovascular elements that course through the intercostal spaces. The major elements in each space consist of an intercostal vein, artery, and nerve. The primary neurovascular bundle courses along the costal groove of the upper rib, between the internal and innermost intercostal muscles. The anterior and posterior intercostal arteries supply the intercostal spaces and form anastomoses with each other. The intercostal...

Wrist Complex

The wrist complex consists of the radiocarpal and midcarpal joints that result in wrist flexion and extension and in radial and ulnar deviation (Figure 32-5A and B). Radiocarpal joint. Articulation between the radius and the radioulnar disc (triangular fibrocartilage complex) with the proximal row of carpal bones (scaphoid, lunate, and tri-quetrum). Midcarpal joint. Articulation between the proximal row of carpal bones (scaphoid, lunate, and triquetrum) with the distal row of carpal bones...

Pharyngeal Plexus Of Nerves

Pharyngeal nerves from CN IX and CN X and a small contribution from CN V-2 form the pharyngeal plexus (Figure 27-3B). The plexus lies along the middle pharyngeal constrictor muscle and is responsible for sensory and motor innervation. SENSORY INNERVATION The three regions of the pharynx each receive a unique cranial nerve supply. Nasopharynx. Sensory neurons travel from the mucosa of the nasopharynx, through the palatovaginal canal, and on through the pterygopalatine ganglion to CN V-2. CN V-2...

Olecranon Bursa

The most important bursa associated with the elbow complex is the olecranon bursa, which is located between the capsule of the elbow complex and the triceps tendon. The olecranon bursa diminishes friction between the two surfaces as they cross over each other. Figure 31-3 A. Joints of the elbow. B. Joint capsule of the elbow. C. Joint capsule cut and open revealing the articulations. D. Superior view of the proximal radioulnar joint demonstrating the annular ligament. Flexion of shoulder and...

Suprahyoid Muscles

The suprahyoid muscles (i.e., digastric, stylohyoid, mylohyoid, and geniohyoid muscles) are located deep to the investing fascia of the deep cervical fascia (Figure 25-3A Table 25-1). These muscles raise the hyoid bone during swallowing because the mandible is stabilized. Digastric muscle. Has two bellies connected by a central tendon, which is attached to the hyoid bone. The posterior belly arises from the mastoid process, whereas the anterior belly arises from the mandible. Because of the two...

Branches Of The Internal Iliac Artery

Internal Iliac Artery

The internal iliac artery divides into an anterior and a posterior trunk near the greater sciatic foramen (Figure 12-3A and B). ANTERIOR TRUNK Branches from the anterior trunk supply the pelvic viscera, perineum, gluteal region, and medial compartment of the thigh. The branches off the anterior trunk of the internal iliac artery are as follows Umbilical artery. Is usually the first branch off the anterior trunk and ascends out of the pelvis along the internal surface of the anterior abdominal...

Veins Of The Forearm

The veins in the forearm consist of a superficial and a deep venous system. The superficial system consists of the basilic vein, located medially, and the cephalic vein, located laterally. Anterior to the elbow complex, the median cubital vein forms a connection between the basilic and cephalic veins. The deep venous system may consist of two or three veins that course with each artery. VThe median cubital vein is part of the superficial venous system. Because of its location, the median...

Prevertebral Ganglia And Plexus

The prevertebral (preaortic) plexus is a network of autonomic nerve fibers covering the abdominal aorta and extending into the pelvic cavity between the common iliac arteries. This plexus serves as a common pathway for the following autonomics (Figure 11-4A and B) Preganglionic sympathetic nerves. From greater, lesser, least, and lumbar splanchnic nerves. Preganglionic parasympathetic nerves. From the vagus nerve (CN X) and pelvic splanchnics (S2-S4). Visceral afferents. From both sympathetic...

Somatic Nerves

The somatic nerves of the posterior abdominal wall are the ventral rami of the subcostal and lumbar spinal nerves (Figure 11-3). Subcostal (T12), iliohypogastric (L1), and ilioinguinal (L1) nerves. These three nerves emerge along the lateral surface of the psoas major muscle and course between the internal oblique and transverse abdominis muscles, innervating these abdominal wall muscles. Iliohypogastric nerve (L1) In addition the provides cutaneous innervation to the skin in the hypogastric...

Muscles Of The Anterior Compartment Of The Thigh

The muscles in the anterior compartment of the thigh are primarily flexors of the hip or extensors of the knee because of their anterior orientation (Figure 36-1C). The femoral nerve (L2-L4) innervates these muscles however, each muscle does not necessarily receive each spinal nerve level between L2 and L4. Iliopsoas musculature. Originates from two muscles, the psoas major and iliacus muscles, which join to form a common tendon. The psoas major muscle attaches along vertebrae T12-L5, discs,...

Ascending And Transverse Colon

Female Abdominal Anatomy Diagram

The ascending colon arises from the cecum and courses vertically to the liver, where the colon bends at the right colic (hepatic) flexure (Figure 10-1B). The parietal peritoneum covers its anterior surface, and thus the ascending colon is considered a retroperitoneal organ. A depression between the lateral surface of the ascending colon and the abdominal wall is known as the right paracolic gutter. Branches of the right colic artery that supply the ascending colon enter the bowel on its medial...

Vertebral Curvatures

In utero, the entire vertebral column has a primary or kyphotic curvature (concave anteriorly) (Figure 1-1C). After birth, with the demands of walking, weightbearing, and gravity, the cervical and lumbar regions form secondary or lor-dotic curvatures (concave posteriorly) (Figure 1-1D). Primary (kyphotic) curvatures occur in the thoracic and sacral regions, where the vertebrae curve posteriorly. This allows increased space for the heart and lungs in the thorax and birth canal in the sacral...

Study Questions

Directions Each of the numbered items or incomplete statements is followed by lettered options. Select the one lettered option that is best in each case. 1. During a rugby match, a 22-year-old player experiences a violent blow to the side of his head, resulting in a loss of consciousness. The player regains consciousness approximately 30 seconds later and sits on the sideline recuperating. A half-hour later, he becomes nauseous, disoriented, and falls over unconscious. He is taken to the...

Anterior Division Of The Sacral Plexus

The anterior division of the sacral plexus consists of ventral rami from L4 to S4, which form a network and give rise to the following five nerves (Figure 35-2A) Pudendal nerve (S2-S4). Exits the pelvis via the greater sciatic foramen, enters the gluteal region, and courses to the perineum through the lesser sciatic foramen. The pudendal nerve provides motor innervation to the muscles of the pelvic floor and sensory innervation to the skin of the perineum, penis, and clitoris. Posterior femoral...

Muscles Of The Medial Compartment Of The Thigh

The muscles in the medial compartment of the thigh are primarily adductors of the hip because of their medial orientation. The obturator nerve (L2-L4) innervates most of the muscles in the medial compartment of the thigh. However, each muscle does not necessarily receive each spinal nerve level between L2 and L4 (Figure 36-2A and B). Pectineus muscle. Attaches to the pectineal line of the pubis and the posterior surface of the proximal femur. The pectineus muscle adducts and flexes the thigh at...

Lymphatics

All lymphatic vessels throughout the body return their lymph to the blood stream by either the thoracic or the right lymphatic ducts. Both lymphatic ducts drain lymph into the subclavian veins. Thoracic duct. This duct is a major lymphatic vessel that begins in the abdomen and passes superiorly through the thorax entering the root of the neck, on the left side. Arching laterally, the duct passes deep to the carotid sheath and courses inferiorly to terminate in the junction between the left...

Male Genital Organs And Glands

The following genital organs and glands comprise the male reproductive system (Figure 13-1A) Testes. The primary male sex organ. The testes produce sperm and sex hormones (e.g., testosterone) and are located within the scrotum. Epididymis. A convoluted duct that sits on the superior pole of each testis. Sperm are stored in the epididymis during the maturation process. Ductus deferens. A thick-walled tube in the spermatic cord that transports sperm from the epididymis to the ejaculatory ducts in...

Sternocleidomastoid And Trapezius Muscles

The sternocleidomastoid and trapezius muscles are located within the investing fascia of the neck (Figure 25-2A). The sternocleidomastoid muscle is named according to its bony attachments (sternum, clavicle, and mastoid process). The sternocleidomastoid muscle creates the borders for both the anterior and the posterior triangles of the neck, and is innervated by the spinal accessory nerve (CN XI). This muscle flexes the neck, pulls the chin upward, and assists in elevating the rib cage during...

Spinal Roots Spinal Nerves And Rami The Big Picture

Gray Ramus

At each spinal cord segment, ventral and dorsal spinal roots join to form spinal nerves that bifurcate into ventral and dorsal rami. Spinal roots carry sensory (dorsal root) or motor (ventral root) neurons, whereas the spinal nerves and rami contain a mixture of sensory and motor neurons. The dorsal rami seg-mentally innervate deep back muscles (motor) and the skin of the back (sensory). This section of the chapter helps to differentiate among vertebral levels, spinal cord levels, and spinal...

Floor Of The Posterior Triangle

Supraclavicular

The prevertebral fascia forms the floor of the posterior triangle of the neck (Figure 26-1C and D). The following structures are superficial to the prevertebral tascia Interior belly ot the omohyoid muscle. Courses from the hyoid bone en route to the scapula within the pretracheal fascia. Transverse cervical artery. A branch from the thyrocervical trunk that courses along the floor of the posterior triangle en route to the deep surface of the trapezius muscle. The artery bifurcates into a...

Boundaries And Divisions Of The Anterior Triangle

Submandibular Lymph Nodes

The borders, or boundaries, of the anterior triangle are as follows (Figure 26-2A) Anteriorly. The midline down the neck. Posteriorly. The sternocleidomastoid muscle. Superiorly. The lower border of the mandible. The anterior triangle is subdivided by three structures the omohyoid muscle, the hyoid bone, and the digastric muscle into submandibular, carotid, submental, and muscular triangles (Figure 26-2B). The submental and muscular triangles have little clinical value and, therefore, will not...

Anal Canal

The anal canal is located inferior to the pelvic diaphragm in the ischioanal fossa. The anal canal is divided into an upper two-thirds (visceral portion), which is part of the large intestine, and a lower one-third (somatic portion), which is part of the perineum. The pectinate line (anorectal junction) is an important landmark in that it divides the anal canal into upper and lower portions. Developmentally, the pectinate line is the junction between the development of the hindgut (gut tube)...

Deep Cervical Fascia

Cross Sectional Neck Anatomy

The deep cervical fascia is deep to the superficial fascia. The deep cervical fascia is condensed in various regions to form the following sublayers the investing layer of the deep cervical fascia, the pretracheal fascia, the prevertebral fascia, and the carotid sheath. The function of the deep fascia is to provide containment of muscles and viscera in compartments, to enable structures to slide over each other, and to serve as a conduit for neurovascular bundles. INVESTING FASCIA The investing...

Portalcaval Anastomoses

To better understand the portal-caval anastomoses, recall that veins in the abdomen return blood to the heart via two routes (Figure 10-4B) Portal system. Veins from the foregut, midgut, and hindgut drain blood to the liver before the blood enters the inferior vena cava and ultimately returns to the heart. Caval system. Veins from the lower limbs, pelvis, and posterior abdominal wall transport blood directly to the inferior vena cava before the blood returns to the heart. Portal-caval...

External Genitalia

Labia Majora Matlab

The follow structures form the external genitalia of the female reproductive system (Figure 14-2A) Mons pubis. A rounded area superficial to the pubic symph-ysis containing adipose tissue. Labia majora. Paired longitudinal ridges of skin that are inferior and posterior to the mons pubis. The outer surfaces are covered with pubic hair. The round ligaments of the uterus are attached to the labia majora. Labia minora. Paired hairless skin ridges flanking a midline space known as the vestibule. The...

Muscular Support

Any muscle that crosses the glenohumeral joint and produces a compressive force between the head of the humerus and the glenoid cavity will produce muscle stability (Figure 30-7D). Muscle stability is best exemplified by the rotator cuff muscles, which provide support to all sides, except the inferior aspect of the glenohumeral joint. Supraspinatus muscle. Provides superior support. Infraspinatus muscle. Provides posterior support. Teres minor muscle. Provides posterior support. Subscapularis...

Superficial Fascia

Transpyloric Plane Anatomy

The superficial fascia of the anterior abdominal wall consists of two layers an external layer of adipose tissue (Camper's fascia) and an internal layer of dense collagenous connective tissue (Scarpa's fascia). Camper's fascia is absent in the perineum. In contrast, Scarpa's fascia continues into the perineum, but the nomenclature is changed relative to the region in which it is located. For example, Scarpa's fascia becomes Colles' fascia when surrounding the roots of the penis and clitoris it...

Fascial Compartments Of The Dorsal Side Of The Wrist

Fascia The Ulna Bone

The extensor retinaculum of the hand divides the dorsum of the wrist into the following six compartments Compartment 1. Contains the abductor pollicis longus and extensor pollicis brevis muscles. Compartment 2. Contains the extensor carpi radialis longus and brevis muscles. Compartment 3. Contains the extensor pollicis longus muscles. Compartment 4. Contains the extensor digitorum and extensor indicis muscles. Compartment 5. Contains the extensor digiti minimi muscles. Compartment 6. Contains...

Muscles Of The Posterior Compartment Of The Thigh

Hamstrings Muscles Posterior Thigh

The muscles in the posterior compartment of the thigh are primarily extensors of the hip or flexors of the knee because of their posterior orientation. The tibial nerve (L4-S3) innervates the muscles in the posterior compartment of the thigh, with the exception of the short head of the biceps femoris muscles (common fibular nerve). Muscles in this compartment do not receive all the innervation levels from the tibial nerve rather, they receive innervation from the spinal nerve level between L5...

Posterior Tibial Artery

Posterior Tibial Artery

The posterior tibial artery originates from the popliteal artery and quickly gives rise to the fibular artery (Figure 37-4A and B). The posterior tibial and fibular arteries descend deep to the soleus muscle. Posterior tibial artery. Curves medially, as it courses inferi-orly, giving rise to the posterior lateral malleolar artery, which joins the arterial network around the ankle. The posterior tibial artery supplies blood to the posterior compartment of the leg and continues distally, under...

Innervation Of The Kidneys And The Proximal Part Of The Ureters

Ureter Nerves

The autonomic innervation of the kidneys and proximal ureters is as follows Sympathetic innervation. Preganglionic neurons course through the lesser, least, and lumbar splanchnic nerves.They synapse in the aorticorenal and superior mesenteric ganglia, where postganglionic neurons course in a renal plexus to the kidneys. Parasympathetic innervation. Preganglionic parasympa-thetic neurons originate in the brainstem and course in the vagus nerve to enter the abdomen. The vagus nerve branches to...

Inferior Hypogastric Plexus

Hypogastric

The inferior hypogastric plexus is formed by the union of nerves from the superior hypogastric plexus, sacral splanchnic nerves, and pelvic splanchnic nerves (Figure 12-4A). The inferior hypogastric plexus is located diffusely around the lateral walls of the rectum, bladder, and vagina. The plexus contains ganglia in which both sympathetic and parasympathetic pre-ganglionic fibers synapse. Therefore, the inferior hypogastric plexus consists of preganglionic and postganglionic sympathetic and...

Superficial Perineal Space

Perineal Membrane

The superficial perineal space (pouch) is the region inferior to the urogenital diaphragm. It is enclosed by the superficial perineal (Colles') fascia. The superficial perineal space contains (Figure 13-1A-D) Deep (Buck's) fascia of the penis. Continuous with the external spermatic fascia and deep perineal fascia. The deep dorsal vein of the penis is inside this fascial layer. CRURA OF THE PENIS Each crus of the penis is composed of erectile tissue that is continuous with the paired corpus...

Posterior Division Of The Sacral Plexus

Tensor Fascia Lata Nerve

The posterior division of the sacral plexus consists of ventral rami from L4-S3, which form a network and give rise to the following six nerves Perforating cutaneous nerve (S2-S3). Pierces the sacro-tuberous ligament and travels to the inferior edge of the glu-teus maximus muscle, providing sensory innervation to the skin over the inferior aspect of the gluteus maximus (inferior gluteal fold). Nerve to piriformis muscle (S1-S2). Travels directly from the plexus to the piriformis muscle,...

Blood Flow Of The Portal System

The liver is unique in that it receives both nutrient-rich deoxy-genated blood (portal vein) and oxygenated blood (hepatic arteries). The portal vein branches as it enters the liver, where its blood percolates around hepatocytes in tiny vascular channels known as sinusoids. Hepatocytes detoxify the blood, metabolize fats, carbohydrates, and drugs, and produce bile. The sinusoids receive deoxygenated blood from the portal veins (provide blood for metabolism and detoxification) and oxygenated...

Answers

1-A The clavicle connects the manubrium of the sternum to the acromion of the scapula. 2-B The infraspinatus is a rotator cuff muscle that stabilizes the glenohumeral joint. The tendons of the rotator cuff reinforce the ligaments of glenohumeral joint capsule. 3-C The roots of the brachial plexus pass between the anterior and middle scalene muscles. Spasm of these muscles may entrap the brachial plexus roots. 4-B The musculocutaneous nerve courses through the coraco-brachialis muscle and...

Rectum And Anus

Peritoneal Reflection

In the pelvic cavity, the rectum is the terminal, straight portion of the colon and ultimately terminates as the anus. The transition from sigmoid colon to rectum occurs at approximately the S3 vertebral level, where the rectum is covered anteriorly by parietal peritoneum and thus is a retroperitoneal structure. Superior rectal a. Sigmoid colon Rectum Anus Figure 10-2 A. Hindgut with the small intestine removed. B. Primary blood supply to the hindgut is through the inferior mesenteric artery.

Directions

Each of the numbered items or incomplete statements is followed by lettered options. Select the one lettered option that is best in each case. 1. Which of the following structures is the only osteologic connection between the axial skeleton and the upper limb skeleton 2. Damage to which of the following muscles would most likely decrease the stability of the glenohumeral joint 3. Spasm of the scalene muscles may entrap which region of the brachial plexus 4. A 43-year-old man is experiencing...