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The origin of the pain relates to ureteral distention. A series of peristaltic waves along the ureter transport urine along the length of the ureter from the kidney to the bladder. As the ureteric stone obstructs the kidney, the ureter becomes distended, resulting in an exacerbation of the pain. The peristaltic waves a...
This elevation of the right hemidiaphragm was due to the pus tracking from the hepatorenal space around the lateral and anterior aspect of the liver to sit on top of the liver in a subphrenic position. An ultrasound scan demonstrated this collection of fluid. The abscess cavity could be clearly seen by placing the ultr...
In patients with portal hypertension small anastomoses develop between the veins of the portal system and the veins of the systemic circulation. These portosystemic anastomoses are usually of little consequence; however, at the gastroesophageal junction, they lie in a submucosal and mucosal position and are subject to ...
The tumor grew along the renal vein and into the inferior vena cava toward the heart. Renal tumors can grow rapidly; in this case the tumor grew rapidly into the inferior vena cava, occluding it. This increased the pressure in the leg veins, resulting in swelling and pitting edema of the ankles. The patient unfortunate...
A 72-year-old man was brought to the emergency department with an abdominal aortic aneurysm (an expansion of the infrarenal abdominal aorta). The aneurysm measured 10 cm, and after discussion with the patient it was scheduled for repair. The surgical and endovascular treatment options were explained to the patient. Tre...
The superior region related to upper parts of the pelvic bones and lower lumbar vertebrae is the false pelvis (greater pelvis) and is generally considered part of the abdominal cavity (Fig. 5.1). The true pelvis (lesser pelvis) is related to the inferior parts of the pelvic bones, sacrum, and coccyx, and has an inlet a...
Two ligaments—the sacrospinous and the sacrotuberous ligaments—are important architectural elements of the walls because they link each pelvic bone to the sacrum and coccyx (Fig. 5.5A). These ligaments also convert two notches on the pelvic bones—the greater and lesser sciatic notches—into foramina on the lateral pelvi...
Posteriorly, the anal triangle contains the anal aperture. The cavity of the true pelvis is continuous with the abdominal cavity at the pelvic inlet (Fig. 5.10A). All structures passing between the pelvic cavity and abdomen, including major vessels, nerves, and lymphatics, as well as the sigmoid colon and ureters, pass...
Most of the skeletal muscles contained in the perineum and the pelvic floor, including the external anal sphincter and external urethral sphincter, are innervated by spinal cord levels S2 to S4. Much of the somatic motor and sensory innervation of the perineum is provided by the pudendal nerve from spinal cord levels S...
The bowl-shaped pelvic cavity is continuous above with the abdominal cavity. The rim of the pelvic cavity (the pelvic inlet) is completely encircled by bone. The pelvic floor is a fibromuscular structure separating the pelvic cavity above from the perineum below. The perineum is inferior to the pelvic floor and its mar...
The entire superior margin of the ilium is thickened to form a prominent crest (the iliac crest), which is the site of attachment for muscles and fascia of the abdomen, back, and lower limb and terminates anteriorly as the anterior superior iliac spine and posteriorly as the posterior superior iliac spine. A prominent ...
The sacrum, which has the appearance of an inverted triangle, is formed by the fusion of the five sacral vertebrae (Fig. 5.22). The base of the sacrum articulates with vertebra LV, and its apex articulates with the coccyx. Each of the lateral surfaces of the bone bears a large L-shaped facet for articulation with the i...
Each sacro-iliac joint is stabilized by three ligaments: the anterior sacro-iliac ligament, which is a thickening of the fibrous membrane of the joint capsule and runs anteriorly and inferiorly to the joint (Fig. 5.24B); the interosseous sacro-iliac ligament, which is the largest, strongest ligament of the three, and i...
The sacrotuberous ligament is also triangular and is superficial to the sacrospinous ligament. Its base has a broad attachment that extends from the posterior superior iliac spine of the pelvic bone, along the dorsal aspect and the lateral margin of the sacrum, and onto the dorsolateral surface of the coccyx. Laterally...
The lesser sciatic foramen is formed by the lesser sciatic notch of the pelvic bone, the ischial spine, the sacrospinous ligament, and the sacrotuberous ligament (Fig. 5.31). The tendon of the obturator internus muscle passes through this foramen to enter the gluteal region of the lower limb. Because the lesser sciatic...
At the midline, the muscles blend together posterior to the vagina in women and around the anal aperture in both sexes. Posterior to the anal aperture, the muscles come together as a ligament or raphe called the anococcygeal ligament (anococcygeal body) and attaches to the coccyx. Anteriorly, the muscles are separated ...
The perineal membrane and adjacent pubic arch provide attachment for the roots of the external genitalia and the muscles associated with them (Fig. 5.36C). The urethra penetrates vertically through a circular hiatus in the perineal membrane as it passes from the pelvic cavity, above, to the perineum, below. In women, t...
The anal canal begins at the terminal end of the rectal ampulla where it narrows at the pelvic floor. It terminates as the anus after passing through the perineum. As it passes through the pelvic floor, the anal canal is surrounded along its entire length by the internal and external anal sphincters, which normally kee...
The inferolateral surfaces of the bladder are cradled between the levator ani muscles of the pelvic diaphragm and the adjacent obturator internus muscles above the attachment of the pelvic diaphragm. The superior surface is slightly domed when the bladder is empty; it balloons upward as the bladder fills. Neck of bladd...
Prostatic part. The prostatic part of the urethra (Fig. 5.45C) is 3 to 4 cm long and is surrounded by the prostate. In this region, the lumen of the urethra is marked by a longitudinal midline fold of mucosa (the urethral crest). The depression on each side of the crest is the prostatic sinus; the ducts of the prostate...
Each testis (Fig. 5.47B) is composed of seminiferous tubules and interstitial tissue surrounded by a thick connective tissue capsule (the tunica albuginea). Spermatozoa are produced by the seminiferous tubules. The 400 to 600 highly coiled seminiferous tubules are modified at each end to become straight tubules, which ...
The prostate is shaped like an inverted rounded cone with a larger base, which is continuous above with the neck of the bladder, and a narrower apex, which rests below on the pelvic floor. The inferolateral surfaces of the prostate are in contact with the levator ani muscles that together cradle the prostate between th...
Implantation of the blastocyst normally occurs in the body of the uterus. During pregnancy, the uterus dramatically expands superiorly into the abdominal cavity. The uterine tubes extend from each side of the superior end of the body of the uterus to the lateral pelvic wall and are enclosed within the upper margins of ...
During intercourse, semen is deposited in the vaginal vault. Spermatozoa make their way into the external os of the cervical canal, pass through the cervical canal into the uterine cavity, and then continue through the uterine cavity into the uterine tubes where fertilization normally occurs in the ampulla. Fascia in t...
The broad ligament is a sheet-like fold of peritoneum, oriented in the coronal plane that runs from the lateral pelvic wall to the uterus, and encloses the uterine tube in its superior margin and suspends the ovary from its posterior aspect (Fig. 5.59A). The uterine arteries cross the ureters at the base of the broad l...
Gray rami communicantes from ganglia of the sympathetic trunk connect with each of the anterior rami and carry postganglionic sympathetic fibers destined for the periphery to the somatic nerves (Fig. 5.62). In addition, special visceral nerves (pelvic splanchnic nerves) originating from S2 to S4 deliver preganglionic p...
The superior gluteal nerve, formed by branches from the dorsal divisions of L4 to S1, leaves the pelvic cavity through the greater sciatic foramen superior to the piriformis muscle and supplies muscles in the gluteal region—gluteus medius, gluteus minimus, and tensor fasciae latae (tensor of fascia lata) muscles. The i...
In addition to gray rami communicantes, other branches (the sacral splanchnic nerves) join and contribute to the pelvic part of the prevertebral plexus associated with innervating pelvic viscera (Fig. 5.63A). Pelvic extensions of the prevertebral plexus The pelvic parts of the prevertebral plexus carry sympathetic, par...
The major artery of the pelvis and perineum is the internal iliac artery on each side (Fig. 5.64). In addition to providing a blood supply to most of the pelvic viscera, pelvic walls and floor, and structures in the perineum, including erectile tissues of the clitoris and the penis, this artery gives rise to branches t...
The superior vesical artery normally originates from the root of the umbilical artery and courses medially and inferiorly to supply the superior aspect of the bladder and distal parts of the ureter. In men, it also may give rise to an artery that supplies the ductus deferens. The inferior vesical artery occurs in men a...
The median sacral artery (Figs. 5.65A and 5.66) originates from the posterior surface of the aorta just superior to the aortic bifurcation at vertebral level LIV in the abdomen. It descends in the midline, crosses the pelvic inlet, and then courses along the anterior surface of the sacrum and coccyx. It gives rise to t...
Lymphatics from the ovaries and related parts of the uterus and uterine tubes leave the pelvic cavity superiorly and drain, via vessels that accompany the ovarian arteries, directly into lateral aortic or lumbar nodes and, in some cases, into the pre-aortic nodes on the anterior surface of the aorta. In addition to dra...
Because the levator ani muscles course medially from their origin on the lateral pelvic walls, above, to the anal aperture and urogenital hiatus, below, inverted wedge-shaped gutters occur between the levator ani muscles and adjacent pelvic walls as the two structures diverge inferiorly (Fig. 5.70). In the anal triangl...
Between the perineal membrane and the membranous layer of superficial fascia is the superficial perineal pouch. The principal structures in this pouch are the erectile tissues of the penis and clitoris and associated skeletal muscles. Structures in the superficial perineal pouch The superficial perineal pouch contains:...
The penis is composed mainly of the two corpora cavernosa and the single corpus spongiosum, which contains the urethra (Fig. 5.71B.) As in the clitoris, it has an attached part (root) and a free part (body): The root of the penis consists of the two crura, which are proximal parts of the corpora cavernosa attached to t...
In women, each bulbospongiosus muscle is anchored posteriorly to the perineal body and courses anterolaterally over the inferior surface of the related greater vestibular gland and the bulb of the vestibule to attach to the surface of the bulb and to the perineal membrane (Fig. 5.72A). Other fibers course anterolateral...
Lateral to the labia minora are two broad folds, the labia majora, which unite anteriorly to form the mons pubis. The mons pubis overlies the inferior aspect of the pubic symphysis and is anterior to the vestibule and the clitoris. Posteriorly, the labia majora do not unite and are separated by a depression termed the ...
The major somatic nerve of the perineum is the pudendal nerve. This nerve originates from the sacral plexus and carries fibers from spinal cord levels S2 to S4. It leaves the pelvic cavity through the greater sciatic foramen inferior to the piriformis muscle, passes around the sacrospinous ligament, and then enters the...
The branches of the internal pudendal artery are similar to those of the pudendal nerve in the perineum and include the inferior rectal and perineal arteries, and branches to the erectile tissues of the penis and clitoris (Fig. 5.77). One or more inferior rectal arteries originate from the internal pudendal artery in t...
Veins in the perineum generally accompany the arteries and join the internal pudendal veins that connect with the internal iliac vein in the pelvis (Fig. 5.78). The exception is the deep dorsal vein of the penis or clitoris that drains mainly the glans and the corpora cavernosa. The deep dorsal vein courses along the m...
Imaginary lines that join the ischial tuberosities with the pubic symphysis in front, and with the tip of the coccyx behind, outline the diamond-shaped perineum. An additional line between the ischial tuberosities divides the perineum into two triangles, the urogenital triangle anteriorly and anal triangle posteriorly....
The roots of the clitoris occur deep to surface features of the perineum and are attached to the ischiopubic rami and the perineal membrane. The bulbs of the vestibule (Fig. 5.84F), composed of erectile tissues, lie deep to the labia minora on either side of the vestibule. These erectile masses are continuous, via thin...
Pelvic inletAla of sacrumSacro-iliac jointCoccyxIschial spineAnterior superior iliac spineObturator foramenIschial tuberosityPubic symphysisIschiopubic ramusPubic tubercleSI body Fig. 5.5 Pelvic walls. A. Bones and ligaments of the pelvic walls. B. Muscles of the pelvic walls. Greater sciatic foramenLesser sciatic fora...
Fig. 5.19 Right pelvic bone. A. Medial view. B. Lateral view. Fig. 5.20 Ilium, ischium, and pubis. Fig. 5.21 Components of the pelvic bone. A. Medial surface. B. Lateral surface. Fig. 5.22 Sacrum and coccyx. A. Anterior view. B. Posterior view. C. Lateral view. Fig. 5.23 Lumbosacral joints and associated ligaments. A. ...
Fig. 5.41 Bladder. A. Superolateral view. B. The trigone. Anterior view with the anterior part of the bladder cut away. Internal urethralorificeOpening of uretersUretersUretersUrethraUrethraInferolateralsurfacesSuperior surfaceApexTrigoneTrigoneMedianumbilicalligamentABBase Fig. 5.42 Ligaments that anchor the neck of t...
Fig. 5.49 Axial T2-weighted magnetic resonance images of prostate problems. A. A small prostatic cancer in the peripheral zone of a normal-sized prostate. B. Benign prostatic hypertrophy. Fig. 5.50 Reproductive system in women. Glans clitorisBladderOvaryVaginaUterine tubeLigament of ovaryRound ligamentof uterusDeep ing...
Lumbosacral trunkSuperior gluteal nerveInferior gluteal nerveNerve to piriformis muscleObturator nerve(from lumbar plexus)Sciatic nervePosterior femoralcutaneous nervePudendal nervePerforatingcutaneous nerveNerves to coccygeus,levator ani, and externalanal sphincter musclesAnococcygeal nervesCoccygeal plexusL4L5S1S2S3S...
C. Anterolateral view with pelvic walls and diaphragm removed. Obturator internus muscleIschio-anal fossaeAnterior recesses of ischio-anal fossaeSacrotuberous ligamentSacrospinous ligamentCoccygeus muscleAObturator internus muscleTendon of obturatorinternus muscleIschio-anal fossaeAnterior recesses of ischio-anal fossa...
S2S3S4Obturator internus muscleInferior rectal nerveDorsal nerve of penisSacrospinous ligamentCoccygeus muscleLevator animusclePerineal nervePosterior scrotal nervePudendal nervePudendal canal infascia of obturator internusMotor branches to skeletal muscle in urogenital triangleA Dorsal nerve of clitorisPosterior labia...
Fig. 5.84 Structures in the urogenital triangle of a woman. A. Inferior view of the urogenital triangle of a woman with major features indicated. B. Inferior view of the vestibule. The labia minora have been pulled apart to open the vestibule. Also indicated are the glans clitoris, the clitoral hood, and the frenulum o...
Table 5.4 Branches of the sacral and coccygeal plexuses (spinal segments in parentheses do not consistently participate) Table 5.5 Muscles of the anal triangle Table 5.6 Muscles of the superficial perineal pouch In the clinic In certain diseases (e.g., leukemia), a sample of bone marrow must be obtained to assess the s...
At the beginning of defecation, closure of the larynx stabilizes the diaphragm and intraabdominal pressure is increased by contraction of abdominal wall muscles. As defecation proceeds, the puborectalis muscle surrounding the anorectal junction relaxes, which straightens the anorectal angle. Both the internal and the e...
Given the position of the colon and rectum in the abdominopelvic cavity and its proximity to other organs, it is extremely important to accurately stage colorectal tumors; a tumor in the pelvis, for example, could invade the uterus or bladder. Assessing whether or not spread has occurred usually involves computed tomog...
Bladder cancer (Fig. 5.44) is the most common tumor of the urinary tract and is usually a disease of the sixth and seventh decades, although there is an increasing trend for younger patients to develop this disease. Approximately one-third of bladder tumors are multifocal; fortunately, two-thirds are superficial tumors...
Surgical removal of the malignant testis is often carried out using an inguinal approach. The testis is not usually removed through a scrotal incision, because it is possible to spread tumor cells into the subcutaneous tissues of the scrotum, which has a different lymphatic drainage than the testis. In the clinic Inter...
Benign prostatic hypertrophy is a disease of the prostate that occurs with increasing age in most men (Fig. 5.49B). It generally involves the more central regions of the prostate (see Fig. 5.48), which gradually enlarge. The prostate feels “bulky” on DRE. Owing to the more central hypertrophic change of the prostate, t...
A simple and effective method of birth control is to surgically ligate (clip) the uterine tubes, preventing spermatozoa from reaching the ovum. This simple short procedure is performed under general anesthetic. A small laparoscope is passed into the peritoneal cavity and special equipment is used to identify the tubes....
This is a new and innovative way of performing radical prostatectomy in patients with prostate cancer. The patient is placed on an operating table near a so-called patient unit consisting of a high-resolution camera and three arms containing microsurgical instruments. The surgeon operates the robot from a computer cons...
Pulsatile emission of semen from the penis is generated by the reflex contraction of the bulbospongiosus muscle that forces semen from the base of the penis and out of the external urethral meatus. Bulbospongiosus muscle is innervated by somatic motor fibers carried in the pudendal nerve (S2–S4). Contraction of the int...
The worst and most serious urethral rupture is related to serious pelvic injuries where there is complete disruption of the puboprostatic ligaments. The prostate is dislocated superiorly not only by the ligamentous disruption but also by the extensive hematoma formed within the true pelvis. The diagnosis can be made by...
A 19-year-old woman presented to the emergency department with a 36-hour history of lower abdominal pain that was sharp and initially intermittent, later becoming constant and severe. The patient also reported feeling nauseated and vomited once in the ER. She did not have diarrhea and had opened her bowels normally 8 h...
A 65-year-old man was examined by a surgical intern because he had a history of buttock pain and impotence. On examination he had a reduced peripheral pulse on the left foot compared to the right. On direct questioning, the patient revealed that he experienced severe left-sided buttock pain after walking 100 yards. Aft...
A 25-year-old woman was admitted to the emergency department with a complaint of pain in her right iliac fossa. The pain had developed rapidly over approximately 40 minutes and was associated with cramps and vomiting. The surgical intern made an initial diagnosis of appendicitis. The typical history for appendicitis is...
This patient’s pregnancy test was negative. After the patient emptied her bladder, there was no change in the mass. The physician thought the mass might be a common benign tumor of the uterus (fibroid). To establish the diagnosis, he obtained an ultrasound scan of the pelvis, which confirmed that the mass stemmed from ...
The lower limb is directly anchored to the axial skeleton by a sacroiliac joint and by strong ligaments, which link the pelvic bone to the sacrum. It is separated from the abdomen, back, and perineum by a continuous line (Fig. 6.1), which: joins the pubic tubercle with the anterior superior iliac spine (position of the...
During walking, many anatomical features of the lower limbs contribute to minimizing fluctuations in the body’s center of gravity and thereby reduce the amount of energy needed to maintain locomotion and produce a smooth, efficient gait (Fig. 6.7). They include pelvic tilt in the coronal plane, pelvic rotation in the t...
Muscles of the gluteal region consist predominantly of extensors, rotators, and abductors of the hip joint (Fig. 6.11). In addition to moving the thigh on a fixed pelvis, these muscles also control the movement of the pelvis relative to the limb bearing the body’s weight (weight-bearing or stance limb) while the other ...
Anteriorly, the obturator nerve and vessels pass between the pelvis and thigh through the obturator canal. This canal is formed between bone at the top of the obturator foramen and the obturator membrane, which closes most of the foramen during life. Structures pass between the perineum and gluteal region through the l...
Most muscles in the medial compartment are innervated mainly by the obturator nerve (except the pectineus, which is innervated by the femoral nerve, and part of the adductor magnus, which is innervated by the tibial division of the sciatic nerve). Most muscles in the posterior compartment of the thigh and the leg and i...
The upper fan-shaped part of the ilium is associated on its inner side with the abdomen and on its outer side with the lower limb. The top of this region is the iliac crest, which ends anteriorly as the anterior superior iliac spine and posteriorly as the posterior superior iliac spine. A prominent lateral expansion of...
The smooth crescent-shaped articular surface (the lunate surface) is broadest superiorly where most of the body’s weight is transmitted through the pelvis to the femur. The lunate surface is deficient inferiorly at the acetabular notch. The acetabular fossa provides attachment for the ligament of the head of the femur,...
The middle third of the shaft of the femur is triangular in shape with smooth lateral and medial margins between anterior, lateral (posterolateral), and medial (posteromedial) surfaces. The posterior margin is broad and forms a prominent raised crest (the linea aspera). The linea aspera is a major site of muscle attach...
Three ligaments reinforce the external surface of the fibrous membrane and stabilize the joint: the iliofemoral, pubofemoral, and ischiofemoral ligaments. The iliofemoral ligament is anterior to the hip joint and is triangular shaped (Fig. 6.33B). Its apex is attached to the ilium between the anterior inferior iliac sp...
The sciatic nerve, inferior gluteal nerve and vessels, pudendal nerve and internal pudendal vessels, posterior cutaneous nerve of the thigh, nerve to the obturator internus and gemellus superior, and nerve to the quadratus femoris and gemellus inferior pass through the greater sciatic foramen below the muscle. The less...
The obturator nerve, like the femoral nerve, originates from L2 to L4. It descends along the posterior abdominal wall, passes through the pelvic cavity and enters the thigh by passing through the obturator canal (Fig. 6.36 and Table 6.1). The obturator nerve innervates: all muscles in the medial compartment of the thig...
The nerve to the quadratus femoris (L4 to S1) and the nerve to the obturator internus (L5 to S2) are small motor nerves that originate from the sacral plexus. Both nerves pass through the greater sciatic foramen inferior to the piriformis muscle and enter the gluteal region (Fig. 6.36 and Table 6.1): The nerve to the o...
The great saphenous vein originates from the medial side of the dorsal venous arch and then ascends up the medial side of the leg, knee, and thigh to connect with the femoral vein just inferior to the inguinal ligament. The small saphenous vein originates from the lateral side of the dorsal venous arch, ascends up the ...
The tensor fasciae latae and gluteus maximus muscles, working through their attachments to the iliotibial tract, hold the leg in extension once other muscles have extended the leg at the knee joint. The iliotibial tract and its two associated muscles also stabilize the hip joint by preventing lateral displacement of th...
The sciatic nerve enters the lower limb from the pelvic cavity by passing through the greater sciatic foramen and descending through the gluteal region into the posterior thigh and then into the leg and foot. The pudendal nerve and internal pudendal vessels pass between the pelvic cavity and perineum by passing first t...
The gemellus superior and inferior (gemelli is Latin for “twins”) are a pair of triangular muscles associated with the upper and lower margins of the obturator internus tendon (Fig. 6.45): The base of the gemellus superior originates from the gluteal surface of the ischial spine. The base of the gemellus inferior origi...
The tensor fasciae latae muscle is the most anterior of the superficial group of muscles in the gluteal region and overlies the gluteus minimus and the anterior part of the gluteus medius (Fig. 6.47). The tensor fasciae latae originates from the outer margin of the iliac crest from the anterior superior iliac spine to ...
The nerve to the obturator internus enters the gluteal region through the greater sciatic foramen inferior to the piriformis muscle and between the posterior cutaneous nerve of the thigh and the pudendal nerve (Fig. 6.48). It supplies a small branch to the gemellus superior and then passes over the ischial spine and th...
In addition to adjacent muscles, the superior gluteal artery contributes to the supply of the hip joint. Branches of the artery also anastomose with the lateral and medial femoral circumflex arteries from the deep femoral artery in the thigh, and with the inferior gluteal artery (Fig. 6.51). Inferior and superior glute...
The middle part of the shaft of the femur is triangular in cross section (Fig. 6.53D). In the middle part of the shaft, the femur has smooth medial (posteromedial), lateral (posterolateral), and anterior surfaces and medial, lateral, and posterior borders. The medial and lateral borders are rounded, whereas the posteri...
The proximal end of the tibia is expanded in the transverse plane for weight-bearing and consists of a medial condyle and a lateral condyle, which are both flattened in the horizontal plane and overhang the shaft (Fig. 6.55). The superior surfaces of the medial and lateral condyles are articular and separated by an int...
The shaft of the tibia is triangular in cross section and has three surfaces (posterior, medial, and lateral) and three borders (anterior, interosseous, and medial) (Fig. 6.55D): The anterior border is sharp and descends from the tibial tuberosity where it is continuous superiorly with a ridge that passes along the lat...
The medial compartment of the thigh contains six muscles (gracilis, pectineus, adductor longus, adductor brevis, adductor magnus, and obturator externus). All except the pectineus, which is innervated by the femoral nerve, and part of the adductor magnus, which is innervated by the sciatic nerve, are innervated by the ...
The vastus lateralis is the largest of the vastus muscles (Fig. 6.59). It originates from a continuous line of attachment, which begins anterolaterally from the superior part of the intertrochanteric line of the femur and then circles laterally around the bone to attach to the lateral margin of the gluteal tuberosity a...
The pectineus is a flat quadrangular muscle (Fig. 6.61). It is attached above to the pectineal line of the pelvic bone and adjacent bone, and descends laterally to attach to an oblique line extending from the base of the lesser trochanter to the linea aspera on the posterior surface of the proximal femur. From its orig...
The adductor magnus adducts and medially rotates the thigh at the hip joint. The adductor part of the muscle is innervated by the obturator nerve and the hamstring part is innervated by the tibial division of the sciatic nerve. The obturator externus is a flat fan-shaped muscle. Its expansive body is attached to the ex...
The semimembranosus flexes the leg at the knee joint and extends the thigh at the hip joint. Working with the semitendinosus muscle, it medially rotates the thigh at the hip joint and the leg at the knee joint. The semimembranosus muscle is innervated by the tibial division of the sciatic nerve. Three arteries enter th...
The main trunk of the medial circumflex femoral artery passes over the superior margin of the adductor magnus and divides into two major branches deep to the quadratus femoris muscle: One branch ascends to the trochanteric fossa and connects with branches of the gluteal and lateral circumflex femoral arteries. The othe...
Branches of the femoral nerve (Fig. 6.68) include: anterior cutaneous branches, which penetrate deep fascia to supply skin on the front of the thigh and knee; numerous motor nerves, which supply the quadriceps femoris muscles (rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis muscles) and the sa...
The tibial nerve innervates: all muscles in the posterior compartment of the leg, all intrinsic muscles in the sole of the foot including the first two dorsal interossei muscles, which also may receive innervation from the deep fibular nerve, and skin on the posterolateral side of the lower half of the leg and lateral ...
The synovial membrane of the knee joint attaches to the margins of the articular surfaces and to the superior and inferior outer margins of the menisci (Fig. 6.75A). The two cruciate ligaments, which attach in the intercondylar region of the tibia below and the intercondylar fossa of the femur above, are outside the ar...
The major ligaments associated with the knee joint are the patellar ligament, the tibial (medial) and fibular (lateral) collateral ligaments, and the anterior and posterior cruciate ligaments. The patellar ligament is basically the continuation of the quadriceps femoris tendon inferior to the patella (Fig. 6.76). It is...
The small proximal tibiofibular joint is synovial in type and allows very little movement (Fig. 6.82). The opposing joint surfaces, on the undersurface of the lateral condyle of the tibia and on the superomedial surface of the head of the fibula, are flat and circular. The capsule is reinforced by anterior and posterio...
The roof of the popliteal fossa is covered by superficial fascia and skin (Fig. 6.83C). The most important structure in the superficial fascia is the small saphenous vein. This vessel ascends vertically in the superficial fascia on the back of the leg from the lateral side of the dorsal venous arch in the foot. It asce...
The distal end of the tibia is shaped like a rectangular box with a bony protuberance on the medial side (the medial malleolus; Fig. 6.81). The upper part of the box is continuous with the shaft of the tibia while the lower surface and the medial malleolus articulate with one of the tarsal bones (talus) to form a large...
Posterior compartment of leg Muscles in the posterior (flexor) compartment of the leg are organized into two groups, superficial and deep, separated by a layer of deep fascia. Generally, the muscles mainly plantarflex and invert the foot and flex the toes. All are innervated by the tibial nerve. The superficial group o...