Lab 6— Anterior, Medial—Thigh & Leg 1 1. Fracture of This Structure

Lab 6— Anterior, Medial—Thigh & Leg Skeletal—Questions 1 of 1

1. Fracture of this structure would most likely cause weakness in adduction, flexion, and extension of the thigh.

2. A 20-year-old man developed foot drop following a fracture in the leg. What is the most likely site of the fracture? A. Upper tibia B. Upper fibula C. Lower tibia D. Lower fibula E. Middle tibia

3. A 71-year-old grandmother fell half way down the basement stairs while carrying a laundry basket after dinner. She didn’t lose con- sciousness, but sat at the bottom of the stairs gathering her wits and the scattered laundry. She didn’t think she had broken any bones as she could move all her limbs. Her husband, who had heard the noise and came to check on her, helped her stand up. It was then that she felt a slight pain in her left hip when she placed weight on it. She limped about for the rest of the day. The next morning her husband brought her into your family practice office where you could clearly see that she walked with her pelvis tilted as if her left leg was slightly shorter. She still had left hip pain. You order a plain film of the left femur from hip to knee expecting to find which of the following? A. Femoral neck fracture with compression B. Femoral neck fracture with complete displacement C. A spiral fracture of the femoral shaft D. A transverse supracondylar fracture E. An intercondylar fracture

1 Lab 6— Anterior, Medial—Thigh & Leg Skeletal—Answers

1. Answer A. (1) The adductor tubercle is fractured. The adductor magnus inserts on the adductor tubercle on the femur and functions to adduct, flex, and extend the thigh.

2. Answer B. (2) One of the most frequently injured nerves in the body is the common peroneal nerve as it crosses the head of the fibula. This nerve gives rise to the deep fibular nerve which innervates the dorsiflexors in the anterior compartment of the leg - tibialis anterior, extensor digitorum longus, and extensor hallucis longus - thus causing foot drop.

3. Answer A. (7) Fractures of the femoral neck, com- monly called “hip fractures” are extremely common in old- er women as a consequence of osteoporosis. Since the woman was still able to bear some weight on her leg it is very unlikely that she had complete displacement of the femoral neck (answer b), rather a compression fracture with the fall. None of the symptoms are consistent with fracture in either the shaft (answer c) or distal portion (answers d and e) of the femur.

2 Lab 6— Anterior, Medial—Thigh & Leg Ligaments — Questions 1 of 1

1. A 20-year-old college student receives a severe blow on the inferolateral side of the left knee joint while playing football. Radiographic examination reveals a fracture of the head and neck of the fibula. If the lateral (fibular) collateral ligament is torn by this fracture, which of the following conditions may occur? A. Abnormal passive abduction of the extended leg B. Abnormal passive adduction of the extended leg C. Anterior displacement of the femur on the tibia D. Posterior displacement of the femur on the tibia E. Maximal flexion of the leg

3 Lab 6— Anterior, Medial—Thigh & Leg Ligament — Answers

1. Answer B. (1) The lateral (fibular) collateral ligament prevents adduction at the knee. Therefore, a torn lateral collateral ligament can be recognized by abnormal passive adduction of the extended leg. Abnormal passive abduction of the extended leg may occur when the medial (tibial) collateral ligament is torn. The anterior cruciate ligament prevents posterior displacement of the femur on the tibia; the posterior cruciate ligament prevents anterior displacement of the femur on the tibia. In addition, the posterior cruciate ligament is taut when the knee is fully flexed.

4 Lab 6— Anterior, Medial—Thigh & Leg Muscles; Tendons — Questions 1 of 3

1. A 14-year-old male severs his right leg just below the 4. A 21-year-old man was involved in a motorcycle acci- hip in a motorcycle accident involving a guardrail. You are dent, resulting in destruction of the groove in the lower attempting to reattach the limb. As you complete the reat- surface of the cuboid bone. Which of the following muscle tachment of the muscles, you reflect up the structure of tendons is most likely damaged? the muscle that you are sewing. The rectus femoris of the A. Flexor hallucis longus quadriceps group is an example of which type of muscle? B. Peroneus brevis C. Peroneus longus A. Unipennate D. Tibialis anterior B. Bipennate E. Tibialis posterior C. Multipennate D. Parallel E. Convergent

2. Which tendons insert on the first metatarsal bone? 5. A 52-year-old woman slipped and fell and now com- A. Flexor hallucis longus and extensor hallucis longus plains of being unable to extend her leg at the knee joint. B. Peroneus longus and tibialis anterior Which of the following muscles was paralyzed as a result C. Peroneus longus and tibialis posterior of this accident? D. Flexor hallucis longus and tibialis anterior A. Semitendinosus E. Peroneus brevis and tibialis anterior B. Sartorius C. Gracilis D. Quadriceps femoris E. Biceps femoris

3. A rupture of the tendon superior to which lettered site 6. A patient experiences weakness in dorsiflexing and or structure in the following radiograph below would most inverting the foot. Which of the following muscles is dam- likely cause an inability to extend the knee joint? aged? A. Peroneus longus B. Peroneus brevis C. Tibialis anterior D. Extensor digitorum longus E. Peroneus tertius

3. 7. A patient experiences paralysis of the muscle that originates from the femur and contributes directly to the stability of the knee joint. Which of the following muscles is involved? A. Vastus lateralis B. Semimembranosus C. Sartorius D. Biceps femoris (long head) E. Rectus femoris

5 Lab 6— Anterior, Medial—Thigh & Leg Muscles; Tendons — Answers

1. Answer B. (2) A unipennate muscle has its fascicle 4. Answer C. (1) The groove in the lower surface of arranged in one direction. The vastus lateralis is an exam- the cuboid bone is occupied by the tendon of the pe- ple of an unipennate muscle. This type of muscle gener- roneus longus muscle. The flexor hallucis longus tendon ates considerable force, but relatively slowly. The fasci- occupies a groove on the posterior surface of the body of cles of the rectus femoris are arranged in a bipennate the talus and a groove on the inferior surface of the calca- arrangement. This type of arrangement affords the mus- neus during its course. The tibialis posterior muscle ten- cle an increase in power while limiting its length of con- don occupies the medial malleolar groove of the tibia. traction. Most muscles in the body have a multipennate Other muscle tendons are not in the groove of the tarsal fascicle arrangement. These muscles have intermediate bones. strength and range of motion. Muscles with parallel fascicles, such as the biceps brachii, have greater range of contraction, but limited strength. Convergent fascicles are seen in postural muscles and have great strength of contraction with limited range of contraction.

2. Answer B. (2) Peroneus longus and tibialis anterior 5. Answer D. (2) The quadriceps femoris muscle in- is the correct answer. Tibialis anterior is the main dorsi- cludes the rectus femoris muscle and the vastus medialis, flexor of the ankle, and also assists with foot inversion. It intermedialis, and lateralis muscles. They extend the leg is located on the anterior aspect of the leg. Its tendon de- at the knee joint. The semitendinosus, semimembra- scends over the front of the ankle, and continues over the nosus, and biceps femoris muscles (the hamstrings) ex- dorsum of the foot onto the medial side. There it inserts tend the thigh and flex the leg. The sartorius and gracilis on the medial cuneiform and first metatarsal. muscles can flex the thigh and the leg.

Peroneus longus and peroneus brevis are the main evert- ors of the foot, and also assist with plantar flexion of the ankle. They are located on the lateral side of the leg. Their tendons descend together on the lateral side of the ankle, passing behind the lateral malleolus, and continuing forward along the lateral surface of the calcaneus. Peroneus brevis inserts on the tuberosity of the fifth metatarsal. Peroneus longus crosses the cuboid bone, travels in a groove on the cuboid's plantar surface, and continues 6. Answer C. (1) The tibialis anterior can dorsiflex and medially across the sole of the foot to insert on the medial invert the foot. The peroneus longus and brevis muscles cuneiform and first metatarsal. can plantar flex and evert the foot, the peroneus tertius can dorsiflex and evert the foot, and the extensor digitorum longus can dorsiflex the foot and extend the toes.

3. The Answer is C. (1) The quadriceps tendon is rup- 7. Answer A. (1) The vastus lateralis muscles arise tured. The quadriceps muscle is a powerful knee extensor from the femur and all the other muscles originate from used in climbing, running, jumping, and rising from a seat- the hip (coxal) bone. The biceps femoris inserts on the ed position. fibula, and other muscles insert on the tibia; thus, all of them contribute to the stability of the knee joint.

6 Lab 6— Anterior, Medial—Thigh & Leg Muscles; Tendons — Questions 2 of 3

8. A 24-year-old woman presents to her physician with 12. Which structure in this radiograph may be fractured, weakness in flexing the hip joint and extending the knee resulting in loss of the chief flexor of the thigh? joint. Which muscle is most likely involved in this scenar- io? A. Sartorius B. Gracilis C. Rectus femoris D. Vastus medialis E. Semimembranosus

9. A patient has weakness when flexing both her thigh 13. A 17-year-old boy was stabbed during a gang fight and leg. Which of the following muscles is most likely in- resulting in transection of the obturator nerve. Which of jured? the following muscles is completely paralyzed? A. Rectus femoris A. Pectineus B. Semitendinosus B. Adductor magnus C. Biceps femoris C. Adductor longus D. Sartorius D. Biceps femoris E. Adductor longus E. Semimembranosus

10. A 35-year-old man has difficulty in dorsiflexing the 14. A 25-year-old gladiator sustains a penetrating injury foot. Which of the following muscles is most likely dam- that severs the superficial peroneal nerve. This will most aged? likely cause paralysis of which of the following muscles? A. Tibialis posterior A. Peroneus tertius B. Flexor digitorum longus B. Peroneus brevis C. Tibialis anterior C. Flexor hallucis longus D. Peroneus longus D. Tibialis anterior E. Peroneus brevis E. Tibialis posterior

11. A full leg walking cast on the leg after a fracture re- 15. The obturator nerve and the sciatic (tibial portion) sults in atrophy of the quadriceps femoris muscle. Which nerve of a 15-year-old boy are transected as a result of a muscle is most affected? motorcycle accident. This injury would result in complete A. Rectus femoris paralysis of which of the following muscles? B. Vastus medialis A. Rectus femoris C. Vastus intermedius B. Biceps femoris, short head D. Vastus lateralis C. Pectineus E. All are equally affected D. Adductor magnus E. Sartorius

7 Lab 6— Anterior, Medial—Thigh & Leg Muscles; Tendons — Answers

8. Answer C. (1) The rectus femoris flexes the thigh 12. Answer D. (1) The iliopsoas muscle is the chief and extends the leg. The sartorius can flex both the hip flexor of the thigh and inserts on the lesser trochanter. and knee joints. The gracilis adducts and flexes the thigh and flexes the leg, the vastus medialis extends the knee joint, and the semimembranosus extends the hip joint and flexes the knee joint.

9. Answer D. (1) The sartorius can flex and rotate the 13. Answer C. (1) The adductor longus is innervated thigh laterally, and flex and rotate the leg medially. The by only the obturator nerve. Thus, injury here could com- rectus femoris flexes the thigh and extends the leg. The pletely paralyze the adductor longus. The pectineus is semimembranosus extends the thigh and flexes and ro- innervated by both the obturator and femoral nerves. The tates the leg medially. The biceps femoris extends the adductor magnus is innervated by both the obturator thigh and flexes and rotates the leg laterally. The adduc- nerve and tibial part of the sciatic nerve. The biceps femo- tor longus adducts and flexes the thigh. ris is innervated by the tibial portion (long head) and common peroneal portion (short head) of the sciatic nerve. The semimembranosus is innervated by the tibial portion of the sciatic nerve.

10. Answer C. (1) The tibialis anterior muscle can dor- 14. Answer B. (1) The peroneus brevis muscle is in- siflex the foot, whereas all other muscles are able to plan- nervated by the superficial peroneal nerve. The peroneus tar flex the foot. tertius and tibialis anterior muscles are innervated by the deep peroneal nerve. The flexor hallucis longus and tibialis posterior muscles are innervated by the tibial nerve.

11. Answer B. (1) It has been suggested that the mus- 15. Answer D. (1) The adductor magnus is innervated cles with the most to lose by immobilization will lose the by both the obturator and sciatic (tibial portion) nerves. most mass. The rectus femoris is involved in knee exten- Hence, a lesion here could cause paralysis. The rectus sion but also hip flexion, so it will be exercised when the femoris and sartorius are innervated by the femoral nerve. patient weight bears. The vastus intermedius and lateralis The biceps femoris long head is innervated by the tibial only extend the leg. The medialis extends the leg but also portion of the sciatic nerve, whereas the short head is stabilizes the patella. Both actions will be limited by immo- innervated by the common peroneal portion of the sciatic bilization so its activity will be restricted the most and nerve. The pectineus is innervated by both the femoral show the greatest amount of atrophy. and obturator nerves.

8 Lab 6— Anterior, Medial—Thigh & Leg Muscles; Tendons — Questions 3 of 3

16. A 52-year-old woman comes to an orthopedic sur- 20. Which of the following will flex the hip and extend the geon complaining of an uncomfortable feeling in her knee knee? and ankle joints. After a thorough examination, she is di- A. Semimembranous agnosed as having arthritis with mild discomfort with pas- B. Vastus lateralis sive movements. The muscles acting at the ankle joint C. Rectus femoris appear normal with good strength. Which muscle can D. Biceps femoris both dorsiflex and invert her foot? E. Sartorius A. Peroneus longus B. Peroneus brevis C. Peroneus tertius D. Extensor hallucis longus E. Extensor digitorum longus

17. Fracture of which structure may destroy the site of in- 21. The function of the muscles in the extensor compart- sertion of the muscle that can rotate the thigh laterally and ment of the thigh, by definition, is quite obvious. Which of its tendon that passes through the lesser sciatic foramen? the following muscles crosses over two joints? A. Pectoralis muscle B. Iliacus muscle C. Vastus medialis muscle D. Rectus femoris muscle E. Vastus intermedius muscle

18. Injury to the superficial peroneal nerve will result in 22. A 20-year-old college student receives a severe blow motor loss of which muscle? on the inferolateral side of the left knee joint while playing A. Peroneus longus football. Radiographic examination reveals a fracture of B. Extensor digitorum brevis the head and neck of the fibula. C. Extensor hallucis longus After injury to this nerve, which of the following muscles D. Peroneus tertius could be paralyzed? E. Extensor digitorum longus A. Gastrocnemius B. Popliteus C. Extensor hallucis longus D. Flexor digitorum longus E. Tibialis posterior

19. A motorcyclist falls from his bike in an accident and 23. The femoral triangle is bounded superiorly by the in- gets a deep gash that severs the superficial peroneal guinal ligament. Which of the following structures form the nerve near its origin. Which of the following muscles is lateral and medial borders of the femoral triangle? paralyzed? A. Adductor longus and gracilis A. Peroneus longus B. Adductor longus and sartorius B. Extensor hallucis longus C. Gracilis and pectineus C. Extensor digitorum longus D. Gracilis and sartorius D. Peroneus tertius E. Pectineus and sartorius E. Extensor digitorum brevis

9 Lab 6— Anterior, Medial—Thigh & Leg Muscles; Tendons — Answers

16. Answer D. (1) The extensor hallucis longus can dor- 20. Answer C. (2) For a muscle to act on both the hip and siflex and invert the foot. The peroneus longus, peroneus knee, it must arise on the hip and insert on the tibia. The tertius, and extensor digitorum longus can dorsiflex and evert rectus femoris arises on the pelvis and inserts on the tibia, foot. The peroneus brevis can plantar flex and evert the foot. so it can both flex the hip and extend the knee. The semimembranous and biceps femoris are hamstrings which extend the hip and flex the knee. The sartorius is synergistic with the hamstrings, even though it is in the anterior compartment. The vastus lateralis extends the knee, but because it arises from the femur, it cannot flex the hip.

17. Answer B. (1) The greater trochanter is the site for 21. Answer D. (2) The rectus femoris muscle helps flex insertion of the obturator internus muscle tendon, which the hip and extends the knee joint. It originates at the anteri- leaves the pelvis through the lesser sciatic foramen. or inferior iliac spine and inserts via the tendon of the quadriceps femoris muscle in the tibia's tuberosity. All other muscles of the list either span only the hip joint or only the knee joint.

18. Answer A. (2) The superficial peroneal nerve sup- 22. Answer C. (1) The extensor hallucis longus is inner- plies the peroneus longus and brevis and sensation to the vated by the deep peroneal nerve, whereas other muscles lateral aspect of the lower part of the leg and the dorsum of are innervated by the posterior tibial nerve. the foot. Foot drop does not occur but eversion of the foot is lost. The deep peroneal nerve supplies the tibialis anterior, extensor hallucis longus, extensor digitorum longus, the peroneus tertius, and sensation to the adjacent sides of the first and second toes.

19. Answer A. (1) The superficial peroneal nerve sup- 23. Answer B. (4) You should know the boundaries of the plies the peroneus longus and brevis muscles. Other mus- femoral triangle: the inguinal ligament above, the medial bor- cles are innervated by the deep peroneal nerve. der of the sartorius laterally, and the medial border of the adductor longus on the inner aspect of the thigh. The gracilis muscle (choices A, C, and D) runs roughly parallel to the adductor longus but is not usually considered part of the triangle. The pectineus muscle (choices C and E) is found on the floor of the femoral triangle.

10 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Questions 1 of 4

1. All the following statements about the femoral nerve 5. A 25-year-old track and field athlete presents to his are true, EXCEPT physician complaining of right lower extremity weakness A. It is the smallest branch of the lumbar plexus and an unsteady gait for the past 2 months. His symp- B. It innervates the vastus lateralis toms worsen markedly with exercise. On examination, the C. The saphenous nerve is regarded as the terminal physician notes atrophy of the medial portion of the right branch thigh and weakness to adduction. What nerve is most D. It innervates the rectus femoris likely involved? E. It is lateral to the femoral vessels posterior to the ingui- A. Femoral nerve nal ligament B. Inferior gluteal nerve C. Nerve to obturator internus D. Obturator nerve E. Sciatic nerve

2. The sartorius and quadriceps femoris are innervated by 6. A fracture of which lettered site or structure in the fol- what nerve? lowing radiograph below would most likely cause a lesion A. Obturator nerve of the common peroneal nerve, resulting in paralysis of B. Femoral nerve the muscles in the anterior and lateral compartments of C. Tibial branch of the sciatic nerve the leg? D. Inferior gluteal nerve E. Superior gluteal nerve

3. Shrapnel from an antipersonnel land mine damaged 6. the saphenous branch of the femoral nerve. What areas have lost sensation? A. Posterior calf B. Medial side of the leg below the knee C. Lateral side of the leg below the knee D. Dorsal surface of the foot E. Plantar surface of the foot

4. Sensations of the lateral aspect of the thigh from the hip to the knee have been lost. There is likely a problem with the: A. Lateral femoral cutaneous nerve B. Intermediate femoral cutaneous nerve C. Medial femoral cutaneous nerve D. Posterior femoral cutaneous nerve

11 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Answers

1. Answer A. (2) The femoral nerve is the largest 5. Answer D. (7) The obturator nerve passes through branch of the lumbar plexus. It enters the thigh behind the the obturator foramen to innervate the adductor muscles inguinal ligament, lateral to the femoral vessels where the in the medial compartment of the thigh. The nerve can nerve remains outside of the femoral sheath. In the thigh become entrapped between the adductor muscles of ath- the femoral nerve divides into an anterior division, which letes. These patients will develop difficulties adducting the gives off the intermediate and the medial cutaneous thigh. nerves and twigs to the sartorius; and a posterior division, which give off muscular branches to the rectus femoris, A is not correct. The femoral nerve innervates the mus- the vastus lateralis, the vastus intermedius, and the cles in the anterior compartment of the thigh, which act to vastus medialis. The saphenous nerve is regarded as the flex the thigh and extend the knee. B is not correct. termination of the femoral nerve. The inferior gluteal nerve innervates the gluteus maximus, which extends and laterally rotates the thigh. C is not correct. The nerve to the obturator internus innervates the obturator internus and the superior gemellus, which laterally rotate and flex the thigh. E is not correct. The sciatic nerve (tibial and common peroneal divisions) innervates 2. Answer B. (2) The obturator innervates mostly the the hamstrings, or the posterior thigh muscles, which ex- adductor muscles. The inferior gluteal nerve innervates tend the thigh and flex the leg. Bottom Line: The obturator the gluteus maximus while the superior branch innervates nerve can become compressed by the adductor muscles the gluteus minimus and medius. The tibial branch of the of an athlete, causing difficulty in adducting the thigh. sciatic innervates muscles of the lower leg.

3. Answer B. (2) The skin of the posterior calf is inner- 6. Answer E. (1) The common peroneal nerve is vul- vated by the medial sural cutaneous nerve. The lateral nerable to injury as it passes behind the head of the fibula side of the lower leg is innervated by the lateral sural cu- and then winds laterally around the neck of the fibula. taneous (upper leg) and superficial peroneal nerve (lower Fracture of the fibular head causes a lesion of the com- aspect of leg). The dorsal surface is also innervated by mon peroneal nerve, resulting in paralysis of the muscles the superficial peroneal nerve. The plantar surface is in- in the anterior and lateral compartments of the leg. nervated by both the medial and lateral plantar nerves.

4. Answer A. (2) The lateral femoral cutaneous nerve innervates the skin on the lateral aspect of the thigh from the hip to the knee. The intermediate femoral cutaneous nerve innervates the anterior aspect of the skin of the thigh. The medial femoral cutaneous nerve innervates the medial and lower half of the skin of the thigh. The skin of the posterior thigh is innervated by the posterior femoral cutaneous nerve.

12 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Questions 2 of 4

7. A 41-year-old man was involved in a fight and felt 10. A patient presents with sensory loss on adjacent sides weakness in extending the knee joint. On examination, he of the great and second toes and impaired dorsiflexion of was diagnosed with a lesion of the femoral nerve. Which the foot. These signs probably indicate damage to which of the following symptoms would be a result of this nerve of the following nerves? damage? A. Superficial peroneal A. Paralysis of the psoas major muscle B. Lateral plantar B. Loss of skin sensation on the lateral side of the foot C. Deep peroneal C. Loss of skin sensation over the greater trochanter D. Sural D. Paralysis of the vastus lateralis muscle E. Tibial E. Paralysis of the tensor fasciae latae

8. A 20-year-old college student receives a severe blow 11. A 40-year-old man presents with a 3-week history of on the inferolateral side of the left knee joint while playing abnormal sensation in the left leg and difficulty walking. football. Radiographic examination reveals a fracture of On physical exam, he shows an abnormal sensation of the head and neck of the fibula. Which of the following the web space of the 1 toe area and weakness to the dor- nerves is damaged? siflexion of the foot (foot drop). This clinical picture is sug- A. Sciatic gestive of a lesion of what nerve? B. Tibial A. Deep peroneal nerve C. Common peroneal B. Femoral nerve D. Deep peroneal C. Common peroneal nerve E. Superficial peroneal D. Superficial peroneal nerve E. Tibial nerve

9. The nerves that exit the pelvic cavity through the fo- 12. A medical student has difficulty walking after getting ramina indicated by the arrows supply motor innervation up out of his seat following a long anatomy lecture. On to the questioning, he admitted that he frequently sits with his A. Anterior compartment of the thigh right knee crossed over his left. On examination he is B. Posterior compartment of the thigh found to be unable to extend his right hallux or to dorsi- C. Medial compartment of the thigh flex, then invert, his right foot. He has an area of numb- D. Flexors of the knee ness and tingling on the dorsum of his foot between the E. Extensors of the knee right hallux and second digit. The most likely diagnosis is compression neuropathy of the A. Deep peroneal nerve B. Tibial nerve C. Sciatic nerve D. Superficial peroneal nerve E. Obturator nerve

9. 13. A 72-year-old woman complains of a cramp-like pain in her thigh and leg. She was diagnosed as having a severe intermittent claudication. Following surgery, an infec- tion was found in the adductor canal, damaging the en- closed structures. Which of the following structures remains intact?

A. Femoral artery B. Femoral vein C. Saphenous nerve D. Great saphenous vein E. Nerve to the vastus medialis

13 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Answers

7. Answer D. (1) The femoral nerve innervates the 10. Answer C. (1) The deep peroneal nerve supplies the ante- quadratus femoris, sartorius, and vastus muscles. There- rior muscles of the leg, including the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius mus- fore, damage to this nerve results in paralysis of these cles, which dorsiflex the foot. The medial branch of the deep pero- muscles. The second and third lumbar nerves innervate neal nerve supplies the skin of adjacent sides of the great and the psoas major muscle, the sural nerve innervates the second toes, whereas the lateral branch supplies the extensor skin on the lateral side of the foot, the iliohypogastric digitorum brevis and extensor hallucis brevis. The superficial pero- nerve and superior clunial nerves supply the skin over the neal nerve innervates the peroneus longus and brevis, which plantar flexes the foot, and supplies the skin on the side of the lower greater trochanter, and the superior gluteal nerve inner- leg and the dorsum of the ankle and foot. The tibial nerve innervates the tensor fasciae latae. vates the muscles of the posterior compartment that plantar flexes and supplies the skin on the heel and plantar aspect of the foot. The lateral plantar nerve innervates muscles and skin of the lateral plantar aspect of the foot. The sural nerve supplies the skin on the posterolateral aspect of the leg and the lateral aspect of the foot and the little toe.

8. Answer C. (1) The common peroneal nerve is vul- 11. Answer A. (2) lesion of the deep peroneal nerve produc- nerable to injury as it passes behind the head of the fibula es a weak inversion, loss of extension of the toes, abnormal and then winds around the neck of the fibula and pierces sensation of the anterolateral area of the leg, and foot drop. A the peroneus longus muscle, where it divides into the lesion of the femoral nerve produces a weakness in knee extension and sensorial abnormalities on the anterior thigh and the deep and superficial peroneal nerves. In addition, the medial area of the leg. Proximal lesions can cause weak hip deep and superficial peroneal nerves pass superficial to flexion. A lesion of the common peroneal nerve manifests with a the neck of the fibula in the substance of the peroneus combination of symptoms that present with a deficit of the deep longus muscle and are less susceptible to injury than the and the superficial peroneal nerves. The nerve runs subcutane- common peroneal nerve. Other nerves are not closely ously, winding around the neck of the fibula; this makes it very associated with the head and neck of the fibula. vulnerable to lesions caused by trauma or pressure. A lesion of the superficial peroneal nerve produces sensorial abnormalities on the dorsum of the foot (except the 1 web space) and an inability to evert the foot. A lesion of the tibial nerve produces a weakness in the flexion of the knee and toes, abnormal sensation on the back of the leg and sole, and weak plantar flexion.

9. Answer C. (2) The obturator nerve exits through the 12. Answer A. (2) The student has compromised func- obturator foramen to enter the medial compartment of the tion of the tibialis anterior muscle, as indicated by his ina- thigh. There it innervates the adductors of the thigh. The bility to dorsiflex and then invert his foot, and of extensor nerve of the anterior compartment of the thigh is the fem- hallucis longus and brevis muscles, as indicated by his oral nerve, innervating the muscles of the quadriceps inability to extend his hallux. These muscles are innervat- femoris group, which act as extensors of the knee. The ed by the deep peroneal (fibular) nerve. This nerve also nerve of the posterior compartment of the thigh is the tibi- supplies sensory innervation to the area on the dorsum of al nerve, a component of the sciatic nerve, which inner- the foot between the 1 and 2nd digits. Injury to the nerve vates the strong flexors of the knee joint, the hamstrings, occurred near the point of bifurcation of the common pe- and gastrocnemius. roneal nerve into its components – the superficial and deep peroneal nerves. The facts that eversion of the foot and sensory innervation of most of the dorsum of the foot are intact indicate that the superficial peroneal nerve is not affected.

13. Answer D. (1) The great saphenous nerve remains intact because it is not in the adductor canal. The adductor canal contains the femoral vessels, the saphenous nerve, and the nerve to the vastus medialis.

14 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Questions 3 of 4

14. A patient is involved in a motorcycle wreck that results 18. A patient experienced a prolonged stay in one posi- in avulsion of the skin over the anterolateral leg and an- tion during a recent surgery and postoperative recovery kle. Which of the following structures is most likely de- that resulted in compression of the common fibular stroyed with this type of injury? (peroneal) nerve against the fibular head. Which of the A. Deep peroneal nerve following motor deficits would be most likely to occur? B. Extensor digitorum longus muscle tendon A. Loss of extension at the knee C. Dorsalis pedis artery B. Loss of plantar flexion D. Great saphenous vein c. Loss of flexion at the knee E. Superficial peroneal nerve d. Loss of eversion e. Loss of medial rotation of the tibia

15. What might you expect to see if the obturator nerve is 19. The muscles of the anterior compartment of the leg damaged? are innervated primarily by which of the following nerves? A. Deep fibular A. Waddling gait B.. Lateral sural cutaneous B. Lateral swinging of the leg when walking C. Saphenous C. Foot drop D. Superficial fibular D. High stepping gait E. Sural

16. Your female patient is unable to walk on her tiptoes. 20. Following surgery involving the lateral wall of the pel- You immediately suspect damage to which of the follow- vis, a patient reported anesthesia over the medial thigh. ing nerves? Subsequent examination revealed weakened adduction of

the thigh. Which nerve was most likely injured during the A. Sural nerve pelvic surgery? B. Tibial nerve C. Common fibular nerve A.. Pudendal nerve D. Superficial fibular nerve B. Genitofemoral nerve E. Deep fibular nerve C. Superior gluteal nerve D. Femoral nerve E. Obturator nerve

17. A 12-year-old boy was riding his bicycle across an intersection 21. A 19-year-old woman comes to the emergency depart- when an elderly woman tried to pull out into the busy street just as ment after falling while on roller-blades. There is a 3-cm lacer- the boy was riding in front of her, hitting the boy. Fortunately the boy landed on the hood of the car, but the bumper struck the boys legs ation over the lateral aspect of the knee penetrating so deep just below the knee and created a very large cut. The boy presents that the head of the fibula is apparent. A radiograph of the leg to the emergency room bleeding and walking with a distinct left foot- is negative for any fractures. A noticeable foot-drop occurs drop. The boy has also lost most of his ability to flex his left ankle or evert his left foot and he has lost sensation on the lateral side of his while the patient walks. Further examination reveals inability leg distal to the cut. Plain films show that there are no broken bones to dorsiflex or evert the foot. Which of the following best ex- and examination of the knee reveals that is appears intact. You call plains her injury? in a plastic surgeon, to reanastomose which of the following? A. The common peroneal nerve was severed A. Sciatic nerve B. Tibial nerve B. The peroneal muscles were detached from the head of the C. Common fibular (peroneal) nerve fibula D. Deep fibular nerve C. The superficial peroneal nerve was severed E. Obturator nerve D. The tibial nerve was severed

15 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Answers

14. The Answer is E. (1) The superficial peroneal 18. Answer D. (7) Compression of the common fibular nerve emerges between the peroneus longus and pe- (peroneal) nerve would affect all muscles innervated by this roneus brevis muscles and descends superficial to the nerve, including tibialis anterior, peroneus longus, and ex- extensor retinaculum of the ankle on the anterolateral tensor digitorum longus. Loss of dorsiflexion and eversion side of the leg and ankle, innervating the skin of the lower is usually complete. The extensors of the knee joint leg and foot. The great saphenous vein begins at the me- [(answer a) quadriceps femoris] are supplied by the femoral dial end of the dorsal venous arch of the foot and ascends nerve, whereas the flexors of the knee joint [(answer c) the in front of the medial malleolus and along the medial side hamstrings and gracilis] are supplied by the tibial nerve and of the tibia along with the saphenous nerve. Other struc- obturator nerve, respectively. The gastrocnemius and so- tures pass deep to the extensor retinaculum. leus muscles are the principal plantar flexors of the foot (answer b) and are innervated by the tibial nerve. The popliteus is the prime medial rotator of the tibia (answer e) and is also innervated by the tibial nerve.

15. Answer B. (2) Adequate motor control of a limb is 19. Answer A. (7) The common fibular (peroneal) nerve bifur- a coordinated interplay of antagonistic muscle groups. If a cates into superficial and deep branches. The deep fibular nerve group is not functioning, the opposing muscle are unre- innervates all muscles of the anterior compartment of the leg. stricted. In this case, when the obturator nerve is dam- The lateral sural cutaneous (answer b) is a cutaneous branch of the common fibular nerve. The superficial fibular nerve (answer aged, control of the adductors is lost. Therefore, abduc- d) emerges from the deep fascia and descends in the lateral tors are unrestrained and the leg swings laterally during compartment, where it innervates the fibularis (peroneus) longus walking. and brevis muscles before dividing into median dorsal cutaneous and intermediate dorsal cutaneous nerves, which supply the distal third of the leg, dorsum of the foot, and all the toes. The saphenous nerve [(answer c); the terminal branch of the common femoral nerve] distributes cutaneous branches to the anterior and medial aspects of the leg as well as to the dorsomedial aspect of the foot. The sural nerve (answer e) follows the course of the lesser saphenous vein and becomes the lateral sural cutaneous nerve to supply the anterolateral aspect of the foot.

16. Answer B. (11) Plantarflexion of the foot at the an- 20. Answer E. (9) The obturator nerve runs on the lat- kle is produced by the muscles in the calf, which are in- eral surface of the pelvic wall and exits the pelvis through a nervated by the tibial nerve. canal in the obturator membrane. It innervates the adductor muscles of the medial thigh (a. magnus, a. longus, a. brevis, pectineus, and gracilis). The pudendal nerve exits the pelvic cavity via the greater sciatic foramen and enters the perineum via the lesser sciatic foramen. It innervates the perineal muscles and the skin of the genitalia. The genitofemoral nerve supplies skin over the femoral triangle and scrotum/labia majora. The superior gluteal nerve innervates the gluteus medius and gluteus minimus, which are powerful abductors of the thigh. The femoral nerve innervates the quadriceps muscles, which extend the leg at the knee joint.

17. Answer C. (7) The common fibular (peroneal) nerve 21. Answer A. (4) The common peroneal nerve wraps around wraps around the fibular shaft just distal to its proximal head. the lateral aspect of the head of the fibula and is highly suscepti- This places it close to the skin, where it is easily damaged. ble to damage during lacerations or blunt injuries to the lateral knee. Foot-drop with loss of dorsiflexion or eversion is character- The common fibular nerve then divides into the deep fibular istic. Only the peroneus longus completely attaches to the fibular nerve, which innervates the anterior compartment leg mus- head (choice B). Other muscles that attach in other places along cles and the superficial fibular nerve, which innervates the the tibia and fibula provide dorsiflexion and eversion for the foot lateral compartment leg muscles. Both of these nerves also (e.g., extensor digitorum longus, peroneus brevis, extensor hallu- have cutaneous distribution as well. The inability to dorsiflex cis longus, and tibialis anterior). The common peroneal nerve the ankle and evert the foot is consistent with the boy’s clini- then branches into the superficial (choice C) and deep peroneal cal presentation. The sciatic (answer a) and obturator nerves, which supply the muscles of the anterior compartment of the leg and cutaneous areas of the distal anterior leg, dorsum of (answer e) nerves are in the thigh. The deep fibular nerve the foot, and most of the digits. The tibial nerve (choice D) sup- (answer c) is also involved, but does not explain all the boy’s plies all the muscles in the posterior compartment of the leg findings. The tibial nerve (answer b) runs more medial (e.g., tibialis posterior, flexor digitorum longus, gastrocnemius, through the popliteal fossa, thus is not involved. and soleus).

16 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Questions 4 of 4

22. A 40-year-old man complains of loss of sensation over the right scrotum and on the medial right thigh. Dam- age to which of the following nerves would result in such symptoms? A. Genitofemoral B. Iliohypogastric C. Ilioinguinal D. Lateral cutaneous E. Pudendal

23. A patient presents to the physician complaining of "something wrong with her foot" that causes her to trip and fall. Physical examination reveals an inability to dorsiflex (extend) the foot and a loss of sensation between the first and second toes. There is no other motor or sensory loss. Which of the following nerves was most likely injured? A. Deep peroneal B. Femoral C. Superficial peroneal D. Sural E. Tibial

24. A 15-year-old high school football player is brought to the emergency room. On examination, his right lower limb is de- formed and swollen around the knee. At full extension, there is valgus instability, suggestive of knee dislocation. The patient is in great pain and there is a concern for concomitant vascular and nervous injuries. Palpation of the dorsalis pedis artery reveals a normal pulse. However, neurological examination reveals impaired dorsiflexion of the foot with decreased sensation in the space between digits 1and 2. Which of the following nerves is affected? A. deep peroneal (fibular) nerve B. femoral nerve C. saphenous nerve D. superficial peroneal (fibular) nerve E. tibial nerve

25. A 15-year-old boy presents to the emergency department after falling off his skateboard. On physical examination he is unable to dorsiflex or evert at the ankle. In addition, the patient reports pain and numbness in the lateral leg and dorsum of the foot. When asked to walk, he raises his affected leg high off the ground and his foot slaps the ground when walking. He is diagnosed with a fracture. Which of the following structures is most likely to be compromised by this fracture? A. Common fibular (peroneal) nerve B. Femoral nerve C. L4 nerve root D. Obturator nerve E. Tibial nerve

17 Lab 6— Anterior, Medial—Thigh & Leg Nerves—Answers

22. Answer C. (4) This question allows us to review 24. Answer A. (12) The deep peroneal (fibular) nerve the sensory innervation of the perineum and vicinity. The innervates the muscles responsible for dorsiflexion in the ilioinguinal nerve supplies the skin of the scrotum and the anterior compartment of the leg. It also provides for the medial thigh with sensory fibers. cutaneous innervation of the space between digits 1 and 2. The femoral nerve (choice B) innervates muscles in the The genitofemoral nerve (choice A) supplies motor fibers anterior compartment of the thigh and the skin of the me- to the cremaster muscle and a small area of skin on the dial aspect of the leg by a continuing branch, the saphe- thigh, giving rise to the cremasteric reflex. The iliohypo- nous nerve (choice C). The superficial peroneal (fibular) gastric nerve (choice B) supplies the skin of the anterior nerve (choice D) innervates the lateral compartment of lower abdominal wall. The lateral cutaneous nerve the leg and muscles responsible for foot eversion. The (choice D) of the thigh supplies the skin over the lateral tibial nerve (choice E) innervates the posterior compart- surface of the thigh. The pudendal nerve (choice E) gives ment of the leg and the muscles responsible for plantar off branches that supply the external anal sphincter, the flexion. lower half of the anal canal, perianal skin, and skin on the posterior surface of the scrotum. 25. Answer A. The common fibular (peroneal) nerve courses around the neck of the fibula, making it vulnerable to damage by a fracture at the fibular neck. The common fibular (peroneal) nerve gives rise to the superficial and deep fibular (peroneal) nerves. The superficial fibular (peroneal) nerve innervates the muscles of the lateral compartment of the leg that cause eversion (fibularis [peroneus] longus & brevis). The deep fibular (peroneal) nerve innervates the anterior compartment of the leg that is responsible for dorsiflexion and inversion. The common fibular (peroneal) nerve is the most frequently lesioned nerve in the lower limb. Patients experience foot drop, which results from a loss of dorsiflexion at the ankle, as well as a loss of eversion. Patients will have pain and par- esthesia in the lateral leg and dorsum of the foot. Patients 23. Answer A. (4) The deep peroneal nerve arises with foot drop may also have a steppage gait, as de- from the common peroneal nerve (L4-S2). It innervates scribed in the vignette. Common fibular (peroneal) nerve the muscles of the anterior compartment of the leg, which injury can occur with fracture to the fibular neck and pa- dorsiflex (extend) the foot. Damage to the nerve therefore produces "foot-drop"-a classic clue to deep peroneal tients will present with an inability to dorsiflex or evert, as nerve pathology. The nerve gives rise to many branches, well as a foot drop gait. one of which innervates the skin between the first and second toes.

The femoral nerve (choice B) contains fibers from L2-L4. It supplies flexor muscles of the thigh, extensors at the knee joint, and cutaneous areas of the thigh. The saphenous nerve branches off it and supplies the knee joint and the skin on the medial aspect of the foot. The superficial peroneal nerve (choice C) supplies the muscle~ of the lateral compartment of the leg and is responsible for foot eversion. It also conveys sensory information from most of the dorsal surface of the foot. The sural nerve (choice D) arises from the common peroneal and tibial nerves and innervates the skin of the calf. The tibial nerve (choice E) innervates the hamstrings, as well as muscles of the calf and sole of the foot.

18 Lab 6— Anterior, Medial—Thigh & Leg Vessels—Questions 1 of 2

1. A thoracic surgeon is going to collect a portion of the 5. Which structure becomes necrotic after the medial fem- greater saphenous vein for coronary bypass surgery. He oral circumflex artery is severed? has observed that this vein runs: A. Posterior to the medial malleolus B. Into the popliteal vein C. Anterior to the medial condyles of the tibia and femur D. Superficial to the fascia lata of the thigh E. Along with the femoral artery

2. A basketball player was hit in the thigh by an oppo- 6. One of your patients had a CT of his legs, for knee and calf nent’s knee. Which of the following arteries is likely to pain. Sonography ruled out deep vein thrombosis, and radiog- compress and cause ischemia because of the bruise and raphy ruled out boney abnormalities, but continued complaints led to the performance of a CT. Cross sectional anatomy that is damage to the extensor muscles of the leg? seen on computerized tomography and magnetic resonance A. Popliteal imaging, give a different perspective on anatomy. Refer to the B. Deep femoral image. What is the circular structure labeled A in the image be- C. Anterior tibial low? D. Posterior tibial A. Greater saphenous vein E. Peroneal B. Lesser saphenous vein C. Femoral vein D. Femoral artery E. Profunda vein F. Profunda artery G. Popliteal artery H. Inferior medial genicular artery

3. Before knee surgery, a surgeon ligates arteries partici- 6. pating in the anastomosis around the knee joint. Which of the following arteries is most likely spared? A. Lateral superior genicular B. Medial inferior genicular C. Descending branch of the lateral femoral circumflex D. Saphenous branch of the descending genicular E. Anterior tibial recurrent

4. A patient presents with a thrombosis in the popliteal 7. A patient with hereditary blood clotting problems pre- vein. This thrombosis most likely causes reduction of sents with pain in the back of her knee. An arteriogram blood flow in which of the following veins? reveals a blood clot in the popliteal artery at its proximal A. Greater saphenous end. Which of the following arteries will allow blood to B. Lesser saphenous reach the foot? C. Femoral A. Anterior tibial D. Posterior tibial B. Posterior tibial E. Anterior tibial C. Peroneal D. Lateral circumflex femoral E. Superior medial genicular

19 Lab 6— Anterior, Medial—Thigh & Leg Vessels—Answers

1. Answer D. (1) The greater saphenous vein ascends 5. Answer A. (1) The distal part of the femoral head superficial to the fascia lata. It courses anterior to the me- receives blood mainly from the medial femoral circumflex dial malleolus and posterior to the medial condyles of the artery, whereas the proximal part is supplied by a branch tibia and femur and terminates in the femoral vein by from the posterior division of the obturator artery. passing through the saphenous opening. The small saphenous vein drains into the popliteal vein. The greater saphenous vein does not run along with the femoral artery.

2. Answer C. (1) A muscular spasm or hypertrophy of 6. Answer A. (2) On a computerized tomography (CT) the extensor muscles of the leg may compress the anteri- radiograph, arteries and veins appear as circular struc- or tibial artery, causing ischemia. The popliteal artery sup- tures. The structure "A", is the greater saphenous vein. plies muscles of the popliteal fossa. The deep femoral This can be determined since the structure is outside the artery supplies deep muscles of the thigh. The posterior muscle layers in the skin, and fat tissue in the medial por- tibial and peroneal arteries supply muscles of the posteri- tion of the upper leg. The lesser saphenous would be or and lateral compartments of the leg. found in the same tissue layer but in the lower leg. The femoral artery and vein, plus the profunda artery and vein, are considered deep vessels. The Popliteal artery and vein are found lower in the area of the knee. The medial genicular artery is found in the knee.

3. Answer D. (1) The descending genicular artery gives off the articular branch, which enters the anastomosis around the knee joint, and the saphenous branch, which is not involved in the anastomosis but supplies the superficial tissue and skin on the medial side of the knee. Other arteries are involved in the anastomosis around the knee joint.

4. Answer C. (1) The popliteal vein drains blood into 7. Answer D. (1) If the proximal end of the popliteal the femoral vein; thus, blood flow in the femoral vein is artery is blocked, blood may reach the foot by way of the reduced. The great saphenous vein drains into the upper descending branch of the lateral circumflex femoral ar- part of the femoral vein. Other veins empty into the poplit- tery, which participates in the anastomosis around the eal vein. knee joint. Other blood vessels are direct or indirect branches of the popliteal artery.

20 Lab 6— Anterior, Medial—Thigh & Leg Vessels—Questions 2 of 2

8. A 20-year-old college student receives a severe blow 12. A 62-year-old woman slips and falls on the bathroom on the inferolateral side of the left knee joint while playing floor. As a result, she has a posterior dislocation of the hip football. Radiographic examination reveals a fracture of joint and a fracture of the neck of the femur. Fracture of the head and neck of the fibula. Which of the following the neck of the femur results in avascular necrosis of the conditions would occur from this fracture? femoral head, probably resulting from lack of blood supply A. Ischemia in the gastrocnemius from which of the following arteries? B. Loss of plantar flexion A. Obturator C. Trendelenburg’s sign B. Superior gluteal D. Anterior tibial compartment syndrome C. Inferior gluteal E. Flat foot D. Medial femoral circumflex E. Lateral femoral circumflex

9. The descending genicular artery branches from the 13. A 62-year-old woman slips and falls on the bathroom floor. femoral artery and anatomoses avascular necrosis be- As a result, she has a posterior dislocation of the hip joint and a cause of a lack of blood supply from which artery? fracture of the neck of the femur. The woman undergoes hip A. Obturator and inferior gluteal arteries surgery. If all of the arteries that are part of the cruciate anasto- B. Superior gluteal and femoral arteries mosis of the upper thigh are ligated, which of the following arter- C. Superior and inferior gluteal arteries ies maintains blood flow? D. Medial and lateral circumflex arteries A. Medial femoral circumflex E. Deep femoral artery B. Lateral femoral circumflex C. Superior gluteal D. Inferior gluteal E. First perforating

10. A 65-year-old man who has recently retired notices pain in his 14. In elderly patients (over 60 years of age), fractures of right foot that develops midway through his golf round. He presents the neck of the femur following a fall are common. Arterial to the clinic and is observed to have thickened nails on his right big branches supplying the femoral head and neck are vul- toe, a small ulcer at the ball of his foot (medial side at the head of the first metatarsal), and lack of hair on the anterior surface of his nerable to injury during these fractures, and the resulting right ankle and lower leg. An arteriogram reveals occlusive arterial post-traumatic avascular necrosis affects the head of the disease in the right popliteal artery just inferior to the adductor hia- femur. In the adult, the most important direct vascular tus. Which of the following is most likely in this patient? source to the femoral head and neck is which of the fol- A. His popliteal artery may be palpated medial to the tibial nerve lowing? within the popliteal fossa B. Branches of the femoral artery will provide some perfusion to the A. artery to the head of the femur lower leg B. femoral artery C. Branches of the profunda femoris (deep femoral) artery will pro- C. lateral circumflex femoral artery vide some perfusion to the lower leg D. medial circumflex femoral artery D. The medial and lateral heads of gactrocnemius will be particularly E. superior gluteal artery subject to ischemia E. The dorsalis pedis pulse will be easily palpable

11. A 62-year-old woman slips and falls on the bathroom floor. As a result, she has a posterior dislocation of the hip joint and a fracture of the neck of the femur. Rupture of the ligamentum teres capitis femoris may lead to damage to a branch of which of the following arteries? A. Medial circumflex femoral B. Lateral circumflex femoral C. Obturator D. Superior gluteal E. Inferior gluteal

21 Lab 6— Anterior, Medial—Thigh & Leg Vessels—Answers

8. Answer D. (1) Anterior tibial compartment syn- 11. Answer C. (1) The obturator artery gives rise to an drome is characterized by ischemic necrosis of the mus- acetabular branch that runs in the round ligament of the cles of the anterior tibial compartment of the leg resulting head of the femur. from damage to the anterior tibial artery. The gastrocnemius receives blood from sural branches of the popliteal artery. Loss of plantar flexion is due to necrosis of the posterior muscles of the leg, which are supplied by the posterior tibial and peroneal arteries. Trendelenburg’s sign is caused by weakness or paralysis of the gluteus medius and minimus muscles. Flat foot results from the collapse of the medial longitudinal arch of the foot.

9. Answer D. (2) The medial and lateral circumflex ar- 12. Answer D. (1) In adults, the chief arterial supply to teries are the primary arteries of the femoral head. The the head of the femur is from the branches of the medial deep femoral artery gives rise to the medial and lateral femoral circumflex artery. The lateral femoral circumflex circumflex arteries. The superior and inferior gluteal arter- artery may supply the femoral head by anastomosing with ies nourish the gluteal muscles. the medial femoral circumflex artery. The posterior branch of the obturator artery gives rise to the artery of the head of the femur, which runs in the round ligament of the femoral head and is usually insufficient to supply the head of the femur in adults but is an important source of blood to the femoral head in children. The superior and inferior gluteal arteries do not supply the head of the femur.

10. Answer B. (2) Anastomosis of arteries around the 13. Answer C. (1) The superior gluteal artery does not knee joint will provide blood to the leg even in the case of participate in the cruciate anastomosis of the thigh. The occlusion of the popliteal artery, normally its main blood inferior gluteal artery, transverse branches of the medial supply. The descending genicular artery branches from and lateral femoral circumflex arteries, and an ascending the femoral artery and anatomoses with the superior me- branch of the first perforating artery form the cruciate dial genicular artery on the medial side of the knee, while anastomosis of the thigh. the descending branch of the lateral femoral circumflex artery, also a branch off the femoral, contributes blood to the superior lateral genicular artery on the lateral side of the knee. In the case of popliteal artery occlusion, there is reverse flow into the inferior genicular arteries which then feed blood to the lower leg through their anastomoses to the anterior and posterior tibial arteries.

The profunda femoris artery supplies the thigh and rarely, if ever, contributes blood supply to the geniuclar anastomosis. In occlusion of the popliteal artery the genicular 14.. Answer D. (12)The medial circumflex femoral artery anastomosis usually supplies adequate blood supply to supplies the most important source of blood to the femoral head the gastrocnemius muscles to prevent claudication (pain and neck. This artery anastomoses with the artery to the head in the calves, which is more characteristic of femoral ar- of the femur (choice A), which arises from the obturator artery. tery occlusion), but ischemic foot pain is common. Both However, if the medial circumflex femoral artery is injured, the blood flow in the small artery to the head of the femur may not the popliteal artery and the dorsalis pedis artery, a contin- be sufficient to prevent posttraumatic avascular necrosis of the uation of the anterior tibial artery, would have diminished femoral head. Normally, the medial and lateral circumflex femo- pulses. ral arteries arise from the deep artery of the thigh, but occasion- ally they arise from the femoral artery (choice B). However, the femoral artery is not a direct vascular source to the head of the femur. The lateral circumflex femoral artery (choice C) and superior gluteal artery (choice E) also supply the hip joint, but their contribution to the head and neck of the femur is Jess than that of the medial femoral circumflex artery.

22 Lab 6— Anterior, Medial—Thigh & Leg Features—Questions 1 of 1

1. Which of the following is bounded superiorly by the inguinal ligament, laterally by the sartorius, and medially by the adductor longus muscle? A. Femoral triangle B. Femoral ring C. Femoral sheath D. Adductor canal E. Femoral canal

2. Which of the following contains the femoral vessels, the saphenous nerve, and the nerve for the vastus medialis muscle? A. Femoral triangle B. Femoral ring C. Femoral sheath D. Adductor canal E. Femoral canal

3. Which of the following is the abdominal opening of the femoral canal and is bounded anteriorly by the inguinal ligament, laterally by the femoral vein, medially by the lacunar ligament, and posteriorly by the pectineal ligament? A. Femoral triangle B. Femoral ring C. Femoral sheath D. Adductor canal E. Femoral canal

23 Lab 6— Anterior, Medial—Thigh & Leg Features—Answers

1. Answer A. (2) The femoral sheath contains the femoral artery and vein as well as the femoral canal. The adductor canal lies at the femoral triangle's apex. The name "triangle" suggests an area bounded by three landmarks.

2. Answer D. (2) The femoral ring is the abdominal opening of the femoral canal. The femoral triangle contains the femoral nerve and vessels. The femoral canal transmits lymphatics into the abdominal cavity. The femoral sheath contains the femoral artery and vein as well as the femoral canal. The adductor canal contains the saphenous nerve as well as some femoral vessels.

3. Answer B. (2) The femoral ring is the abdominal opening of the femoral canal. The femoral triangle contains the femoral nerve and vessels. The canal transmits lymphatics into the abdominal cavity. The femoral sheath contains the femoral artery and vein as well as the femoral canal. Among other things, the adductor canal contains the saphenous nerve.