Chap. 3 Anatomy Brs Questions

Front 1

27-year-old patient exhibits a loss of
skin sensation and paralysis of muscles on the plantar aspect of the medial side of the foot.
Which of the following nerves is most likely
damaged?
(A) Common peroneal
(B) Tibial
(C) Superficial peroneal
(D) Deep peroneal
(E) Sural

Back 1

B. The common peroneal nerve divides into the deep peroneal nerve, which innervates the anterior muscles of the leg and supplies the adjacent skin of the first and second
toes, and the superficial peroneal nerve, which innervates the lateral muscles of the leg and supplies the skin on the side of the lower leg and the dorsum of the ankle and foot. The sural nerve supplies the lateral aspect of the foot and the little toe.

Front 2

2. A patient with a deep knife wound in the buttock walks with a waddling gait that is characterized by the pelvis falling toward one side at each step. Which of the following
nerves is damaged?
(A) Obturator nerve
(B) Nerve to obturator internus
(C) Superior gluteal nerve
(D) Inferior gluteal nerve
(E) Femoral nerve

Back 2

C. The superior gluteal nerve innervates the gluteus medius muscle. Paralysis of this muscle causes gluteal gait, a waddling gait characterized by a falling of the pelvis toward
the unaffected side at each step. The gluteus medius muscle normally functions to stabilize the
pelvis when the opposite foot is off the ground. The inferior gluteal nerve innervates the gluteus
maximus, and the nerve to the obturator internus supplies the obturator internus and superior
gemellus muscles. The obturator nerve innervates the adductor muscles of the thigh, and the
femoral nerve supplies the flexors of the thigh.

Front 3

3. A patient is unable to prevent anterior displacement of the femur on the tibia when the knee is flexed. Which of the following ligaments is most likely damaged?
(A) Anterior cruciate
(B) Fibular collateral
(C) Patellar
(D) Posterior cruciate
(E) Tibial collateral

Back 3

D. The posterior cruciate ligament is important because it prevents forward displacement of the femur on the tibia when the knee is flexed. The anterior cruciate ligament
prevents backward displacement of the femur on the tibia.

Front 4

4. A 41-year-old man was involved in a fight and felt weakness in extending the knee joint. On examination, he was diagnosed
with a lesion of the femoral nerve. Which of the following symptoms would be a result of this nerve damage?
(A) Paralysis of the psoas major muscle
(B) Loss of skin sensation on the lateral side
of the foot
(C) Loss of skin sensation over the greater
trochanter
(D) Paralysis of the vastus lateralis muscle
(E) Paralysis of the tensor fasciae latae

Back 4

D. The femoral nerve innervates the quadratus femoris, sartorius, and vastus muscles. Therefore, damage to this nerve results in paralysis of these muscles. The second and
third lumbar nerves innervate the psoas major muscle, the sural nerve innervates the skin on the lateral side of the foot, the iliohypogastric nerve and superior clunial nerves supply the skin over the greater trochanter, and the superior gluteal nerve innervates the tensor fasciae latae.

Front 5

5. A 47-year-old woman is unable to invert her foot after she stumbled on her driveway. Which of the following nerves are most likely injured?
(A) Superficial and deep peroneal
(B) Deep peroneal and tibial
(C) Superficial peroneal and tibial
(D) Medial and lateral plantar
(E) Obturator and tibial

Back 5

B. The deep peroneal and tibial nerves innervates the chief evertors of the foot, which are the tibialis anterior, tibialis posterior, triceps surae, and extensor hallucis
longus muscles. The tibialis anterior and extensor hallucis longus muscles are innervated by the deep peroneal nerve, and the tibialis posterior and triceps surae are innervated by the tibial nerve.

Front 6

6. A 22-year-old patient is unable to "unlock" the knee joint to permit flexion of the leg. Which of the following muscles is most likely
damaged?
(A) Rectus femoris
(B) Semimembranosus
(C) Popliteus
(D) Gastrocnemius
(E) Biceps femoris

Back 6

C. The popliteus muscle rotates the femur laterally ("unlocks" the knee) or rotates the tibia medially, depending on which bone is fixed. This action results in unlocking
of the knee joint to initiate flexion of the leg at the joint. The rectus femoris flexes the thigh and extends the knee. The gastrocnemius flexes the knee and plantar flexes the foot. The semi-membranosus extends the thigh and flexes and rotates the leg medially. The biceps femoris
extends the thigh and flexes and rotates the leg laterally.

Front 7

7. A patient presents with sensory loss on adjacent sides of the great and second toes and impaired dorsiflexion of the foot. These
signs probably indicate damage to which of the following nerves?
(A) Superficial peroneal
(B) Lateral plantar
(C) Deep peroneal
(D) Sural
(E) Tibial

Back 7

C. The deep peroneal nerve supplies the anterior muscles of the leg, including the tibialis anterior, extensor hallucis longus, extensor digitorum longus, and peroneus tertius muscles, which dorsiflex the foot. The medial branch of the deep peroneal nerve supplies the
skin of adjacent sides of the great and second toes, whereas the lateral branch supplies the
extensor digitorum brevis and extensor hallucis brevis. The superficial peroneal nerve innervates
the peroneus longus and brevis, which plantar flexes the foot, and supplies the skin on the side
of the lower leg and the dorsum of the ankle and foot. The tibial nerve innervates 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.

Front 8

8. A motorcyclist falls from his bike in an accident and gets a deep gash that severs the superficial peroneal nerve near its origin. Which of the following muscles is paralyzed?
(A) Peroneus longus
(B) Extensor hallucis longus
(C) Extensor digitorum longus
(D) Peroneus tertius
(E) Extensor digitorum brevis

Back 8

A. The superficial peroneal nerve supplies the peroneus longus and brevis muscles. Other muscles are innervated by the deep peroneal nerve.

Front 9

9. A 67-year-old patient has been given a course of antibiotics by gluteal intramuscular injections after a major abdominal surgery. To
avoid damaging the sciatic nerve during an injection, the needle should be inserted into which of the following areas?
(A) Over the sacrospinous ligament
(B) Midway between the ischial tuberosity
and the lesser trochanter
(C) Midpoint of the gemelli muscles
(D) Upper lateral quadrant of the gluteal region
(E) Lower medial quadrant of the gluteal region

Back 9

D. To avoid damaging the sciatic nerve during an intramuscular injection, the clinician should insert the needle in the upper lateral quadrant of the gluteal region. The inserted needle in the lower medial quadrant may damage the pudendal and sciatic nerves. The inserted
needle midway between the ischial tuberosity and the lesser trochanter may damage the sciatic and posterior femoral cutaneous nerves on the quadratus femoris. The inserted needle over the
sacrospinous ligament may damage the pudendal nerve and vessels.

Front 10

10. A 20-year-old patient cannot flex and medially rotate the thigh while running and climbing. Which of the following muscles is most likely damaged?
(A) Semimembranosus
(B) Sartorius
(C) Rectus femoris
(D) Vastus intermedius
(E) Tensor fasciae latae

Back 10

E. The tensor fasciae latae can flex and medially rotate the thigh, so this is the muscle most likely damaged. The hamstring muscles (semitendinosus, semimembranosus, and biceps femoris) can extend the thigh and flex the leg. The sartorius can flex the thigh and leg. The rectus femoris can flex the thigh and extend the leg. The vastus intermedius can extend the leg.

Front 11

11. A 21-year-old man was involved in a motor- cycle accident, resulting in destruction of the groove in the lower surface of the cuboid bone.
Which of the following muscle tendons is most likely damaged?
(A) Flexor hallucis longus
(B) Peroneus brevis
(C) Peroneus longus
(D) Tibialis anterior
(E) Tibialis posterior

Back 11

C. The groove in the lower surface of the cuboid bone is occupied by the tendon of the peroneus longus muscle. The flexor hallucis longus tendon occupies in a groove on the posterior surface of the body of the talus and a groove on the inferior surface of the cal- caneus during its course. The tibialis posterior muscle tendon occupies in the medial malleolar groove of the tibia. Other muscle tendons are not in the groove of the tarsal bones.

Front 12

12. A construction worker falls feet-first from a roof. He sustains a fracture of the groove on the
undersurface of the sustentaculum tali of the calcaneus bone. Which of the following muscle tendons is most likely torn?
(A) Flexor digitorum brevis
(B) Flexor digitorum longus
(C) Flexor hallucis brevis
(D) Flexor hallucis longus
(E) Tibialis posterior

Back 12

D. The tendon of the flexor hallucis longus muscle occupies first the groove on the posterior surface of the talus and then the groove on the undersurface of the sustentaculum
tali. None of the other tendons would have been affected in such an injury.

Front 13

13. A thoracic surgeon is going to harvest a portion of the greater saphenous vein for coronary bypass surgery. He 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

Back 13

D. The greater saphenous vein ascends superficial to the fascia lata. It courses anterior to the medial malleolus and posterior to the medial condyles of the tibia and femur and terminates in the femoral vein by 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.

Front 14

14. A 52-year-old woman slipped and fell and complained of being unable to extend her leg at the knee joint. Which of the following muscles was paralyzed as a result of this accident?
(A) Semitendinosus
(B) Sartorius
(C) Gracilis
(D) Quadriceps femoris
(E) Biceps femoris

Back 14

D. The quadriceps femoris muscle includes the rectus femoris muscle and the vastus medialis, interomedialis, and lateralis muscles. They extend the leg at the knee joint. The semitendinosus, semimembranosus, and biceps femoris muscles (the hamstrings) extend the thigh and flex the leg. The sartorius and gracilis muscles can flex the thigh and the leg.

Front 15

15. A patient experiences weakness in dorsi- flexing and inverting the foot. Which of the following muscles is damaged?
(A) Peroneus longus
(B) Peroneus brevis
(C) Tibialis anterior
(D) Extensor digitorum longus
(E) Peroneus tertius

Back 15

C. The tibialis anterior can dorsiflex and invert the foot. The peroneus longus and brevis muscles 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.

Front 16

Questions 16-20: 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.

16. 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

Back 16

C. The obturator artery gives rise to an acetabular branch that runs in the round ligament of the head of the femur.

Front 17

17. Fracture of the neck of the femur results in avascular necrosis of the femoral head, probably resulting from lack of blood supply from which of the following arteries?
(A) Obturator
(B) Superior gluteal
(C) Inferior gluteal
(D) Medial femoral circumflex
(E) Lateral femoral circumflex

Back 17

D. In adults, the chief arterial supply to the head of the femur is from the
branches of the medial femoral circumflex artery. The lateral femoral circumflex artery may supply
the femoral head by anastomosing with 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.

Front 18

18. If the acetabulum is fractured at its pos- terosuperior margin by dislocation of the hip joint, which of the following bones could be involved?
(A) Pubis
(B) Ischium
(C) Ilium
(D) Sacrum
(E) Head of the femur

Back 18

C. The acetabulum is a cup-shaped cavity on the lateral side of the hip bone and is formed superiorly by the ilium, posteroinferiorly by the ischium, and anteromedially by the pubis. The sacrum and the head of the femur do not participate in the formation of the ac- etabulum.

Front 19

19. The woman experiences weakness when abducting and medially rotating the thigh after this accident. Which of the following muscles is most likely damaged?
(A) Piriformis
(B) Obturator internus
(C) Quadratus femoris
(D) Gluteus maximus
(E) Gluteus minimus

Back 19

E. The gluteus medius or minimus abducts and rotates the thigh medially. The piriformis, obturator internus, quadratus femoris, and gluteus maximus muscles can rotate the thigh laterally.

Front 20

20. The woman undergoes hip surgery. If all of the arteries that are part of the cruciate anasto- mosis of the upper thigh are ligated, which of the following arteries maintains blood flow?
(A) Medial femoral circumflex
(B) Lateral femoral circumflex
(C) Superior gluteal
(D) Inferior gluteal
(E) First perforating

Back 20

C. The superior gluteal artery does not participate in the cruciate anastomosis of the thigh. The inferior gluteal artery, transverse branches of the medial and lateral femoral circumflex arteries, and an ascending branch of the first perforating artery form the cruciate anastomosis of the thigh.

Front 21

21. A 34-year-old woman sustains a deep cut on
the dorsum of the foot just distal to her ankle
joint by a falling kitchen knife. A physician in
the emergency department has ligated the
dorsalis pedis artery proximal to the injured
area. Which of the following conditions most
likely occurs as a result of the injury?
(A) lschemia in the peroneus longus muscle
(B) Aneurysm in the plantar arterial arch
(C) Reduction of blood flow in the medial
tarsal artery
(D) Low blood pressure in the anterior tibial
artery
(E) High blood pressure in the arcuate artery

Back 21

C. Reduction of blood flow in the medial tarsal artery occurs because it is a
branch of the dorsalis pedis artery, which begins at the ankle joint as the continuation of the
anterior tibial artery. The anterior tibial and peroneal arteries supply the peroneus longus
muscle. The deep plantar arterial arch is formed mainly by the lateral plantar artery. Blood
pressure in the anterior tibial artery should be higher than normal. The arcuate artery should
have a low blood pressure because it is a terminal branch of the dorsalis pedis artery.

Front 22

22. A patient experiences paralysis of the mus-
cle that originates from the femur and con-
tributes 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

Back 22

A. The vastus lateralis muscles arise from the femur and all the other muscles
originate from the hip (coxal) bone. The biceps femoris inserts on the fibula and other muscles
insert on the tibia; thus, all of them contribute to the stability of the knee joint.

Front 23

23. A patient is involved in a motorcycle
wreck that results in avulsion of the skin over
the anterolateral leg and ankle. Which of the
following structures is most likely destroyed
with this type of injury?
(A) Deep peroneal nerve
(B) Extensor digitorum longus muscle tendon
(C) Dorsalis pedis artery
(D) Great saphenous vein
(E) Superficial peroneal nerve

Back 23

E. The superficial peroneal nerve emerges between the peroneus longus and
peroneus brevis muscles and descends superficial to the extensor retinaculum of the ankle on the
anterolateral side of the leg and ankle, innervating the skin of the lower leg and foot. The great
saphenous vein begins at the medial end of the dorsal venous arch of the foot and ascends in
front of the medial malleolus and along the medial side of the tibia along with the saphenous
nerve. Other structures pass deep to the extensor retinaculum.

Front 24

24. A knife wound penetrates the superficial vein that terminates in the popliteal vein. Bleed- ing occurs from which of the following vessels?
(A) Posterior tibial vein
(B) Anterior tibial vein
(C) Peroneal vein
(D) Great saphenous vein
(E) Lesser saphenous vein

Back 24

E. The lesser (small) saphenous vein ascends on the back of the leg in company
with the sural nerve and terminates in the popliteal vein. The peroneal vein empties into the posterior tibial vein. The anterior and posterior tibial veins are deep veins and join to form the popliteal vein. The great saphenous vein drains into the femoral vein.

Front 25

25. A 10-year-old boy falls from a tree house. The resultant heavy compression of the sole of his foot against the ground caused a fracture of the head of the talus. Which of the following
structures is unable to function normally?
(A) Transverse arch
(B) Medial longitudinal arch
(C) Lateral longitudinal arch
(D) Tendon of the peroneus longus
(E) Long plantar ligament

Back 25

B. The keystone of the medial longitudinal arch of the foot is the head of the talus, which is located at the summit between the sustentaculum tali and the navicular bone. The medial longitudinal arch is supported by the spring ligament and the tendon of the flexor hallucis longus muscle. The cuboid bone serves as the keystone of the lateral longitudi-nal arch, which is supported by the peroneus longus tendon and the long and short plantar
ligaments. The transverse arch is formed by the navicular, three cuneiform, the cuboid, and five metatarsal bones and is supported by the peroneus longus tendon and the transverse head of the adductor hallucis.

Front 26

26. A 24-year-old woman complains of weak-
ness when she extends her thigh and rotates it
laterally. Which of the following muscles is
paralyzed?
(A) Obturator externus
(B) Sartorius
(C) Tensor fasciae latae
(D) Gluteus maximus
(E) Semitendinosus

Back 26

D. The gluteus maxinius can extend and rotate the thigh laterally. The obturator
extemus rotates the thigh laterally. The sartorius can flex both the hip and knee joints. The tensor
fasciae latae can flex and medially rotate the thigh. The semitendinosus can extend the thigh and
medially rotate the leg.

Front 27

27. A patient with hereditary blood clotting
problems presents with pain in the back of her
knee. An arteriogram reveals a blood clot in the
popliteal artery at its proximal end. Which of
the following arteries will allow blood to reach
the foot?
(A) Anterior tibial
(B) Posterior tibial
(C) Peroneal
(D) Lateral circumflex femoral
(E) Superior medial genicular

Back 27

D. It the proximal end of the popliteal artery is blocked, blood may reach the
foot by way of the descending branch of the lateral circumflex femoral artery, which participates
in the anastomosis around the knee joint. Other blood vessels are direct or indirect branches of
the popliteal artery.

Front 28

28. A 72-year-old woman complains of a
cramplike pain in her thigh and leg. She was
diagnosed as having a severe intermittent
claudication. Following surgery, an infection
was found in the adductor canal, damaging
the enclosed structures. Which of the following
structures remains intact?
(A) Femoral artery
(B) Femoral vein
(C) Saphenous nerve
(0) Great saphenous vein
(E) Nerve to the vastus medialis

Back 28

D. 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 medians.

Front 29

29. A basketball player was hit in the thigh by
an opponent's knee. Which of the following
arteries is likely to compress and cause ischemia
because of the bruise and damage to the exten-
sor muscles of the leg?
(A) Popliteal
(B) Deep femoral
(C) Anterior tibial
(D) Posterior tibial
(E) Peroneal genicular

Back 29

C. A muscular spasm or hypertrophy of the extensor muscles of the leg may
compress the anterior tibial artery, causing ischemia. The popliteal artery supplies muscles of the
popliteal fossa. The deep femoral artery supplies deep muscles of the thigh. The posterior tibial
and peroneal arteries supply muscles of the posterior and lateral compartments of the leg.

Front 30

30. An elderly woman fell at home and frac-
tured the greater trochanter of her femur.
Which of the following muscles would continue
to function normally?
(A) Pi ri formis
(B) Obturator internus
(C) Gluteus medius
(D) Gluteus maximus
(E) Gluteus minimus

Back 30

D. The gluteus maximus is inserted into the gluteal tuberosity of the femur
and the iliotibial tract. All of the other muscles insert on the greater trochanter of the femur and
their functions are impaired.

Front 31

Questions 31-35: A 20-year-old college student receives a severe blow on the infero- lateral side of the left knee joint while play-ing football. Radiographic examination re-
veals a fracture of the head and neck of the fibula.
31. Which of the following nerves is damaged?
(A) Sciatic
(B) Tibial
(C) Common peroneal
(D) Deep peroneal
(E) Superficial peroneal
(A) Extensor digitorum longus
(B) Tibialis anterior
(C) Tibialis posterior
(D) Peroneus longus
(E) Peroneus brevis

Back 31

C. The common peroneal nerve is vulnerable to injury as it passes behind the head of the fibula and then winds around the neck of the fibula and pierces the peroneus
longus muscle, where it divides into the deep and superficial peroneal nerves. In addition, the deep and superficial peroneal nerves pass superficial to the neck of the fibula in the substance of the peroneus longus muscle and are less susceptible to injury than the common peroneal nerve. Other nerves are not closely associated with the head and neck of the fibula.

Front 32

32. After injury to this nerve, which of the following muscles could be paralyzed?
(A) Gastrocnemius
(B) Popliteus
(C) Extensor hallucis longus
(D) Flexor digitorum longus
(E) Tibialis posterior

Back 32

C. The extensor hallucis longus is innervated by the deep peroneal nerve,
whereas other muscles are innervated by the posterior tibial nerve.

Front 33

33. 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

Back 33

B. 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.

Front 34

34. Which of the following arteries could also be damaged by this fracture?
(A) Popliteal
(B) Posterior tibial
(C) Anterior tibial
(D) Peroneal
(E) Lateral inferior genicular

Back 34

C. The anterior tibial artery, which arises from the popliteal artery, enters the anterior compartment by passing through the gap between the fibula and tibia at the upper end
of the interosseous membrane. The other arteries would not be affected because they are not closely associated with the head and neck of the fibula.

Front 35

35. Which of the following conditions would occur from this fracture?
(A) Ischemia in the gastrocnemius
(B) Loss of plantar flexion
(C) Trendelenburg's sign
(D) Anterior tibial compartment syndrome
(E) Flat foot

Back 35

D. Anterior tibial compartment syndrome is characterized by ischemic necrosis of the muscles of the anterior tibial compartment of the leg resulting 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 longi- tudinal arch of the foot.

Front 36

36. A construction worker is hit on the leg with a concrete block and is subsequently unable to plantar flex and invert his foot. Which of the
following muscles is most likely damaged?
(A) Extensor digitorum longus
(B) Tibialis anterior
(C) Tibialis posterior
(D) Peroneus longus
(E) Peroneus brevis

Back 36

C. The tibialis posterior can plantar flex and invert the foot. The extensor
digitorum longus can dorsiflex and evert the foot, the tibialis anterior can dorsiflex and invert the foot, and the peroneus longus and brevis can plantar flex and evert the foot.

Front 37

37, The obturator nerve and the sciatic (tibial portion) nerve of a 15-year-old boy are tran-sected as a result of a motorcycle accident. This
injury would result in complete paralysis of which of the following muscles?
(A) Rectus femoris
(B) Biceps femoris short head
(C) Pectineus
(D) Adductor magnus
(E) Sartorius

Back 37

D. The adductor magnus is innervated by both the obturator and sciatic (tibial portion) nerves. Hence, a lesion here could cause paralysis. The rectus femoris and sartorius are
innervated by the femoral nerve. The biceps femoris long head is innervated by the tibial portion
of the sciatic nerve, whereas the short head is innervated by the common peroneal portion of the
sciatic nerve. The pectineus is innervated by both the femoral and obturator nerves.

Front 38

38. A 24-year-old woman presents to her physi- cian with weakness in flexing the hip joint and extending the knee joint. What muscle is most
likely involved in this scenario?
(A) Sartorius
(B) Gracilis
(C) Rectus femoris
(D) Vastus medialis
(E) Semimembranosus

Back 38

C. The rectus femoris flexes the thigh and extends the leg. The sartorius can flex both the hip 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.

Front 39

39. A 17-year-old boy was stabbed during a gang fight resulting in transection of the obtu-rator nerve. Which of the following muscles is
completely paralyzed?
(A) Pectineus
(B) Adductor magnus
(C) Adductor longus
(D) Biceps femoris
(E) Semimembranosus

Back 39

C. The adductor longus is innervated only by the obturator nerve. Thus, injury here could completely paralyze the adductor longus. The pectineus is innervated by both the obturator and femoral nerves. The adductor magnus is innervated by both the obturator nerve and tibial part of the sciatic nerve. The biceps femoris is innervated by 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.

Front 40

40. A 32-year-old carpenter fell from the roof. The lateral longitudinal arch of his foot was flattened from fracture and displacement of the
keystone for the arch. Which of the following bones is damaged?
(A) Calcaneus
(B) Cuboid bone
(C) Head of the talus
(D) Medial cuneiform
(E) Navicular bone

Back 40

B. The keystone for the lateral longitudinal arch is the cuboid bone,
whereas the keystone for the medial longitudinal arch is the head of the talus. The calcaneus, navicular, and medial cuneiform bones form a part of the medial longitudinal arch, but they are not keystones. The calcaneus also forms a part of the lateral longitudinal arch.

Front 41

41. While playing football, a 19-year-old college student receives a twisting injury to his knee when being tackled from the lateral side. Which of the following conditions most likely has occurred?
(A) Tear of the medial meniscus
(B) Ruptured fibular collateral ligament
(C) Tenderness on pressure along the fibular
collateral ligament
(D) Injured posterior cruciate ligament
(E) Swelling on the back of the knee joint

Back 41

A. The "unhappy triad" of the knee joint is characterized by tear of the medial meniscus, rupture of the tibial collateral ligament, and rupture of the anterior cruciate ligament.
This injury may occur when a cleated shoe, as worn by football players, is planted firmly in the
turf and the knee is struck from the lateral side. Tenderness along the medial collateral ligament and over the medial meniscus and swelling on the front of the joint are due to excessive produc- tion of synovial fluid, which fills the joint cavity and the suprapatellar bursa.

Front 42

42. A patient has weakness when flexing both her thigh and leg. Which of the following muscles is most likely injured?
(A) Rectus femoris
(B) Semitendinosus
(C) Biceps femoris
(D) Sartorius
(E) Adductor longus

Back 42

D. The sartorius can flex and rotate the thigh laterally and flex and rotate the leg medially. The rectus femoris flexes the thigh and extends the leg. The semimembranosus extends the
thigh and flexes and rotates the leg medially. The biceps femoris extends the thigh and flexes and
rotates the leg laterally. The adductor longus adducts and flexes the thigh.

Front 43

43. A 35-year-old man has difficulty in dorsi- flexing the foot. Which of the following muscles is most likely damaged?
(A) Tibialis posterior
(B) Flexor digitorum longus
(C) Tibialis anterior
(D) Peroneus longus
(E) Peroneus brevis

Back 43

C. The tibialis anterior muscle can dorsiflex the foot, whereas all other muscles are able to plantar flex the foot.

Front 44

44. An injury to the leg of a golfer results in loss of the ability to invert the foot. Which of the following muscles is most likely paralyzed?
(A) Tibialis posterior
(B) Peroneus longus
(C) Peroneus brevis
(D) Peroneus tertius
(E) Extensor digitorum longus

Back 44

A. The tibialis posterior inverts the foot. The peroneus longus, brevis, and tertius and extensor digitorum longus can evert the foot.

Front 45

45. An orthopedic surgeon ligates the posterior tibial artery at its origin. Which of the following arteries has no blood flow immediately after the
ligation?
(A) Peroneal
(B) Dorsalis pedis
(C) Superior medial genicular
(D) Anterior tibial
(E) Descending genicular artery

Back 45

A. The peroneal artery is a branch of the posterior tibial artery. The dorsal is pedis artery begins anterior to the ankle as the continuation of the anterior tibial artery. The superior
medial genicular artery is a branch of the popliteal artery, and the descending genicular artery arises
from the femoral artery.

Front 46

46. Before knee surgery, a surgeon ligates arteries participating 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

Back 46

D. 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.

Front 47

47. A 25-year-old gladiator sustains a penetrat- ing injury that severs the superficial peroneal nerve. This will most likely cause paralysis of
which of the following muscles?
(A) Peroneus tertius
(B) Peroneus brevis
(C) Flexor hallucis longus
(D) Tibialis anterior
(E) Tibialis posterior

Back 47

B. The peroneus brevis muscle is innervated by the superficial peroneal nerve. The peroneus 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.

Front 48

48. A patient presents with a thrombosis in the popliteal vein. This thrombosis most likely causes reduction of blood flow in which of the following veins?
(A) Greater saphenous
(B) Lesser saphenous
(C) Femoral
(D) Posterior tibial
(E) Anterior tibial

Back 48

C. The popliteal vein drains blood into the femoral vein; thus, blood flow in the femoral vein is reduced. The great saphenous vein drains into the upper part of the femoral
vein. Other veins empty into the popliteal vein.

Front 49

Questions 49-52: Choose the appropriate lettered site or structure in this computed tomography (CT) image of the hip and pelvis
(see page 133, top) to match the following de- scriptions.

49. A 62-year-old woman stands on her left limb, and her pelvis (buttock) on the right side falls instead of rising. Which muscle in the CT
scan is most likely paralyzed?

Back 49

D. When a patient with paralysis of the gluteus medius stands on the affected
limb, the pelvis falls or sags on the sound side. Normally, the pelvis rises.

Front 50

50. A 34-year-old man with a fracture of the lesser trochanter has difficulty in flexing his thigh. Which muscle in the CT scan is most
likely paralyzed?

Back 50

A. The iliopsoas muscle inserts on the lesser trochanter and is a chief flexor
of the thigh.

Front 51

51. A 41-year-old woman is diagnosed with a large tumor in the lateral pelvic wall. Which muscle that passes through the greater sciatic foramen is ischemic by tumor-induced arterial compression and is most likely paralyzed?

Back 51

B. The piriformis muscle passes through the greater sciatic foramen and inserts on the greater trochanter.

Front 52

52. A 19-year-old man receives a knife stab in his buttock and injures the inferior gluteal nerve. Which muscle in the CT scan is most likely paralyzed?

Back 52

E. The gluteus maximus muscle is innervated by the inferior gluteal nerve.

Front 53

Questions 53-56: Choose the appropriate lettered site or structure in the following com- puted tomography (CT) image of the hip (see below) to match the following descriptions.

53. Which muscle indicated in this CT scan, if paralyzed, would impair flexion of the thigh and leg?

Back 53

B. The sartorius can flex both the thigh and the knee, whereas the rectus
femoris can flex the thigh and extend the knee.

Front 54

54. Which muscle in this CT scan would be paralyzed as a result of a lesion of the superior gluteal nerve?

Back 54

D. The tensor fasciae latae is innervated by the superior gluteal nerve.

Front 55

55. After ligation of the popliteal and greater saphenous veins, which vessel in this CT scan has a markedly low blood pressure?

Back 55

E. The femoral vein receives the greater saphenous vein, which passes through the saphenous ring.

Front 56

56. Which vessel in this CT scan is vulnerable to injury because of its relatively superficial po-sition in the femoral triangle?

Back 56

A. The femoral artery descends through the femoral triangle, where it is
vulnerable to injury because of its relatively superficial position.

Front 57

Questions 57-60: Choose the appropriate lettered site or structure in the radiograph of the hip and pelvis (page 134, top) to match
the following descriptions.
57. Which structure in this radiograph may be
fractured, resulting in loss of the chief flexor of
the thigh?

Back 57

D. The iliopsoas muscle is the chief flexor of the thigh and inserts on the lesser trochanter.

Front 58

58. Fracture of which structure may destroy the site of insertion of the muscle that can ro- tate the thigh laterally and its tendon that passes through the lesser sciatic foramen?

Back 58

B. The greater trochanter is the site for insertion of the obturator internus
muscle tendon, which leaves the pelvis through the lesser sciatic foramen.

Front 59

59. Which fractured structure is likely to cause paralysis of the adductor magnus?

Back 59

C. The ischiopubic ramus and ischial tuberosity provide attachment for the
adductor magnus.

Front 60

60. Which structure becomes necrotic after the medial femoral circumflex artery is severed?

Back 60

A. The distal part of the femoral head receives blood mainly from the medial femoral circumflex artery, whereas the proximal part is supplied by a branch from the posterior division of the obturator artery.

Front 61

Questions 61-64: Choose the appropriate lettered site or structure in the following ra-diograph of the ankle and foot (below) to match the following descriptions.

61. The flexor hallucis longus tendon is dam-aged in a groove on the posterior surface of a
tarsal bone. Which bone in the radiograph is likely fractured?

Back 61

A. The body of the talus has a groove on its posterior surface for the flexor hallucis longus tendon. This tendon also occupies the groove on the undersurface of the
sustentaculum tali.

Front 62

62. The tibialis anterior and peroneus longus muscles are weakened. Which bone in the radiograph is most likely fractured?

Back 62

E. The first or medial cuneiform bone provides insertions for the tibialis
anterior, tibialis posterior, and peroneus longus muscles.

Front 63

63. The medial longitudinal arch of the foot is flattened because the spring ligament is torn. Which bone in the radiograph is most likely fractured?

Back 63

D. The spring (plantar calcaneonavicular) ligament extends from the sustentaculum tali of the calcaneus to the navicular bone.

Front 64

64. The peroneus longus muscle tendon is damaged in a groove of a tarsal bone by fracture. Which bone in the radiograph is most likely fractured?

Back 64

B. The cuboid bone has a groove for the peroneus longus muscle tendon.