Download 1. During recovery from a gunshot wound of the right pelvis, the

1. During recovery from a gunshot wound of the right pelvis, the
patient notices a lurch in his gait. When he lifts his left foot off of
the ground, his pelvis dips down on the left side. The nerve that
appears to have been injured is the:
nerve to piriformis
nerve to obturator internus
sciatic nerve
femoral nerve
superior gluteal nerve
2. The team doctor tells a football player that he has "a pulled
hamstring" muscle. This results from a tearing of the origin of a
hamstring muscle from the:
sacrum
posterior gluteal line
ischial tuberosity
obturator membrane
iliac tubercle
3. If the head of the femur is dislocated postero-medially,
compression of which nerve is likely to result?
Femoral
Lumbosacral trunk
Obturator
Sciatic
Superior gluteal
4. What muscle passes through the lesser sciatic foramen?
Gluteus minimus
Obturator internus
Piriformis
Quadratus femoris
Superior gemellus
5. In order to avoid injury to the sciatic nerve, intramuscular injections
should be given in which quadrant of the buttock?
upper medial
upper lateral
lower medial
lower lateral
middle
6. The femoral artery enters the popliteal fossa (becoming the
popliteal artery) by passing through the:
Adductor hiatus
Femoral canal
Femoral sheath
Femoral triangle
Saphenous opening
7. The short head of biceps femoris muscle is innervated by which
nerve?
Common fibular
Femoral
Inferior gluteal
Obturator
Tibial
8. As a patient with paralyzed gluteus medius and minimus muscles
on the left side attempts to stand on the left limb only, the right side
of the pelvis typically:
Drops
Elevates
Rotates laterally
Rotates medially
Thrusts forward
9. When the femur is fractured, the broken distal end often turns
posteriorly to enter the popliteal fossa due to muscle traction.
Because of its position deepest in the fossa, which structure is
most vulnerable to laceration?
Common fibular n.
Lesser saphenous v.
Popliteal a.
Popliteal v.
Tibial n.
10.
The deep femoral artery is the principle blood source for the
muscles in which compartment of the thigh?
Anterior
Lateral (gluteal)
Medial (adductor)
Posterior (hamstring)
11.
After suffering a deep stab wound in the medial upper
quadrant of the right buttock, an emergency room patient found
walking to be very difficult. The basic problem was that, during
stepping, her left hip sagged down as soon as the left foot was
lifted off the ground to swing forward. What nerve was damaged?
Femoral
Inferior gluteal
Obturator
Pudendal
Superior gluteal
12.
A fracture of the ischial tuberosity might be expected to most
directly affect the muscles that produce which lower limb
movement?
Abduction at the hip
Adduction at the hip
Extension at the knee
Flexion at the hip
Flexion at the knee
13.
When, in approximately 12% of people, the common fibular
nerve passes through the piriformis muscle, the nerve may be
compressed. This would affect part of which muscle?
Adductor magnus
Biceps femoris
Gluteus maximus
Semimembranosus
Semitendinosus
14.
An elderly patient complains of difficulty in walking up stairs.
Tests by her doctor reveal weakness in extension at her hip, but
no change in hip flexion, or flexion or extension of the knee. Based
upon these results, what muscle is most likely not functioning
properly.
Adductor magnus
Gluteus maximus
Gluteus medius
Iliopsoas
Semitendinosus
15.
Weakness in climbing stairs or jumping would indicate a
lesion of which nerve?
Tibial
Superior gluteal
Inferior gluteal
Obturator
Femoral
16.
During surgical repair of a popliteal artery aneurism, ligation
of the femoral artery at mid-thigh would not interrupt supply to the
hamstring muscles because the
Genicular anastomosis ensures blood supply to the posterior
thigh
Cruciate anastomosis ensures blood supply to the posterior
thigh
Perforating branches of the deep femoral artery supply the
posterior thigh
Obturator artery supplies the posterior thigh
Anterior and posterior femoral circumflex arteries anastomose
with the inferior gluteal artery
17.
The medial thigh muscles rotate the femur medially,
counterbalanced by muscles of the _____________ thigh,
including the ___________ muscle, which rotates the femur
laterally.
Lateral; tensor fasciae latae
Anterior; rectus femoris
Lateral; piriformis
Posterior; biceps femoris
Posterior; quadriceps femoris
18.
Following a major operation, a patient was placed on a
course of antibiotics which were delivered via intramuscular
injection to the buttocks. After one injection in the right buttock, the
patient complained of more pain than usual in the region of the
injection. Later, as he was walking in the hall, the nurse noticed
that he had a limp that had not been present before--his left hip
dropped every time he lifted his left foot off the floor. Which nerve
had been injured by the injection?
Femoral
Inferior gluteal
Obturator
Sciatic
Superior gluteal
19.
The hamstrings muscles are supplied by branches of which
artery?
Deep femoral
Fibular
Obturator
Pudendal
Superficial femoral
20.
Of the branches of the internal iliac artery, the one exiting
from the greater sciatic foramen superior to the piriformis muscle is
the:
Iliolumbar artery
Internal pudendal artery
Lateral sacral artery
Superior gluteal artery
21.
Because of its muscle attachments, a fracture to the ischial
tuberosity would affect which movement of the lower limb?
Abduction of the thigh
Dorsiflexion of the foot
Extension of the leg
Flexion of the leg
Flexion of the thigh
22.
When the distal femur is fractured, the sharp broken ends of
the bone often damage the structure that lies closest to the femur
in the popliteal fossa, i.e., the:
Descending genicular artery
Greater saphenous vein
Popliteal artery
Popliteal vein
Sciatic nerve
23.
In a hunting accident, an arrow pierces the mid-calf of a
hunter. A major artery is lacerated in the posterior leg, and you
notice that the sole of his foot is cold and pale. The dorsum of the
foot is warm and normally colored. The artery that seems to be
injured is the:
fibular artery
posterior tibial artery
femoral artery
popliteal artery
medial plantar artery
24.
A patient complains of localized pain in a swollen lower calf
and cannot strongly plantar flex his foot. What tendon may have
ruptured?
calcaneal
fibularis tertius
flexor digitorum longus
flexor hallucis longus
tibialis anterior
25.
A tennis player feels a "pop" in her calf as she is playing. Her
calf becomes tender and there is some slight amount of swelling.
Upon examination, her physician informs her that she has ruptured
the slender tendon of a small muscle that attaches to the
calcaneus. She has apparently ruptured the:
gastrocnemius
plantaris
popliteus
soleus
tibialis posterior
26.
A football player tears his calcaneal tendon. You would
expect to find weakness in:
dorsifiexion of the foot
eversion of the foot
extension of the knee
inversion of the foot
plantarflexion of the foot
27.
While on vacation in Florida following her final exams, a
scuba diving medical student is accidentally speared by her diving
partner. The end of the spear passes medial to lateral, posterior to
the medial malleolus. It severs an artery there, which is the:
anterior tibial
dorsalis pedis
fibular
medial plantar
posterior tibial
28.
A patient with painful swelling in the distal calf cannot plantar
flex at the ankle with any power. Which tendon was likely
ruptured?
Calcaneal
Extensor digitorum longus
Extensor hallucis longus
Plantaris
Tibialis anterior
1. The correct answer is:
superior guteal nerve
The superior gluteal nerve supplies gluteus minimus and medius--two
muscles that are important abductors of the hip--as well as tensor
fasciae latae. These muscles stabilize the pelvis when walking. The
gluteus medius and minimus work in such a way that when you are
standing on your right leg only, the muscles on the right side are
supporting the left side of the pelvis. When you are standing on your left
leg only, the muscles of the left side are supporting the right side of the
pelvis. If a patient exhibits a characteristic hip drop on the uninjured side
(in this case, the left side) while standing on the injured side (right), this
is called Trendelenburg's sign. It occurs when the superior gluteal nerve-the nerve supply to the abductors of the thigh--is disrupted due to injury
or disease.
Nerve to piriformis and nerve to obturator internus allow those muscles
to laterally rotate the thigh. However, if one of these muscles was
denervated, the other might be able to compensate and prevent a
significant loss of function. The sciatic nerve has no direct muscular
branches; however, its two branches, common fibular and tibial nerves,
innervate the posterior compartment of the thigh and all the muscles of
the leg. A disruption to the sciatic nerve would lead to a significant motor
deficit. The femoral nerve innervates the quadriceps. If this nerve were
damaged, a patient would present with an inability to extend the knee.
2. The correct answer is:
ischial tuberosity
The hamstring muscles are: biceps femoris, semimembranosus, and
semitendinosus. They originate from the ischial tuberosity and insert on
the tibia and fibula (biceps). They comprise the posterior compartment of
the thigh and are innervated by the tibial nerve, with the exception of the
short head of biceps femoris which is innervated by the common fibular
nerve. These muscles allow for extension at the hip and flexion at the
knee. The anterior sacrum is the origin of the piriformis muscle, while the
posterior sacrum and ilium posterior to the superior gluteal line serve as
the origin of gluteus maximus. Obturator internus and externus take
origin from the obturator membrane and the margins of the obturator
foramen.
3. The correct answer is:
sciatic nerve
The sciatic nerve is closely related to the posterior hip joint, which
makes this nerve very vulnerable in cases where the femur is dislocated
postero-medially. If the sciatic nerve was completely paralyzed, the
compartments innervated by its two branches: the common fibular and
tibial nerves, would lose function. This would mean that the hamstrings
and all the muscles of below the knee would lose their innervation.
(Luckily, complete paralysis of the sciatic nerve is very rare.) The hip
joint is very stable, so it is difficult to dislocate the femur. Most
dislocations occur when the hip is flexed and the thigh is adducted. In
flexion, the joint capsule is lax, and the femoral head tends to dislocate
posteriorly when forces drive the femur posteriorly. This means that the
sciatic nerve will be very vulnerable when the femur is dislocated!
The other nerves listed in the question are not closely related to the hip
joint. The femoral nerve innervates the quadriceps and is on the anterior
of the thigh. The lumbosacral trunk is located in the pelvis. The obturator
nerve innervates the adductor compartment, and is on the anteromedial
side of the thigh. Although the superior gluteal nerve innervates muscles
near the hip socket (gluteus medius, minimus, and tensor fasciae latae),
it would not be damaged by a dislocated hip.
4. The correct answer is:
obturator internus
Obturator internus leaves the pelvis by passing through the lesser sciatic
foramen. It eventually inserts on the greater trochanter of the femur and
helps to laterally rotate and abduct the thigh. Piriformis leaves the pelvis
through the greater sciatic foramen and also inserts of the greater
trochanter of the femur. It helps with the same movements as obturator
internus--lateral rotation and abduction of the thigh.
The other muscles listed act at the hip, but they are not related to the
greater or lesser sciatic foramen. Gluteus minimus originates on the
ilium and inserts on the greater trochanter of the femur--it abducts and
medially rotates the thigh. Quadratus femoris is a lateral rotator of the
thigh which originates on the ischial tuberosity and inserts on the
quadrate line. Superior gemellus is another lateral rotator of the thigh
which inserts with obturator internus on the obturator tendon.
5. The correct answer is:
upper lateral
An injection in the posterior hip region is best placed in the upper, outer
quadrant of the hip, just inferior and posterior to the anterior superior
iliac spine. This is an area where there are not many nerves and vessels
that could be injured by the injection. There are several nerves in the
posterior hip region that may be injured if intramuscular injections are
carelessly placed in the other quadrants of the buttock, including the
sciatic nerve, posterior femoral cutaneous nerve, inferior gluteal nerve,
and superior gluteal nerve.
6.
The correct answer is:
Adductor hiatus
The adductor hiatus is a split in the adductor magnus muscle found at
the end of the adductor canal. At the adductor hiatus, the femoral
vessels pass through to reach the posterior surface of the leg, changing
names to become the popliteal vessels. The femoral triangle is an area
in the proximal anteromedial thigh, bounded by the inguinal ligament,
sartorius, and the medial edge of adductor longus. It contains the
femoral nerve and the three structures covered by the femoral sheath:
the femoral artery, vein, and canal. The femoral canal is a structure in
the femoral sheath that usually holds a deep inguinal lymph node; it may
also be the site of a femoral hernia. The saphenous opening is an
opening in the fascia lata where the great saphenous vein passes deep
to join the femoral vein.
7. The correct answer is:
Common fibular
The short head of biceps femoris is innervated by the common fibular
nerve; all the other muscles in the hamstring compartment are
innervated by the tibial nerve. Both of these nerves are branches of the
sciatic nerve. The inferior gluteal nerve innervates gluteus maximus. The
obturator nerve innervates the medial, adductor compartment of the
thigh. The femoral nerve innervates the muscles of the anterior thigh.
8. The correct answer is:
Drops
When gluteus medius and minimus are injured, a patient will show a
positive Trendelenburg sign. This means that when this patient attempts
to stand on the left leg only, the uninjured right hip will drop. This is
because gluteus medius and minimus on the stable left leg support the
pelvis so that it will remain level when the right leg is lifted--when these
muscles are injured on the supported left side, the right side of the pelvis
will drop.
Make sure you understand what Trendelenburg sign is, what it means,
and why the pelvis drops on the uninjured side!
9. The correct answer is:
Popliteal artery
The popliteal fossa contains the popliteal artery, popliteal vein, common
fibular nerve, and tibial nerve. The popliteal artery is the deepest
structure in the fossa--it lies on the posterior side of the knee joint. So, it
is the structure that would be most likely to be lacerated by the broken
distal end of the femur. The popliteal vein lies superficial to the artery,
and the tibial nerve lies superficial to the popliteal vein. These three
structures are right in the middle of the fossa. The common fibular nerve
descends toward the fibular neck, on the lateral side of the popliteal
fossa. The lesser saphenous vein drains the superficial posterolateral
lower limb. It eventually terminates in the popliteal vein.
10. The correct answer is:
Posterior
The deep femoral artery supplies the posterior compartment of the thigh
with three to four perforating arteries. These arteries pierce adductor
magnus and supply blood to the hamstrings--biceps femoris,
semitendinosus, and semimembranosus. The anterior compartment of
the thigh (the quadriceps) receives blood from the femoral artery. The
medial compartment of the thigh receives blood from the obturator artery
and medial circumflex femoral artery, as well as the deep femoral. The
gluteal region receives blood from the superior and inferior gluteal
arteries.
11. The correct answer is:
superior gluteal
The superior gluteal nerve supplies gluteus minimus and medius--two
muscles that are important abductors of the hip--and tensor fasciae
latae. These muscles stabilize the pelvis when walking. They work in
such a way that when you are standing on your right leg only, the
muscles on the right side are holding the left side of the pelvis level.
When you are standing on your left leg only, the muscles of the left side
are supporting the right side of the pelvis. So, if a patient exhibits this
characteristic hip drop on the uninjured side while standing on the
injured side, this is called Trendelenburg sign. It demonstrates that the
superior gluteal nerve was injured and the gluteus minimus and medius
can no longer support the hip.
12. The correct answer is:
flexion at the knee
The ischial tuberosity is the origin for the hamstrings muscles which are
the muscles that allow for extension at the hip and flexion at the knee. If
the ischial tuberosity was fractured, the hamstrings would be separated
from their origin and would not function properly. The most important hip
abductors are gluteus medius and minimus. These muscles are most
commonly damaged by an injury to the superior gluteal nerve. The hip
adductors are adductor longus, brevis and magnus, which insert on the
linea aspera of the femur and are innervated by the obturator nerve. The
muscles responsible for extending the knee are the quadriceps. They
take origin from the surface of the femur and the anterior inferior iliac
spine (rectus femoris). The quadriceps are innervated by the femoral
nerve. Finally, the hip flexors are rectus femoris (from the quadriceps),
pectineus, iliopsoas, and sartorius. These muscles have diverse origins,
and are mostly innervated by the femoral nerve.
13. The correct answer is:
Biceps femoris
To answer this question, you need to determine the innervations of all
the muscles listed. Biceps femoris, semimembranosus, and
semitendinosus are all part of the hamstrings compartment, which is
innervated by the tibial nerve. But, the short head of biceps femoris is
the one part of the hamstring compartment that is innervated by the
common fibular nerve instead of the tibial nerve. So biceps femoris is the
answer you're looking for!
Adductor magnus is innervated by the obturator nerve--it's in the medial
compartment of the leg. Gluteus maximus is innervated by the inferior
gluteal nerve.
14. The correct answer is:
Gluteus maximus
Gluteus maximus is the most important muscle for powerfully extending
the thigh. This is the muscle that is used for forceful extension at the hip
joint, which is what you need to go up the stairs or to jump powerfully.
That's why gluteus maximus is the answer. Semitendinosus is the other
muscle mentioned which extends the thigh--it's one of the hamstrings
muscles in the posterior compartment of the thigh. However,
semitendinosus flexes the leg, and there is no weakness with this
motion. Also, you should remember that gluteus maximus is the key
muscle for very forceful extension--not semitendinosus.
Adductor magnus adducts and medially rotates the thigh, while gluteus
medius abducts and medially rotates the thigh. Iliopsoas is a hip flexor.
There is no weakness in any of these movements, so you should know
that these muscles are not injured.
15. The correct answer is:
Inferior gluteal nerve
The first thing that you want to do with this question is determine which
muscle was impaired. Since the question specifies that there is a
weakness when climbing steps or jumping, you should know that there is
a problem with powerfully extending the hip. And that's what gluteus
maximus does. The nerve to gluteus maximus, the inferior gluteal nerve,
must be the nerve that was injured. The tibial nerve innervates the
hamstring compartment. Although the hamstrings are involved in
extending the hip, they are not the most important muscles for these
powerful motions. Gluteus maximus and the inferior gluteal nerve enable
the type of powerful extension used to climb steps or jump
The superior gluteal nerve innervates gluteus minimus and medius.
These muscles are important for stabilizing the pelvis on the supported
side of the hip when the opposite leg is lifted. If the superior gluteal
nerve is damaged on the supported side of the hip, the unsupported side
of the hip will drop. This is called Trendelenburg gait. The obturator
nerve innervates the medial, adductor compartment of the hip. The
femoral nerve innervates the anterior compartment of the hip, including
the quadriceps. This nerve allows for extension at the knee.
16. The correct answer is: Perforating branches of the deep femoral
artery supply the posterior thigh
The deep femoral artery supplies the posterior compartment of the thigh
with three to four perforating arteries. These arteries pierce adductor
magnus and supply blood to the hamstrings--biceps femoris,
semitendinosus, and semimembranosus. Genicular anastomosis supply
the knee joint, not the posterior thigh. The cruciate anastomosis supply
blood to the area around the head of the femur. The medial and lateral
circumflex arteries and the inferior gluteal artery also supply the hip joint.
The obturator artery supplies the medial hip and thigh.
17. The correct answer is:
Lateral; piriformis
A good way to answer this question is to look for a muscle that is a
lateral rotator of the thigh and then make sure that the compartment that
it is listed with is correct. Piriformis laterally rotates the thigh; it is a
member of the lateral compartment which includes other muscles that
laterally rotate the thigh, like obturator internus and the superior and
inferior gemellus muscles. So, this is the best answer.
Tensor fasciae latae is in the lateral compartment, but it's a medial
rotator of the thigh, so this is not a correct answer. Rectus femoris is one
of the quadriceps muscles, found in the anterior compartment of the
thigh. This compartment extends the knee and flexes the hip, but these
muscles do not rotate the thigh. Biceps femoris is a muscle in the
posterior compartment--it's a hamstring muscle that extends the hip and
flexes the knee.
18. The correct answer is:
Superior gluteal
The superior gluteal nerve supplies gluteus minimus and medius--two
muscles that are important abductors of the hip. These muscles stabilize
the pelvis when walking. They work in such a way that when you are
standing on your right limb only, the muscles on the right side are
holding the left side of the pelvis level. When you are standing on your
left leg only, the muscles of the left side are supporting the right side of
the pelvis. This patient has injured his right superior gluteal nerve. He is
exhibiting a characteristic hip drop on the uninjured side while standing
on the injured side--a positive Trendelenburg sign. The superior gluteal
nerve was evidently damaged during the injection. This is why it's
important to place injections in the upper, outer quadrant of the buttock-that's the quadrant of the buttock that has fewer nerves that might be
damaged by a needle. Nerves that could be injured from careless
injections include the sciatic nerve, posterior femoral cutaneous nerve,
inferior gluteal nerve, and superior gluteal nerve.
An injury to the femoral nerve would weaken the quadriceps--the patient
would not be able to extend his leg. An injury to the obturator nerve
would denervate the adductors and impair adduction of the hip. Damage
to the sciatic nerve would paralyze the hamstrings and all the muscles in
the leg and foot. Finally, injuring the inferior gluteal nerve would paralyze
gluteus maximus and impair extension of the hip.
19. The correct answer is:
Deep femoral
The deep femoral artery supplies the posterior compartment of the thigh
with three to four perforating arteries. These arteries pierce adductor
magnus and supply blood to the hamstrings--biceps femoris,
semitendinosus, and semimembranosus. The fibular artery is a branch
of the posterior tibial artery which supplies the muscles and fascia of the
lateral leg and ankle. The obturator artery comes from the anterior
division of the internal iliac artery; it delivers blood to the medial thigh
and hip. The internal pudendal artery is the major source of blood to the
perineum. The superficial femoral artery is the name used clinically for
the femoral artery after the deep femoral is given off. Therefore, the
short segment of femoral artery proximal to the deep/superficial division
is sometimes called the common femoral.
20. The correct answer is:
Superior gluteal artery
Piriformis is the key to the posterior thigh, and there are many important
nerves and arteries that exit the greater sciatic foramen and enter the
posterior thigh either above or below piriformis. The superior gluteal
artery and nerve are 2 structures that travel through the greater sciatic
foramen superior to piriformis. There are many structures that travel
through the greater sciatic foramen inferior to piriformis and lie in the
posterior thigh. From medial to lateral, these structures are: pudendal
nerve, nerve to obturator internus, nerve to quadratus femoris, inferior
gluteal artery, posterior femoral cutaneous nerve, inferior gluteal nerve,
and sciatic nerve. See Netter plates 502 and 503 for a picture. You
should know what nerves and vessels are superior and inferior to
piriformis!
None of the other arteries mentioned travel superior to piriformis to
reach the posterior thigh. The iliolumbar artery is a branch of the
posterior division of the internal iliac. It travels on the posterior body wall
to supply blood to the iliacus, psoas major, and quadratus lumborum.
The internal pudendal artery is a branch from the anterior division of the
internal iliac artery. It leaves the pelvis with the inferior gluteal artery,
traveling inferior to piriformis. It enters the perineum through the lesser
sciatic foramen to supply muscles, skin, and the erectile bodies there.
Finally, the lateral sacral arteries are branches of the posterior division of
the internal iliac artery--they are on the posterior body wall and they
supply the sacrum, sacral nerve rootlets, meninges, and the nearby
muscles.
21. The correct answer is:
Flexion of the leg
The ischial tuberosity is the origin of the hamstrings muscles, so
fracturing this bone would disrupt this origin. The hamstrings are
important for flexing the leg and extending the thigh; this means that
these motions would be impaired following the fracture.
Gluteus minimus and medius are important abductors of the hip. These
muscles both take origin from the ilium. So, a fracture to the ilium might
impair abduction of the hip, although these muscles are more commonly
impaired by damage to the superior gluteal nerve. The tibialis anterior, in
the anterior compartment of the leg, is responsible for dorsiflexion of the
foot. It originates on the lateral condyle of the tibia, so breaking off the
lateral condyle of the tibia might impair dorsiflexion.
The quadriceps, in the anterior compartment of the thigh, are
responsible for extending the leg. Rectus femoris takes origin from the
anterior inferior iliac spine, while the vastus muscles originate from the
body of the femur. Finally, the muscles responsible for flexing the hip are
pectineus, iliopsoas, sartorius, and rectus femoris. Pectineus originates
from the pecten pubis, iliopsoas originates on the lumbar vertebrae and
the iliac fossa, and sartorius originates on the anterior superior iliac
spine.
22. The correct answer is:
Popliteal artery
The popliteal fossa contains the popliteal artery, popliteal vein, common
fibular nerve, and tibial nerve. The popliteal artery is the deepest
structure in the fossa--it lies on the posterior side of the knee joint. So, it
is the structure that would be most likely to be lacerated by the broken
distal end of the femur. The descending genicular artery is one of the
arteries that supplies the knee through the genicular anastomoses. It is
found on the medial side of the knee, not in the popliteal fossa. The
greater saphenous vein is a superficial vein that drains the lower limb. It
is found traveling posterior to the medial epicondyle, but it's not in the
popliteal fossa. The sciatic nerve is found in the superior part of the
thigh--it quickly splits into the common fibular and tibial nerves which are
found in the popliteal fossa.
23. The correct answer is:
Posterior tibial artery
The popliteal artery divides into two arteries: the posterior tibial artery
and anterior tibial artery. The posterior tibial artery supplies the posterior
compartment of the leg with blood. It also passes into the sole of the
foot, where it branches to form the medial and lateral plantar arteries.
So, the injury to the posterior surface of the leg and the lack of perfusion
to the foot all point to an injury to the posterior tibial artery.
The fibular artery is a branch of the posterior tibial artery that gets blood
to the fibular compartment of the leg. You can tell that this was not the
main artery damaged because this artery is not important for perfusing
the foot. The femoral artery is an artery of the anterior thigh--it would not
be damaged by a mid-calf injury. The popliteal artery is the artery that
branches to form the posterior and anterior tibial arteries. It is clear that
this artery is intact because the anterior of the leg and dorsum of the
foot--areas supplied by the anterior tibial artery and its continuation,
dorsalis pedis--are normal. Finally, the medial plantar artery is found on
the plantar side of the foot--it would not even be close to an arrow in the
mid-calf.
24. The correct answer is:
calcaneal
Gastrocnemius and soleus insert on the calcaneus via the calcaneal
tendon, a tendon of the lower calf which is the thickest and strongest
tendon of the body. These muscles are important plantarflexors of the
foot, so it is likely that the tendon connected to these muscles has been
damaged.
The other tendons/muscles listed and their actions are as follows:
flexor halluc
dorsiflexes the foot. Since none of these actions is disrupted, the other
tendons are probably fine.
25. The correct answer is:
plantaris
Plantaris is a very small muscle in the posterior compartment of the leg.
It has a very long and thin tendon that attaches directly to the calcaneus-it does not insert on the calcaneal tendon along with gastrocnemius and
soleus. Plantaris acts to flex the leg and plantarflex the foot, but is is not
the major muscle responsible for either of these motions. Like the other
muscles of the posterior compartment, it is innervated by the tibial nerve.
Gastrocnemius and soleus are large muscles of the posterior
compartment that attach to calcaneus via the thick calcaneal tendon. If
that tendon was ruptured, the patient would have impaired plantarflexion
and significant pain. Popliteus is a muscle on the posterior knee which
allows the knee to rotate medially and unlock to initiate flexion of the
knee. Tibialis posterior is also a muscle in the posterior compartment--it
plantarflexes and inverts the foot.
26. The correct answer is:
Plantarflexion of the foot
The calcaneal tendon is the thickest and strongest tendon of the body. It
is the tendon that gastrocnemius and soleus--the major plantarflexors of
the posterior compartment--use to insert on the dorsum of calcaneus.
So, if this tendon was ruptured, gastrocnemius and soleus would not be
inserting on the calcaneus, and the football player would be unable to
plantarflex his leg.
Dorsiflexion would be impaired if there was damage to the anterior
compartment of the leg. Specifically, an injury to tibialis anterior or the
deep fibular nerve would lead to a weakness in dorsiflexion. Eversion
would be impared if there was an injury to the fibularis muscles--fibularis
tertius, fibularis longus, and fibularis brevis--which are all responsible for
everting the foot. Inversion would be impaired if there was damage to
tibialis anterior and tibialis posterior. These are the two muscles which
invert the foot. And remember--extending the knee is done by the
quadriceps muscles in the anterior thigh. They are innervated by the
femoral nerve, so an injury to this nerve or to the quadriceps muscles
themselves might impair extension at the knee.
27. The correct answer is:
Posterior tibial
The posterior tibial artery passes from the posterior compartment of the
leg, behind the medial malleolus, before entering the foot. In the foot, it
splits to form the medial and lateral plantar arteries. Remember--this is
one of the structures that is lined up behind the flexor retinaculum in a
very characteristic way. To review, the order here is, from anterior to
posterior: tendon of Tibialis posterior, tendon of flexor Digitorum longus,
posterior tibial Artery (and vein), tibial Nerve, and tendon of flexor
Hallucis longus. So, T, D, A, N, H equals Tom, Dick, ANd Harry.
The anterior tibial artery comes from the anterior compartment of the
leg--it changes name to the dorsalis pedis artery at the level of the ankle.
If the spear had stabbed the student on the dorsum of the foot or leg,
either above or below the ankle, one of these two arteries might have
been injured. The fibular artery is a branch of posterior tibial artery that
supplies the lateral compartment of the leg--an injury to the lateral leg
might damage this artery. The medial plantar artery is a branch of the
posterior tibial artery in the foot--if the spear had stabbed her medial foot
on the plantar surface, this is the artery that might have been injured.
28. The correct answer is:
Calcaneal
The calcaneal tendon is the thickest and strongest tendon of the body. It
is the tendon that gastrocnemius and soleus--the major plantarflexors of
the posterior compartment--use to insert on the dorsum of calcaneus.
Tearing this tendon is painful, and it means that a patient won't be able
to plantarflex the foot. So, the symptoms of this patient fit with a rupture
to the calcaneal tendon.
Extensor digitorum longus is important for extending the digits, while
extensor hallucis longus allows the great toe to extend. Tibialis anterior
is important for dorsiflexion. These three muscles are all in the anterior
compartment of the leg, so injuries to these tendons would not fit with
pain in the distal calf. Plantaris is a very small muscle in the posterior
compartment which flexes the leg and plantar flexes the foot--an injury to
plantaris would not cause such severe symptoms.