Leg Flashcards
What are the boundaries of the popliteal fossa?
- Biceps femoris m.
- Semimembranosus m.
- Gastrocnemius, medial head
- Gastrocnemius, lateral head
What is contained w/in the popliteal fossa?
- Tibial n.
- Common fibular n.
- Popliteal a.
- Popliteal v.
What are the anastomotic aa. about the knee? What do they branch from?
- Superior medial genicular a.
- Superior lateral genicular a.
- Inferior medial genicular a.
- Inferior lateral genicular a.
All branch from popliteal a. (descending branch of lateral circumflex femoral a. gets in on it too)
Where does the popliteal a. divide, and what does it divide into?
Which is more of a continuation of the popliteal a.?
- Distal end of popliteal fossa (just below popliteus m.)
- Anterior and posterior tibial arteries (posterior is more of a continuation)
Where is the anterior tibial a. generally located?
b/w tibia and fibula bones (above interosseous membrane)
What m. does the beginning of the posterior tibial a. course over?
Tibialis posterior m.
After passing beneath the superior extensor retinaculum, What branches does the anterior tibial a. give off near the ankle?
Medial and lateral malleolar aa.
After passing beneath the inferior extensor retinaculum, what does the anterior tibial a. become?
Dorsalis pedis a.
Tibialis anterior m: OIIA?
O: Upper tibial shaft/interosseous membrane
I: Medial cuneiform/base of 1st metatarsal
I: Deep fibular n.
A: Dorsiflexes and inverts foot. (Plays role in medial longitudinal arch of foot)
Extensor digitorum longus m: OIIA?
O: Upper tibial shaft/interosseous membrane
I: Extensor expansion of lateral 4 toes
I: Deep fibular n.
A: Extends lateral 4 digits and dorsiflexes foot
Extensor hallucis longus m: OIIA?
O: Mid ant fibula
I: Base of 1st distal phalanx
I: Deep fibular n.
A: Extends great toe, dorsiflexes foot
Fibularis tertius m: OIIA?
O: Mid ant shaft of fibula
I: Shaft and base of 5th metatarsal
I: Deep fibular n.
A: Dorsiflexes and everts foot
What is a common action of mm. innervated by the deep fibular n?
Dorsiflexion of the foot
anterior leg mm.
What is a common action of mm. innervated by the superficial fibular n?
Eversion of the foot
lateral leg mm.
Fibularis longus m: OIIA?
O: Upper fibular & joint above
I: Plantar aspect of 1st metatarsal/medial cunieform, passing deep to long plantar ligament
I: Superficial fibular n.
A: Everts foot + weak plantarflexion
FIbularis brevis m: OIIA?
O: Inferior 1/3 fibular shaft
I: Base of 5th metatarsal
I: Superficial fibular n.
A: Everts foot + weak plantarflexion
Which is deeper, fibularis longus or brevis?
Brevis (longus sits on top)
Muscle paralysis of which leg m. would cause foot drop? Which n. is affected?
Tibialis anterior m.
- Deep fibular n.
What sensory area does the saphenous n. innervate?
What n. is the saphenous n. a continuation of?
- Medial leg and ankle
- Femoral n.
What sensory area does the deep fibular n. innervate?
Area b/w hallux and 2nd toe
What sensory area does the superficial fibular n. innervate?
Lateral leg up to mid shaft + dorsum of foot
Gastrocnemius m: OIIA?
O: Just above medial and lateral condyles
I: Calcaneal tendon/calcaneus
I: Tibial n.
A: Plantarflexion, some knee flexion
Soleus m: OIIA?
O: Mid tibia + upper fibula
I: Calcaneal tendon/calcaneus
I: Tibial n.
A: Plantarflexion, aids venous return
Plantaris m: OIIA?
O: Lateral supracondylar ridge of femur
I: Calcaneal tendon
I: Tibial n.
A: Plantarflexes foot, flexes knee
Which muscle’s tendon is nicknamed the “freshman n.”?
Where do you see it?
Tendon of plantaris, runs near medial soleus
Popliteus m: OIIA?
O: Upper posterior tibial shaft
I: Lateral condyle of femur
I: Tibial n.
A: Medially rotates and flexes leg at knee; *helps unlock fully extended knee
Tibialis posterior m: OIIA?
O: Upper tibia, fibula, and interosseous membrane
I: Navicular, all tarsal bones except talus, spring ligament (comes over medial talus)
I: Tibial n.
A: Plantarflexes, inverts, and adducts foot
Flexor digitorum longus: OIIA?
O: Post tibial shaft, upper
I: Base of distal phalanges of lateral 4 toes
I: Tibial n.
A: Flexes lateral 4 phalanges, plantarflexion, supports foot’s longitudinal arch
Flexor hallucis longus: OIIA?
O: Lower 2/3 post fibula
I: Base of distal phalanx of hallux
I: Tibial n.
A: Flexes big toe, weak plantarflexion and inversion
What all pass distal to the medial malleolus, under the flexor retinaculum?
Tom, Dick, And Nervous Harry
- Tibialis posterior tendon sheath
- flexor Digitorum longus tendon sheath
- posterior tibial Artery
- tibial Nerve
- flexor Hallucis longus tendon sheath
What does the tibial n. branch from? Where?
- Sciatic n.
- Above popliteal fossa
What does the tibial n. become in the foot?
Divides to become the medial and lateral plantar nn. (arteries do the same)
What does the common fibular n. branch from? Where?
- Sciatic n.
- Above popliteal fossa
What are the branches of the common fibular n. and which compartments do they innervate?
- Superficial fibular n.–lateral compartment
- Deep fibular n.–anterior compartment
During a routine physical exam, the physician taps a patient’s patellar ligament with a reflex hammer and elicits a knee-jerk reflex. Which of the following nerves mediates this patellar reflex?
A. Common fibular B. Femoral C. Obturator D. Saphenous E. Tibial
B. Femoral
You are called to see a 35-year-old man who was admitted to hospital earlier that day. He was involved in a road traffic accident and sustained a fracture of his left tibia. He is now complaining of pain, and on examination his leg appears white and cold. You are unable to palpate his foot pulses. He is diagnosed with compartment syndrome affecting the extensor compartment of his leg. Which nerve supplies the extensor compartment of the leg?
A. Deep peroneal nerve B. Femoral nerve C. Sciatic nerve D. Superficial peroneal nerve E. Sural nerve
A. Deep peroneal nerve
A long-distance runner is examined by her physician after complaining of pain along the anteromedial aspect of her left leg, extending from just below the knee to just above the ankle. She has been running on a hard surface and notices that the pain is especially acute as she pushes off from the ground with the affected limb. Which one of the following muscles of the leg is most likely affected by this stress injury?
A. Extensor digitorum longus B. Fibularis longus C. Gastrocnemius D. Popliteus E. Tibialis posterior
E. Tibialis posterior
What a. does the fibular/peroneal a. branch off of?
Posterior tibial a.
What nn. combine to form the sural n?
Medial sural cutaneous n. (off tibial n.) and lateral sural cutaneous n. (off common peroneal n.)
What sensory area does the sural n. innervate?
Mainly posterolateral ankle
What sensory area does the lateral sural cutaneous n. innervate?
Superolateral leg area
What sensory area does the medial sural cutaneous n. innervate?
Patch in middle of posterior leg, inferior to popliteal fossa
What cutaneous nn. innervate the skin overlying the buttocks?
Superior, middle, and inferior cluneal nn.