Week 4

Question 1

Arch of the foot

Answer 1

longitudinal arch

Question 2

Structures that form/maintain the arch

Answer 2

1: bone shape 2: four layers of fibrous CT 3: Intrinsic muscles and tendons of extrinsic muscles

Question 3

Pes planus

Answer 3

-flexible: most common– caused by loose or degenerative ligaments -rigid, “fallen arches”: acquires–caused by tibialis posterior

Question 4

Boundaries of popliteal fossa

Answer 4

-superolaterally: bicep femoris -superomedially: semimembranous -inferolaterally: lateral head of gastoc -inferomedially: medial head of gastroc -posteriorly: popliteal fascia (roof)

Question 5

Contents of politeal fossa

Answer 5

-termination of small saphenous vein -popliteal arteries and veins and their branches -tibial and common fibular nerves -posterior cutaneous nerve of thigh -popliteal lymph nodes and lymph vessels

Question 6

Nerves of popliteal fossa

Answer 6

-sciatic, medial sural cuteaneous, tibial, nerve to gastroc medial and lateral head, nerve to popliteus, sural nerve, sommon fibular nerve, sural communicating branch

Question 7

Popliteal artery -origin -name change -termination

Answer 7

-femoral artery -changes name at adductor hiatus -inferior border of popliteus where it divides into anterior and posterior tibial arteries

Question 8

Popliteal vein -drainage

Answer 8

begins at the distal border of the popliteus as a continuation of the posterior tibial vein

Question 9

Genicular branches of popliteal artery

Answer 9

-supply the capsule and ligaments of the knee joint - provides collateral circulation capable of maintaining blood supply to the leg during full knee flexion, which may kink the popliteal artery.

Question 10

Posterior compartment of lower leg -what does it contain (muscles [superficial vs deep], nerve, vessels)

Answer 10

-plantar flexors of foot and toes (S: Gastroc, soleus, D: flexor hallus longus, flexor digitlais longus, tibialis posterior); tibial nerve; fibular vessels, posterior tibial vessels

Question 11

What separates the subcompartments in the posterior compartment?

Answer 11

-intermuscular septa

Question 12

Major arterial supply of posterior leg? -main vessel what it bifurcates into

Answer 12

Posterior tibial artery– gives rise to fibular artery, and divides into medial and lateral plantar arteries at level of abductor hallucis

Question 13

Tibial nerve

Answer 13

-medial, larger terminal branch of sciatic nerve - branches to muscles of soleus, gastrocnemius, plantaris, and popliteus muscles -gives rise to medial sural cutaneous nerve in popliteal fossa

Question 14

Calcaneal tendon reflex -What is it -Nerve root -Normal response

Answer 14

-Stretch reflex illicited by putting fast, direct pressure onto the tendon to ensure that nerves are working -S1 - Plantar flexion

Question 15

What exam do you need to perform to check for torn ACL/ PCL?

Answer 15

-ACL: anterior drawer and lachmans -PCL: posterior drawer

Question 16

What exam do you need to perform to check for torn MCL/LCL?

Answer 16

-MCL:valgus -LCL: varus

Question 17

What is the abnormality?

Answer 17

-Muscle hypertrophy

Question 18

Contrast the atrophy in the images

Answer 18

Left: rounded fibers with individual muscle fiber atrophy (myopathic in nature)

Right: Neuropathic in nature; Clustered flattened “angulated” atrophic fibers ( group atrophy ) are a typical finding associated with disrupted innervation

Question 19

Explain pathology of muscle hytrophy caused by myopathy and neurogenic cause

Answer 19

myopathy: will be caused by disease of muscle
neurogenic: muscle hypertrophy due to disorder of nerve

Question 20

x-linked muscular dystrophies

Answer 20

• Duchenne
• Becker

Question 21

Dystrophin

• function
• defects

Answer 21

• provide mechanical stability to the myofiber and its cell membrane during muscle contraction.
• lead to small membrane tears that permit influx of calcium, triggering events that result in myofiber degeneration

Question 22

Deuchenne

Answer 22

• loss of function mutation: no dystrophin available
• severe muscular dystrophy
• usually seen by age 5

Question 23

Becker

• what does it do?
• serverity
• onset

Answer 23

• loss of function mutation, causes miss-shapen dystrophin
• less severe than deuchene
• 10-20 years old