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Question 1

Radial n.

• roots
• where are common injuries
• classic sign

Answer 1

• C5-T1
• midshaft fx of humerus, compression of axilla.
• wrist drop

Question 2

Median n.

• roots
• where are common injuries
• classic sign

Answer 2

• C5-T1
• Supracondylar fx of humerus (proximal lesion); carpal tunnel syndrome and wrist laceration (distal lesion).
• Hand of benediction.

Question 3

Ulnar n.

• roots
• where are common injuries
• classic sign

Answer 3

• C8-T1
• medial epicondyle of humerus (funny bone). Hook of hamate. Guyon canal syndrome.
• Ulnar claw on digit extension.

Question 4

Which brachial plexus terminal nerves do NOT give branches in axilla or upper arm?

Answer 4

Median, Ulnar

Question 5

What innervates:

-lateral flexor digitorum profundus & lateral 2 lumbricals.

Answer 5

median n.

Question 6

What innervates:

-medial flexor digitorum profundus & medial 2 lumbricals.

Answer 6

ulnar n.

Question 7

Atrophy of hypothenar eminence

Answer 7

-ulnar n. lesion

Question 8

Is “clawing” seen w/distal or proximal lesions?

Answer 8

-distal

Question 9

Actin are bound to __ line

Answer 9

Z

Question 10

Myosin are bound to ___ line

Answer 10

M

Question 11

I band =
H band =
A band =

Answer 11

I band = just actin
H band = just myosin
A band = entire length of myosin, stays the same.

Question 12

PTH effect at low, intermittent levels.

Answer 12

-exerts anabolic effects.

Question 13

Serum chemistry in osteoporosis

Answer 13

-normal serum chemistry!

Question 14

What type of bone is lost in osteoporosis?

Answer 14

Trabecular (spongy) (cancellous)

-dorsolumbar vertebral bodies, neck of femur (50/50 trabecular & corticol)

Question 15

What type of bone is lost in hyperparathyroidism?

Answer 15

corticol (your limbs)

-subperiosteal thinning.

Question 16

denosumab

Answer 16

• Tx for osteoporosis

- monoclonal antibody against RANKL

Question 17

osteopetrosis - can lead to marrow fibrosis

Answer 17

• pancytopenia

- extarmedullary hematopoesis.

Question 18

Serum chemistry in osteomalacia

Answer 18

• dec Calcium (leads to inc. PTH which leads to =>
• dec. phosphate
• inc. ALP (hyperactivity of osteoblasts).

Question 19

Serum chemistry in Pagets disease of bone.

-inc. risk for what cancer?

Answer 19

• Ca, Phosphate, PTH = normal
• inc. ALP (after lytic & mixed phase)
• inc. risk of osteogenic sarcoma

Question 20

Pagets: inc. vascularity. How?

Answer 20

• osteoclasts release cytokines that promote prolif of fibroblasts and endothelial cells.
• AV shunts made
• high output cardiac failure

Question 21

Most common location of avascular necrosis?

Which artery feed that location?

Answer 21

Femoral head, fed by medial circumflex femoral art.