MSK Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

What is the most commonly dislocated carpal bone; which nerve most likely to be affected?

A

Lunate; may compress median n.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which protein mediates Ca2+ activation of the contractile apparatus in cardiac and skeletal muscle?

A

Troponin (Tn)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Why is cartilage, such as the hyaline cartilage in the knee joint particularly vulnerable to infection?

A

Cartilage is relatively avascular; immune system cannot access in an efficient fashion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Most of the blood supply to the head of the femur arise from which artery?

A

Medial Circumflex Femoral a.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Rheumatoid nodules will show what histologically?

A

Central areas of fibrinoid necrosis surrounded by palisading rim of epitheliod cells –> resembles granuloma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which virus has been implicated as a cause of Paget disease of bone?

A

Paramyxovirus (measeles and RSV) in osteoclasts of bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Axillary nerve runs closest to the humerus at which location?

A

Surgical neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Quadrangular space is formed by which structures?

A
  • Teres minor
  • Teres major
  • Long head of triceps
  • Surgical neck of humerus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which artery accompanies the axillary nerve in close proximity to the surgical neck of the humerus?

A

Posterior humeral circumflex a. (branch of axillary a.)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Which nerve and roots innervate the serratus anterior m.?

A

Long thoracic n. (C5-C7)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Which bands of skeletal muscle are delineated by the sarcomere, actin thin filaments and myosin thick filaments; how do they change during contraction?

A
  • I-band contains a Z-disk, delineating a sarcomere and actin thin filaments; during contraction the I-band shortens
  • A-band, delineated by ends of myosin thick filaments; does not change during contraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which muscle is responsible for protrusion of the tongue and its innervation?

A

Genioglossus m. (CN XII)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the only muscle of the tongue innervated by CN X and its function?

A

Palatoglossus ms. = pull tongue upward toward the palate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Which 2 muscles of the hand have their origins on the hook of the hamate?

A

Flexor digiti minimi and opponens digiti minimi

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A sample of urine that turns black upon standing at room temperature is classically associated with what condition?

A

Onchronosis aka Alkaptonuria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Alkaptonuria (ochronosis) is due to a deficiency of what; inherited how?

A

Deficiency of homogentisic acid oxidase –> Autosomal recessive

17
Q

What is the MOA of succinylcholine and what are 2 potentially life-threatening complications

A
  • Binds and stimulates nAChR’s on skeletal muscle motor end plate –> Na+ and K+ out of cell = constant depolarization
  • Hyperkalemia and malignant hyperthermia
18
Q

What is the effect of tensioning a skeletal muscle on both passive tension (preload) and maximal active tension?

A
  • Preloading muscle ↑ passive tension
  • Stretching skeletal muscle ↓ its ability to generate force = ↓ active tension
19
Q

Which vein drains lymph from the lateral side dorsum of foot and into which LN’s?

A

Short saphenous vein —> LN’s in popliteal fossa

20
Q

How can you calculate active tension of skeletal muscle generated using preload and total tension?

A

Active tension = Total tension - Passive tension

21
Q

Pain and tenderness at the anatomic snuffbox after a “FOOSH” injury is pathognomonic for what?

A

Scaphoid fracture (forms floor of snuffbox)

22
Q

Which 2 muscles and their associated CN are responsible for elevating the tongue?

A
  • Styloglossus (CN XII)
  • Palatoglossus (CN X)
23
Q

Which nerve is found in the musculospiral groove of the humerus and is commonly involved in fractures at this location; which signs/sx’s seen?

A
  • Radial nerve
  • Inability to extend the wrist (wrist drop); trouble making tight fist
  • Sensory loss of posterior forearm and hand
24
Q

Which structure is found extending from the right border of the sternum to approximately 2 inches to the left the sternum of the 3rd, 4th, and 5th ICS?

A

Right ventricle

25
Q

Osgood-Schlatter disease (OSD) is an overuse injury of the 2’ ossification center (apophysis) located where and what is the involved ligament?

A

Pain/swelling at tibial tubercle, the insertion point of patellar ligament

26
Q

Osteocytes have long intracanalicular processes extending thru the ossified bone matrix which connect to osteocytes within neighboring lamellae via what?

A

Gap junctions

27
Q

During the skeletal muscle contraction cycle what is the result of ATP binding to myosin?

A

Causes release of the myosin head from its binding site on the actin filament

28
Q

How can you tell the difference btw a demyelinating neuropathy vs. axonal neuropathy using a nerve conduction study?

A
  • Demyelinating due to damage of myelin sheath –> delayed (or blocked) nerve conduction velocity
  • Axonal due to damage of nerve axon –> reduced signal amplitude
29
Q

The common peroneal n. divides into a superficial and deep branch; what is each of these nerves responsible for?

A
  • Deep: innervates anterior compartment ms., which dorsiflex the foot and toes + sensation btw 1st and 2nd toe
  • Superficial: innervates lateral compartment ms., which evert foot + sensation to dorsum of foot and lateral shin
30
Q

A midshaft hemeral fracture should raise concern for deficits involving which nerve and artery?

A
  • Radial n.
  • Deep brachial a.
31
Q

What should be included in the initial tx and work-up for Dermatomyositis?

A
  • Initial tx is systemic glucocorticoids
  • Should evaluate for underlying occult malignancy: as is often part of a paraneoplastic syndrome (especially adenocarcinoma)
32
Q

What are the major differences between Type I and Type II muscle fibers?

A
  • Type I = slow twitch; actions requiring low-level sustained force; aerobic metabolism; high myoglobin, are glycogen poor and contain many mitochondria
  • Type II = fast twitch; rapid forceful pulses of movement; IIb derive ATP from anaerobic glycogenolysis and subsequent glycolysis and IIa generates ATP via aerobic metabolism
33
Q

The deep inguinal ring and superficial inguinal rings are physiologic openings in what?

A
  • Deep ring is physiologic opening in the transversalis fascia
  • Superficial ring is physiologic opening in the external oblique muscle aponeurosis
34
Q

What is seen on biopsy which can differentiate Dermatomyositis from Polymyositis?

A
  • Dermatomyositis: shows perifascicular inflammation (around blood vessels) in a segmental pattern without vasculopathy
  • Polymyositis: shows a patchy endomysial inflammation (direct invasion of individual muscle fibers) without prominent vascular involvement

*Both associated with anti-tRNA synthetase (anti-Jo-1) autoantibodies*