Musculoskeletal/skin- Anatomy and physiology

Question 1

What are tight junctions composed of?

Answer 1

claudins and occludins

Question 2

What are adherens junctions composed of?

Answer 2

Cadherins (Ca2+ dep) and actin cytoskeleton

Question 3

What do desmosomes connect to?

Answer 3

support keratin interactiosns, desmoplakin

Question 4

What are the channel proteins in gap junctions?

Answer 4

connexons (permit electrical and chemical communication

Question 5

What do integrins interact with?

Answer 5

bind collagen and laminin of basement membrane

Question 6

What type of injury is indicated by the anterior drawer sign?

Answer 6

ACL injury

Question 7

What are the sites of attachment of the ACL and PCL?

Answer 7

ACL- attaches anterior tibia to lateral condyle of femur (prevents anterior movement of tibia)
PCL- attaches posterior tibia to medial condyle of femur (prevents posterior movement of tibia)

Question 8

What type of injury is indicated by the posterior drawer sign?

Answer 8

PCL injury

Question 9

What is the unhappy triad injury?

Answer 9

lateral force applied to a planted leg

ACL, MCL, medial lemniscus

Question 10

What is the McMurray test of knee pain?

Answer 10

pain on external rotation- medial meniscus

pain on internal rotation- lateral meniscus

Question 11

What injury is indicated by abnormal passive abduction? (valgus stress)

Answer 11

MCL injury

Question 12

What injury is indicated by abnormal passive adduction?

Answer 12

LCL injury

Question 13

What bony marker is used to do a pudendal nerve block?

Answer 13

ischial spine

Question 14

What boney landmark is used for a lumbar puncture?

Answer 14

iliac crest

Question 15

What is the innervation and action of the supraspinatus muscle?

Answer 15

Innervation: suprascapular

Abducts arm initially

Question 16

What is the innervation and action of the infraspinatus muscle?

Answer 16

suprascapular nerve

latterally rotates arm

Question 17

What is the most common rotator cuff injury?

Answer 17

injury to supraspinatus

Question 18

What rotator cuff muscle is a common pitching injury?

Answer 18

infraspinatus

Question 19

What is the innervation and action of the teres minor?

Answer 19

axillary nerve

adducts and laterally rotates arm

Question 20

What is the innervation and action of the subscapularis?

Answer 20

subscapular nerve

medially rotates and adducts arm

Question 21

What nerve roots innervate the rotator cuff muscles?

Answer 21

C5-C6

Question 22

What are the wrist bones?

So long to pinky, here comes the thumb

Answer 22

scaphiod
lunate
triquetrum
pisiform
hamate
capitate
trapezoid
trapezium

Question 23

What wrist bone can be palpated in the anatomical snuff box?

Answer 23

scaphoid

Question 24

What is the most commonly fractured carpal bone? What damage can fracture lead to?

Answer 24

Scaphoid

can lead to avascular necrosis

Question 25

What carpal bone is commonly dislocated? What nerve is damaged by this?

Answer 25

lunate | median nerve damaged (acute carpal tunnel)

Question 26

What nerve and carpal bone can be injured by falling on an outstretched hand?

Answer 26

hook of hamate | ulnar nerve

Question 27

What is Guyon canal syndrome? Who typically gets this?

Answer 27

compression of ulnar nerve | cyclists- pressure from handlebars

Question 28

What nerve is damaged by carpal tunnel syndrome?

Answer 28

median- paresthesia, pain, numbness along distribution

Question 29

What is damaged by Erb Palsy and what are the functional defecits

Answer 29

upper trunk, C5-C6 roots | abduction, lateral roatation, flexion/supination

Question 30

What is damaged by klumpke palsy? What are functional deficits?

Answer 30

``` lower trunk, C8-T1 roots claw hand (lumbricals, interossei, thenar, hypothenar) ```

Question 31

What muscle and nerve are lesioned with a winged scapula?

Answer 31

long thoracic nerve | serratus anterior

Question 32

What is injured from thoracic outlet syndrome? How does this present?

Answer 32

lower trunk, subclavian vessels | same as Klumpke palsy (+ischemia, pain, edema)

Question 33

Describe the sensory distribution of the median nerve?

Answer 33

palm + distal dorsal of 2nd and 3rd digits

Question 34

Describe the sensory distribution of the radial nerve?

Answer 34

dorsal surface of thumb+ proximal 2nd and 3rd

Question 35

Describe the sensory distribution of the ulnar nerve?

Answer 35

4th and 5th digits

Question 36

What are the muscles of the thenar eminence? What nerve supplies? How would you describe atrophy?

Answer 36

opponens pollicis, abductor pollicis brevis, flexor pollicis brevis median nerve "Ape hand"

Question 37

What are the muscles of the hypothenar eminence? What nerve supplies?

Answer 37

opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis ulnar

Question 38

What do the dorsal interosseus muscles do?

Answer 38

abduct fingers

Question 39

What do the palmar interosseus muscles do?

Answer 39

adduct fingers

Question 40

What do the lumbrical muscles do?

Answer 40

flex at the MCP joint, extend PIP and DIP

Question 41

What nerve is injured by fracture of the surgical neck of the humerus?

Answer 41

Axillary

Question 42

What nerve is injured by midshaft fracture of the humerus?

Answer 42

Radial

Question 43

What nerve is injured by compression of the axilla?

Answer 43

Radial

Question 44

What nerve is injured by supracondylar fracture of the humerus?

Answer 44

Median

Question 45

What nerve is injured by medial epicondyle ("funny bone") fracture of the humerus?

Answer 45

Ulnar

Question 46

What lesion results in a claw with 4th and 5th digits at rest?

Answer 46

distal ulnare nerve | ulnar claw

Question 47

What lesion results in a "pope's blessing" when making a fist?

Answer 47

proximal median nerve lesion

Question 48

What lesion results in claw of 2nd and 3rd digits when at rest?

Answer 48

distal median nerve | median claw

Question 49

What lesion results in an "OK gesture" when making a fist?

Answer 49

proximal ulnar nerve lesion

Question 50

How do proximal vs distal lesions of the median /ulnar nerves present?

Answer 50

Distal lesions- clawing at rest (extend at MCP, flex at DIP and PIP) Proximal lesions- less pronounced, present during voluntary flexion

Question 51

lesion of what nerve results in wrist drop?

Answer 51

radial nerve

Question 52

What does superficial laceration of the palm result in?

Answer 52

laceration of recurrent branch of median | loss of thenar muscle group, no loss of sensation

Question 53

What lesion presents as decreased adduction of the leg?

Answer 53

Oburator (L2-L4)

Question 54

What lesion presenst as decr thigh felxion and leg extension?

Answer 54

Femoral (L2-L4)

Question 55

What lesion presents as foot drop, loss of sensation on dorsum of foot?

Answer 55

Common peroneal (L4-S2)

Question 56

What lesion presents as inabiilty to curl toes and loss of sensation on sole?

Answer 56

Tibial (L4-S3)

Question 57

What lesion presents as loss of hip extension? (difficulty climbing stairs, rising from seated position)

Answer 57

inferior gluteal (L5-S2)

Question 58

What lesion presents as tilt of pelvis when standing on one foot?

Answer 58

Superior gluteal (lesioned on standing foot)

Question 59

What artery supplies the surgical neck of the humerus?

Answer 59

posterior circumflex (axial n)

Question 60

What artery supplies the midshaft of the humerus?

Answer 60

deep brachial (radial n)

Question 61

What nerve and artery are present along the distal humerus?

Answer 61

brachial artery, radial n

Question 62

What nerve and artery are present in the poplitieal fossa?

Answer 62

Popliteal artery, tibial nerve

Question 63

What nerve and artery are present in the posterior to medial malleolus?

Answer 63

posterior tibial arterh, tibial nerve

Question 64

What nerve is commonly injured with knee trauma?

Answer 64

Tibial nerve

Question 65

What nerve is commonly injured by trauma or compression of the lateral aspect of the leg?

Answer 65

common peroneal

Question 66

What nerve is commonly injured by pelvic fracture

Answer 66

femoral nerve

Question 67

What nerve is commonly injured by pelvic surgery?

Answer 67

obturator nerve

Question 68

What nerves are commonly injured by posterior hip dislocation?

Answer 68

superior gluteal and inf gluteal

Question 69

What does Ca2+ bind in muscle?

Answer 69

Troponin C

Question 70

What is the voltage-sensitive receptor of skeletal muscle? What does it attach to?

Answer 70

Dihydropyridine on cell membrane | attached to ryanodine receptor of sarcoplasmic reticulum

Question 71

What is the H zone?

Answer 71

Myosin only, at center | shortens with contraction

Question 72

What is the I band?

Answer 72

Actin only | shortens with contraction

Question 73

What is the A band?

Answer 73

length of myosin, doesnt change

Question 74

What type of metabolism predominates in type 1 vs Type 2 muscle?

Answer 74

Type 1: oxidative phosphyorylation (slow twitch) | Type 2: anaerobic glycolysis (fast twitch- hypertrophy with weight training)

Question 75

What type of muscle has more mitochondria and myoglobin?`

Answer 75

Type 1- slow twitch

Question 76

When doe myosin of smooth muscle contract?

Answer 76

Contracts in phosphorylated form- myosin light-chain kinase active

Question 77

What activates myosin-light-chain kinase?

Answer 77

Ca2+ calmodulin complex (from L-type voltage gated Ca2+ channel opening) results in muscle contraction

Question 78

What activates myosin-light-chain phosphatase?

Answer 78

cGMP (Via NO) | results in muscle relaxation

Question 79

What do osteoblasts and osteoclasts do?

Answer 79

osteoblast: build bone osteoclasts: dissolve bone

Question 80

Describe the origin and appearance of osteoclasts

Answer 80

multinucleate giant cells, secret acid and collagenases | from monocytes/macrophages

Question 81

Describe the origin of osteoblasts? Where are stem cells located?

Answer 81

mesenchymal | periosteum

Question 82

Compare endochondral vs membranous ossification?

Answer 82

Endochondral: cartilagenous model made by chondrocytes, replaced by woven bone, remodeled to lamellar bone membranous: woven bone formed drirectly, remodeled to lamellar bone (calvarium + facial bone(

Question 83

What is the effect of estrogen on bone?

Answer 83

inhibits apoptosis of osteoblasts | induces apoptosis of osteoclasts

Question 84

What are the effects of parathyroid hormone on bone?

Answer 84

Low, intermittent levels- anabolic (build bone) | chronic high levels- catabolic (osteitis fibrosa cystica)

Question 85

What is osteitis fibrosa cystica?

Answer 85

results in chronic high PTH levels