Elbow and Wrist anatomy Flashcards Preview

Medicine > Elbow and Wrist anatomy > Flashcards

Flashcards in Elbow and Wrist anatomy Deck (52)
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1
Q

how many degrees of freedom does the elbow have?

A

one

2
Q

where do the flexor muscles originate?

A

medial epicondyle of the humerus

3
Q

where do the extensor muscles originate?

A

lateral epicondyle of the humerus

4
Q

which ligament anchors radius to the ulna?

A

anular ligament

5
Q

what type of joint is the radioulnar jt?

A

pivot (pronation, supination)

6
Q

when is there no contact between humerus and radius?

A

extension

7
Q

what reinforces the elbow capsule?

A

ligaments and tendons of muscles

it is otherwise weak

8
Q

what is normal carrying angle of the arm?

A

cubitus valgus (15 degrees)

9
Q

what are the parts of the medial (ulnar) collateral ligament?

A

anterior (most resistant to valgus force)
oblique
posterior

10
Q

what is the shape of the lateral (radial) collateral ligament?

A

fan shaped

11
Q

which elbow ligament is stronger?

A

ulnar collateral

12
Q

who are major elbow flexors?

A

biceps brachii
brachialis
bracioradialis

13
Q

who are the major elbow extensors?

A

triceps

anconeus

14
Q

where does the short head of the biceps originate?

A

coracoid process

15
Q

how many joints does the biceps affect?

A

2 (shoulder, elbow)

2 joint muscles tend to cause more clinical problems

16
Q

what is the function of the coracobrachialis?

A

primarily a shoulder flexor

17
Q

where does the brachialis insert?

A

coronoid process of the ulna

18
Q

which is the thickest of the flexor muscles?

A

brachialis

19
Q

where is the O/I of the brachioradialis?

A

O: lateral supracondylar ridge
I: radial styloid process

20
Q

when is the brachioradialis NOT active?

A

eccentric contraction

21
Q

when is brachioradialis MOST active?

A

load and forearm is pronated (biceps is best during supination)

22
Q

where does the long head of the triceps originate?

A

infraglenoid tubercle of scapula

23
Q

where do the medial and lateral heads of triceps originate?

A

humerus

24
Q

where do all 3 heads of the triceps insert?

A

olecranon

25
Q

what is the anconeus muscle?

A

small triangle muscle
O: lateral epicondyle to olecranon
assists triceps

26
Q

what lines the inside of the annular ligament?

A

hyaline cartilage

27
Q

which forearm bone takes 80% of the weight bearing?

A

radius

28
Q

what are the ligaments present at the radioulnar joint?

A

annular
quadrate
oblique

29
Q

when is the interosseus ligament tense?

A

when forearm is neutral (its relaxed when fully pronated or supinated)

30
Q

what type of bone is the pisiform?

A

sesamoid bone

31
Q

what type of joints are the midcarpal joints?

A

plane joints with no true capsule

32
Q

which muscles make up the snuff box?

A

extensor pollicus longus

extensor pollicus brevis

33
Q

why are snuff box injuries dangerous?

A

low, low perfusion

34
Q

what are the dorsal radiocarpal ligaments??

A

from radial styloid to the lunate and and triquetrum (contact between lunate and radius)

35
Q

what are the volar radiocarpal ligaments?

A

radiocapitate
radiotriquetral (strongest and supports lunate)
radioscaphoid

36
Q

what are attachments of ulnar collateral ligament of the wrist?

A

from ulna to pisiform and triquetrum

37
Q

what are the attachments of radial collateral ligament of the wrist?

A

from radius to scaphoid, trapezium and 1st MC

38
Q

what are the attachments of the ulnocarpal ligament?

A

triangular fibrocartilage to lunate and capitate

39
Q

which nerve innervates most of the flexor muscles of the forearm?

A

median nerve (except for flexor carpi ulnaris)

40
Q

what action do flexor digitorum superficialis do?

A

movement at PIP joint (not DIP) phalnx 2-5

41
Q

what does flexor digitorum profundus cause?

A

DIP joints of phalnx 2-5

42
Q

what innervates flexor digitorum profundus?

A

ulnar and median nerve

43
Q

what action does flexor pollicis longus do?

A

thumb motion

44
Q

what innervates most of the extensor muscles?

A

radial nerve

45
Q

who is the largest carpal bone and the keystone of the proximal transverse arch?

A

capitate bone

46
Q

what gives MCP joints their stability?

A

ligaments

47
Q

what joint is doing the work for the thumb?

A

CMC joint (that’s the saddle joint) not the MCP

48
Q

what is the functional positional of the hand?

A
claw look (beer grasp)
tenodesis (important for quadroplegics)
49
Q

which nerve innervates the intrinsic hand muscles?

A

ulnar

50
Q

what are lumbricals?

A

intrinsic muscle of the hand that pulls hand into a bucket position

51
Q

what is the role of the interossei muscles?

A

ab/adduct hands

52
Q

which palmar interosseus is responsible for abduction of the hand?

A

dorsal

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