Lecture 11: Brachium and Elbow

Question 1

3 joints that compose elbow

Answer 1

radiohumeral
ulnohumeral
proximal radioulnar

Question 2

what kind of joint is elbow (3)

Answer 2

synovial = 3 joints within 1 capsule
hinge joint
pivot joint

Question 3

4 ligaments that support elbow joint

Answer 3

lateral collateral
medial collateral
annular ligament of radius
oblique ligament

Question 4

ulno humeral joint between

Answer 4

trochlea of humerus with ulna

Question 5

condyle of humerus: 2 components

Answer 5

trochlea
capitulum

Question 6

articular surface of humerus =

Answer 6

condyle

Question 7

condyle of humerus articulates with what bones: elbow joint

Answer 7

radius
ulna

Question 8

function of lateral collateral ligament: elbow

Answer 8

prevent excessive adduction of radius and ulna relative to humerus

Question 9

function of medial collateral ligament: elbow

Answer 9

prevent excessive abduction of radius and ulna relative to humerus

Question 10

4 movements permitted at elbow

Answer 10

flexion
extension
pronation
supination

Question 11

2 joints of elbow that accomplish flexion/extension

Answer 11

radiohumeral
ulnohumeral

Question 12

function of oblique ligament: elbow

Answer 12

prevent over extension of elbow

Question 13

pronation/supination of elbow: how accomplished

Answer 13

ulna around the radius
requires rotation of humeral head at proximal radioulnar joint

Question 14

can horses pronate/supinate elbow, why or why not

Answer 14

no
radius and ulna are fused

Question 15

annular ligament of radius: definition, function

Answer 15

round ligament that runs from ulna to radius
does not attach to radius
rotates radial head around ulna

Question 16

flexor compartment of elbow: 2 muscles

Answer 16

biceps brachi
brachialis

Question 17

biceps brachii/brachialis: innervation, blood supply, actions

Answer 17

musculocutaneous nerve
brachial artery
flexion of arm and forearm

Question 18

extensor compartment of elbow: 3 muscles

Answer 18

triceps brachi
tensor fasciae antebrachi
anconeus

Question 19

triceps brachi, tensor fascia antebrachi, anconeus: inervation, blood supply, action

Answer 19

radial nerve
deep brachial artery
extend arm and forearm

Question 20

4 heads of triceps brachi

Answer 20

long head
lateral head
medial head
accessory head

Question 21

insertion of all 4 heads of triceps brachi

Answer 21

olecranon process of ulna

Question 22

which head of triceps flexes the glenohumeral joint

Answer 22

long head

Question 23

result of avulsion fracture of elecranon (functional loss if triceps brachii attachment is lost)

Answer 23

no elbow extension
can’t support weight of limb
dropped elbow appearance

Question 24

how many heads is biceps brachi

Answer 24

1

Question 25

biceps brachi: origin, 2 insertions, action

Answer 25

O - supraglenoid tubercle of scapula deep insertion - radial tuberosity and medial ulna superficial insertion - antebrachial fascia around biceps flex forearm, assist with pronation

Question 26

what does biceps brachi do at glenohumeral joint

Answer 26

crosses it

Question 27

brachialis: origin, insertion, action

Answer 27

caudal part of proximal humerus ulnar tuberosity between 2 deep insertions of biceps brachi flex elbow

Question 28

biceps brachi in horses: specialization, benefit at faster gait

Answer 28

internal tendon joints tendons of origin/insertion of biceps brachi internal tendon stores energy when stretched during support phase --> use energy to accelerate forward movement of limb

Question 29

lacertus fibrosus: horses

Answer 29

splits away from internal tendon and emerges on surface palpable taut in standing animal but slackens as joint is flexed

Question 30

what muscles protect the brachial plexus

Answer 30

pectoral serratus ventralis

Question 31

radial nerve innervates what muscles (3)

Answer 31

triceps brachi anconeus tensor fasciae antebrachii

Question 32

path of radial nerve

Answer 32

origin from C7-T1 runs distally with arm caudal to brachial artery dives between long and medial heads of triceps, follows groove of humerus continues into cranial forearm

Question 33

path of musculocutaneous nerve: dogs

Answer 33

origin from C7-C8 proximal branch to coracobrachialis communicating branch to median nerve passes under deep part of biceps (brachialis) divides into 2 branches: distal to brachialis, medial cutaneous nerve of forearm

Question 34

musculocutaneous nerve provides cutaneous innervation from:

Answer 34

skin of antebrachium

Question 35

muscles innervated by musculocutaneous nerve (3)

Answer 35

coracobrachialis biceps brachii brachialis

Question 36

path of musculocutaneous nerve: ungulates

Answer 36

loops around axillary artery to join median nerve branches in brachium to separate from median nerve similar to dog

Question 37

difference of musculocutaneous nerve: horses

Answer 37

cutaneous branch extends beyond carpus to fetlock

Question 38

path of median nerve

Answer 38

origin from C8-T1 down medial surface of arm caudal to axillary enters forearm over medial collateral ligament of elbow joint

Question 39

path of ulnar nerve

Answer 39

origin from C8-T1 runs down brachium beside/united with median nerve splits off at olecranon to cross caudal elbow joint wraps around medial epicondyle of humerus "funny bone"

Question 40

deep brachial artery runs with what nerve

Answer 40

radial

Question 41

last branch of brachial artery

Answer 41

common interosseous artery

Question 42

what artery is the continuation of brachial artery into forelimb

Answer 42

median artery

Question 43

2 branches of median artery

Answer 43

ulnar radial

Question 44

what branches supply palmar foot

Answer 44

metacarpal and carpal arteries

Question 45

cephalic vein joins with what vein

Answer 45

accessory cephalic vein on palmar surface

Question 46

median cubital vein: significance

Answer 46

great place to draw blood connects cephalic and brachial veins

Question 47

what nerves/veins/arteries are found in cubital fossa (6)

Answer 47

brachial artery and vein cephalic vein medial cubital vein median nerve ulnar nerve