Lecture 10: Organization of Thoracic Limb and Shoulder

Question 1

shoulder joint =

Answer 1

glenohumeral

Question 2

which way does forelimb rotate during development

Answer 2

dorsally

Question 3

which way does the forearm have to rotate during development and why

Answer 3

ventrally = pronate
to bring palmar surface of manus with the ground

Question 4

3 elements of the pectoral girdle (general)

Answer 4

scapula
coracoid
clavicle

Question 5

pectoral girdle in reptiles/birds

Answer 5

3 complete bones

Question 6

pectoral girdle in monotremes/platypus

Answer 6

coracoid is a separate bone
other 2 complete

Question 7

pectoral girlde in mammals

Answer 7

reduced to coracoid process on scapula

Question 8

clavicle in most quadrupedal animals

Answer 8

reduced or absent

Question 9

what does clavicle connect

Answer 9

limb to thorax

Question 10

what kind of joint is glenohumeral

Answer 10

ball and socket

Question 11

glenohumeral joint: what inserts into what

Answer 11

head of humerus inserts into glenoid of scapula

Question 12

3 movements of glenohumeral joint

Answer 12

flexion
extension
rotation

Question 13

rotation of glenohumeral joint cranially

Answer 13

advances the limb

Question 14

rotation of glenohumeral joint ventrally

Answer 14

retract limb back

Question 15

2 directions that glenohumeral joint can rotate

Answer 15

cranially-caudally
dorsally-ventrally

Question 16

8 extrinsic muscles of the shoulder

Answer 16

trapezius
omotransversarius
rhomboideus
serratus ventralis
brachiocephalicus
pectoralis superficialis
pectoralis profundus
latissimus dorsi

Question 17

4 intrinsic muscles of shoulder: lateral scapula and shoulder

Answer 17

deltoideus
infraspinatus
teres minor
supraspinatus

Question 18

3 intrinsic muscles of shoulder: medial scapula and shoulder

Answer 18

subscapularis
teres major
coracobrachialis

Question 19

2 bellies of deltoideus

Answer 19

scapular
acromial

Question 20

2 muscles that elevate shoulder

Answer 20

trapezius
rhomboideus

Question 21

muscle that depresses the shoulder

Answer 21

serratus ventralis

Question 22

3 muscles that extend shoulder at glenohumeral joint

Answer 22

supraspinatus
triceps
brachiocephalicus

Question 23

5 muscles that flex the shoulder at glenohumeral joint

Answer 23

deltoideus
teres major
teres minor
latissimus dorsi
pectoralis profundus

Question 24

muscle that adducts the shoulder at the scapula

Answer 24

rhomboideus

Question 25

3 muscles that adduct the shoulder at glenohumeral joint

Answer 25

pectoral muscles
subscapularis
coracobrachialis

Question 26

3 muscles that advance shoulder (glenoid rotates cranially)

Answer 26

trapezius
omotransversarius
brachiocephalicus

Question 27

3 muscles that retract shoulder (glenoid rotates ventrally)

Answer 27

trapezius
latissimus dorsi
pectoralis profundus

Question 28

3 muscles that cross glenohumeral joint (rotate scapula AND move arm at GH joint)

Answer 28

brachiocephalicus
latissimus dorsi
pectoralis profundus

Question 29

movement of pectoralis profundus when limb is advanced and fixed

Answer 29

pull trunk cranially to advance body

Question 30

2 movements of pectoralis profundus when limb is not supporting weight

Answer 30

draw limb caudally and flex shoulder joint

Question 31

shoulder suspension mechanism

Answer 31

thorax suspended from synscarcosis = muscular sling
serratus ventralis and pectoralis profundus form supportive sling to suspend body between forelimbs when standing
prevent thorax from collapsing by spreading weight from thorax to limbs
girdle muscle stabilizes scapula to prevent unwanted displacement of scapula

Question 32

brachial plexus definition

Answer 32

intersection of ventral rami from C6-T2

Question 33

2 brachial plexus nerves that arise from C6

Answer 33

suprascapular
musculocutaneous

Question 34

brachial plexus nerve that arises from C7

Answer 34

axillary

Question 35

brachial plexus nerve that arises from C8

Answer 35

radial

Question 36

2 brachial plexus nerve that arises from T1

Answer 36

median
ulnar

Question 37

blood supply to right thoracic limb (general artery)

Answer 37

right subclavian

Question 38

blood supply to left thoracic limb (general artery)

Answer 38

left subclavian

Question 39

artery that is continuation of subclavian artery

Answer 39

axillary

Question 40

axillary artery continues as

Answer 40

brachial

Question 41

brachial artery continues as

Answer 41

median artery

Question 42

branch of brachial artery before it continues as median artery

Answer 42

common interosseous

Question 43

2 branches of median artery

Answer 43

ulnar
radial

Question 44

3 branches off axillary artery

Answer 44

subscapular
thoracodorsal
lateral thoracic

Question 45

which vein is clinically accessible

Answer 45

cephalic vein

Question 46

venous drainage of left thoracic limb

Answer 46

left subclavian –> left brachiocephalic –> cranial vena cava

Question 47

venous drainage of right thoracic limb

Answer 47

right subclavian –> right brachiocephalic –> cranial vena cava

Question 48

2 muscles innervated by suprascapular nerve

Answer 48

supraspinatus
infraspinatus

Question 49

muscle innervated by subscapular nerve

Answer 49

subscapularis

Question 50

3 muscles innervated by musculocutaenous nerve

Answer 50

brachialis
biceps brachi
coracobrachialis

Question 51

3 muscles innervated by axillary nerve

Answer 51

deltoideus
teres major
teres minor

Question 52

omotransversarius, brachiocephalicus and trapezius innervation (2)

Answer 52

accessory spinal nerve = cranial nerve XI
cervical spinal nerve

Question 53

rhomboideus innervation

Answer 53

dorsal rami of cervical spinal nerves

Question 54

latissimus dorsi innervation

Answer 54

thoracodorsal nerve

Question 55

serratus ventralis innervation

Answer 55

long thoracic

Question 56

pectoralis superficialis innervation

Answer 56

cranial pectoral nerve

Question 57

pectoralis profundus innervation

Answer 57

caudal pectoral nerve