Lecture 10: Organization of Thoracic Limb and Shoulder Flashcards
shoulder joint =
glenohumeral
which way does forelimb rotate during development
dorsally
which way does the forearm have to rotate during development and why
ventrally = pronate
to bring palmar surface of manus with the ground
3 elements of the pectoral girdle (general)
scapula
coracoid
clavicle
pectoral girdle in reptiles/birds
3 complete bones
pectoral girdle in monotremes/platypus
coracoid is a separate bone
other 2 complete
pectoral girlde in mammals
reduced to coracoid process on scapula
clavicle in most quadrupedal animals
reduced or absent
what does clavicle connect
limb to thorax
what kind of joint is glenohumeral
ball and socket
glenohumeral joint: what inserts into what
head of humerus inserts into glenoid of scapula
3 movements of glenohumeral joint
flexion
extension
rotation
rotation of glenohumeral joint cranially
advances the limb
rotation of glenohumeral joint ventrally
retract limb back
2 directions that glenohumeral joint can rotate
cranially-caudally
dorsally-ventrally
8 extrinsic muscles of the shoulder
trapezius
omotransversarius
rhomboideus
serratus ventralis
brachiocephalicus
pectoralis superficialis
pectoralis profundus
latissimus dorsi
4 intrinsic muscles of shoulder: lateral scapula and shoulder
deltoideus
infraspinatus
teres minor
supraspinatus
3 intrinsic muscles of shoulder: medial scapula and shoulder
subscapularis
teres major
coracobrachialis
2 bellies of deltoideus
scapular
acromial
2 muscles that elevate shoulder
trapezius
rhomboideus
muscle that depresses the shoulder
serratus ventralis
3 muscles that extend shoulder at glenohumeral joint
supraspinatus
triceps
brachiocephalicus
5 muscles that flex the shoulder at glenohumeral joint
deltoideus
teres major
teres minor
latissimus dorsi
pectoralis profundus
muscle that adducts the shoulder at the scapula
rhomboideus
3 muscles that adduct the shoulder at glenohumeral joint
pectoral muscles
subscapularis
coracobrachialis
3 muscles that advance shoulder (glenoid rotates cranially)
trapezius
omotransversarius
brachiocephalicus
3 muscles that retract shoulder (glenoid rotates ventrally)
trapezius
latissimus dorsi
pectoralis profundus
3 muscles that cross glenohumeral joint (rotate scapula AND move arm at GH joint)
brachiocephalicus
latissimus dorsi
pectoralis profundus
movement of pectoralis profundus when limb is advanced and fixed
pull trunk cranially to advance body
2 movements of pectoralis profundus when limb is not supporting weight
draw limb caudally and flex shoulder joint
shoulder suspension mechanism
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
brachial plexus definition
intersection of ventral rami from C6-T2
2 brachial plexus nerves that arise from C6
suprascapular
musculocutaneous
brachial plexus nerve that arises from C7
axillary
brachial plexus nerve that arises from C8
radial
2 brachial plexus nerve that arises from T1
median
ulnar
blood supply to right thoracic limb (general artery)
right subclavian
blood supply to left thoracic limb (general artery)
left subclavian
artery that is continuation of subclavian artery
axillary
axillary artery continues as
brachial
brachial artery continues as
median artery
branch of brachial artery before it continues as median artery
common interosseous
2 branches of median artery
ulnar
radial
3 branches off axillary artery
subscapular
thoracodorsal
lateral thoracic
which vein is clinically accessible
cephalic vein
venous drainage of left thoracic limb
left subclavian –> left brachiocephalic –> cranial vena cava
venous drainage of right thoracic limb
right subclavian –> right brachiocephalic –> cranial vena cava
2 muscles innervated by suprascapular nerve
supraspinatus
infraspinatus
muscle innervated by subscapular nerve
subscapularis
3 muscles innervated by musculocutaenous nerve
brachialis
biceps brachi
coracobrachialis
3 muscles innervated by axillary nerve
deltoideus
teres major
teres minor
omotransversarius, brachiocephalicus and trapezius innervation (2)
accessory spinal nerve = cranial nerve XI
cervical spinal nerve
rhomboideus innervation
dorsal rami of cervical spinal nerves
latissimus dorsi innervation
thoracodorsal nerve
serratus ventralis innervation
long thoracic
pectoralis superficialis innervation
cranial pectoral nerve
pectoralis profundus innervation
caudal pectoral nerve