Vet Anatomy 2 Quiz 2

what nerve innervates trapezius, omotransversarius, and brachiocephalicus

accessory n & cervical spinal n

what nerve innervates rhomboideus

dorsal rami cerival spinal n

what nerve innervates latissimus dorsi

thoracodorsal n.

what nerve innervates serratus ventralis

long thoracic n

what nerve innervates pectoralis superficialis

cranial pectoral n

what nerve innervates pectoralis profundus

caudal pectoral n

what nerve innervates deltoid, teres major, teres minor

axillary n

what nerve innervates infraspinatus and supraspinatus

suprascapular n

what nerve innervates subscapularis

subscapular n

what nerve innervates coracobrachialis

musculocutaneous n

what muscles elevate the scapula

trapezius and rhomboid

what muscles depress the scapula

serratus ventralis

what muscles advance/move forward/move glenoid cranially (of scapula)

trapzeius, brachiocephalicus, omotransversarius

what muscles retract/move back/ move glenoid caudally (of scapula)

trapezius, latissimus dorsi, pectoralis profundus

what muscles extend the glenohumeral joint

supraspinatus and brachiocephalicus

what muscles flex the glenohumeral joint

deltoid, teres minor, teres major, latissimus dorsi, pectoralis profundus, long head of triceps brachii

what muscles ABduct the glenohumeral joint

infraspinatus

what muscles ADduct the glenohumeral joint

pectoralis profundus, pectoralis superficialis, subscapularis, coracobrachialis

what nerve innervates yellow area on forelimb

ulnar nerve

what nerve innervates green area on forelimb

radial nerve

what nerve innervates orange area on forelimb

musculocutaneous

what nerve innervates teal area on chest

brachiocephalic nerve

what nerve innervates blue area on chest

C5 ventral cutaneous branch

what nerve innervates purple area on chest

axillary nerve

what nerve innervates pink area (next to purple) on chest

T2 lateral cutaneous branch

what nerve innervates light orange (cranial one along dorsal spine)

C5 dorsal cutaneous branches

what nerve innervates dark orange (next to light orange, along dorsal spine)

C6 dorsal cutaneous branches

what nerve innervates brown area

T2 dorsal cutaneous branches

what nerve innervates salmon area (along dorsal spine)

T3 dorsal cutaneous branches

parts of pectoral girdle

clavicle, coracoid, scapula

how is the forelimb connected

via fibromuscular attachments

above red arrow

subclavian artery

red arrow

axillary a

pink arrow

brachial a

yellow arrow

common interosseous a

light blue arrow

median a.

green arrow

ulnar a.

dark blue arrow

radial a.

black arrow

metacarpal & carpal arteries

what are the 3 branches of the axillary artery

long thoracic, thoracodorsal, and subscapular arteries

what is the branch of the brachial artery

deep brachial a

where does the suprascapular artery come from

directly off subclavian artery

external jugular vein →

omobrachial v. → axillobrachial v. → cephalic v.

flexors of arm muscles (also flex forearm)

biceps brachii & brachilais

extensors of arm muscles (also extend forearm)

all heads of triceps brachii, tensor fascia antebrachii, anconeus

innervation of flexor of arm muscles

musculocutaneous n.

innervation of extensors of arm muscles

radial n.

where do all the heads of triceps brachii muscle insert

olecranon of ulna

what happens when there is problems/damage to olecranon of ulna “alvusion fracture”

dropped elbow apperance, loss of elbow extension, inability to support weight of limb; radial n issue; loss of triceps brachii

why can biceps brachii affect both the radius and ulna at the same time

bc it has 2 insertions, one deep one superficial

brachial v and cephalic v come together via

median cubital vein

what is within the cubital fossa

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

dorsal collateral lig in wrist of dogs

short; connect neighboring bones

medial/lateral collateral ligs in wrist of dogs

prevent excessive AB/Dduction

deep palmar lig in wrist of dogs

covers entire skeletal surface, hides unevenness of bones so they dont impact the limb

superficial transverse lig in wrist of dogs

“flexor retinacula”; encloses carpal tunnel

distal ligs of accessory bone in wrist of dogs

helps prevent overextension while not affecting flexion

craniolateral muscles of antebrachium

supinator, brachioradialis, extensor carpi radialis, common digitial extensor, lateral digital extensor, ulnaris lateralis, abductor digiti 1 longus, extensor digiti 1 and 2

innervation of craniolateral muscles of antebrachium

radial n

function of craniolateral muscles of antebrachium

extensors and supinators

exceptions to craniolateral muscles of antebrachium

ulnaris lateralis acts as a flexor

origin of craniolateral muscles of antebrachium

lateral epicondlye of humerus

caudal muscles of antebrachium

pronator teres, pronator quadratus (very deep), flexor carpi radialis, flexor carpi ulnaris, superficial digital flexor, deep digitial flexor

innervation of caudal muscles of antebrachium

median nerve

function of caudal muscles of antebrachium

flexion and pronation

origin of caudal muscles of antebrachium

medial epicondyle of humerus

exceptions to caudal muscles of antebrachium

flexor carpi ulnaris is innervated by ulnar n

deep digital flexor is innervated by median & ulnar n

cranial to caudal lateral antebrachium muscles

extensor carpi radialis → common digital extensor → lateral digital extensor → ulnaris lateralis → flexor carpi ulnaris

cranial to caudal medial antebrachium muscles

extensor carpi radialis→ pronator teres → flexor carpi radialis → superficial digital flexor → deep digital flexor (2 heads, below sdf) → flexor carpi ulnaris (2 heads)

muscles of the manus

4 interosseous muscles

what innervates the 4 interosseous manus muscles

ulnar n. primarily, also median n.

gait disorder: infraspinatus contracture

degeneration and atrophy of infraspinatus muscle fibers; unable to rotate the shoulder internally therefore circumducts limb when walking

gait disorder: coxofemoral luxation

results of extreme trauma (hbc) or extreme ABduction of hip joint; limb appears shorter from behind; thigh adducted, stifle rotated outward, tarsus rotated inward

gait disorder: medial patellar luxation

bow legged stance; external rotation of hip; often asymptomatic

gait disorder: calcaneal tendon rupture

often traumatic; initially nonweight bearing lameness; stifle extends and tarsocrural join hyperflexes

gait disorder: CCL rupture

most common ortho sx; usually nonweight bearing in rear limb; can be partial weight bearing (toe touching)

gait disorder: “sweeney” or suprascapular nerve injury

suprascapular nerve damage via high speed collision or neck injury; muscle atrophy of supra or infraspinatus renders joint unstable; prominent scapular spine; characteristic shoulder roll during weight bearing

gait disorder: radial nerve injury

result of being in lateral recumbency for prolonged periods of time (ex- during anesthesia); only motor damage; 1/2 -1 hr of ischemia can cause conduction failure; 3 hrs of ischemia can cause permanent damage

gait disorder: femoral nerve paralysis

ischemic injury; compression of nerve roots from birth canal or by prolonged rough pulling of hind limbs or prolonged stretch/increased tissue pressure during anesthesia in dorsal recumbency

gait disorder: stringhalt

involuntary & exaggerated flexion or one or both hind limbs; limb is jerked forwards toward abdomen

conventional: in US, unknown etiology, rare, lateral digital extensor myotenectomy sx performed

outbreak: in Australia, etiology from dandelions, more freq, can also affect left recurrent laryngeal nerve

gait disorder: fibrotic myopathy

mechanical gait created when semitendonosus muscle has been injured and heals with a dense scar; fibrotic scar tissue restricts the normal elastic properties of muscle and limit the forward motion of limb; a slapping of foot to ground is evident

gait disorder: perneous tertius rupture

result of overextension of tarsus with normal flexed stifle; reciprocal apparatus of hind limb no longer functional (flex/flex)

gait disorder: upward fixation of patella

patella lock mechanism is stuck; can develop bc of poor quadricep development; evident gait abnormality; leg locks in extension and is dragged behind

what are the muscles involved in the synsarcosis (shoulder suspension mechanism)

serratus ventralis and deep pectoral muscle primarily

superficial venous drainage

cephalic vein → axillobrachial vein → omobrachial vein → external jug → brachiocephalic vein → cranial vena cava

what do horses have on their biceps brachii that dogs dont

internal tendon

function of internal tendon of biceps brachii

stores kinetic energy to allow a quick “snap” of flexion during a fast gait

what does the internal tendon have

lacertus fibrosus

function of lacertus fibrosis

a thickened band that blends and extends to wrist on ECR

what head of triceps brachii acts on both GH and elbow joints

long head

brachialis inserts on

ulnar tuberosity

joint #3?

antebrachiocarpal joint

joint #19?

distal radioulnar joint

joint #6?

midcarpal joint

joint #12?

carpo-metacarpol joint

what is a ginglymus

a hinge with some lateral movement: at the joints of the wrist

high rise injuries

wrist ligaments cannot handle force of landing from a high surface; bc elbow is outwardly angled it creates a valgus angle; force can cause lateral condylar fractures, tendons passing through carpal tunnel cannot function normally

what muscles do horses have instead of abductor digiti 1 longus since they do not have a first digit

extensor carpi obliquis

traveling companions of forearm: brachial a. +

median n

traveling companions of forearm:

common interosseous a. +

median n