Equine/Ruminant Thoracic Limb Anatomy

antebrachiocarpal joint has the ___ amount of movement

most movement

midcarpal joint has the ____ amount of movement

medium amount of movement

carpometacarpal joint ____ amount of movement

least movement

___ ___ a. supplies the carpometacarpal joint

proximal radial a.

function of synovial tendon sheaths

insulation, folded bursa

tendons that have synovial tendon sheaths

flexor carpi ulnaris, ulnaris lateralis

extensor retinaculum holds ___ tendons in their positions over the dorsal ___/___ so they track straight to ___

dorsal, carpus/metacarpus, insertions

flexor retinaculum holds ___ tendons and their ___ ___ in place at the level of the ___/___ canal, form the ___ tunnel/canal, and help transmit forces while preventing ___ ___

flexor, synovial sheath, fetlock/carpal, palmar, tendon bowing

dorsal extensor group

common digital extensor, lateral digital extensor

palmar flexor group

SDF, DDF, accessory/fibrous components, interosseous apparatus

interosseous suspensory group

interosseous

digital annular ligaments

-encircle the ___ ___ sheath at the ___/___ pastern and hold the ____ tendons in close apposition to the digit

-prevent _____ and maintain tendon alignment during ___-___ and motion

-digital flexor, fetlock/proximal, flexor

-bowstringing, weight-bearing

exaples of digital annular ligaments

Palmar Annular Ligament

Proximal Digital Annular Ligament

Distal Digital Annular Ligament

fetlock joint other name

metacarpophalangeal joint

pastern joint other name

proximal interphalangeal joint

coffin joint other name

distal interphalangeal joint

fetlock/metacarpophalangeal joint

between distal metacarpus (cannon) and proximal phalanx (P1)

pastern/proximal interphalangeal joint

between P1 (proximal phalanx) and P2 (middle phalanx)

coffin/distal interphalangeal joint

between P2 and P4

extensors

common digital extensor, lateral digital extensor

common digital extensor & lateral digital extensor course ___ and insert on the ___ process of P__ and __ surfaces of P_/P_ if appropriate

distally, extensor, 3, dorsal 1, 2

DDF

runs in the ____ canal, passes _____ bone region, and inserts on the ____/____ surface of P3

palmar, navicular, flexor/palmar

SDF inserts primarily on P__

2

suspensory/interosseous splits to insert ___ to the proximal ___ bones and supports the ______ aspect of the fetlock

proximally, sesamoid, proximopalmar

navicular syndrome

degenerative disease that causes inflammation of the bone bursa and DDF

navicular bursitis

inflammation of the navicular bursa due to a penetrating wound

bowed tendons

strain in flexor tendons causing inflammation

path of major blood flow through equine thoracic limb

Axillary a. → Brachial a. → Median a. → Medial palmar a. → Medial & Lateral Digital a. → Arcus Terminalis

principal blood supply to the digit

medial palmar artery

branches of axillary a.

suprascapular, subscapular, cranial circumflex humeral.

suprascapular a. goes towards ___ side

lateral

subscapular a. runs ____ to ___

caudal, scapula

subarteries of subscapular a.

caudal circumflex humeral a., thoracodorsal a.

caudal circumflex humeral a.

wraps around caudal humerus

thoracodorsal a.

goes until latissimus dorsi

cranial circumflex humeral a.

wraps around cranial humerus

what is the last branch of axillary a.

cranial circumflex humeral a.

branches of brachial a.

deep brachial, bicipital, collateral ulnar, transverse cubital, common interosseous

bicepital a. goes directly into ___, can be _1

biceps, >1

t/f: there is only one deep brachial a.

false, there can be multiple

collateral ulnar a. fans ____ surface, continues ___

medial, distally

transverse cubital a. contributes to the ___ ___ ___ and goes to the __ joint

rete carpi dorsale, elbow

rete carpi dorsale

formed by branches of transverse cubital and cranial interosseous a. That gives rise to medial dorsal metacarpal a. and lateral dorsal metacarpal a.

last branch of brachial a.

common interosseous a.

branches of median a.

deep antebrachial a., proximal radial a., median a. (palmar supply), palmar branch of median a. radial a.

deep antebrachial a. supplies ______m. of the antebrachium, can be ___ than one, always __ branch of median artery

caudomedial, more, 1st

what artery is always the first branch of the median artery?

deep antebrachial a.

priximal radial a. supplies

carpal joint

principle blood flow to the digit via:

median a. palmar supply

when does the median a. become median palmar a.?

after it passes through the carpal canal

medial digital a.

dorsal and palmar branches to PI-III

lateral digital a.

dorsal and palmar branches to PI-III

arcs terminalis

solar canal, anastamost here

palmar branch of median a.

courses toward the lateral side of the limb to fuse with Collateral ulnar a.

how can the palmar branch of median a. travel?

lateral palmar a.

lateral palmar a.

courses distally down the side of the limb to fuse with the lateral digital a.

radial a.

arises from the ____ a. at the same level as the ____ branch of the median a. and courses toward the ____ side of the limb

median, palmar, medial

which a. gives rise to the deep palmar arch?

radial a.

veins in the thoracic limb

median cubital, cephalic-brachial v.

origin of brachial plexus

cervical and thoracic spinal nerves of c6,7,8 t1,2

brachial plexus exits the ___ ____ and begins to separate into the individual nerves that innervate the ______ limb

intervertebral foramen, thoracic

major nerves originating from the brachial plexus

Long Thoracic n.

Lateral Thoracic n.

Suprascapular n.

Subscapular n.

Thoracodorsal n.

Axillary n.

Cranial pectoral n.

Caudal pectoral n.

Radial n.

Musculocutaneous n.

Median n.

Ulnar n.

major nerves within the median n.

medial palmar n., lateral palmar n., communicating branch

medial palmar n.

at level of fetlock joint, name change to medial digital n.

medial digital n.

gives rise to dorsal branch of medial digital n. Just distal to fetlock joint

lateral palmar n.

at level of fetlock joint name changes to lateral digital n.

lateral digital n.

gives rise to Dorsal branch of Lateral digital n. Just distal to fetlock joint

major nerves in the ulnar n.

dorsal branch, palmar branch

palmar branch of ulnar n.

fuses with lateral palmar n. from the median n.

origin of cranial cutaneous antebrachial n.

axillary n.

origin of caudal cutaneous antebrachial n.

ulnar n.

origin of medial cutaneous antebrachial n.

musculocutaneous n.

origin of lateral cutaneous antebrachial n.

radial n.

hoof wall location

epidermis

periople location

epidermis

perioplic groove location

epidermis

coronary groove location

epidermis

epidermal laminae location

epidermis

spine of frog location

epidermis

stratum internum location

epidermis

stratum medium location

epidermis

stratum externum location

epidermis

stratum internum appearance

ridges

stratum medium

thickest layer

stratum externum

thin and short layer

perioplic corium location

dermis/corium

coronary corium location

dermis/corium

corium of the wall location

dermis/corium

corium of the bar location

dermis/corium

corium of the frog location

dermis/corium

corium of the sole location

dermis/corium

classifying dermal structures by location

-___ corium

-___ corium

-corium of: ___, ____, ____, ___

-periolic

-coronary

-wall, bar, frog, sole

laminar corium

sheets, walls turn into bars

papillary corium

projections

interlocking mechanism of the foot with the hoof wall

Primary & Secondary Epidermal laminae interlock with Primary & Secondary Dermal laminae

passive stay apparatus

series of tendons in ligaments in both the thoracic and pelvic limb that mechanically lock joints of the limb

what does the passive stay apparatus allow horses to do?

stand for awhile without a lot of exertion

MC II common name

medial splint bone

MC II function

support, ligament attachment

is MC II weight-bearing?

no