31 terms

Forelimb 2

Suspensory Apparatus function / mechanism
limit hyperextension of distal limbs + energy springboard VIA stabilizing palmar side of fetlock and digital joints
suspensory apparatus present in
horse and ox
components of suspensory apparatus
interosseus, prox sesamoids and distal sesamoidian ligaments
interosseus in the ox and horse
dog - muscle on palmar metatcarpals
ox - m w/ tendinous tissue
horse - ligamentous aka suspensory ligament
interosseus attachments
prox metacarpal -> (splits) abaxial prox sesamoids
extensor branch -> CDE
extensor branch of interosseus function
from distal interosseus parts -> CDE to prevent DDF from flexing coffin joint too far
interosseus in the ox
2 fused interossei along axial borders
Proximal sesamoids
@ palmar aspect of fetlock joint
name the distal sesamoidian ligaments
superficial (straight)
middle (oblique)
deep (cruciate)
intersesamoidian ligament
superficial ligament
aka straight
from sesamoids to P1 and P2
middle ligament
aka oblique
from sesamoids -> P1
deep ligament
aka cruciate
from sesamoids -> P1
intersesamoidean ligament
joint proximal sesamoids to each other
*not officially part of suspensory apparatus but important for stability
When is the suspensory apparatus in use?
weight bearing (motion or rest)
components of stay apparatus
1) triceps m
2) dorsoscapular ligament
3) Biceps muscle
4) collateral ligaments
5) palmar carpal ligament
stay apparatus 1st step
triceps muscle gets initiates standing
stay apparatus 2nd step dorsoscapular lig
once standing weight transferred to forelimb via serratus ventralis attachment - strengthened via dorsoscapular lig
stay apparatus 3rd step
prox bicep attachment levered upwards w/ weight on prox scapula -> extends carpal and metacarpal joints.
lacertus fibrosis:
links biceps to extensor carpi radialis
4th step of stay apparatus collateral ligament of elbow
located caudal to axis of rotation -> favors extension
palmar carpal ligaments
cranial pull of lacertus fibrosus -> prevent flexion of carpus. palmar carpal ligament prevents extension
Check ligaments
SDF and DDF tendons - transfers muscles transfer the force of this stretch to bone, protecting the muscle bellies/limiting hyperextension at fetlock
Musculocutaneous termination
medial cutaneous antebrachial - runs dorsally down medial antebrachium to distal metacarpal
radial termination
lateral cutaneous antebrachial - runs medial and terminates at carpus
dorsal hoof nerves
dorsal branch of medial/lateral palmar digital
palmar limb nerves
medial -> median palmar and lateral palmar
Ulnar -> palmar and dorsal branches
nerve blocks
high 4 pt (high palmar)
low 4 pt (low palmar)
abaxial sesamoidean n block
palmar digital nerve block
high 4 point blocks?
lateral and medial palmars (from median)
below carpal
low 4 pt blocks
medial and lateral palmars and palmar metacarpals
buttons as landmarks
abaxial sesamoidean n block
medial n lateral
palmar digital block
lateral and medial palmar