Lecture 12: Antebrachium and Carpus Flashcards
carpus vs manus
carpus = bones of wrist
manus = metacarpals and phalanges
why do many muscles of forearm move carpus and manus
cross wrist and insert on phalanges
3 bones of antebrachium
radius
ulna
carpals
5 joints of antebrachium
elbow
carpal
carpo metacarpal
metacarpophalangeal
interphalangeal
why is radius palpable through skin
medial aspect of antebrachium not covered by any msucles
what part of radius and ulna contribute to the wrist
distal epiphysis
what is special about equine ulna/radius
distal ulna fused to distal radius
cows often lack which carpal
1
proximal row of carpal bones from most medial to lateral
radial
intermediate
ulnar
accessory
what do radial and intermediate carpal bones do in dogs
fuse
what makes accessory carpal bone special
palpable
looks like an appendage
distal row of carpal bones from most medial to lateral
1, 2, 3, 4, 5
5th carpal bone: specialization
never separate
usually suppressed or fused with 4th carpal bone
2nd and 3rd carpal bones: ruminants
fused
carpal bones in cows
1st absent
2nd and 3rd fused
joints of the wrist: 5
distal radioulnar
antebrachiocarpal
midcarpal
carpometacarpal
intercarpal
which joints share a joint capsule: 2 capsules, 4 joints
distal radioulnar + antebrachiocarpal
midcarpal + carpometacarpal
ginglymus definition
hinge with some lateral movement
what kind of joint is wrist
ginglymus/hinge
which wrist joint is very mobile
antebrachiocarpal
which wrist joint allows some adduction/abduction
carpometacarpal
carpometacarpal joint in ruminants
no movement
function of medial and collateral ligaments of wrist
connect arm forearm to carpus
3 ligaments in palmar carpus
deep palmar
superficial, transverse
distal ligaments of accessory bone
deep palmar ligament
cover entire palmar surface of skeleton
hides unevenness of bones
superficial transverse ligament aka
flexor retinaculum
superficial transverse ligament
completes enclosure of carpal canal
conveys flexor tendons from antebrachium
distal ligaments of accessory bone
joins accessory bone to adjacent carpal and metacarpals
prevents overextension but doesn’t interfere with flexion
high rise injuries: cause, result
permanently pronated antebrachium causes valgus = outwardly angled elbow joint
too much load on capitulum = lateral condyle fracture
hyperextension of carpus = torn ligaments
muscles that are developmentally dorsal end up
caudal in brachium
cranial in antebrachium
muscles that are developmentally ventral end up
cranial in brachium
caudal in antebrachium
compartments that radial nerve innervates
caudal and lateral arm
cranial and medial forearm
craniolateral compartment of antebrachium: 8 muscles
brachioradialis
extensor carpi radialis
extensor digitorum communis
extensor digitorum lateralis
ulnar lateralis = extensor carpi ulnaris
abductor digiti I longus
extensor digiti I and II
supinator
craniolateral compartment of antebrachium: ONA
O - lateral epicondyle of humerus
N - radial nerve
A - extension and supination
caudal compartment of antebrachium: 6 muscles
pronator teres
pronator quadratus
flexor carpi radialis
flexor carpi ulnaris
flexor digitorum superficialis
flexor digitorum profundus
caudal compartment: ONA
O- medial epicondyle of humerus
median nerve
flexion and pronation
flexor carpi radialis: innervation exception
ulnar nerve
flexor digitorum profundus: innervation difference
median and ulnar nerves
function of retinacula
pulleys to distribute muscle forces
direct where force goes
make tendon stay close to bone
2 retinacula in manus/carpus
flexor retinaculum
extensor retinaculum
abductor digiti I longus called what in horses (and why)
extensor carpi obliquus
no 1st digit
extensor carpi obliquus: definition, insertion
abductor digit I longus of dog
inserts on medial split bone
muscles innervated by radial nerve (general)
carpal and digital extensors
ulnaris lateralis
muscles innervated by median nerve (general)
flexor muscles of carpus and digit
path of median nerve in forearm
down medial surface of arm caudal to axillary and brachial
enters forearm over medial collateral ligament of elbow
passes deep to flexor carpi radialis and remains deep until reaching the carpus
muscles innervated by ulnar nerve (2)
flexor carpi ulnaris
part of flexor digitorum profundus
path of ulnar nerve in forearm
down brachium beside/united with median nerve
splits off by olecranon to cross caudal elbow
branches
narrows as it continues
divides close to accessory carpal bone
brachial artery travels with what nerve
median
ulnar artery travels with what nerve
ulnar nerve
radial artery travels with what nerve
radial
most popular vein choice for IV injections
cephalic vein
cephalic vein: definition, features, location
follows cranial forearm
lies on extensor carpi radialis
palpable when raised
connected to deep veins at elbow via median cubital vein
where should you compress cephalic for IV injections
distal to anastamosis (between cephalic and median cubital veins)
carpal tunnel
tendons of digital flexors and median nerve
deep to flexor retinaculum
constrained by carpal bones
which nerve is compressed with carpal tunnel syndrome
median nerve
