Manus

Question 1

equine equivalent to carpal and metacarpal pads

Answer 1

carpal - chestnut
metacarpal - ergot

Question 2

what is the major difference between the bones of digit I in carnivores and the others?

Answer 2

digit I only has two phalanges (distal and proximal, no middle)

Question 3

why does the palmar aspect of the manus/antebrachium receive more blood than the dorsal aspect?

Question 4

functions of the accessory carpal bone?

Answer 4

• diverts pull of flexor carpi ulnaris
• insertion point for extensor carpi ulnaris (ulnaris lateralis) IN UNGULATES
• shock absorption? impact distributed across all carpal bones

Question 5

dorsal sesamoid bones location

Answer 5

in the extensor tendons as they run over the metacarpophalangeal joint

Question 6

what is present between the accessory carpal bone and MC IV and V? what is its function?

Answer 6

• ligamentar/fascial “guy ropes”
• transmit the force of flexor carpi ulnaris distally

Question 7

where is the flexor retinaculum found? what does it look like?

Answer 7

• attaches on the palmar aspect of the medial carpal bones
• creates a triangular space called the carpal canal

Question 8

which tendons pass through the carpal canal?

Answer 8

• superficial digital flexor
• deep digital flexor
• flexor carpi radialis

Question 9

what is deep to the tendons passing through the carpal canal? what is its function?

Answer 9

• palmar carpal ligament
• provides palmar support for the carpal bones

Question 10

what are the interflexorii? where are they found?

Answer 10

• tendinous strips
• arising from DDF on antebrachium
• passes through carpal canal and inserts onto SDF in manus

Question 11

what are lumbricales? where are they found? what is their function?

Answer 11

• tiny fleshy capsular muscles between the dividing tendons of the deep digital flexor
• insert on the capsule of the metacarpophalangeal joint
• tense the metacarpophalangeal joints

Question 12

interosseus muscles

Answer 12

origin: proximally on the palmar surface of MC II-V

route:
- runs distally and splits into two tendons
- each tendon has a sesamoid bone (proximal sesamoid bones)

insertions:
- paired tubercles on the proximal, palmar surface of P1 of digits II-V
- tendinous slips that pass around digits to extensor tendons of the same digits

functions:
- flex metacarpophalangeal joint
- prevent over-extension

Question 13

what do proximal sesamoid bones do?

Answer 13

guide interosseus tendons over metacarpophalangeal joints

Question 14

what muscles/tendons insert on which phalanx? therefore which joint do they primarily act on?

Answer 14

interosseus muscles:
- insert on proximal phalanx
- acts on the metacarpophalangeal joint

SDF:
- inserts on middle phalanx
- acts on proximal interphalangeal joint

DDF:
- inserts on distal phalanx
- acts on distal interphalangeal joint

Question 15

three annular ligaments, where are they found?

Answer 15

• palmar annular ligament - held onto a deep scutum
• proximal annular ligament - binds tendons to P1
• distal annular ligaments - binds tendons to P2