2 Anatomy: Equine Fl

Front 1

major blood vessels

Back 1

major blood vessels:
1. axillary a
2. brachial a
3. median a (continuation of brachial after giving of common interosseus a)

Front 2

median a

Back 2

median a:
- caudally to palmar surface of FL
- gives off 2 small aa: palmar branch of median a and radial a
- continues distally as medial palmar a: main a of manus
- lateral palmar: smaller, descends from deep palmar arch

Front 3

medial palmar a

Back 3

medial palmar a:
- main artery of manus
- continuation of median a
- above fetlock divides into med/lat palmar digital aa

Front 4

med/lat palmar digital aa

Back 4

med/lat palmar digital aa:
- division of medial palmar a starting above fetlock
- courses on abaxial surfaces of the proximal sesamoids
- then courses on borders of DDF tendon, gaining entry to hoof
- give off branches to dorsal surfaces of proximal and middle phalanges

Front 5

pulse of med/lat palmar digital aa

Back 5

pulse of med/lat palmar digital aa:
- can be felt, especially in laminitis

Front 6

arterial circle around phalanx

Back 6

arterial circle around phalanx:
- anastamoses of medial and lateral dorsal branches of the palmar digital aa

Front 7

terminal arch

Back 7

terminal arch:
- anastamoses of proper digital aa after passing through the sole foramina into the sole canal
- branches leave the bone, radiate, break up in the laminar and sole dermis
- several branches go to other structures of the hoof

Front 8

med/ lat palmar metacarpal aa

Back 8

med/lat palmar metacarpal aa:
- from joining and branching of:
1. lat palmar a -and-
2. radial a
- lie close to bones
- join the medial palmar a

Front 9

venous drainage

Back 9

venous drainage:
- med/lat digital vv formed by:
1.dorsal venous plexus
2. palmar and plantar venous plexus
3. coronary venous plexus
- digital v--> palmar vv--> cephalic v

Front 10

med/lateral digital vv

Back 10

med/lateral digital vv:
- formed by 3 interconnected, valveless venous plexuses in the foot:
1.dorsal venous
2. palmar and plantar venous
3. coronary venous

Front 11

dorsal and palmar venous plexuses

Back 11

- both form digital vv:
1. dorsal venous plexus:
- deep in laminar dermis
2. palmar/ plantar venous plexus:
- deep in sole dermis, acial surfaces of the cartilages of distal phalanx

Front 12

coronary venous plexus

Back 12

coronary venous plexus:
- component of digital vv
- coronary cushion, overlying the common (long) DE tendon and abaxial surfaces of the cartilages of the distal phalanx
- anastamoses w/ palmar (plantar) plexus via foramina of the cartilages
- huge capacity

Front 13

nerves of the manus

Back 13

nerves of the manus from:
1. median n
2. ulnar n

Front 14

median n

Back 14

median n:
- main innervation of manus
- divides above carpus into med/lat palmar nn descending limb

Front 15

ulnar n

Back 15

ulnar n:
- generally overlaps the median n
- palmar branch: small contribution to innervation of the manus

Front 16

med palmar n

Back 16

med palmar n:
- descends FL
- between interosseus and DDF tendon
- mid metacarpus: oblique ventrolateral communicating branch to lat palmar n

Front 17

medial palmar digital n

Back 17

med palmar digital n:
- continuation of med palmar n starting just above fetlock
- runs along with digital vessels on abaxial aspect of the prox sesamoid
- dips into hoof

Front 18

lat palmar n

Back 18

lat palmar n:
- with ulnar n: detaches deep branch
- behaves like med after giving off deep branch

Front 19

med/ lat palmar metacarpal nn

Back 19

med/lat palmar metacarpal nn:
- from division of deep branch of lat palmar n in the metacarpal groove
- supplies deeper structures: jts, ligs

Front 20

innervation of distal FL

Back 20

innervation of distal FL:
1. dorsal branch of ulnar n
2. medial cutaneous antebrachial n (branch of musculocutaneous)
3. dorsal branches from med/ lat palmar digital nn

Front 21

med/ lat palmar digital nn

Back 21

med/ lat palmar digital nn:
- give off 1-2 dorsal branches each

Front 22

nerve-blocking

Back 22

nerve-blocking:
start distally and move up
1. perineural anesthesia
2. wait for anesthetic action
3. test effectiveness
4. walk horse
5. observe

Front 23

types of blocks

Back 23

types of blocks:
1. palmar/ plantar digital n
2. ringfield block
3. four-point palmar/ plantar nerve block: important