hoof and claw

Question 1

perinchyium

Answer 1

hoof slipper, protects the uterus and fetal membranes

Question 2

sensitive tissues

Answer 2

bone, hypodermis, dermis (corium) and epidermis

Question 3

insensitive tissue

Answer 3

specialised epidermal concretion - keratin

Question 4

horn production

Answer 4

secreted by papillae around the top of the hoof wall and on the sole - point in direction horn grows
each has a dermis core with and epidermal covering
epidermis not sloughed - compacts into thick layer of keratin

Question 5

solar papillae

Answer 5

produces sole horn

Question 6

coronary papillae

Answer 6

produces most wall horn

Question 7

perioplic papillae

Answer 7

more proximal to coronary, produces superficial shiny layer of wall horn

Question 8

stratum medium

Answer 8

tubular horn made by coronary papillae

Question 9

stratum externum/tectorium

Answer 9

made by perioplic papillae, outer layer

Question 10

stratum internum/lamellum

Answer 10

insensitive laminae, innermost layer

Question 11

horn migration

Answer 11

once made by the papillae, wall horn migrates down foot towards ground sliding down laminae

• secondary sensitive laminae crawl down the primary sensitive laminae
• repeatedly breaking and reforming desmosomes - focal points of intercellular attachment

Question 12

laminae

Answer 12

attach the hoof wall to the underlying sensitive tissues - longitudinal leaves of dermis/epidermis which interleaves with leaves of horn

1. allow the horn yo migrate
2. suspend the weight of then horse from then inner surface of the hoof wall

Question 13

secondary laminae

Answer 13

tiny leaves hanging of the surface of the primary laminae

Question 14

white line

Answer 14

marks where the sensitive/insensitive interface reaches the distal surface - the ground
- allows differential movement of wall and sole due to different growth rates and biomechanical properties

Question 15

heel/frog complex

Answer 15

when horse bears weight heels splay abaxially - stores elastic potential energy
as heels rebound axially they press on unfurl cartilages deep to them

Question 16

ungual cartilages

Answer 16

extensions of P3 palmar processes

Question 17

digital cushion

Answer 17

thickened wedge of hypodermis palmar to P3 full of veins, compression encourages venous return

Question 18

venous return mechanism

Answer 18

foot lifted – heels recoil axially – ungual cartilages compress digital cushion – increases venous return

Question 19

ox differences

Answer 19

1. sole and heel bulb both weight bearing
2. no digital cushion - hypodermis is thin
3. wall thicker abaxially
4. lateral claw bigger than medial claw and bears more weight
5. coronary dermis more extensive
6. no secondary laminae

Question 20

cat claw retraction

Answer 20

P3 retracted passively by axial and abaxial dorsal elastic ligaments

Question 21

cat claw baring

Answer 21

bared actively by pull of DDFT while proximal Interphalangeal joint and metacarpophalangeal joint fixed

Question 22

forelimb pads

Answer 22

5 digital
1 metacarpal - big
1 carpal

Question 23

hindlimb pads

Answer 23

4 digital
1 metatarsal - big
0 tarsal

Question 24

rabbit differences

Answer 24

no pads