hooves, footpads, antlers and horns

Question 1

footpads in differnet species

Answer 1

-cushions on which animals walk
-the bulb in ruminants and pigs
-the frog in horses

Question 2

what is the structure of the footpad

Answer 2

-thick subcutis with adipose tissue, partitioned by collagen and elastic fibres

Question 3

what anchors the pads to the skeleton

Answer 3

ligaments

Question 4

structure of the footpads

Answer 4

-hairless
-thickly cornified epithelium (protects the dermis)
-stratum lucidum visible
- eccrine sweat glands (increased grip)

Question 5

similar components of the nails, claws and hooves

Answer 5

-sole
-wall
-footpad

Question 6

functions of the hooves, claw and nails

Answer 6

-Protect the distal digit
-Tools for scratching, digging etc
-Defence / hunting
-Blood circulation (e.g. horse)

Question 7

what is hoof horn made of

Answer 7

highly keratinised epidermis

Question 8

junction between epidermis and dermis where hoof horn grows

Answer 8

coronet

Question 9

what anchors nail/ hoof horn/ claw to the dermis

Answer 9

interdigitations of the laminae

Question 10

do nails, hooves and claws have suncutis

Answer 10

NO

Question 11

what is the dermis also known as in claws

Answer 11

the quick

Question 12

what is the subcutis replaced with in claws

Answer 12

periosteum of distal phalanx

Question 13

what is the subcutis replaced with in claws

Answer 13

periosteum of distal phalanx

Question 14

what keeps cats claws retracted

Answer 14

dorsal elastic ligamanets

Question 15

special considerations of horse hooves

Answer 15

-poor venous return
-muscle mass concentrated proximally
-motion restricted protraction and retraction

Question 16

name of dermis/ quick in horse hooves

Answer 16

corium

Question 17

what are the 5 parts to hoof dermis

Answer 17

-perioplic
-coronary
-lamellar
-solar
-frog

Question 18

what is the subcutis called in horse hooves

Answer 18

coronary cushion and digital cushion

Question 19

3 layers of epidermis in horse hoof

Answer 19

-stratum externum (thin, glossy, produced by perioplic
papillae)
-stratum medium ( partially pigmented, bulk of hoof wall)
-stratum internum (unpigmented, epidermal (horn) laminae)

Question 20

does hoof epidermis have blood vessels or nerves

Answer 20

no, all comes from diffusion from dermis

Question 21

travel time for horn from top to bottom

Answer 21

• 9–12 months at toe in adult
• 4 – 6 months at heel

Question 22

what is the white line made up of

Answer 22

worn end of the epidermal laminae and interlamellar horn from terminal papillae

Question 23

what does the white line mark the junction between

Answer 23

the sole of the foot and the hard hoof wall

Question 24

why do horse hooves have poor venous return

Answer 24

no muscles in the hoof

Question 25

how does venous return happen in the horse hoof

Answer 25

-compression of the frog pushes the digital cushion outwards and squashes the hoof cartilage
-venous plexuses in the cartilages are squashed, squeezing blood out into the digital veins

Question 26

which animals have antlers

Answer 26

cervids (deer)

Question 27

which animals have ‘true’ horn

Answer 27

bovids eg- cattle, sheep, antelope

Question 28

similarities between horns and antlers

Answer 28

-initially formed from bony core covered by integument
-located on the frontal bone
-paired and usually symmetrical
-present or larger in males
-used as weapons or social signals

Question 29

antlers

Answer 29

-grow from attachment on the skull (pedicle)
-when growing they are covered in well vascularised skin (“in velvet”)
-when finished growing, blood supply to the skin cuts off and velvet is shed
-mature antler is exposed living bone
-they are shed (cast) and regrown every year

Question 30

horns

Answer 30

-horn bud starts in the subcutis and later fuses to the skull
-have keratin sheath covering a bony core
-not branched
-never shed
-grow with age

Question 31

disbudding

Answer 31

-horn bud starts out ‘floating’ in integument
-later attaches to frontal bone
-at 6 months, frontal sinus starts extending into horns bony core