hooves, footpads, antlers and horns Flashcards
footpads in differnet species
-cushions on which animals walk
-the bulb in ruminants and pigs
-the frog in horses
what is the structure of the footpad
-thick subcutis with adipose tissue, partitioned by collagen and elastic fibres
what anchors the pads to the skeleton
ligaments
structure of the footpads
-hairless
-thickly cornified epithelium (protects the dermis)
-stratum lucidum visible
- eccrine sweat glands (increased grip)
similar components of the nails, claws and hooves
-sole
-wall
-footpad
functions of the hooves, claw and nails
-Protect the distal digit
-Tools for scratching, digging etc
-Defence / hunting
-Blood circulation (e.g. horse)
what is hoof horn made of
highly keratinised epidermis
junction between epidermis and dermis where hoof horn grows
coronet
what anchors nail/ hoof horn/ claw to the dermis
interdigitations of the laminae
do nails, hooves and claws have suncutis
NO
what is the dermis also known as in claws
the quick
what is the subcutis replaced with in claws
periosteum of distal phalanx
what is the subcutis replaced with in claws
periosteum of distal phalanx
what keeps cats claws retracted
dorsal elastic ligamanets
special considerations of horse hooves
-poor venous return
-muscle mass concentrated proximally
-motion restricted protraction and retraction
name of dermis/ quick in horse hooves
corium
what are the 5 parts to hoof dermis
-perioplic
-coronary
-lamellar
-solar
-frog
what is the subcutis called in horse hooves
coronary cushion and digital cushion
3 layers of epidermis in horse hoof
-stratum externum (thin, glossy, produced by perioplic
papillae)
-stratum medium ( partially pigmented, bulk of hoof wall)
-stratum internum (unpigmented, epidermal (horn) laminae)
does hoof epidermis have blood vessels or nerves
no, all comes from diffusion from dermis
travel time for horn from top to bottom
- 9–12 months at toe in adult
- 4 – 6 months at heel
what is the white line made up of
worn end of the epidermal laminae and interlamellar horn from terminal papillae
what does the white line mark the junction between
the sole of the foot and the hard hoof wall
why do horse hooves have poor venous return
no muscles in the hoof
how does venous return happen in the horse hoof
-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
which animals have antlers
cervids (deer)
which animals have ‘true’ horn
bovids eg- cattle, sheep, antelope
similarities between horns and antlers
-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
antlers
-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
horns
-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
disbudding
-horn bud starts out ‘floating’ in integument
-later attaches to frontal bone
-at 6 months, frontal sinus starts extending into horns bony core
