Anatomy and Phys Flashcards
(172 cards)
What is the outside of the hoof wall made out of?
Keratin
What are the three general layers of the hoof wall?
Stratum externum
Stratum medium
Stratum internum
What are the more specific layers of the walls if you break the general layers further?
Stratum externum
Pigmented stratum medium
Non pigmented stratum medium
Epidermal laminae
Dermal laminae
Dermis
(T/F) Only the epidermal laminae is the only one that has primary and secondary layers.
False - dermal laminae also contains primary and secondary layers.
What is the epidermal laminae made out of? What about the dermal laminae?
Epidermal - keratin
Dermal - collagen
Where are the basement membranes and basal cells located?
In the secondary layer of the dermal laminae
Which location does the blood end up on to nourish the hoof wall?
Primary dermal laminae
Where are the matrix metalloproteinases located?
Lamellar basal cells
What two enzymes allow the growing hoof wall to move past the stationary distal phalanx?
MMP (Matrix metalloproteinases) and TIMP
Lamellar epidermal cells and adjacent basement membranes are constantly responding to the stress and strains of growth and locomotion by releasing ____ to accomplish whatever cellular reorganization is required.
MMP (Matrix metalloproteinases) and TIMP
What are the two requirements to maintain the bond in the lamellar interface?
Oxygen and glucose
How much does the hoof wall grow in a month?
6-10mm in a month
What are the approximate times of regeneration of the hoof wall (depending on the location of the growth)?
Toe - 12 months
Quarter - 6-8 months
Heel - 4-5 months
What are the factors affecting hoof wall growth?
Genetics, Nutrition, Season (time of year), Conformation, Pathologies, Exercise
What are the two general aspects of hoof shape?
Wider at the ground than the coronet
Sole slightly concave
If a horse foot is more round than bow shaped (at the bottom) is it a hind foot or a front foot?
Front foot
(T/F) The toe is thinner while the heel is thicker so loading can happen and prevent hoof capsule fractures.
False - toe is thicker while heel is thinner
What does it mean that you want to achieve a matched hoof pastern axis?
The dorsal wall of the hoof will match the angle of the bony column of the foot → allows spreading of the load evenly between all structures of the foot
What should the length and angle of the heel be in relation to the dorsal hoof wall in an appropriately trimmed horse hoof?
Angle should match the dorsal hoof wall and the heel would optimally be about ⅓ the length of the dorsal hoof wall
The frog would optimally extend over what percentage of the length of the hoof?
60%
(T/F) A positive palmar angle is optimal, average is usually 3-5 degrees.
T, do not want a flat/negative palmar angle
What is a broken back hoof pastern axis?
When the angle of P2 and P1 are steeper than P3
What structures are overloaded with a broken back HPA and what conditions can that predispose the horse to?
Overloaded → DDFT, navicular bone, P2, and P1; conditions → navicular dz, ring bone, coffin joint inflammation, hoof cracks, and sheared heels
What is the main positive function of a hoof pad?
Recruits the sole and frog in load sharing, others → protect and support, align the hoof pastern axis, protect wounds, act as artificial sole depth, aid with shock dissipation