Blood Vessels (IB) Flashcards
The coronary venous plexus functions to…
Give nutrition to coronet
What’s important about the solear venous plexus?
When horses pick up their feet, there is no pressure on foot at that time. Arteries pulsate (veins do not). So, to bring blood to the leg, they need help. Veins fill with blood when they pick up their feet. Blood is squeezed and expanded and shoots blood upward
When horses are shoed, what happens?
Hoof picked up to trim so the foot is contracted. When the hoof is placed back down on the ground, it is a little tight due to lack of proper blood flow.
What are the external (insensitive) structures of the foot?
Hoof wall
Sole
Frog
White line
The hoof wall originates from the _____ and grows approximately _____ per month, taking 9-12mo months to grow from coronet to _____ and 6 months from coronet to _____.
Coronary band; 6mm; toe’ heel
As the hoof wall grows, the horn of the wall becomes _____.
Harder
The horn of the wall is generally harder and thicker at the _____, more pliable at the _____.
Toe; heel
The hoof wall is _____% water
25%
The perioplic ring secretes a varnish-like horn called _____.
Periople
Periople covers the wall and helps to prevent…
Excessive evaporation of moisture from within
Periople protects
New wall growth
A plate of hard horn, approximately 2 cm. Secreted by papillae from within the sensitive sole. Flakes away in a natural shedding process
Sole
The sole is _____% water
30%
Wedge-shaped mass of elastic horn. Made up of the same horn as the wall but contains more glutinous inter-tubular horn and approximately 40% water.
Frog
The most elastic and pliable structure of external foot
Frog
On the ground surface of the sole, the union between the sole and the wall. Secreted by papillae on the lower edge of the sensitive laminae
White line
What are the internal (sensitive) structures of the foot?
Sensitive frog
Sensitive sole
Digital cushion
Laminae
Closely associated with the digital cushion, upon which it is molded.
Sensitive frog
It is covered with papillae that secrete horny frog.
Composed of a dense network of blood vessels and papillae. Firmly attached to the palmar surface of the coffin bone
Sensitive sole
It secretes the horny sole and supplies nutrition for it.
Wedge-shaped fibro-elastic pad that fills the hollow behind the heels
Digital cushion
The digital cushion is _____ but yielding consistency.
Firm
The digital cushion lies beneath the _____ and _____, filling the space between the heels of the hoof
Sensitive frog and horny frog
The digital cushion forms _____
The bulbs of the heels
The digital cushion adheres to the _____ and diminishes _____.
Adheres to deep digital flexor tendon
Diminishes concussion
_____ pressure compresses the digital cushion. This causes expansion of the _____
Frog pressure
Collateral cartilages
The digital cushion aids the circulation of _____ within the foot and helps reduce _____
Blood; concussion
The blood in the hoof contributes to the _____ effect by spreading….
Shock-absorbing effect by spreading pressure in a hydraulic manner
What is the purpose of laminae?
To increase surface area of the foot to allow the horse to stand all day long
The hoof is attached to the coffin bone by means of hundreds of?
Leaf-like structures known as laminae
Sensitive laminae are fleshy leaves attached to the _____ of the coffin bone.
Periosteum
Flat plates of horn that grow on the interior surface of the hoof wall and interlock with sensitive laminae
Horny or secondary laminae
The laminae helps distribute _____ of the horse more evenly, to ease the stress on the _____
Weight; coffin bone
What are the 5 different germinative areas that produce horn?
- Perioplic ring
- Coronary corium
- Sensitive laminae
- Sensitive sole
- Sensitive frog
The _____ produces the periople
Perioplic ring
The _____ produces the stratum medium and stratum internum
Coronary corium
Stratum medium
Hoof wall
Stratum internum
Horny laminae
The distal ends of the sensitive laminae produce the _____
White line
The _____ secretes the horny sole
Sensitive sole
The _____ secretes the horny frog
Sensitive frog
As the foot touches the ground, the weight is transmitted via the _____ to the bearing surfaces of the _____ and _____.
Bones to surfaces of hoof and frog
The _____ touches the ground first.
Heel
_____ structures are strategically located at the rear of the foot
Anti-concussion
Pressure on the frog exerts pressure on the _____, which forces the lateral cartilages apart, against the _____
Pressure on the digital cushion; horny wall
When cartilages are forced apart, this flattens and empties the _____, causing the _____
Blood vessels; heels to expand
When the foot is lifted off the ground, relieving the pressure, the _____ relaxes and the _____ will refill.
Digital cushion relaxes, blood vessels refill
