Lecture 7: Musculoskeletal - Equine hoof (Exam 1) Flashcards
(78 cards)
1
Q
No hoof = ?
A
No horse
2
Q
Define the periople
A
Protective layer to prevent desiccation analogous to a cuticle
3
Q
Label the orange circle
A
Periople
4
Q
Define the wall of the hoof
A
Primary weight bearing structure protection, force dissipation, traction, keratinized, & tubular epidermis
5
Q
What are the three parts of the wall
A
- Toe
- Quarter
- Heel
6
Q
Label the following
A
7
Q
Define the Bars
A
- Extension of the wall
- Provides additional weight bearing surface
- Prevents excessive expansion (buttress)
- Strengthens the palmar aspect
8
Q
Label the teal & pink line
A
- Teal: Bar
- Pink: Wall
9
Q
What does the heel do
A
- Shock absorption
- Distributes of forces
10
Q
Describe the while line
A
- Junction btw/ the solar & laminar epidermis
- Area where nails are driven in on a shod horse
11
Q
What is this
A
The white line
12
Q
Label the following:
A
13
Q
Describe the sole
A
- Protects the bottom of P3
- Bears less weight compared to the wall (bottom of the hoof is concave)
- Provides traction
14
Q
Label the purple area & the black arrow:
A
- Purple: Sole
- Black arrow: Angle of the sole
15
Q
Define the frog
A
- Lies over the digital cushion (peripheral pump)
- Provides traction
16
Q
Label the blue triangle, yellow lines, & orange line
A
- Blue = Frog
- Yellow = Collateral sulci
- Orange = Central sulcus
17
Q
Why is it called the frog
A
Probably reminded the early railroad men of the triangular area where 2 tracks met
18
Q
Define the coronary band
A
Hoof wall (coronary epidermis) Overlying the coronary dermis
19
Q
Label the yellow line
A
Coronary band
20
Q
Describe the coronet
A
Junction btw/ the hoof wall & the skin (epidermis)
21
Q
Label the blue line
A
Coronet
22
Q
Label the following:
A
23
Q
Corium = ?
A
Dermis
24
Q
Hoof epidermis is (Keratinized/unkeratinized)
A
Keratinized
25
List the dermal layers
* Coronary Dermis
* Laminar Dermis
26
Label the following:
27
Describe the coronary dermis
* Supplies keratinized coronary epidermis that forms the tubule & intertubule horn
28
What does the laminar dermis supply
The laminar epidermis
29
Label the epidermal layers
30
What is the mm of hoof growth per month
* 6 to 9 mm
* may be ~ 3 mm in winter
31
Label the following
32
Explain the steps of hoof wall growth
1. Keratinized coronary epidermis formed by basal epidermal cells @ the coronary band (tubular) (purple line)
2. Continuous w/ keratinized laminar epidermis (orange line)
3. Desmosomes detach btw/ epidermal & dermal lamina to let coronary laminar epidermis "ratchet" (move down) (blue arrow)
33
Label the following:
34
Describe sole growth
* Horn tubules orientated vertically
* Growth limited by curling of tubules @ ground
* Slower than wall growth
35
T/F: Horses walk on the third phalanx
F; P3 is suspended in the hoof capsule by the lamina
36
Laminar dermis -blank- & supplies the laminar -blank-
* interdigitates
* Epidermis
37
Label the following:
38
What happens if the suspensory apparatus fails
* Rotating
* Sinking
39
Why does the suspensory apparatus of P3 fail
* Under investigation
* Insuling dysreg
* Endothelial cell & vascular dysfun
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What conditions can cause the suspensory appartus of P3 to fail
* Metabolic syndrom & insulin resistance
* Pars Pituitary Intermedia Dysfunction (PPID or Cushing's)
* Endotoxemia (like colic, retained placenta, colitis)
* Physical demand
43
How do arteries enter the palmar & plantar aspect of P3
Through a foramen
44
Where does venous drainage primarily occur on the palmar & plantar aspect of P3
Along the dorsal border of P3
45
Name the extensive branching of veins found in the hoof
Venous Plexuses
46
Label the following:
47
Describe the palmar venous plexus
* In the sole corium
* Around the toe
* Btw/ the sole & digital cushion
48
48
Where is the dorsal venous plexus
The laminar corium
49
Describe the coronary venous plexus
* At the coronet - in the coronary & perioplic corium
* Drains into the digital veins
* Cuts @ the coronet bleed
50
Label the following:
51
Digital vein?
52
Describe the collateral cartilages
* Attaches to P3
* Structural support for heel bulbs
* Shock absorption (dissipates force through their expansion)
* Involved in blood pumping action of the foot
53
Label the following:
54
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55
What functions as a "pump" in the hoof (or digit 3)
Digital cushion b/c there is no muscle in the digit
56
Explain how the digital cushion functions as a pump
* When the horse bears weight the digital cushion expands & the veins are compressed which causes blood to pool in the venous plexus & digital cushion (diastolic phase)
* When the horse lifts the hoof the digital cushion contracts & the veins open so that blood is forced out (systolic phase)
57
Describe the navicular bone (Distal sesamoidean bone)
* Functions as any other sesamoidean bone
* Acts as a pulley to decreas strain on the DDF tendon as it changes direction to cross the coffin joint & decreases the work of the DDF tendon to act on the P3 (increases the mechanical effect)
58
Label the red line
The navicular bone
59
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72
What parts/how of the hoof are needed for traction
* Frog
* Concave shape of the hoof
* Wall
73
How does the hoof help with support of the skeletal column
* Weight of the horse being transmitted via the lamina to the hoof wall
* Suspends P3
73
What parts/how of the hoof is needed for shock absorption
* Digital cushion
* The ability to expand the hoof @ the heels
74
Whats parts/ how does the hoof protect the inner structures
* Periople protects them from evaporation
* Hoof wall protects the lamina
75
What parts/how does the hoof use for venous return (peripheral pump)
* Frog
* Digital cushion
* Collateral cartilages
76
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