Stay Apparatus

Question 1

What is the function of the stay apparatus?

Answer 1

To lock the middle joints in the limb
- Allows the horse to sleep while standing
- minimizes stress on the leg
(same in the lower part of limbs)

Question 2

What is the stay apparatus?

Answer 2

A collective term referring to specially adapted muscles, tendons, and ligaments that lock the major joints in the limbs of the horse

Question 3

What does the stay apparatus do?

Answer 3

• reduce muscle fatigue and exhaustion while standing
• reduces muscular efforts while the horse is moving during exercise
• lock the major joints in the limbs of the horse

Question 4

The lower part of the stay apparatus is the ___ in both limbs

Answer 4

same

Question 5

The upper portion of the stay apparatus is ___ for both limbs.

Answer 5

different

Question 6

What carries 60% of the horse’s weight?

Answer 6

tendons and ligaments

Question 7

What is the product of the SDF and DDF together?

Answer 7

The check ligament

Question 8

What makes up the suspensory apparatus?

Answer 8

ligaments- primarily suspensory
supporting ligament- distal sesamoid ligament

Question 9

What are the metacarpal bones in the horse?

Answer 9

M2, M3,M 4
*1 and 5 are absent

2 & 4 = splint bones, 3 = cannon bone

Question 10

M4 is known as the:

Answer 10

lateral splint bone

Question 11

M3 is known as the:

Answer 11

Cannon bone

Question 12

M2 is known as the:

Answer 12

medial splint bone

Question 13

P1 is known as:

Answer 13

Long pastern bone

Question 14

P2 is known as:

Answer 14

Short pastern bone

Question 15

P3 is known as:

Answer 15

coffin bone

Question 16

Sesamoid bones are ______. (directionally)

Answer 16

palmer

Question 17

In the horse, are there muscles in the pes or manus?

Answer 17

no

Question 18

What are the 7 (2 pairs) bones in the horse leg below the knee and hock?

Answer 18

• Cannon bone
• 2 splint bones
• 2 sesamoid bones
• long pastern
• short pastern
• navicular bone
• coffin bone

Question 19

What is the joint between the cannon bone and the long pastern bone?

Answer 19

• metacarpal phalangeal joint (forelimb)
• metatarsal phalangeal joint (hindlimb)
• referred to as the fetlock joint

Question 20

What is the joint between the long and short pastern bones?

Answer 20

proximal interphalangeal joint
also called pastern joint

Question 21

What is the joint between the short pastern bone and the coffin bone?

Answer 21

distal interphalangeal joint
also called the coffin joint

Question 22

What is splint disease?

Answer 22

callous growth on the splint bone, encroaching on the region of the ligaments
The medial splint bone is mostly affected

Question 23

What causes splint disease?

Answer 23

• trauma
• damage to the splint bone or the ligament between the splint and cannon bone

Question 24

Splint disease is common in:

Answer 24

younger horses that are used for training

Question 25

Ringbone

Question 26

What replaces the interosseous ligament in horses? (in FL and HL)

Answer 26

the suspensory ligament

Question 27

The suspensory ligament courses the ______ joint.

Answer 27

fetlock joint

Question 28

In the forelimb, the suspensory ligament courses distally on the dorsal surface of P1, to join ____ _____ _______.

Answer 28

common digital extensor

Question 29

In the hindlimb, the suspensory ligament courses distally on the dorsal surface of P1, to join the ______ ____ ______.

Answer 29

long digital extensor

Question 30

When is the interosseous muscle present in horses?

Answer 30

At a young age, but over time it is replaced with fibrous connect tissue (suspensory ligament)

Question 31

Where is the interosseus muscle in the forelimb?

Answer 31

the palmar surface of the 3rd metacarpal *also called the accessory ligament

Question 32

What is the origin of the suspensory ligament?

Answer 32

- caudal proximal surface of the metacarpals - caudal surface of the carpals

Question 33

What is the insertion of the suspensory ligament?

Answer 33

- proximal phalanx - proximal sesamoid bone

Question 34

The distal sesamoid ligaments help:

Answer 34

- suspend ligaments in supporting the fetlock and pastern joints - supports susspensory ligament in locking both joints

Question 35

What ligaments compose the suspensory apparatus?

Answer 35

- suspensory ligament - distal sesamoid ligament

Question 36

Where does the CDE originate?

Answer 36

lateral epicondyle of the humerus

Question 37

Where does the CDE insert?

Answer 37

the extensor process of P3

Question 38

The suspensory ligament helps:

Answer 38

locks fetlock joint and pastern joint

Question 39

What are the 3 sesamoid ligaments?

Answer 39

- 1 straight - 2 oblique

Question 40

The check apparatus/ligaments emerge from the:

Answer 40

DDF and SDF

Question 41

equine tendonitis

Question 42

The distal flexors help with:

Answer 42

- stabilizing the fetlock and pastern joints - limit hyperextension of the joints

Question 43

The check apparatus helps:

Answer 43

attach tendons to bones to prevent extension and flexion of the joints

Question 44

The proximal accessory ligament is located on which limb?

Answer 44

the forelimb

Question 45

Which structures help stabilize the carpals?

Answer 45

- extensor carpi radialis - accessory ligament of SDF and DDF (proximal [FL] and distal) - lacertus fibrosis

Question 46

What is the origin of the SDF?

Answer 46

medial epicondyle

Question 47

What is the insertion of the SDF?

Answer 47

P1 + P2

Question 48

What is the innervation of the SDF?

Answer 48

Ulnar nerve

Question 49

What is the origin of the DDF?

Answer 49

medial epicondyle

Question 50

What is the insertion of the DDF?

Answer 50

flexor surface of P3

Question 51

What is the innervation of the DDF?

Answer 51

Median + Ulnar nerve

Question 52

The check ligaments of the SDF are attached to the _____ surface of the radius and fused with the ______.

Answer 52

caudal; SDF

Question 53

How many heads does the DDF have? What are they?

Answer 53

3 - ulnar head - medial head - radial head

Question 54

What are the origins of each head of the DDF?

Answer 54

- ulnar: medial surface of the olecranon - medial: medial epicondyle - radial: caudal surface of the radius

Question 55

Which muscles support synsarcosis and prevent flexion of the elbow?

Answer 55

- serratus ventralis - rhomboideus - trapezius - brachioradial muscle - latissimus dorsi - pectoralis - omo

Question 56

What muscle stabilizes the elbow joint?

Answer 56

biceps brachii

Question 57

What structures stabilize the stifle joint?

Answer 57

- triceps brachii - medial collateral ligaments - lateral collateral ligaments

Question 58

Upward sliding movement of the patella is _____.

Answer 58

Extension

Question 59

Downward sliding movement of the patella is ______.

Answer 59

flexion

Question 60

Where does the patella sit?

Answer 60

In the deep groove between the medial and lateral trochlear ridge

Question 61

The patellar locking mechanism stabilizes and immobilizes the ____ joint.

Answer 61

stifle

Question 62

How many patellar ligaments are in equine and bovine?

Answer 62

3

Question 63

How many patellar ligaments are in dogs and cats?

Answer 63

1

Question 64

What happens to the patella when the tendon of the quadriceps contracts?

Answer 64

it moves up/ glides upwards

Question 65

What happens to the patella when the patellar ligaments contact?

Answer 65

it is pulled/slid downwards

Question 66

How does the locking mechanism work in the hindlimb?

Answer 66

The quadriceps muscle contracts, pulling the patella upwards. The medial patellar ligament is hooked over the medial trochlea of the femur, and the limb is locked.

Question 67

How does the unlocking mechanism work in the hindlimb?

Answer 67

1. the quadriceps are contracted again, pulling the patella up again 2. the medial patellar ligament is lifted up and moves back to its original place 3. the patella becomes loose and slides down into its usual position

Question 68

What are the parts of the reciprocal mechanism?

Answer 68

- Peroneus Tertius - SDFT + DDF - Gastrocnemius

Question 69

The semitendinosus helps:

Answer 69

unlock the hip joint

Question 70

Why do horses lie down without putting weight on the stifle joint?

Answer 70

The amount of weight would shatter the joint