Comparative Muscles/Passive Stay Flashcards
(50 cards)
What are the primary components of the passive stay apparatus in the thoracic limb of horses?
Prox sesamoids, sesamoidean ligaments, suspensory ligament
## Footnote
These structures allow horses to doze while standing with minimal muscular activity.
List the superficial pectoral muscles.
- Descending pectoral
- Transverse pectoral
These muscles are involved in the movement and stabilization of the thoracic limb.
What is the clinical importance of the muscles and structures of the passive stay apparatus?
They relate to the weight bearing and movement of the horse
Understanding these structures is crucial for diagnosing and managing equine lameness.
How do the structures of the passive stay apparatus prevent joint flexion or extension in resting horses?
By supporting weight through tendons and ligaments
This system allows horses to maintain posture without muscular contraction.
What is the role of the serratus ventralis muscle?
It attaches the forelimb to the trunk and assists with shock absorption
This muscle is crucial for the stability of the thoracic limb.
What modifications occur at the shoulder joint in horses?
Thickened bicipital tendon of origin of biceps brachii
This tendon helps resist shoulder flexion.
True or False: The triceps muscle in horses has four heads.
False
The triceps has three heads in ungulates and no accessory head in horses.
Fill in the blank: The __________ of the deep digital flexor passes through the carpal canal.
Deep belly
The deep digital flexor has multiple bellies, with specific roles in joint movement.
What is the function of the lacertus fibrosus?
Transmits force to keep the carpus in position
It connects the biceps brachii to the extensor carpi radialis.
List the components of the suspensory apparatus.
- Suspensory ligament
- Sesamoids
- Sesamoidean l
These components work together to support the fetlock joint.
What prevents flexion of the elbow joint in horses?
Collateral ligaments and passive resistance from tendons
Flexion requires active contraction of the biceps.
What is the average length of sleep for horses?
3 hours
This includes a shorter REM sleep compared to humans.
What anatomical feature helps prevent collapse of the thoracic limb joints?
The passive stay apparatus
This system allows horses to stand and doze without collapsing.
True or False: The distal check ligament is an accessory ligament of the superficial digital flexor.
False
The distal check ligament is an accessory ligament of the deep digital flexor.
What does the term ‘flying scapula’ refer to?
Rupture of the dorsoscapular ligament / serratus ventralis mm
This condition affects the stability and movement of the scapula.
Fill in the blank: The __________ joint is supported by proximal and distal check ligaments.
Carpal
These ligaments are crucial for maintaining joint stability.
What is the average REM sleep duration for horses?
½ hour
This is significantly shorter than that of humans.
List the joints in the thoracic limb.
- Shoulder
- Elbow
- Carpus
- Fetlock
- Pastern
- Coffin
These joints are critical for limb movement and stability.
Which muscle wraps around the shoulder that gives it its roundness in horses; it is a part of the deep pectoral?
Subclavius
Where does the dorsocapular ligament fuse to?
surface of thoracolumbar fascia and to the scapula
How many heads of the deltoideus are there in the horse?
1, the scapular part
How many tricep heads in ungulates?
3, no accessory in equine
What connects the biceps brachial and extensor carpi radialis mm?
Lacertus fibrosis
What is the only flexor of the carpus that is innervated by the radial n?
Ulnaris lateralis
