Equine Anatomy & Physiology Flashcards

Which ligament runs along the dorsal aspect of the equine spine and plays a key role in the 'bow and string' mechanism?

Answer: Nuchal ligament

The nuchal ligament forms the 'string' of the bow-and-string mechanism, storing elastic energy during locomotion to support the head and neck.

The cervical vertebrae of the horse number how many, and which is the most mobile segment?

Answer: 7 vertebrae; C2-C3

Horses have 7 cervical vertebrae, and the C2-C3 (axis-third cervical) junction exhibits the greatest range of lateral flexion.

What is the primary function of the interosseous muscle (suspensory ligament) in the equine distal limb?

Answer: Passively support the fetlock against hyperextension

The suspensory ligament is a largely fibrous structure that passively suspends the fetlock, preventing hyperextension under weight-bearing.

Which thoracic vertebrae in the horse are known as the 'anticlinal vertebrae' and what is their significance?

Answer: T14-T16, where spinous processes change direction

The anticlinal vertebrae (typically T14-T16) are where spinous processes transition from caudally inclined to vertically or cranially inclined, marking a biomechanical transition zone.

The equine atlantoaxial joint primarily permits which type of movement?

Answer: Axial rotation

The atlantoaxial joint (C1-C2) is a pivot joint that primarily allows axial rotation of the head and atlas around the dens of the axis.

Which muscle group is primarily responsible for dorsiflexion (extension) of the equine thoracolumbar spine?

Answer: Longissimus dorsi and multifidus

The longissimus dorsi and multifidus muscles run along the dorsal spine and contract to extend (dorsiflex) the thoracolumbar region.

How many lumbar vertebrae does the horse typically have, and how does this compare to cattle?

Answer: 5 lumbar vertebrae; cattle have 6

Horses typically have 5 (sometimes 6) lumbar vertebrae, whereas cattle typically have 6, reflecting differences in lumbosacral conformation.