Anatomy & Physiology Flashcards

Which reflex arc is tested when the patellar tendon is tapped in a dog, and which spinal cord segments does it evaluate?

Answer: Patellar (knee-jerk) reflex; L4-L6

The patellar reflex (stifle jerk) tests the femoral nerve and spinal cord segments L4-L6 in dogs.

The triceps brachii muscle in dogs performs which primary action at the elbow?

Answer: Elbow extension

The triceps brachii is the primary extensor of the elbow joint, acting via the olecranon process.

In companion animal anatomy, which structure connects the fibula to the tibia at the level of the tarsus and is important in supporting the hock?

Answer: Calcaneofibular ligament

The calcaneofibular ligament connects the fibula to the calcaneus and is a key lateral stabilizer of the tarsocrural joint.

What is the primary role of the iliopsoas muscle in canine hindlimb biomechanics?

Answer: Hip flexion and external rotation of the femur

The iliopsoas (iliacus + psoas major) flexes the hip and externally rotates the femur, initiating the swing phase of gait.

In the canine spine, which intervertebral disc region is most predisposed to Hansen Type I disc extrusion due to chondroid metaplasia?

Answer: Thoracolumbar T11-L3

The thoracolumbar junction (T11-L3) is most commonly affected by Hansen Type I disc extrusions, especially in chondrodystrophic breeds.

Which type of synovial joint allows the greatest range of motion in multiple planes, as seen in the canine hip joint?

Answer: Ball-and-socket (spheroidal) joint

The ball-and-socket joint, exemplified by the hip (coxofemoral) joint, permits flexion, extension, abduction, adduction, and rotation.

In companion animals, the 'myotatic stretch reflex' is initiated by sensory receptors located where within the muscle?

Answer: Muscle spindles (intrafusal fibers) within the muscle belly

Muscle spindles (intrafusal fibers) detect muscle stretch and initiate the monosynaptic stretch reflex via Ia afferent fibers.