CCAT Anatomy & Physiology 4 — Questions and Answers
Question 1: Which reflex arc is tested when the patellar tendon is tapped in a dog, and which spinal cord segments does it evaluate?
- Flexor reflex; L1-L3
- Patellar (knee-jerk) reflex; L4-L6 (Correct answer)
- Gastrocnemius reflex; L7-S1
- Cranial tibial reflex; L6-L7
Correct answer: Patellar (knee-jerk) reflex; L4-L6
The patellar reflex (stifle jerk) tests the femoral nerve and spinal cord segments L4-L6 in dogs.
Question 2: The triceps brachii muscle in dogs performs which primary action at the elbow?
- Elbow flexion
- Elbow extension (Correct answer)
- Supination of the antebrachium
- Pronation of the antebrachium
Correct answer: Elbow extension
The triceps brachii is the primary extensor of the elbow joint, acting via the olecranon process.
Question 3: 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?
- Lateral collateral ligament
- Long plantar ligament
- Short plantar ligament
- Calcaneofibular ligament (Correct answer)
Correct answer: Calcaneofibular ligament
The calcaneofibular ligament connects the fibula to the calcaneus and is a key lateral stabilizer of the tarsocrural joint.
Question 4: What is the primary role of the iliopsoas muscle in canine hindlimb biomechanics?
- Hip extension and stifle flexion
- Hip flexion and external rotation of the femur (Correct answer)
- Hip abduction and internal rotation
- Stifle extension and hip stabilization
Correct 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.
Question 5: In the canine spine, which intervertebral disc region is most predisposed to Hansen Type I disc extrusion due to chondroid metaplasia?
- Cervical C1-C2
- Thoracolumbar T11-L3 (Correct answer)
- Lumbosacral L7-S1
- Mid-thoracic T5-T8
Correct answer: Thoracolumbar T11-L3
The thoracolumbar junction (T11-L3) is most commonly affected by Hansen Type I disc extrusions, especially in chondrodystrophic breeds.
Question 6: Which type of synovial joint allows the greatest range of motion in multiple planes, as seen in the canine hip joint?
- Hinge (ginglymus) joint
- Pivot (trochoid) joint
- Ball-and-socket (spheroidal) joint (Correct answer)
- Condylar joint
Correct answer: Ball-and-socket (spheroidal) joint
The ball-and-socket joint, exemplified by the hip (coxofemoral) joint, permits flexion, extension, abduction, adduction, and rotation.
Question 7: In companion animals, the 'myotatic stretch reflex' is initiated by sensory receptors located where within the muscle?
- Golgi tendon organs at the musculotendinous junction
- Muscle spindles (intrafusal fibers) within the muscle belly (Correct answer)
- Free nerve endings in the epimysium
- Pacinian corpuscles in the peritenon
Correct 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.
CCAT Anatomy & Physiology 4
Which reflex arc is tested when the patellar tendon is tapped in a dog, and which spinal cord segments does it evaluate?