CCAT Canine Anatomy and Biomechanics 3 — Questions and Answers
Question 1: Which structure forms the roof of the vertebral canal and can hypertrophy to cause spinal cord compression in dogs?
- Anulus fibrosus
- Nucleus pulposus
- Ligamentum flavum (Correct answer)
- Anterior longitudinal ligament
Correct answer: Ligamentum flavum
The ligamentum flavum (yellow ligament) connects adjacent vertebral laminae and, when hypertrophied, can narrow the vertebral canal and compress the spinal cord.
Question 2: The popliteal lymph node in dogs is located in which anatomical region?
- Medial aspect of the stifle
- Caudal aspect of the stifle between the biceps femoris and semitendinosus (Correct answer)
- Within the femoral triangle
- Lateral to the patella
Correct answer: Caudal aspect of the stifle between the biceps femoris and semitendinosus
The popliteal lymph node sits in the popliteal fossa on the caudal aspect of the stifle, between the biceps femoris and semitendinosus muscles.
Question 3: During diagonal gait (trot), which limb pair moves simultaneously in dogs?
- Left fore and left hind
- Right fore and right hind
- Left fore and right hind (Correct answer)
- Both forelimbs together
Correct answer: Left fore and right hind
During trotting, a diagonal gait, the left forelimb and right hindlimb move together, followed by the right forelimb and left hindlimb.
Question 4: Which muscle is the primary hip extensor in dogs and is analogous to the human gluteus maximus?
- Gluteus medius
- Biceps femoris (Correct answer)
- Superficial gluteal
- Middle gluteal
Correct answer: Biceps femoris
In dogs, the biceps femoris is the largest and most powerful hip extensor, taking over the role that gluteus maximus plays in bipedal humans.
Question 5: The cranial cruciate ligament in dogs resists which primary forces at the stifle?
- Internal rotation and valgus stress only
- Cranial tibial thrust and internal tibial rotation (Correct answer)
- Caudal tibial displacement and external rotation
- Compression and varus stress
Correct answer: Cranial tibial thrust and internal tibial rotation
The cranial cruciate ligament primarily resists cranial tibial thrust (forward sliding of the tibia relative to the femur) and internal rotation of the tibia.
Question 6: Which joint in the canine forelimb is considered a synovial pivot joint, allowing primarily rotational movement?
- Shoulder (glenohumeral) joint
- Elbow (humeroulnar) joint
- Proximal radioulnar joint (Correct answer)
- Carpal joint
Correct answer: Proximal radioulnar joint
The proximal radioulnar joint is a synovial pivot (trochoid) joint that allows the radius to rotate about its long axis relative to the ulna, enabling supination/pronation.
Question 7: What anatomical feature of the canine patella helps it remain within the trochlear groove during stifle flexion?
- The medial patellar retinaculum only
- The trochlear ridges and the quadriceps muscle tension (Correct answer)
- The infrapatellar fat pad
- The patellar ligament length
Correct answer: The trochlear ridges and the quadriceps muscle tension
The trochlear ridges of the femur guide the patella, and tension in the quadriceps mechanism keeps it seated within the groove throughout the range of motion.
CCAT Canine Anatomy and Biomechanics 3
Which structure forms the roof of the vertebral canal and can hypertrophy to cause spinal cord compression in dogs?