CCAT Canine Anatomy and Biomechanics 2 — Questions and Answers
Question 1: Which carpal bone in dogs articulates directly with the radius to form the antebrachiocarpal joint?
- Accessory carpal bone
- Radial carpal bone (Correct answer)
- Ulnar carpal bone
- Numbered carpal bone I
Correct answer: Radial carpal bone
The radial carpal bone (equivalent to the scapholunar in humans) is the primary bone articulating with the distal radius at the antebrachiocarpal joint.
Question 2: The biceps brachii muscle in dogs primarily originates from which structure?
- Greater tubercle of the humerus
- Supraglenoid tubercle of the scapula (Correct answer)
- Coracoid process of the scapula
- Spine of the scapula
Correct answer: Supraglenoid tubercle of the scapula
The biceps brachii originates from the supraglenoid tubercle of the scapula and travels through the bicipital groove of the humerus.
Question 3: During the stance phase of canine gait, which muscle group is primarily responsible for preventing elbow flexion under load?
- Biceps brachii and brachialis
- Triceps brachii group (Correct answer)
- Supraspinatus and infraspinatus
- Extensor carpi radialis
Correct answer: Triceps brachii group
The triceps brachii group (long, lateral, medial, and accessory heads) resists elbow flexion during weight-bearing stance phase.
Question 4: Which ligament connects the femoral head to the acetabular fossa and is important in hip joint stability?
- Iliofemoral ligament
- Ischiofemoral ligament
- Round ligament (ligament of the femoral head) (Correct answer)
- Pubofemoral ligament
Correct answer: Round ligament (ligament of the femoral head)
The round ligament (ligamentum capitis femoris) runs from the fovea capitis of the femoral head to the acetabular fossa, providing intracapsular hip stability.
Question 5: What is the primary role of the serratus ventralis muscle in canine forelimb biomechanics?
- Extend the shoulder joint
- Suspend the thorax between the forelimbs (Correct answer)
- Protract the forelimb during swing phase
- Rotate the scapula during overhead reach
Correct answer: Suspend the thorax between the forelimbs
The serratus ventralis forms the muscular sling that suspends the thorax between the forelimbs, acting as the primary weight-bearing connection since dogs lack a clavicle.
Question 6: The gastrocnemius muscle in dogs inserts via the common calcaneal tendon onto which structure?
- Plantar fascia
- Tuber calcanei (Correct answer)
- Sustentaculum tali
- Fibular tarsal bone
Correct answer: Tuber calcanei
The common calcaneal tendon (Achilles tendon complex) inserts onto the tuber calcanei (calcaneal tuberosity), providing the lever arm for hock extension.
Question 7: In a dog with a shortened stride length in the hindlimb, which gait parameter is most directly affected?
- Cadence
- Velocity only if both hindlimbs are affected symmetrically
- Step length (Correct answer)
- Support time
Correct answer: Step length
Stride length is the distance from one footfall to the next footfall of the same limb, while step length measures from one footfall to the contralateral footfall; a shortened excursion reduces step length directly.
CCAT Canine Anatomy and Biomechanics 2
Which carpal bone in dogs articulates directly with the radius to form the antebrachiocarpal joint?