OCC Anatomy & Physiology Relevant to Casting 3 — Questions and Answers
Question 1: Which nerve is at risk of injury when the cast padding is applied too tightly over the medial epicondyle of the humerus?
- Ulnar nerve (Correct answer)
- Median nerve
- Radial nerve
- Musculocutaneous nerve
Correct answer: Ulnar nerve
The ulnar nerve passes through the cubital tunnel posterior to the medial epicondyle and is highly susceptible to pressure injury there.
Question 2: In Volkmann's ischemic contracture, which muscle group is primarily affected due to compartment syndrome of the forearm?
- Deep flexors of the forearm (Correct answer)
- Extensors of the forearm
- Intrinsic muscles of the hand
- Supinator muscle
Correct answer: Deep flexors of the forearm
The deep flexor compartment of the forearm has the highest tissue pressure in forearm compartment syndrome, leading to ischemia and fibrosis of the flexor digitorum profundus and flexor pollicis longus.
Question 3: Which bone in the wrist is most commonly fractured and sits between the radius and the capitate?
- Scaphoid (Correct answer)
- Lunate
- Triquetrum
- Trapezium
Correct answer: Scaphoid
The scaphoid is the most commonly fractured carpal bone, articulating proximally with the radius and distally with the capitate.
Question 4: The deltoid ligament of the ankle is located on which side and resists which movement?
- Medial side; resists eversion (Correct answer)
- Lateral side; resists inversion
- Medial side; resists inversion
- Lateral side; resists eversion
Correct answer: Medial side; resists eversion
The deltoid ligament is a strong medial ligament complex that resists excessive eversion of the ankle.
Question 5: Which layer of the skin, composed of dead keratinized cells, acts as the outermost protective barrier and must be protected during cast application?
- Stratum corneum (Correct answer)
- Stratum granulosum
- Stratum spinosum
- Stratum basale
Correct answer: Stratum corneum
The stratum corneum is the outermost, waterproof layer of the epidermis made of dead keratinized cells that protect deeper tissues.
Question 6: In the forearm, the interosseous membrane connects which two bones and assists in load transfer?
- Radius and ulna (Correct answer)
- Radius and humerus
- Ulna and humerus
- Radius and carpals
Correct answer: Radius and ulna
The interosseous membrane spans between the radius and ulna, transmitting forces between the two bones and providing attachment for deep forearm muscles.
Question 7: Which type of bone cell is responsible for resorbing bone during the remodeling phase of fracture healing?
- Osteoclast (Correct answer)
- Osteoblast
- Osteocyte
- Chondrocyte
Correct answer: Osteoclast
Osteoclasts are multinucleated cells that resorb excess callus during bone remodeling, restoring the original bone architecture.
OCC Anatomy & Physiology Relevant to Casting 3
Which nerve is at risk of injury when the cast padding is applied too tightly over the medial epicondyle of the humerus?