OCC Anatomy & Physiology Relevant to Casting 1 — Questions and Answers
Question 1: Which bone is most commonly fractured in the forearm?
- Ulna
- Humerus
- Radius (Correct answer)
- Scapula
Correct answer: Radius
The radius is the most commonly fractured bone in the forearm, particularly at its distal end, often resulting from falls onto an outstretched hand (Colles' fracture). Its anatomical position and role in wrist articulation make it highly susceptible to injury. While the ulna can also be fractured, the radius bears more of the impact in common injury mechanisms.
Question 2: Which part of the bone contains the growth plate in children?
- Diaphysis
- Metaphysis (Correct answer)
- Periosteum
- Epiphysis
Correct answer: Metaphysis
The metaphysis is the region of a long bone that connects the diaphysis (shaft) to the epiphysis (end). It contains the growth plate, or epiphyseal plate, which is crucial for longitudinal bone growth in children and adolescents. Damage to this area can significantly impact a child's bone development and length.
Question 3: Which nerve must be assessed in a distal humerus fracture?
- Median nerve
- Radial nerve (Correct answer)
- Ulnar nerve
- Sciatic nerve
Correct answer: Radial nerve
The radial nerve runs in close proximity to the posterior aspect of the humerus, making it particularly vulnerable to injury in distal humerus fractures. Damage to this nerve can result in 'wrist drop' and sensory deficits in the hand. Therefore, assessing radial nerve function (e.g., thumb extension, sensation) is a critical step to detect potential nerve impingement or transection.
Question 4: Which structure connects muscles to bones?
- Ligaments
- Tendons (Correct answer)
- Cartilage
- Bursae
Correct answer: Tendons
Tendons are strong, fibrous connective tissues that serve to connect muscles to bones. They are essential for transmitting the force generated by muscle contractions to the skeletal system, thereby facilitating movement. In contrast, ligaments connect bones to other bones, providing stability to joints.
Question 5: Which joint is classified as a hinge joint?
- Shoulder
- Hip
- Elbow (Correct answer)
- Wrist
Correct answer: Elbow
The elbow is classified as a hinge joint because it primarily allows movement in one plane, similar to a door hinge, permitting flexion and extension. This type of joint provides stability while facilitating a specific range of motion. The shoulder and hip, for example, are ball-and-socket joints, offering a much wider range of multi-directional movement.
Question 6: What is the function of the periosteum?
- Cushions joints
- Attaches muscles to bone
- Protects and nourishes bone (Correct answer)
- Stores calcium
Correct answer: Protects and nourishes bone
The periosteum is a dense, vascular connective tissue membrane that covers the outer surface of most bones. Its primary functions include protecting the bone, providing a surface for muscle and ligament attachment, and containing cells vital for bone growth, repair, and nourishment. It also houses nerve endings, contributing to bone sensitivity.
OCC Anatomy & Physiology Relevant to Casting 1
Which bone is most commonly fractured in the forearm?