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Orthopedic Nurse Certification (ONC) – Complete 180-Question Practice Exam
SECTION 1: FOUNDATIONS & ANATOMY
Question 1
Which type of bone cell is responsible for bone resorption (breakdown of bone
matrix)?
A) Osteoblasts
B) Osteocytes
C) Osteoclasts
D) Chondrocytes
Answer: C) Osteoclasts
Rationale: Osteoclasts are large, multinucleated cells responsible for bone
resorption. They secrete enzymes and acids that break down bone matrix,
releasing calcium and phosphate into the bloodstream. Osteoblasts build new
bone, osteocytes maintain bone, and chondrocytes are cartilage cells.
Question 2
Which structure connects muscle to bone?
A) Ligament
B) Tendon
,C) Cartilage
D) Fascia
Answer: B) Tendon
Rationale: Tendons connect muscle to bone. Ligaments connect bone to bone.
Cartilage provides cushioning between bones. Fascia is connective tissue that
surrounds muscles and organs.
Question 3
The knee joint is classified as which type of joint?
A) Synarthrosis (immovable)
B) Amphiarthrosis (slightly movable)
C) Diarthrosis (freely movable)
D) Syndesmosis
Answer: C) Diarthrosis (freely movable)
Rationale: The knee joint is a synovial joint (diarthrosis) that allows free
movement. Sutures are synarthroses (immovable). Symphysis pubis and
intervertebral discs are amphiarthroses (slightly movable).
Question 4
The vertebral column typically consists of how many vertebrae?
A) 24
B) 26
C) 33
D) 35
Answer: C) 33
Rationale: The vertebral column has 33 vertebrae: 7 cervical, 12 thoracic, 5
lumbar, 5 sacral (fused), and 4 coccygeal (fused). Variations may occur.
Question 5
Which bone is the longest and heaviest in the body?
,A) Tibia
B) Fibula
C) Femur
D) Humerus
Answer: C) Femur
Rationale: The femur is the longest and heaviest bone in the body. It transmits
weight from the hip to the knee and is a common fracture site in older adults.
Question 6
The rotator cuff is composed of which muscles? (Select all that apply)
A) Supraspinatus
B) Infraspinatus
C) Teres minor
D) Subscapularis
Answer: A, B, C, D
Rationale: The rotator cuff consists of four muscles: supraspinatus (abduction),
infraspinatus (external rotation), teres minor (external rotation), and subscapularis
(internal rotation). They provide dynamic stability to the shoulder joint.
Question 7
Which movement describes turning the palm upward?
A) Pronation
B) Supination
C) Inversion
D) Eversion
Answer: B) Supination
Rationale: Supination is turning the palm upward (anteriorly). Pronation is turning
the palm downward. Inversion and eversion refer to foot movements.
Question 8
What is the term for the shaft of a long bone?
, A) Epiphysis
B) Metaphysis
C) Diaphysis
D) Periosteum
Answer: C) Diaphysis
Rationale: The diaphysis is the shaft of a long bone. The epiphysis is the end of the
bone, metaphysis is the growth plate area, and periosteum is the outer covering of
the bone.
Question 9
What is the primary blood supply to the femoral head?
A) Lateral circumflex femoral artery
B) Medial circumflex femoral artery
C) Superior gluteal artery
D) Obturator artery
Answer: B) Medial circumflex femoral artery
Rationale: The medial circumflex femoral artery is the primary blood supply to the
femoral head. Disruption (e.g., femoral neck fracture) can lead to avascular
necrosis.
Question 10
Which joint is the largest and most complex synovial joint in the body?
A) Shoulder
B) Hip
C) Knee
D) Elbow
Answer: C) Knee
Rationale: The knee is the largest and most complex synovial joint. It consists of
the femorotibial and patellofemoral articulations and contains multiple ligaments,
menisci, and bursae.