Pectoral Girdle: Clavicle, Scapula and Glenoid Cavity
Biology · Locomotion and Movement · NEET
The pectoral (shoulder) girdle joins your arm to the axial skeleton. Each half is made of two bones: a clavicle (collar bone) and a scapula. On the scapula, a depression called the glenoid cavity holds the head of the humerus to form the ball-and-socket shoulder joint. Memory hook: "CS G-H" - Clavicle + Scapula, and the Glenoid cavity meets the Humerus.
One half of the pectoral girdle: the clavicle meets the acromion of the scapula, and the glenoid cavity of the scapula holds the head of the humerus to form the ball-and-socket shoulder joint.
Your doubts, answered
Is the clavicle part of the pectoral girdle?
Yes. Each half of the pectoral girdle has two bones: the clavicle and the scapula. So the whole girdle (both sides) has 4 bones - 2 clavicles and 2 scapulae. Students often forget the clavicle because the scapula is bigger, but NCERT clearly lists both.
Which bone has the glenoid cavity?
The scapula. The glenoid cavity is a depression on the scapula, sitting just below the acromion. It receives the head of the humerus to make the shoulder (ball-and-socket) joint. The glenoid cavity is NOT on the humerus.
What is the difference between the acromion and the glenoid cavity?
Both are on the scapula but do different jobs. The acromion is a flat, expanded process at the end of the scapular spine, and the clavicle articulates with it. The glenoid cavity is a depression below the acromion that articulates with the head of the humerus. NEET loves to swap these two in match-the-column questions.
Does the scapula connect to the sternum?
No. The scapula lies on the dorsal (back) side of the thorax between the 2nd and 7th ribs and does not directly touch the sternum. It is the clavicle that connects to the sternum in front. This is why the pectoral girdle allows a wide range of arm movement.
What does the glenoid cavity articulate with?
The head of the humerus. This forms the shoulder joint, which is a ball-and-socket joint between the humerus and the pectoral girdle. NEET 2023 and 2024 both tested this exact pairing (ball-and-socket = humerus + pectoral girdle).
⚠️ The NEET trap ✗ The glenoid cavity is found on the humerus and the acromion articulates with the humerus. ✓ The glenoid cavity is on the scapula and receives the head of the humerus; the acromion (on the scapular spine) articulates with the clavicle, not the humerus. 🧠 NTA swaps who-meets-whom. Fix it once: acromion -> clavicle, glenoid cavity -> humerus. Both structures sit on the scapula.
Real NEET questions
NEET 2020
Match the following columns and select the correct option.
Column I: (a) Floating Ribs (b) Acromion (c) Scapula (d) Glenoid cavity
Column II: (i) Located between second & seventh ribs (ii) Head of the Humerus (iii) Clavicle (iv) Do not connect with the sternum
A · (a)-(iii); (b)-(ii); (c)-(iv); (d)-(i)
B · (a)-(iv); (b)-(iii); (c)-(i); (d)-(ii) ✓
C · (a)-(ii); (b)-(iv); (c)-(i); (d)-(iii)
D · (a)-(i); (b)-(i); (c)-(ii); (d)-(iv)
Solution: Floating ribs (11th, 12th) do not connect to the sternum -> (iv). The acromion is the process with which the clavicle articulates -> (iii). The scapula lies between the 2nd and 7th ribs -> (i). The glenoid cavity articulates with the head of the humerus -> (ii). So (a)-iv, (b)-iii, (c)-i, (d)-ii.
NEET 2021
Match List I with List II.
List I: (a) Scapula (b) Cranium (c) Sternum (d) Vertebral column
List II: (i) Cartilaginous joints (ii) Flat bones (iii) Fibrous joints (iv) Triangular flat bone
A · (a)-(iv); (b)-(ii); (c)-(iii); (d)-(i)
B · (a)-(iv); (b)-(iii); (c)-(ii); (d)-(i) ✓
C · (a)-(i); (b)-(iii); (c)-(ii); (d)-(iv)
D · (a)-(ii); (b)-(iii); (c)-(iv); (d)-(i)
Solution: Scapula is a large triangular flat bone -> (iv). The cranium bones are joined by fibrous sutures -> (iii). The sternum is a flat bone -> (ii). Adjacent vertebrae are joined by cartilaginous joints -> (i). So (a)-iv, (b)-iii, (c)-ii, (d)-i.
Solved Locomotion and Movement NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Four in total: 2 clavicles and 2 scapulae. Each half (each shoulder) has 1 clavicle + 1 scapula.
What is the common name of the clavicle?
The collar bone. It is a long, slender bone with two curvatures, and it is one of the most commonly fractured bones.
What kind of joint is the shoulder joint?
A ball-and-socket joint. The rounded head of the humerus fits into the cup-like glenoid cavity of the scapula, allowing movement in many directions.
Where is the scapula located?
On the dorsal (back) part of the thorax, between the 2nd and 7th ribs. It is triangular and flat, with a raised spine ending in the acromion.
Why is the pectoral girdle important for NEET?
NEET repeatedly asks match-the-column questions on scapula, acromion, glenoid cavity and clavicle, and on the shoulder being a ball-and-socket joint. Knowing which structure meets which bone directly earns marks.
