Upper Limb: Pectoral Region

Q-1. Tubercles of Montgomery is seen in
a) Breast
b) Liver
c) Stomach
d) Lung

Answer: Breast
Explanation:
The skin surrounding the base of the nipple is pigmented and forms a circular area called the areola. This region is rich in modified sebaceous glands, particularly at its outer margin. These become enlarged during pregnancy and lactation to form raised tubercles of Montgomery. Oily secretions of these glands lubricate the nipple and areola and prevent them from cracking during lactation.

Q-2. Which of the following does NOT supply the breast with blood?
a) Lateral thoracic artery
b) Thoraco-acromial artery
c) Posterior intercostal arteries
d) Costo-clavicular artery

Answer: Costo-clavicular artery
Explanation:
The mammary gland is extremely vascular. It is supplied by branches of the following arteries:
Internal thoracic artery, a branch of the sub-clavian artery, through its perforating branches.
The lateral thoracic, superior thoracic and acromio-thoracic (Thoraco-acromial) are branches of the axillary artery.
Lateral branches of the posterior intercostal arteries.
Important point:
The arteries converge on the breast and are distributed from the anterior surface. The posterior surface is relatively avascular.

Q-3. Blood supply of breast is from all except
a) Internal mammary artery
b) Intercostal artery
c) Thoraco-dorsal branch of sub-scapular artery
d) Thoraco-acromial artery

Answer: Thoraco-dorsal branch of sub-scapular artery Explanation:
See above explanation.

Q-4. Lymph node which is first to be involved in carcinoma breast
a) Pectoral group
b) Internal mammary
c) Apical
d) Internal mammary

Answer: Pectoral group
Explanation:
The axillary lymph nodes (chiefly the anterior or pectoral) group: The posterior, lateral, central and apical groups of nodes also receive lymph from the breast either directly to indirectly.
About 75% of the lymph from the breast drains into the axillary nodes: 20% into the internal mammary nodes; and 5% into the posterior intercostal nodes.

Q-5. True about pectoralis major muscle-
a) Abductor & Internal rotator of shoulder
b) Blood supply by perforating branch of internal thoracic artery
c) Blood supply by intercostal artery
d) Nerve supply by lateral anterior thoracic nerve
e) Inserted into 2nd to 6th costal cartilage

Answer: Nerve supply by lateral anterior thoracic nerve
Explanation:
Pectoralis major muscle:
Origin:
Anterior surface of medial half of clavicle
Half of breadth of anterior surface of manubrium and sternum up-to 6th costal cartilages
Second to six costal cartilages
Aponeurosis of the external oblique muscle of abdomen
Insertion:
It is inserted by a bi-laminar tendon on the lateral lip of the bicipital groove. The two laminae are continuous with each other inferiorly.
Blood supply:
Pectoral branch of the thoraco-acromial trunk
Nerve supply:
The pectoralis major receives dual motor innervation by the medial pectoral nerve and the lateral pectoral nerve, also known as the lateral anterior thoracic nerve.
Actions:
Acting as whole: Adduction and medial rotation of shoulder/arm
Clavicular part: Flexion of the arm
Sterno-clavicular part: Extension of flexed arm against resistance and climbing

Q-6. Which of the following muscles are enclosed within the clavi-pectoral fascia?
a) Pectoralis major
b) Serratus anterior
c) Coraco-brachialis
d) Sub-clavius

Answer: Sub-clavius
Explanation:
Clavipectoral fascia:
Its upper part splits to enclose the sub-clavius muscle. Inferiorly it splits to enclose the pectoralis minor muscle.

Q-7. Structure piercing the clavi-pectoral fascia is
a) Basilic vein
b) Cephalic vein
c) Thoraco-acromial artery
d) Musculo-phrenic nerve

Answer- b and c
Explanation:
The clavi-pectoral fascia is pierced by the following structures:
Lateral pectoral nerve
Cephalic vein
Thoraco-acromial vessels
Lymphatic passing from the breast and pectoral region to the apical group of axillary lymph nodes

Q-8. All pierce the clavi-pectoral fascia except
a) Lateral pectoral vein
b) Lateral thoracic artery
c) Cephalic vein
d) Thoraco acromial artery

Answer: Lateral thoracic artery
Explanation:
See above explanation.

Q-9. Boxer’s muscle is -
a) Trapezius
b) Serratus anterior
c) Psoas major
d) Latissimus dorsi

Answer: Serratus anterior
Explanation:
Serratus Anterior:
Origin:
Serratus anterior muscle arises by eight digitations from the upper eight ribs, and from the fascia covering the intervening intercostal muscles
Nerve Supply:
The nerve to the serratus anterior is a branch of the brachial plexus. It arises from roots C5, C6 and C7 (Long thoracic nerve).
Action:
Along with the pectoralis minor, the muscle pulls the scapula forwards around the chest wall to protract the upper limb (in pushing and punching movements). When the muscle is paralyzed the medial margin of the scapula gets raised especially when ‘pushing movements’ are attempted. This is called ‘winging of the scapula’.
Paralysis of the serratus anterior produces ‘winging of scapula’ in which the inferior angle and the medial border of the scapula are unduly prominent. The patient is not able to do any pushing action nor can he raise his arm above the head. Any attempt to do these movements makes the inferior angle of the scapula still more prominent.

Q-10. Serratus anterior is supplied by
a) Thoraco-dorsal nerve
b) Nerve to sub-clavius
c) Long thoracic nerve
d) Axillary nerve

Answer: Long thoracic nerve
Explanation:
See above explanation.

Q-11. Winging of scapula is due to injury to
a) Long thoracic nerve
b) Short thoracic nerve
c) Axillary nerve
d) supra-scapular nerve

Answer: Long thoracic nerve
Explanation:
See above explanation.

Q-12. Regarding serratus anterior muscle, which is incorrect?
a) Multi-pinnate muscle
b) Lifts arm above the shoulder
c) Supplied by long thoracic nerve
d) Originates from lower 8 ribs

Answer: Originates from lower 8 ribs
Explanation:
See above explanation.

Q-13. All are sensory except
a) Saphenous nerve
b) Sural nerve
c) Inter-costo-brachial nerve
d) Long thoracic nerve

Answer: Long thoracic nerve
Explanation:
The nerve to the serratus anterior is a branch of the brachial plexus. It arises from roots C5, C6 and C7 (Long thoracic nerve).

Q-14. Winging of Scapula is due to paralysis of
a) Latissimus dorsi
b) Pectoralis major
c) Pectoralis minor
d) Serratus anterior

Answer: Serratus anterior
Explanation:
See above explanation.
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