Muscles - Upper Limb MCQs

Ans. is 'a' i.e., Deep branch of ulnar nerve [Ref BDC 5th le Volume I p. 110-111] Inability to hold paper sheet signifies inability to adduct the fingers. It is nothing else but card test. Deep branch of ulnar nerve supplies the palmar interossei which control the adduction between fingers.

The flexor carpi radialis muscle flexes the hand at the wrist and provides radial deviation of the hand at the wrist as well as helps to pronate the forearm 1 = PRONATOR TERES 2 = FLEXOR CARPI RADIALIS 3 = PALMERIS LONGUS 4 = FLEXOR CARPI ULNARIS Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Upper Limb Page number - 818

A positive response to the myotatic biceps reflex confirms the integrity of the musculocutaneous nerve and the C5 and C6 spinal segments, from which this nerve arises. The musculocutaneous nerve supplies motor innervation and proprioception to the muscles in the anterior compartment of the arm, including the coracobrachialis, biceps brachii (tested here), and brachialis. Lesioning the musculocutaneous nerve would lead to loss of proprioception and weakness in flexing the elbow (via the biceps brachii and brachialis muscles) and supinating the forearm (via the biceps brachii), resulting in a negative myotatic biceps reflex. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Upper Limb Page number - 747

The lymph nodes lateral to the LATERAL edge of the pectoralis minor are the lateral axillary nodes. Pectoral or anterior axillary nodes are deep to the lateral edge of the pectoralis major muscle. Central axillary nodes are found directly under pectoralis minor, while subscapular or posterior axillary nodes are adjacent to the subscapularis muscle. The apical axillary nodes are medial to the medial edge of pectoralis minor and so it won't be removed. level Part of axilla Lymph nodes I Low axilla Lymph nodes lateral to the lateral border of pectoralis minor(central group, lateral group, anterior group, posterior group) II Mid axilla Lymph nodes between the lateral and medial borders of pectoralis minor. plus interpectoral lymph nodes III Apical axilla Lymph nodes medial to medial margin of pectoralis minor (including subclavicular, infraclavicular or apical).

The flexor digitorum superficialis tendon inserts on the middle phalanx of fingers 2-5; the flexor digitorum profundus tendon inserts on the base of the distal phalanx of fingers 2-5. Both muscles flex the metacarpophalangeal and proximal interphalangeal joints, but flexor digitorum profundus is the only muscle that flexes the distal interphalangeal joints. Reference: Gray's Anatomy for Students: Volume 1, 3rd Edition, Page Number-833.

When cutting the ventral side of the wrist, the first tendons cut would be the tendons of flexor digitorum superficialis. These tendons help flex the metacarpophalangeal and proximal interphalangeal joints, but not the distal interphalangeal joints. Flexor digitorum profundus (which has deeper tendons) is responsible for flexing the distal interphalangeal joints. To understand the next part of the question, look at Netter plate 443. The tendons of flexor digitorum superficialis are arranged in a packet with two superficial tendons and two deeper tendons. The tendons that go to fingers 3 and 4 are superficial, while the ones to finger 2 and 5 are underneath. So, the tendons to fingers 3 and 4 will be cut, impairing flexion of the proximal interphalangeal joints of digits 3 and 4. Reference: Textbook of Gray's Anatomy for students, 3rd Edition, Upper Limb Page number - 801

The posterior interosseous nerve, also known as the dorsal interosseous nerve, is the continuation of the deep branch of the radial nerve after it penetrates the supinator muscle. It carries fibers from the C7 and C8 spinal nerves and supplies the majority of the muscles in the posterior compartment of the forearm. Reference- Textbook of Gray's Anatomy for students, 3rd Edition, Upper Limb Page number - 763

Ans. A. Premotor cortex The premotor cortex function is still incompletely understood, but it may be concerned with setting posture at the start of a planned movement and with getting the lndividual prepared to move. It is most involved in control of proximal limb muscles needed to orient the body for movement.