the hand

Question 1

Thenar muscles
Abductor pollicis brevis

Answer 1

origin: Tubercle of scaphoid, trapezium, flexor retinaculum
insertion: Base of proximal phalanx of thumb
nerve: Median nerve
action: Abducts the thumb

Question 2

Flexor Pollicis brevis- Thenar muscle

Answer 2

origin: Flexor retinaculum, trapezium, capitate bones
insertion: Base of proximal phalanx of thumb
nerve: Median nerve
action: Flexes the thumb

Question 3

Opponens pollicis-Thenar muscle

Answer 3

origin: Flexor retinaculum
insertion: Lateral half of palmar surface of shaft of first metacarpal bone
nerve: Median nerve
action: Opposes thumb towards the fingers

Question 4

Adductor pollicis- Thenar muscle

Answer 4

origin: Oblique head - bases of 2nd and 3rd meta-carpals, Transverse head-shaft of 3rd meta carpal
insertion: Base of proximal phalanx of thumb on its medical aspect
nerve: Ulnar nerve (deep branch)
action: Adduction of thumb

Question 5

Hypothenar muscles
Palmaris brevis

Answer 5

origin: Flexor retinaculum
insertion: Skin of palm on medial side
nerve: Ulnar nerve (superficial branch)
action: Wrinkles the skin to improve grip

Question 6

Abductor digiti minimi- Hypothenar muscles

Answer 6

origin: Pisiform bone
insertion: Base of proximal phalanx of little finger
nerve: Ulnar nerve (deep branch)
action: Abducts little finger

Question 7

Flexor Digiti Minimi -Hypothenar muscles

Answer 7

origin: Flexor retinaculum
insertion: Base of proximal phalanx of little finger
nerve: Ulnar nerve (deep branch)
action: Flexes the little finger

Question 8

Opponens digiti minimi -Hypothenar muscles

Answer 8

origin: Flexor retinaculum
insertion: Medial border of 5th metacarpal
nerve: Ulnar nerve (deep branch)
action: Pulls the 5th metacarpal forwards as in cupping of palm

Question 9

What are the attachments of the palmar aponeurosis

Answer 9

The palmar aponeurosis isa strong, well-defined part of the deep fascia of the palm which covers the long flexor tendions and superficial palmar arch.

It is triangular w/ longitudinal fibres and few transverse fibres. Apex is proximal at wrist, and base is distal towards roots of fingers.

It originates from the tendon of the palmaris longus and inserts onto the fibrous flexor sheaths of the phalange.s

Question 10

What are the groups of intrinsic muscles

Answer 10

Groups of Intrinsic muscles:
1. Thenar (thumb)
2. Adductor of thumb
3. Hypothenar muscles (pinky side)
4. Lumbricls
5. Interossei (palmar and Dorsal)

Question 11

Describe the components, nerve supply, and action of the thenar muscles.

Answer 11

Muscles:
1. Abductor pollicis brevis (laterally)
2. Flexor pollicis brevis (medially)
3. Opponens pollicis (Deep)

Nerves:
- Supplied by the recurrent branch of the median nerve,

Action:
- Responsibly for opposition of the thumb

Question 12

Describe the components, nerve supply, and action of the hypothenar muscles.

Answer 12

Muscles:
1. Abductor digit minimi
2. Flexor digiti minimi
3. Opponens digiti minimi

Action:
- Flexion, abduction, lateral rotation, and opposition of little finger

Nerve:
- Deep branch of ulnar nerve

Question 13

Describe the components, nerve supply, and action of the lumbricals muscles.

Answer 13

N: 1st, and 2nd (unipennate) → Median nerve. 3rd and 4th (bipennate) → ulnar nerve

A: Flexes metacarpophalangeal joints and extend interphalangeal joints of 2-5th digits.

Question 14

Describe the components, nerve supply, and action of the interossei muscles.

Answer 14

Muscles:
Palmar interossei muscles are all unipennate. The dorsal interossei muscles are all bipennate (2 origins, between phalanges).

Action:
- Palmar → Adduction
- Dorsal → Abduction

Nerve:
- Deep branch of the ulnar nerve