Muscles of the Hand Flashcards
Where are the extrinsic muscles of the hand
Anterior and posterior compartments of the forearm
What is the action of extrinsic muscles of the hand
Control crude movements and produce a forceful grip
Where are the intrinsic muscles of the hand
Within the hand itself
What do the intrinsic muscles of the hand do
Responsible for fine motor function of the hand
What are the intrinsic muscles of the hand
Adductor pollicis Palmaris brevis Interossei Lumbricals Thenar muscles Hypothenar muscles
Which muscles make up the thenar muscles
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
Which nerve innervates the thenar muscles
Median nerve
Which is the largest of the thenar muscles
Opponens pollicis
Where does opponens pollicis lie
Beneath abductor pollicis brevis and flexor pollicis brevis
Where does opponens pollicis originate
Tubercle of trapezium
Associated flexor retinaculum
Where does opponens pollicis insert
Lateral margin of the metacarpal of the thumb
What is the action of opponens pollicis
Opposes the thumb
Medially rotating and flexing metacarpal on trapezium
Which nerve innervates opponens pollicis
Median nerve
Where is abductor pollicis brevis
Anterior to opponens pollicis
Proximal to flexor pollicis brevis
Where does abductor pollicis brevis originate
Tubercles of scaphoid and trapezium
Associated flexor retinaculum
Where does abductor pollicis brevis insert
Lateral side of proximal phalanx of the thumb
What is the action of abductor pollicis brevis
Abducts the thumb
Which nerve innervates abductor pollicis brevis
Median nerve
Which is the most distal of the thenar muscles
Flexor pollicis brevis
Where does flexor pollicis brevis originate
Tubercle of the trapezium
Associated flexor retinaculum
Where does flexor pollicis brevis insert
Base of the proximal phalanx of the thumb
What is the action of flexor pollicis brevis
Flexes MCPJ of the thumb
Which nerve innervates flexor pollicis brevis
Median nerve
Deep head is innervated by the deep branch of the ulnar nerve
Which are the hypothenar muscles
Opponens digiti minimi
Abductor digiti minimi
Flexor digiti minimi brevis
Which nerve innervates the hypothenar muscles
Ulnar nerve
Which hypothenar muscles lies deepest
Opponens digiti minimi
Where does opponens digiti minimi originate
Hook of hamate
Associated flexor retinaculum
Where does opponens digiti minimi insert
Medial margin of metacarpal V
What is the action of opponens digiti minimi
Rotates metacarpal of little finger towards the palm
Which nerve innervates opponens digiti minimi
Ulnar nerve
Which is the most superficial of the hypothenar muscles
Abductor digiti minimi
Where does abductor digiti minimi originate
Pisiform
Tendon of flexor carpi ulnaris
Where does abductor digiti minimi insert
Base of the proximal phalanx of the little finger
What is the action of abductor digiti minimi
Abducts the little finger
Which nerve innervates abductor digiti minimi
Ulnar nerve
Where does flexor digiti minimi brevis lie
Laterally to abductor digiti minimi
Where does flexor digiti minimi brevis originate
Hook of hamate
Adjacent flexor retinaculum
Where does flexor digiti minimi brevis insert
Base of the proximal phalanx of the little finger
What is the action of flexor digiti minimi brevis
Flexes MCP joint of the little finger
Which nerve innervates flexor digiti minimi brevis
Ulnar nerve
How many lumbricals are there in each hand
4 - link extensor tendons to flexor tendons
Where do the lumbricals originate
Each lumbrical originates from a tendon of the flexor digitorum profundus
Where do the lumbricals insert
Pass dorsally and laterally around each finger and inserts into extensor hood
What is the action of the lumbricals
Flex at the MCP joint
Extend at the interphalangeal joints
Which nerve innervates the lateral two lumbricals
Median nerve
Which nerve innervates the medial two lumbricals
Ulnar nerve
How many dorsal interossei muscles are there
4
Where do the dorsal interossei originate
Each interossei originates from the lateral and medial surfaces of the metacarpals
Where do the dorsal interossei insert
Extensor hood and proximal phalanx of each finger
What is the action of the dorsal interossei
Abduct the fingers at MCPJ
Which nerve innervates dorsal interossei
Ulnar nerve
Where do palmar interossei lie
Anteriorly
How many palmar interossei are there
3
Where do palmar interossei originate
Each interossei originates from a medial or lateral surface of a metacarpal
Where do palmar interossei insert
Extensor hood
Proximal phalanx of same finger
What is the action of palmar interossei
Adducts fingers at MCPJ
Which nerve innervates palmar interossei
Ulnar nerve
Where is palmaris brevis
Found superficially in subcutaneous tissue of hypothenar eminence
Where does palmaris brevis originate
Palmar aponeurosis
Flexor retinaculum
Where does palmaris brevis insert
Dermis of the skin on medial margin of hand
What is the action of palmaris brevis
Wrinkles skin of hypothenar eminence
Deepens curvature of hand, improving grip
Which nerve innervates palmaris brevis
Ulnar nerve
What passes between the two heads of adductor pollicis
Radial artery
Where does adductor pollicis originate
Two heads:-
Metacarpal III
Capitate and adjacent areas of metacarpals II and III
Where does adductor pollicis insert
Base of proximal phalanx of the thumb
What is the action of adductor pollicis
Adduction of the thumb
Which nerve innervates adductor pollicis
Ulnar nerve
