Session 6 - Muscles of the hand Flashcards
What are the two main muscle groups in the hand?
Extrinsic and intrinsic muscles
Where are extrinsic muscles found and what do they do?
Found in the forearm and largely produce the forceful grip of the hand
Where are intrinsic muscles found and what actions are they responsible?
Found within the hand and produce fine motor skills.
What are the 6 intrinsic muscles of the hand?
Adductor pollicis, interossei, thenar, palmaris brevis, lumbricals and hypothenar muscles.
What is B?
Abductor Pollicis Brevis
What is the action of the abductor pollicis brevis?
Abducts the thumb
What is the innervation of the abductor pollicis brevis?
Median nerve
What is A?
Flexor pollicis brevis
What is the action of Flexor pollicis brevis?
Flexes the metacarpalphalngeal joint of the thumb
What is the innervation of flexor pollicis brevis?
Median nerve
What is C?
Oppens pollicis
What is the action of oppens pollicis?
Opposes the thumb by medially rotating and flexing the metacarpal on the trapezium
What is the innervation of oppens pollicis?
Median nerve
What is the hypothenar eminence?
A small eminence on the medial side of the palm at the base of the little finger, made up of three hypothenar muscles
- Abductor digiti minimi
- Flexor digiti minimi brevis
- Opponens digiti minimi
What hand is this?
How can hypothenar and thenar muscles be remembered?
Right
A of A of A
Abductor pollicis brevis, Opponens pollicis, Flexor pollicis brevis, Adductor pollicis, (thenar muscles)
Opponens digiti minimi, Flexor digiti minimi, Abductor digiti minimi (Hypothenar muscles)
What muscle is A?
Oppens Digiti minimi
Where does oppens digiti minimi lie?
Deep to the hypothenar muscles
Where does oppens digiti minimi originat from?
The hook of hamate and associated flexor retinaculum
What are the actions of the oppens digiti minimi?
Rotates the metacarpal of the little finger towards the palm, producing opposition
What is the innervation of the opponens digiti minimi?
Ulnar nerve
What is A?
Flexor digiti minimi brevis
What is the action of flexor digiti minimi brevis?
Flexes the MCP joint of the little finger
What is the innervation of flexor digiti minimi brevis
Ulnar nerve