The hand Flashcards
What type of joint is the carpometacarpal joint (base of thumb)
synovial saddle joint
allows opposition of the thumb
What type of joints are the metacarpophalangeal joints (MCPs)
synovial condyloid joints
allow flexion, extension, abduction, adduction, some circumduction
What type of joints are the interphalangeals (PIP and DIPs)
synovial hinge
Describe the function of the palmar aponeurosis
holds skin in place during movement
prevents loss of grip
protection of nerves and vessels in hand
Describe the action and innervation of palmaris brevis
tightens palmar aponeurosis
innervated by ulnar nerve
Where are the thenar and hypothenar eminences located
thenar - base of thumb
hypothenar - base of little finger
Name the muscles of the thenar eminence
superficial - abductor policis brevis and flexor policis brevis
deep - opponens policis
Innervation of the thenar eminence
recurrent branch of median nerve C8-T1
Which intrinsic muscle of the thumb is not found in the thenar eminence
Adductor pollicis
Describe the actions of adductor pollicis
adducts thumb @ CMCJ
flexion @ MCPJ
Describe the innervation to adductor pollicis
Ulnar nerve C8-T1
this is due to its deep location
Name the 3 muscles of the hypothenar eminence
abductor digiti minimi
flexor digiti minimi
opponens digiti minimi
Describe the attachments and actions of abductor digiti minimi
pisiform to base of 5th proximal phalanx
action - abduction and flexion MCPJ little finger
Describe the attachments and actions of flexor digiti minimi
hamate and flexor retinaculum
to
base of 5th proximal phalanx
flexion of MCPJ little finger
Describe the attachments and actions of opponens digiti minimi
hamate and flexor retinaculum
to
5th metacarpal
weak opposition of little finger
Describe the innervation to the hypothenar eminence
Deep branch of ulnar nerve C8-T1
Describe the lumbricals of the hand
originate from tendons of FDP
insert onto dorsal expansion of fingers 2-5, crossing anterior surface of MCPJs as well as the posterior surface of the IP joints
Describe the action of lumbricals
MCPJ flexion
IP Joint extension
Describe the innervation of the lumbricals
lateral - median nerve C8-T1
medial - deep branch of ulnar nerve C8-T1
Describe the innervation of the palmar interossei
deep branch of ulnar nerve
Describe the action of the palmar interossei
adduction towards middle finger
Describe the action of the dorsal interossei
Abduction - spreads fingers
What is the largest artery to the thumb
Princeps pollicis artery - from radial artery
Describe the general rules of innervation in the hand
lateral - median nerve
medial - ulnar nerve
thenar eminence - median nerve
hypothenar - ulnar nerve
Describe the important dermatome landmarks
C5 - badge patch
C6 - pad of thumb
C7 - pad of middle finger
C8 - pad of little finger
T1 - medial side of elbow