the intrinsic hand Flashcards
the thenar eminence is associated to what part of the hand?
thumb
the hypothenar eminence is associated to what part of the hand?
the pink
what inserts on the palmar aponeurosis
palmaris longus tendon
how can the palmar aponeurosis be described?
its deep fascia that covers the palm and is anchored to the skin
what is the function of the palmaris brevis? where is it located?
no specific function
its a very thin muscle that stretches out on the hypothenar side
what creates the carpal tunnel?
what is its function?
flexor retnaculum
its prevents bowing of the flexors of the forearms
where is the flexor retinaculum located?
it stretches from the pisiform and hook of the hamate to the trapezium and scaphoid
what are the contents of the carpal tunnel?
- 4 tendons of FDS
- 4 tendons of FDP
- tendon of flexor policis longus
- median nerve
what causes carpal tunnel syndrome?
its is a chronic pressure to the median nerve which can result in numbness and weakness in the hand
what is the roof and floor of the carpal tunnel?
roof: flexor retinaculum
floor: carpal bones
what passes through guyon’s canal?
the ulnar N. and artery
what muscles can be found in the thenar eminence?
- Abductor Pollicis brevis
- flexor pollicis brevis
- opponens pollicis (AFO)
- adductor policis
what innervates the AFO of the thenar eminence?
recurrent branch of the median N.
what is the origin and insertion of the adductor policis?
function
innervation?
o: had 2 heads, oblique and transverse head which originate from the base of metacarpals
i: base of the first proximal phalanx (thumb)
fct: adduction of the thumb
innervation: deep ulnar nerve
what muscles compose the hypothenar eminence?
- Abductor digiti minimi
- flexor digiti minimi brevis
- opponens digiti minimi
what is the longus associated the the flexor digiti minimi brevis?
FDS and FDP tendons which pass through the pinky
what nerve innervates the hypothenar eminence?
deep ulnar nerve
what happens to the ulnar N and A. after they pass through the guyon’s canal?
they split into a deep and superficial branch
Lumbricals (4)
o
I
f?
O: Tendon of FDS
I: lateral aspect of the extensor hood
function: concurrent flexion of the MCP joints and extension of the IP joints
what muscles compose the interosseous deep compartment of the hand?
- palmar interossei (3)
- dorsal interossei (4)
what is the fucntion of palmar interossei?
what can be used to remember?
adduction and flexion of MCP, extension of IP joints for digits 2, 4, 5
PAD
what is the fucntion of dorsal interossei?
what can be used to remember?
abduction and flexion of MCP, extension of IP of digits 2, 3 , 4
DAB
what nerve is responsible for the sensory innervation of the medial 1.5 digits of the hand
the superficial branch of the ulnar N.
what nerve is responsible for the motor innervation of the palmaris brevis?
superficial branch of the ulnar nerve
what happens to the common digital branches once they reach the phalanges?
they split into 2 branches per phalanges know as the proper digital branches
what nerve is resonsibk=le for the sensory innervation of the 3.5 lateral digits?
the digital sensory branches of the median nerve
what nerve innervates the thernar eminence laterally (sensory)?
the radial nerve
what is the branch of the median nerve that does not pass through flexor retinaculum?
palmar branch of the median n.
what does the median nerve innervate (motor)?
the lateral 2 lumbricals and the AFO of the thumb
what branch of the median nerve is responsible for motor innervation?
the recurrent branch of the median nerve
what is the deep ulnar nerve responsible of innervating (motor)
-they hypothenar eminence
the medial 2 lumbricals, adductor pollicis and dorsal/palmar interossei
what type of innervation is the found in the dorsum of the hand?
only sensory innervation
what nerve sensorly innervated the DIP of the 3.5 lateral fingers?
median N.
what does the ulnar N. dorsal branch innervate?
the 2,5 medial digits to the wrist except for the DIP of digits 3- half of the fourth
what does the radial N. superficial branch innervate on the dorsal side of the hand
PIP- to wrist of the 2.5 lateral digits
what does the superficial palmar arch arise from?
the superficial branch of the ulnar A.
how is the superficial palmar arch closed by?
laterally it is closed by the superficial branch of the radial nerve
what does the deep palmar arch arise from?
the radial A.
how does the deep palmar arch close off?
it is closed off by the deep ulnar A on the medial side of the hand
what are some branches that immerge from the radial A?
-radial indicis A and prinicpis pollicis digital A
how do the radial indicis A and prinicpis pollicis digital A and deep palmar arch travel relative to the thumb?
posterior to the thumb
what test is used to test the anastamoses between the radial and ulnar A in the hand?
the allen’s test
briefly what is the allen’s test, and what does positive testing result in
- circulation is cut off and then either the ulnar or radial A is released and should allow for circulation throughout the entire hand within 7 seconds
- a positive test demonstrates incomplete anastamoses
what artery supplies the metacarpals of the hand?
dorsal metacarpal A.
what anastamoses in the dorsal carpal arch?
the radial and ulnar A
what arteries supply the digits of the dorsal hand?
dorsal digital arteries
what myotome is responsible for finger flexion, extension of the thumb?
trick?
C7
rock
what myotome is resonsible for finger extension?
trick?
C8
paper
what myotome is responsible for finger ab/adduction?
trick?
T1
scissors
