UL 4: Palm of the hand Flashcards
How many bones and rows of bones are there in the carpus
8 bones
2 rows of 4
The distal radius articulates with the _______ and _______ to form the radiocarpal joint
scaphoid
lunate
what is the most commonly broken carpal and why
scaphoid
falling with open palm
why It is very important not to miss an anterior dislocation of the lunate
compressed median nerve
The metacarpals lie ____ to the
carpus
a)distal
b)proximal
a
what is the difference in phalanges between thumb and rest of fingers
fingers= 3 phalange
thumb = 2
Describe Carpometacarpal joints (CMCJs)
lie between the distal row of carpal bones and the proximal parts (the bases) of the metacarpals.
Describe Metacarpophalangeal joints (MCPJs)
lie between the distal parts (the heads) of the metacarpals and the proximal phalanges
Describe Interphalangeal joints (IPJs)
lie between phalanges
Discuss the fingers (digits 2-5) movements
- Flexion
- Extension
- Abduction (moving the fingers apart)
- Adduction (bringing the fingers together)
discuss the movements in the thumb
- Flexion
- Extension
- Abduction
- Adduction
- Opposition
The muscles of the anterior forearm that are the prime flexors of the wrist are: (and where they insert)
- Flexor carpi radialis - inserts onto the 2nd metacarpal
- Flexor carpi ulnaris - inserts onto the 5th metacarpal
- Palmaris longus (if present) - inserts into the palmar fascia
Anterior compartment muscles also flex the digits. They travel through the carpal tunnel and into the hand:
- Flexor digitorum superficialis (FDS)
- Flexor digitorum profundus (FDP)
- Flexor pollicis longus (FPL)
tendon of flexor digitorum superficialis (FDS) splits into two slips which insert on either side of the middle phalanx of digits 2-5.
It flexes the _____ joints and _____ joints of digits 2-5.
MCP (Metacarpophalangeal)
PIP (proximal interphalangeal)
The tendon of flexor digitorum profundus (FDP) passes through the slit in the FDS tendon to insert onto the palmar aspect of the distal phalanx of digits 2-5.
It is the only muscle capable of flexing the ____ joint. It also flexes the ___ joint and the ___ joint of digits 2-5.
DIP
PIP
MCP
which is the only tendon in the thumb can than flex the IPJ
tendon of flexor pollicis longus (FPL)
why is it beneficial for the long flexor tendons in hand to be covered in synovial sheath
-reduces friction
-allows tendons to slide freely in fibrous sheath during flexion and extension.
what are the 4 groups of intrinsic muscles in the hand and how many muscles each group contains
- thenar eminence – 3
- hypothenar eminence – 3
- lumbricals – 4
- interossei – 7
what is the muscle in the thumb that inserts through the proximal phalanx
adductor pollicis.
what nerves innervate the intrinsic muscles of the hand
Ulnar and median
what 3 muscles are in Thenar Eminence,
-function
-what are their insertion points
-what nerve are they innervated by
- Flexor pollicis brevis (FPB)
- flexes the thumb
-innervated by recurrent branch median nerve
-insertion point = proximal phalanx - Abductor pollicis brevis (APB)
- abducts the thumb
-innervated by recurrent branch median nerve
-insertion point = proximal phalanx lateral aspect - Opponens pollicis - (OP)
- opposes the thumb
-innervated by recurrent branch median nerve
-insertion point = 1st metacarpal
which group of instrincic muscles are affected by carpel tunnel
Thenar eminence
how does the single muscle Adductor Pollicis differ from the Thenar Eminence
- it lies deep in the palm, not in the thenar eminence
- it is innervated by the ulnar nerve
what are the muscles in the Hypothenar Eminence
-their function
-insertion points
-innervation
- Flexor digiti minimi (FDM)
-flexes the little finger
-proximal phalanx
-deep ulnar Nerve - Abductor digiti minimi (ADM)
-abducts the little finger
-proximal phalanx
-deep ulnar nerve - Opponens digiti minimi (ODM)
-opposes the little finger
-proximal phalanx
-deep ulnar nerve
The Interossei muscles
-what bones to they attach to and lie between
-what digits do they insert into
-what are the names of the 2 groups and how many muscles in each
-which group abducts and which group adducts
*metacarpals
*2-5
*palmaris
-3
-adductd
*Dorsal
-4
-abduct
The lumbrical muscles, Describe:
-which tendon they arise form
-what innervates the lateral 2
-what innervates the medial 2
-flexor digitorum profundus
-median
-ulnar
The first palmar interosseous arises from the ____ side of the ____ metacarpal and inserts onto the medial aspect of the ___ proximal phalanx.
medial
2nd
2nd
The second palmar interosseous arises from the ____ side of the ____ metacarpal and inserts onto the lateral aspect of the ___ proximal phalanx.
lateral
4th
4th
The third palmar interosseous arises from the ______ side of the ___ metacarpal and inserts onto the lateral aspect of the ___ proximal phalanx.
lateral
5th
5th
which 2 nerves innervate muscles of hand
-ulnar
-radial
-median
Ulnar
median
what forms the carpal tunnel
carpal bones and flexor retinaculum.
List the important structures passing through he carpal tunnel
- long flexor tendons of FDS, FDP and FPL
- median nerve
Sensation in the hand can be assessed by examining which 2 things
Dermatomes
the territories of the peripheral nerves
which surface of the hand des the median nerve travel across
palmar, lateral 3.5 digits
which surface of the hand does the ulnar Nerve travel
the palmar and dorsal surfaces of the medial side of the hand and the medial 1 1⁄2 digits.
which surface of the hand does the radial nerve travel
dorsal surface of the lateral side of the hand. The skin over the dorsum of the lateral 3 1⁄2 digits as far as the DIP joint.
A patient with carpal tunnel syndrome has normal sensation over the lateral side of their palm. Why is this
branches of the median nerve that innervate the skin of the lateral palm arise in the forearm and do not travel through the carpal tunnel, so are unaffected by compression of the median nerve in the carpal tunnel.
The upper limb is innervated by the ______ plexus and spinal nerves C_to T_
brachial
1
5
Radial and ulnar arteries are temilnal branchs of which artery
brachial
The radial
pulse can be palpated over the ______ aspect of the wrist.
lateral
The ulnar pulse can be palpated over which aspect of wrist
medial
The radial and ulnar arteries anastomose deep in the palm of the hand to form two ______ arches:
palmar
The superficial palmar arch is formed by:?
largely by the ulnar artery with a smaller contribution from the radial artery
The deep palmar arch is formed by:?
largely by the radial artery with a smaller contribution from the ulnar artery.
Discuss each of the dermatomes from C4-T1
● C4: upper shoulder
● C5: lateral side of anterior and posterior arm
● C6: lateral side of anterior and posterior surfaces: forearm,
palm, thumb and index fingers
● C7: anterior and posterior surfaces of the middle finger and middle of the
palm (over the 3rd metacarpal)
● C8: medial side of anterior and posterior surfaces of the forearm + palm+ 4th and 5th fingers
● T1: medial side of anterior and posterior surfaces of arm.
To test the dermatomes, sensation is tested over which areas
● C5: upper lateral arm
● C6: thumb
● C7: middle finger
● C8: medial border of the hand
● T1: medial border of the arm
What is the cutaneous distribution of the median, ulnar and radial nerves in the hand?
Which regions of skin would you test to assess these nerves?
Median: The palmar surface of the lateral 3 1⁄2 digits. The skin over the dorsum of the distal phalanges of the lateral 3 1⁄2 digits.
o Test = palmar surface of the middle finger
● Ulnar: the palmar and dorsal surfaces of the medial side of the hand and the medial 1 1⁄2 digits.
o Test = medial border of the hand
● Radial: dorsal surface of the lateral side of the hand. The skin over the dorsum of the lateral 3 1⁄2 digits as far as the DIP joint.
o Test = dorsum of the hand, lateral aspect
How would a patient present if they injured their median nerve at their wrist? In comparison, how would a median nerve injury at the elbow present?
o The patient presents with weakness of the thumb (but not of adduction) and over time, atrophy of the thenar eminence occurs.
o The patient would also have sensory deficits over the palmar aspect of the lateral 3 1⁄2 fingers
● Median nerve injury at elbow results in weakness / paralysis of the muscles innervated by the nerve distal to the elbow
o patient is unable to flex DIP and PIP joints of the 2nd and 3rd digits (i.e. index and middle fingers).
o Flexion of the MCP joints of these fingers is also impaired due to loss of function in the lumbricals to these fingers.
o Movements of the thumb (except adduction and extension) are also weak due to weakness of FPL and the thenar eminence muscles.
o The patient would also have sensory deficits over the palmar aspect of the lateral 3 1⁄2 fingers and lateral palm.
o Sensation over the lateral palm would also be impaired since this branch of median nerve leaves distal forearm
Which muscles would be affected by an ulnar nerve injury in the mid-forearm?
-adductor pollicis
-hypothenar eminenc
-medial two lumbricals
- all the interossei
