Exam 2: Hand Flashcards
Go to the powerpoint and label the carpal bones
Which carpal bone is most frequently fractured?
Which carpal bone is most frequently dislocated?
Most frequently fractured: scaphoid
Most frequently dislocated: lunate
Explain how the thumb is different from the other fingers in terms of metacarpal and phalanges
Thumb has one metacarpal but only two phalanges (proximal and distal phalynx)
The other fingers have a metacarpal and three phalanges (proximal, intermediate, and distal)
Also, the thumb is the first metacarpal
Hand dermatomes:
____ and ____ stop at the wrist
Explain the hand dermatomes using spock hand
C5 and T1 stop at the hand
Spok hand:
C6 is thum
C7 is index and middle finger
C8 is ring and pinky finger
What is the strong, heavy, dense well defined triangular layer of deep fascia in the middle of the palm called?
Palmar aponeurosis
What is the name for the condition where there is progressive fibrosis causing abnormal bands of fibrous tissue extending from the aponeurosis at the bases of the phalanges, pulling one or more digits into a marked flexion at the metacarophalangeal joints so that they cannot be straightened?
Dupuytren’s Contracture
Carpal Tunnel:
What is the posterior and anterior boundary of the carpal tunnel?
What runs through the carpal tunnel (hint four things)
Which nerve runs through the carpal tunnel?
What runs through the canal of guyon?
Carpal Tunnel:
Posterior boundary: carpal bones
Anterior boundary: flexor retinaculum
Structures that pass through the carpal tunnel:
- Flexor digitorum superficialis (FDS)
- Flexor digitorum profundus (FDP)
- Flexor pollicus longus
- Median nerve
Canal of Guyon: Ulnar nerve and ulnar artery
Carpal Tunnel Syndrome:
Anything than decreases the size of the carpal tunnel (fluid retension, infection, excessive use)
The ________ is the softest structure in the tunnel and is most affected by changes in pressure
What group of muscles get affected by a pinched nerve in carpal tunnel?
Carpal Tunnel Syndrome:
The median nerve is the softest structure in the tunnel and is most affected by changes in pressure
The thenar muscles of the thumb start to waste away
If median nerve gets damaged: thenar emenence of thumb
What are the muscles within the thenar compartment of the hand?
What nerve are they innervated by?
Thenar compartment: THUMB
Opponens pollicis
Abductor pollicis brevis
Flexor pollicus brevis
(OAF, without thumbs and pinky’s we would be oaf’s)
remember, pollicis means thumb
ALL innervated by the recurrent branch of the median nerve
Explain movements of the thumb
Flexion, extension, abduction, adduction, opposition
Hypothenar compartment (pinky)
What are the muscles within the hypothenar compartment?
OAF: but with diggiti minimi
Opponens digiti minimi
Abductor digiti minimi
Flexor digiti minimi
Lumbricles:
What do the lumbricles allow you to do movement wise?
How many are there?
What are they innervated by?
Lumbricles: extend the proximal and distal interphalangeal joints
Lumbricles originate of the FDP
1, 2, 3, 4 (1 and 2 are median nerve, 3 and 4 are ulnar)
1: index finger
2 and 3; middle finger
4: ring finger
Allows you to pinch the pulp of the fingers
Dorsal Interossei:
The dorsal interossi allow ____ of the digits at the MCP joint
DABS: 4
The dorsal interossi allow ABduction of the digits at the MCP joint
ABduction because of DAB
Palmer Interossei:
The palmar interossei ____ the digits at the MCP joint
PADS: 3 (i used to bring three pads to school, and griffin dabbed 4 times)
The palmar interosse ADduct the digits at the MCP joint
Picture the adductor pollicus muslce on your hand
The ______ artery comes down the side of your arm by your thumb and becomes the _____ palmar arch
The ____ artery comes down the side of your arm on the pinky side and becomes the ________ palmar arch
The radial artery comes down thumb side and becomes the deep palmar parch
The ulnar artery comes down the pinky side of arm and becomes the superficial palmar arch
(the word “superficial” has a U in it”
Ulnar Artery:
The superficial branch of the ulnar artery becomes the ________ arch
It anatamoses with the _______
Deep branch of ulnar artery passes between ______ and ______
Ulnar Artery:
Superficial ulnar artery branch becomes the superficial palmar arch (anatamoses with the superficial branch of the radial artery)
Deep branch of ulnar artery passes between abductor digiti minimi and flexor digiti minimi
Radial Artery:
Radial artery continues around carpal bones and extends across the floor of the snuff box, then pierces the ________ muscle to enter the palm
Radial Artery:
Radial artery continus around carpal bones and extends across the floor of the snuff box, then pierces the 1st doral interosseous muscle
Nerves of the hand:
Which muscles of the hand does the median nerve innervate?
Which muscles of the hand does the ulnar nerve innervate>
Median: 1/2 LOAF
1 and 2 lumbricles, opponens pollicis, abductor pollicis brevis, flexor pollicis brevis
Ulnar: all other intrinsic muscles
Ulnar nerve:
-enters hand via _______
Ulnar Nerve:
enters hand via canal of Guyon
Has dorsal cutaneous branch and palmar cutaneous branch
Pinky and half of ring finger
Explain the radial nerve branches in the hand
RADIAL nerve has NO motor branches in the hand
Claw Hand:
- Weakness of intrinsic muscles
- Weakness of lumbricles
This is caused by what?
Claw Hand:
ulnar nerve palsy
Ape Hand:
Wasting of thenar muscles, can’t oppose thumb
Ape hand: thenar muscle wasting and can’t oppose thumb:
Median nerve palsy
Hand of Benediction:
happens when you ask them to make a fist
Due to _____ nerve damage
Hand of Benediction:
Median nerve palsy
benedict was a median saint (middle of the pack)
Wrist Drop:
Loss of motor innervation to wrist extensors.
wrist flops over due to damage to the _____ nerve
Wrist Drop:
Radial nerve damage
Top Hat Questions:
- Carpal tunnel affects which nerve?
- What does the recurrent median nerve innervate?
- What ABducts the index finger? What ADducts the fingers?
- Claw hand is an injury to what nerve?
- Carpal tunnel syndrome affects median nerve
- The recurrent median nerve supplies thenar compartment: opponens pollicus, abducens pollicus, flexor pollicus brevis
- First dorsal interosseous
Remember, DAB and PAD (dorsal interosseous will abduct, palmar interosseous will adduct)
- Claw hand —–> injured ulnar nerve
