Forearm and hand Flashcards
What is the interosseous membrane?
Membrane which separates the radius and the ulna
What are the carpal bones?
Bones of the wrist:
Scaphoid
Lunate
Triquetrium
Pisiform
Hamate
Capitate
Trapeziod
Trapezium
How can you tell the difference between the anterior and posterior of the carpal bones?
Antenterior - can see the pisiform and hook of hamate
What is the carpal tunnel?
Formed by the curvature of the carpal bones and the overlying flexor retinaculum
Prevents the tendons from dangling
What tendons pass through the carpal tunnel?
Flexor palmaris longus
Flexor digitorum superficialis
Flexor digitorum profundus
What nerve passes through the carpal tunnel?
The median nerve
What forms the wrist joint?
The articulation of the scaphoid and lunate with the radius
What are the metacarpals?
Long bones of the hand which sit between the carpals and the phalanges
What is metacarpal I? V?
I is the thumb
V is the little finger
Which digits have 3 phalanges?
II - V:
Proximal
Middle
Distal
How many phalanges does the thumb have?
2:
Proximal and distal
What is ALWAYS the insertion point for pronation/supranation?
The radius
If a muscle crosses a joint, what does it do?
MOVES the joint
What does ‘carpi’ mean?
The wrist
What is the motor innervation of the hand?
ALL ulna apart from:
LOAF - median nerve
(Lateral lumbricals, thenar eminance)
What is the sensory/cutaneous innervation of the hand?
Median nerve - WHOLE of thumb and half of ring finger (palmar side) and the DISTAL IP joint on the posterior side
Ulna - Half of ring finger to little finger (both sides)
Radial - From IP joint on the thumb and half ring finger
In the anterior forearm, all of the muscles are supplied by the median nerve except….
1) ‘The one with ulna in its name’ - Flexor carpi ulnaris (ulna nerve)
2) ‘The profound one’ - Flexor digitorum profundus (1/2 ulna)
3) ‘The imposter’ - Brachioradialis (Radial)
What are the symptoms of carpal tunnel syndrome?
Numbness near thumb and index finger
Difficulty grasping objects
What are the causes of carpal tunnel syndrome?
Pregnancy Diabetes Arthritis Family history Compression
What are the treatments for carpal tunnel syndrome? (2)
1) Surgery - cut flexor retinaculum - relieve pressure
2) Splinting - keeps hand in neutral position (reduce pressure and symptoms)
Where take an arterial blood gas sample from?
RADIAL artery
What innervates all of the muscles of the anterior forearm and arm?
Radial artery
How is the brachioradialis an ‘imposter’?
Extensor origin and innervation
Acts as a flexor of the elbow
Which muscle allows the separate extension of the little finger?
Extensor digiti minimi
What makes the medial border of the anatomical snuffbox?
The tendon of the extensor pollicis longus
What makes the lateral border of the anatomical snuffbox?
The tendon of the extensor pollicis brevis
The tendon of the abductor pollicis longus
Which artery gives rise to the common digital arteries?
Superior palmar arch
What causes wrist drop?
Damage to the radial nerve PROXIMALLY to the elbow (axilla or radial groove)