Lecture - Forearm and Digits Flashcards
(19 cards)
What are the 3 joints of the hand?
- Wrist Joint (the radiocarpal joint)
- Midcarpal joint (located between the proximal and distal row of carpals)
- Carpometacarpal joints (CMC)
What are the two joints in the thumb?
Metacarpophalangeal (MCP) and Interphalangeal (IP)
What are the four carpal bones form the floor of the carpal tunnel?
Trapezium, trapezoid, capitate, hamate
Where do flexion and extension of the wrist occur?
Radiocarpal and midcarpal joints
Where do wrist Abduction and Adduction occur?
Abduction: midcapral joint
Adduction: Radiocarpal joint
Where do the ulnar nerve and artery enter the palm?
What happens when the ulnar nerve becomes compressed?
a) Guyon’s tunnel, which is formed from the Pisiform and hook of the hamate.
b) Cyclist’s palsy
What carpal bones are at the highest risk for injury?
1) scaphoid, not protected by muscle or tendons
2) lunate is subject for dislocation and can easily pop out of place
what are the 3 joints of the fingers?
- MCP (Metacarpophalangeal)
- PIP (Proximal Interphalangeal)
- DIP (Distal Interphalangeal)
What are the origin, insertion, and innervation of Flexor Digitorum superficialis?
Origin: Medial Epicondyle, proximal ulna and shaft of radius
Insertion runs deep and splits into 4 tendons, which attached to the middle phalanges (all fingers except thumb)
Median Nerve
Flexes fingers at PIP joints
What are the origin, insertion, and innervation of Flexor Digitorum profundus?
Origin: anterior shaft of the ulna and interosseous membrane
Insertion: distal phalanges
Action: Flexes fingers at DIP joints
Innervation: median nerve supplies lateral half of muscle and the ulnar nerve supplies the medial half.
What are the origin, insertion, and innervation of flexor pollicis longus?
Origin: anterior shaft of the ulna and interosseous membrane
Insertion: distal phalanx of the thumb
Action: flexes IP joint of thumb
Median nerve
What are the origin, insertion, and innervation of the Extensor Digitorum?
Origin: Lateral epicondyle of humerus
Insertion: dorsal surfaces of the four fingers, which allows it to extend the fingers.
Radial nerve
What are the origin, insertion, and innervation of the Extensor Indicis?
Origin: posterior surface of ulna and interosseous membrane to the posterior aspect of the index finger!!!!!
Radial nerve
What are the origin, insertion, and innervation of the Extensor digit minimi?
Origin: Lateral epicondyle of humerus to the posterior aspect of the little finger.
Radial nerve
What are the origin, insertion, and innervation of the Abductor pollicis longus?
Posterior aspect of the radius, ulna and interosseous membrane and attaches to the 1st MC bone in the thumb.
Abducts the thumb
Radial nerve
What are the origin, insertion, and innervation of the Abductor pollicis longus?
Posterior aspect of the radius, ulna and interosseous membrane and attaches to the 1st MC bone in the thumb.
Abducts the thumb
Radial nerve
What are the origin, insertion, and innervation of the Extensor pollicis brevis?
Origin: posterior surface of radius to proximal phalanx of thumb
Extends the thumb at MCP joint
Radial nerve
What are the origin, insertion, and innervation of the Extensor pollicis longus?
The posterior surface of ulna and attaches to the distal phalanx of the thumb to aid in the extension of MCP joint (thumb)
Radial nerve
What is the significance of the anatomical snuffbox and the borders
the landmark for scaphoid bone and where the radial artery, and nerve enter the hand.
Extensor pollicis longus, brevis and abductor pollicis longus
