Anterior forearm and wrist Flashcards
What is the action of the muscles of the anterior compartment of the forearm?
Flexion of the wrist and digits
Pronation
What is the common flexor origin?
Medial epicondyle of the humerus
What nerve supplies a majority of the muscles of the anterior forearm?
Median
Flexor carpi ulnaris and ring/pinky side of flexor digitorum profundus are supplied by ulnar nerve
What is the most superficial muscle of the anterior forearm?
Palmaris Longus
What muscle is this and what is its innervation?
Plamaris Longus
Median (C7,8)
What are the attachments of Palmaris Longus?
From the medial epicondyle of the humerus to the palmar fascia (aponeurosis)
What is the action of palmaris longus?
Tightens the aponeurosis which aids in wrist flexion
True or False?
Palmaris longus is not present in everyone
True!
What is this muscle and its innervation?
Pronator Teres
Median
What passes between the heads of pronator teres?
Median nerve
What are the attachments of pronator teres?
Medial epicondyle of humerus and coronoid process of ulna
Inserts into lateral surface of radius
What is the action of pronator teres?
Pronation
assists in elbow flexion
What muscle is this and what is its innervation?
Flexor carpi radialis
Median nerve
What is the function of flexor carpi radialis?
Wrist flexion
Abduction of wrist (with extensor carpi radialis)
What are the attachment of flexor carpi radialis?
Medial condyle of humerus
Inserts into base of the 2nd metacarpal
What is this muscle and its innervation?
Flexor carpi ulnaris
Ulnar nerve
What are the attachments of flexor carpi ulnaris?
Medial epicondyle of humerus
Inserts - base of pisiform, hamate and 5th metacarpal
What are the actions of flexor carpi ulnaris?
Flexion of wrist
Adduction (with extensor carpi ulnaris)
What muscle is highlighted and what is its innervation?
Flexor digitorum superficialis
Median nerve
What are the attachments of flexor digitorum superficialis?
Medial epicondule of humerus and coronoid process of ulna
Inserts- middle phalanges (lateral) of digits 2-5
What are the actions of flexor digitorum superficialis?
Flexion of MCPs and PIPs
Flexion of wrist
What is this nerve and its innervation?
Flexor digitorum profundus
- Ring and pinky - ulnar nerve
- Index and middle - anterior interosseous branch of median nerve
What are the attachments of flexor digitorum profundus?
Ulna and interosseous membrane
Inserts to distal phalanges of digits 2-5
What is the action of flexor digitorum profundus?
Flexion of MCPs, PIPs and DIPs of digits 2-5
Flexion of wrist
What is this muscle and its innervation?
Flexor Pollicus Longus
Anterior interosseous branch of Median nerve
What are the attachments of flexor pollicus longus?
Radius and interosseous membrane
Inserts on base of distal phalanx of thumb (palmar)
What are the actions of flexor pollicus longus?
Flexion of MCP and IP of thumb
Flexion of wrist
What is this muscle and what is its innervation?
Pronator Quadratus
Anterior interosseous branch of Median nerve
What is the action of pronator quadratus?
Pronation
Helps stabilise distal radioulnar joint
What are the attachments of pronator quadratus?
Distal anterior ulna to distal anterior radius
What forms the median nerve?
C6-T1 fibres
Medial and lateral cords
What is the major nerve of the anterior compartment of the forearm?
Median nerve
What nerve passes through the carpal tunnel?
Median nerve
True or False?
The radial nerve supplies this area
False!
On the palmar aspect the median nerve supplies the thenar aspect of the hand
What muscle does the median nerve pass between?
The heads of pronator teres
True or False?
The ulnar nerve passes through the carpal tunnel?
False
It passes over it
What forms the ulnar nerve and describe its route?
C7-T1 fibres from the medial cord
Runs in the medial side of the arm then passes along the medial groove in the humerus to reach the anterior forearm. It runs on the medial side between flexor carpi ulnaris and the mdeial side of flexor digitorum profundus then passes over the carpal tunnel close to the pisiform
What is the major arterial contribution to the superficial palmar arch of the hand?
Ulnar artery
What artery gives rise to the ulnar artery?
Brachial artery
True or False?
The radial artery gives off the common interosseous artery
False!
It is the ulnar. This further splits into anterior and posterior interosseous arteries
What classification of joint is the wrist?
Synovial condyloid
What movements occur at the wrist?
Flexion, Extension
Adduction, Abduction
Circumduction
What type of joint is present between the carpal bones?
Synovial plane
Name the proximal carpal bones
Scaphoid
Lunate
Triquestrium (with pisiform on top)
Name the distal row of carpal bones
Trapezium
Trapezoid
Capitate
Hamate
What is highlighted?
Radial collateral ligament of the wrist
What is highlighted?
The ulnar collateral ligament of the wrist
What forms the roof of the carpal tunnel?
Thickened part of the flexor retinaculum
Does the ulna articulate directly with the proximal carpal bones?
No it articulates with an articular disc to improve the congruency of the joint
What do the medial and lateral aspects of the flexor retinaculum attach to?
Medial - pisiform and hook of hamate
Lateral - tubercle of scaphoid and ridge on trapezium
The flexor retinaculum forms a septum at the trapezium. What structure passes through here?
Flexor carpi radialis tendon
What structures pass through the carpal tunnel?
Tendons of flexor digitorum superficialis Tendons of flexor digitorum profundus Tendon of flexor pollicus longus Tendon of flexor carpi radialis Median nerve
