Dissection of the forearm Flashcards
Name the common flexor origin
Medial epicondyle of the humerus
Name the superficial flexor muscles
Palmaris longus
Flexor carpi radialis
Flexor carpi ulnaris
Pronator teres
Name the intermediate flexor muscle
Flexor digitorum superficialis
Where does palmaris longus originate and insert?
Origin: Medial epicondyle
Insertion: Palmar aponeurosis
Where does flexor carpi radialis originate and insert?
Origin: Medial epicondyle
Insertion: 2nd and 3rd metacarpal bones
Where does flexor carpi ulnaris originate and insert?
Origin: Medial epicondyle
Insertion: Pisiform bone and 5th metacarpal
Where does pronator teres originate and insert?
Origin: Medial epicondyle
Insertion: Radius
Where does flexor digitorum superficialis originate and insert?
Origin: Medial epicondyle
Insertion: Proximal interphalangeal joint
Name the 3 deep flexors of the forearm
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
Where does flexor digitorum profundus originate and insert?
Origin: Medial epicondyle
Insertion: Distal phalanges
Where does flexor pollicis longus originate and insert?
Origin: Medial epicondyle
Insertion: Distal phalanx of digit 1
Where does pronator quadratus originate and insert?
Origin: Distal end of ulna
Insertion: Distal end of radius
What is the function of flexor retinaculum?
strong band of fibrous connective tissue
that crosses the wrist and holds the long tendons firmly in place and prevents them from
‘bowstringing’
forms the roof of the carpal tunnel
What is the carpal tunnel?
a fibro-osseous tunnel containing the tendons of the superficial and deep flexors as well as
the median nerve
What does the brachial artery divide into and where?
Radial and ulnar arteries at the cubital fossa
Which muscle overlies radial artery?
Brachioradialis
Which muscle overlies ulnar artery?
Flexor carpi ulnaris
Name the branch at the proximal end of the ulnar artery
Common interosseous artery
What does the common interosseous artery divide into?
anterior and posterior interosseous arteries.
Where are the interosseous arteries located?
These arteries run down each side of the
interosseous membrane, which lies between the radius and ulna.
At the hand which artery is superficial?
Ulnar
Describe the travel of the radial artery
After passing below brachioradialis, winds dorsally at the wrist and crosses the anatomical snuffbox
Describe the travel of the ulnar nerve
Passes through the cubital tunnel to gain
access to the forearm.
It travels down the forearm under cover of flexor carpi ulnaris,which it supplies, lying medial to the ulnar artery
As the nerve crosses the wrist it lies superficial to
the flexor retinaculum.
Within the hand it divides into a deep and superficial branch
What does the ulnar nerve supply?
flexor digitorum profundus.
many of the intrinsic muscles of the hand,
Describe the travel of the median nerve
The median nerve enters the forearm between the two heads of pronator teres, continues into carpal tunnel where it lies between the superficial and deep digital
flexor tendons.
What does the median nerve supply?
All the muscles of the anterior compartment with the exception of flexor carpi ulnaris and the ulnar side of the deep digital flexor
Muscles in the hand forming the ball of the thumb.
What does the musculocutaneous nerve enter the forearm as?
lateral cutaneous nerve of the forearm
What does the lateral cutaneous nerve of the forearm supply?
the skin on the dorsal and ventral side of the forearm as far distally as the ball of
the thumb.
What is the common extensor origin?
Lateral epicondyle of the humerus
Give the origin and insertion of brachioradialis
Origin: Lateral supracondylar ridge of the humerus
Insertion: Styloid process of the radius
Give the function of brachioradialis
Flexor of forearm when half pronated
Give the origin and insertion of extensor carpi radialis brevis
Origin: Lateral supracondylar ridge of the humerus
Insertion: second metacarpal
Give the origin and insertion of extensor carpi radialis longus
Origin: Lateral epicondyle of humerus
Insertion: Base of third metacarpal
Where does extensor carpi ulnaris originate and insert?
Origin: Lateral epicondyle of humerus
Insertion: 5th metacarpal
Give the origin and insertion of extensor digitorum
Origin: Lateral epicondyle of humerus
Insertion: Middle and distal phalanges of d2-5
Name 2 accessory extensors
Extensor digiti minimi
Extensor indicis
Describe the location of the supinator
surrounds the upper third of the radius having taken origin from the ulna and the
humerus. The fibres pass behind the radius and insert into the proximal third of the
anterior aspect of the radius just proximal to pronator teres
Describe the radial nerve
Supplies the muscles and skin over the posterior aspect of the upper
limb.
The nerve enters the anterior compartment of the forearm from the lateral side and
supplies brachioradialis and the extensor carpi radialis longus muscles. As it crosses
supinator, it gives off a large deep branch, the posterior interosseous nerve. The deep branch pierces supinator to enter the posterior compartment of the forearm and
supplies the rest of the extensor muscles in the forearm. The superficial branch of the radial nerve carries on down the forearm under cover of brachioradialis. As it approaches the wrist the superficial branch passes deep to the tendon of brachioradialis and divides into several digital branches to supply the skin on the dorsolateral aspect of
the hand
