Muscles of the forearm Flashcards
How did we classify the muscles of the forearm?
We classified them based on their relationship with various joints, their attachments and mode of action
What is the first group of forearm mucles composed of?
Those are the muscles that are attached to the radius, and are only involved in the movements of bones of the forearm
What is the second group of forearm mucles composed of?
This gorup of muscles extends to the metacarpus and produces the wrist movements
What is the third group of forearm mucles composed of?
Those are the mucles which extend to the phalanges and are responsible for finger movements
What is the main border that separates the muscles of the forearm in 2 big groups?
Those are the ulna, the radius and the interosseous membrane. They divide the muscles into 2 groups:
VENTRAL: flexors
DORSAL: extensors.
It’s the other way around in the leg.
How did we classify the extensors and the flexors?
Into 2 groups: the superficial and the deep muscles
How did we divide the msucles based on their inervations?
The ones from inervated by the:
DORSAL or the VENTRAL side of the plexus
Name all the muscles of the ventral superficial layer
(PFPFF) Pronator teres, Flexor carpi radialis, Palmaris longus, Flexor digitorum superficialis, Flexor carpi ulnaris.
Name all the muscles of the ventral deep layer
(PFF)
Pronator quadratus (rly close to the wrist)
Flexor digitorum profundus
Flexor pollicis longus
What is the origin of m. pronator teres, and what’s the starting muscle structure called?
It has 2 heads. The HUMERAL one, originates from the medial epicondyle and from the MEDIAL INTERMUSCULAR SEPTUM.
The ULNAR ONE that origins from the coronoid process of the ulna.
What is the insertion point of m. pronator teres?
Pronator duberosity of the radius.
What’s m. pronator teres used for?
Pronates the arm w the m. pronator quadratus. It also contibutes to the flexion of the forearm.
What’s the inervation of the m. pronator teres?
Median nerve. C6-C7
What are the origin sites of m. flexor carpi radialis?
- Medial epicondyle
2. Superficial fascia of the forearm
The insertion point of m. flexor carpi radialis?
Palmar surface of the 2nd metacarpal bone. Sometimes it can attach to the third metacarpal as well.
How does the m. flexor carpi radialis get to the insertion point?
Runs through the carpal tunnel, in a groove of the TRAPEZIUM.
Which movements is the m. flexor carpi radialis responsible for?
Weak flexor and pronator of the elbow joint. Participates in palmar flexion and can also produce radial abduction.
What’s the inervation of the m. flexor carpi radialis?
Median nerve. C6-C7.
Explain the position of the m. palmaris longus.
Arises from the medial epicondyle, radiates into the palmar surface of the hand w a palmar aponeurosis (flatlike muscle tendon)
What is the purporse of m. palmaris longus?
Palmar flexion
What’s the inervation of m. palmaris longus.?
Median nerve C7!-T1
What is the origin point of m. flexor digitorum superficialis?
It has 3 heads. The HUMERAL one arises from the medial epicondyle. The ULNAR one arises from the coronoid process (just like pronator teres!!!). The RADIAL one arises from the radius. Close to the r. tuberosity.
What is the structure that stretches between the heads of m. flexor digitorum superficialis?
A tendinous arch.
What structures cross the tendinous arch of the m. flexor digitorum superficialis?
Median nerve, ulnar artery and vein.
How many distal tendons does the m. flexor digitorum superficialis have?
- All of them inserts onto the bony crests of the lateral side of metacarpal bones goint from 2nd to 5th. Here the tendons divide into 2 slips.
THE TENDONS OF M. FLEXOR DIGITORUM PROFUNDUS GLIDE BETWEEN AND THROUGH THEM.
What is the function of m. flexor digitorum superficialis?
It’s a really weak elbow flexor, but a really strong carpal flexor + finger joint flexor.
What is the inervation of the m. flexor digitorum superficialis?
It’s the median nerve.
C7-T1.
The origin points of m. flexor carpi ulnaris?
The medial epicondyle, the olecranon, the 2/3 of the prosterior margin of the ulna.
What is the insertions of the m. flexor carpi ulnaris?
It inserts onto the pisiform, and extends by the pisohamate ligament as far as the hamate. It goes by the pisometacarpal ligament all the way to the 5th metacarpal.
What is the position of the tendon of m. flexor carpi ulnaris in relation to the carpal tunnel?
It runs outside the carpal tunnel.
What are the functions of the m. flexor carpi ulnaris?
It does the palmar flexion, (it’s more effective than the flexor carpi radialis), helps with ulnar adduction (deviation)
What is the nerve supply for the m. flexor carpi ulnaris?
It is the ulnar nerve.
C7-C8.
What is the place of origin of the m. pronator quadratus?
Distal quarter of the palmar surface of the ulna.
What is the insertion point of m. pronator quadratus?
It’s the distal quarter of the palmar surface of the raduis.