Compartments of the arm Flashcards
Which muscles are in the anterior compartment of the arm?
Coracobrachialis
Brachialis
Biceps brachii
Where is the origin of the coracobrachialis?
Coracoid process
Where is the insertion of the coracobrachialis?
Midway down humerus on medial aspect
What is the function of the coracobrachilais?
Adducts shoulder
-letting you hold things underarm
Which nerve supplies the coracobrachialis?
Musculocutaneous
Where is the origin of the long head of the biceps brachiii?
Supraglenoid tubercle of scapula
Where is the origin of the short head of the biceps brachii?
Coracoid process
Where is the insertion of the biceps brachii?
Heads join together at mid humerus
common tendon in radial (bicipital) tuberosity
What is the function of the biceps brachii?
Supinator of forearm when elbow is flexed
Elbow flexor when forearm is supinated
At shoulder it acts to stabilise humeral head within glenoid and is a weak flexor
Which nerve supplies the biceps brachii?
Musculocutaneous
Where is the origin of the brachialis?
Distal half of the anterior humeral shaft
Medial intermuscular septum
Where is the insertion of the brachialis?
Converges distally to form tendon that inserts into coronoid process of ulna
What is the function of the brachialis?
Main flexor of elbow
Which nerve supplies the brachialis?
Musculocutaneous
Which muscle is found in the posterior compartment of the forearm?
Triceps brachii (3 heads)
Where is the origin of the long head of the triceps brachii?
Infraglenoid tubercle of scapula
Where is the origin of the lateral head of the triceps brachii?
Lateral lip of spiral groove above deltoid tuberosity
Where is the origin of the medial head of the tricep s brachii?
Medial aspect of the spiral groove of the humerus
Where is the insertion of the long head of the triceps brachii?
Posterosuperior aspect of olecranon
same as lateral head
Where is the insertion of the lateral head of the triceps brachii?
Posterosuperior aspect of olecranon
same as long head
Where is the insertion of the medial head?
Olecranon
-some fibres insert into capsule of elbow joint
What is the function of the triceps brachii?
Stabilises shoulder joint
Extensor of elbow joint
Aids extension of shoulder
Which nerve supplies the triceps brachii?
Radial
What is the path taken by the musculocutaneous nerve?
Arises from lateral cord of brachial plexus
Perforates and supplies coracobrachialis
Passes to the lateral aspect of the arm between biceps brachii and brachialis
Becomes lateral cutaneous nerve of the forearm just above the elbow
Does the median nerve give branches to the arm?
No
Where is the medial cutaneous nerve of the arm located and what does it supply?
Pierces deep fascia in superior part of arm to supply the skin on the anterior and medial aspects
Where is the medial cutaneous nerve of the forearm located and what does it supply?
Pierces deep fascia on the medial aspect of the arm with the basilic vein. It supplies the skin over the inferior part of the arm, then passes into the medial side of the forearm
The brachial artery is a continuation of which other vessel?
The axillary artery
Where does the brachial artery start?
Lower border of teres major
Where does the brachial artery end?
What does it divide into?
Distal to the radius at the level of the neck of the radius
Radial and ulnar arteries
Where does the brachial artery run?
Along medial border of the coracobrachialis and biceps brachii accompanied by the venae commitantaes
What are the branches of the brachial artery?
Profunda brachii artery
Nutrient branches to the humerus
Superior ulnar collateral artery
Inferior ulnar collateral artery
Muscular branches
Where does the profunda brachii artery run?
Posterolaterally with the radial nerve in the spiral groove of the humerus
Which structure does the superior ulnar collateral artery accompany?
Ulnar nerve
Which muscles are supplied by the muscular branch of the brachial artery?
Biceps brachii, brachialis and coracobrachialis
What is another term for deep veins?
What is their function?
Venae commitantaes
Accompany main arteries (usually paired)
Communicate with superficial veins
Where does blood in the radial and ulnar veins flow to in the upper limb?
Radial and ulnar veins unite to form the brachial veins
After receiving tributaries from corresponding braches of the brachial artery they form the axillary vein at the lower border of teres major
Joined by basilic vein
Describe the path taken by the radial nerve from the brachial plexus to supply the arm
Arises from the posterior cord of the brachial plexus
Lies posterior to the axillary and brachial arteries
Winds between the lateral and medial heads of the triceps in the spiral groove with the profunda brachii artery
Braches given off to supply each head proximal to the part that is being innervated
How does the radial nerve leave the arm?
Pierces the lateral intermuscular septum to reach the cubital fossa where it lies between the brachialis and brachioradialis
