Upper Arm Flashcards
How many muscles are contained within the upper arm?
Four - 3 in the anterior compartment and 1 in the posterior compartment.
What are the muscles of the anterior compartment?
- Biceps brachii
- Brachialis
- Coracobrachialis
Memory Aid: BBC
What the muscle in the posterior compartment?
Triceps Brachii.
How are the muscles of the anterior compartment innervated?
All innervated by the musculocutaneous nerve.
Biceps Brachii: Attachments, Function and Innervation.
Two-headed muscle with a majority of its mass located anteriorly to the humerus.
Origin of long head: supraglenoid tubercle of scapula
Origin of short head: coracoid process of scapula
Insertion: Both heads insert distally into radial tuberosity and the fascia of the forearm via bicipital aponeurosis.
Function: Supination of forearm and flexes arm at elbow and shoulder.
Innervation: Musculocutaneous nerve.
Coracobrachialis: Attachments, Function, Innervation.
Lies deep to the biceps brachii.
Origin: Coracoid process of scapula
Insertion: Medial side of the humeral shaft, at the level of the deltoid tubercle.
Function: Flexion of arm at shoulder and weak adduction.
Innervation: Musculocutaneous nerve.
Brachialis: Attachments, Function, Innervation.
Lies deep to the biceps brachii and forms floor of cubital fossa.
Origin: Medial and lateral surfaces of the humeral shaft.
Insertion: Ulna tuberosity, just distil of the elbow joint.
Function: Flexion at the elbow.
Innervation: Musculocutaneous Nerve.
Triceps Brachii: Attachments, Function, Innervation.
Origin of long head: Infraglenoid tubercle.
Origin of lateral head: humerus, superior to radial groove.
Origin of medial head: humerus, inferior to radial groove.
Insertion: distally, the heads converge onto one tendon and insert into the olecranon of the ulna.
Function: Extension of arm at elbow.
Innervation: Radial nerve.
What is the cubital fossa?
An area of transition between the anatomical arm and the forearm.
- Located as a depression on the anterior surface of the elbow joint.
What are the borders of the cubital fossa?
Lateral border - medial border brachioradialis muscle.
Medial border - lateral border of the pronator trees muscle.
Superior border - an imaginary line between the epicondyles of the humerus.
Floor of cubital fossa - formed proximally by the brachial and distally by the supinator muscle.
What is contained within the cubital fossa?
- Radial Nerve
- Biceps tendon
- Brachial artery
- Median nerve