Lecture 3: Brachial Plexus and Arm Lecture Notes

A set of practice flashcards covering terms related to the brachial plexus, arm muscles, and regional vasculature based on lecture notes.

Brachial Plexus Upper Trunk

Component of the brachial plexus formed from the $C5$ and $C6$ rami.

Brachial Plexus Middle Trunk

Component of the brachial plexus formed from the $C7$ rami.

Brachial Plexus Lower Trunk

Component of the brachial plexus formed from the $C8$ and $T1$ rami.

Anterior Divisions

Branches of the trunks that form the lateral and medial cords of the brachial plexus.

Posterior Divisions

Branches of the trunks that form the posterior cord of the brachial plexus.

Lateral Cord

Formed by the anterior divisions of the upper and middle trunks.

Medial Cord

Formed by the anterior division of the lower trunk.

Posterior Cord

Formed by the posterior divisions of all three trunks.

Axillary Artery

The vessel that begins at the lateral border of Rib $1$.

Axillary Artery Part I branch

The superior/supreme thoracic artery.

Axillary Artery Part II branches

The Thoracoacromial trunk and the lateral thoracic artery.

Axillary Artery Part III branches

The subscapular artery, anterior humeral circumflex artery, and posterior humeral circumflex artery.

Subscapular Artery Branches

Consists of the circumflex scapular artery and the thoracodorsal artery.

Quadrangular Space Superior Border

Teres minor muscle.

Quadrangular Space Inferior Border

Teres major muscle.

Quadrangular Space Medial Border

Long head of the triceps brachii.

Quadrangular Space Lateral Border

The humerus.

Quadrangular Space Contents

The axillary nerve and the posterior humeral circumflex artery.

Arm (Anatomy definition)

The segment of the upper limb between the shoulder and the elbow.

Forearm (Anatomy definition)

The segment of the upper limb between the elbow and the wrist.

Biceps Brachii Innervation

The musculocutaneous nerve.

Biceps Brachii Long Head Origin

Supraglenoid tubercle and labrum.

Biceps Brachii Short Head Origin

Coracoid process.

Biceps Brachii Actions

Flexion and supination of the forearm; flexion of the arm (long head) and adduction of the arm (short head).

Brachialis Origin

Anterior surface of the distal humerus.

Brachialis Insertion

Coronoid process and tuberosity of the ulna.

Coracobrachialis Action

Flexion and adduction of the arm.

Triceps Brachii Innervation

The radial nerve.

Triceps Brachii Long Head Origin

Infraglenoid tubercle.

Triceps Brachii Insertion

Olecranon process.

Anconeus Action

Extension of the forearm.

Anconeus Origin

Lateral epicondyle of the humerus.

Brachial Artery

The continuation of the axillary artery starting at the lower border of the teres major.

Profunda Brachii Artery

An artery that travels with the radial nerve in the posterior compartment of the arm.

Superior/Supreme thoracic artery

The single branch originating from Part I of the Axillary artery.