Subclavian Artery and Axillary Artery Explained Easy
Arteries of the Pectoral Region
The key arteries supplying the pectoral region include the subclavian artery, axillary artery, and their branches.
1. Subclavian Artery
- Origin: The right subclavian artery originates from the brachiocephalic trunk, while the left subclavian artery arises directly from the aortic arch.
- Course: Travels laterally over the first rib and under the clavicle, becoming the axillary artery at the lateral border of the first rib.
Branches:
Subclavian artery gives four branches
- Vertebral Artery: Supplies the posterior part of the brain.
- Internal Thoracic Artery: Descends along the sternum, supplying the anterior chest wall and breasts.
- Thyrocervical Trunk: Gives off several branches, including the inferior thyroid artery, transverse cervical artery, and suprascapular artery.
- Costocervical Trunk: Provides blood to the deep neck muscles and the first two intercostal spaces.
2. Axillary Artery
- Origin: Continuation of the subclavian artery at the lateral border of the first rib.
- Course: Travels through the axilla (armpit), becoming the brachial artery at the inferior border of the teres major muscle.
Divisions:
Division into Three Parts:
it is divided into 3 parts, depending on its position relative to pectoralis minor muscle.
- First Part: it is proximal to pectoralis minor muscle.
- Second Part: Lies deep to the pectoralis minor.
- Third Part: lies distal to pectoralis minor muscle.
First part of Axillary Artery
It gives only one branch.
- Superior Thoracic Artery: Supplies the first and second intercostal spaces and the upper part of the serratus anterior muscle.
Second part of Axillary Artery
it gives 2 Branches.
- Thoracoacromial Artery: Divides into four branches:
- Pectoral Branch: Supplies the pectoral muscles.
- Deltoid Branch: Supplies the deltoid muscle and the shoulder joint.
- Acromial Branch: Supplies the acromion and the deltoid muscle.
- Clavicular Branch: Supplies the subclavius muscle and the sternoclavicular joint.
b. Lateral Thoracic Artery: Supplies the serratus anterior, pectoral muscles, axillary lymph nodes, and the lateral aspect of the breast.
Third part of Axillary Artery
It gives three branches.
- Subscapular Artery: The largest branch of the axillary artery, it further divides into:
- Circumflex Scapular Artery: Supplies the scapula and surrounding muscles.
- Thoracodorsal Artery: Supplies the latissimus dorsi muscle.
b. Anterior Circumflex Humeral Artery: Encircles the humerus and supplies the shoulder joint and deltoid muscle.
c. Posterior Circumflex Humeral Artery: Encircles the humerus and supplies the shoulder joint and deltoid muscle.