The scapula

Question 1

Scapula Structure

Answer 1

The scapula has three main borders: the superior, medial (vertebral), and lateral (axillary) borders.
- It features several important landmarks:
- Spine of the Scapula: A prominent ridge that runs diagonally across the posterior surface.
- Acromion: The lateral extension of the spine that articulates with the clavicle.
- Coracoid Process: A hook-like structure on the anterior surface, serving as an attachment point for ligaments and muscles.
- Glenoid Cavity: A shallow socket that articulates with the head of the humerus, forming the glenohumeral joint.

Question 2

The scapula Muscles

Answer 2

The scapula serves as an attachment site for several muscles that facilitate movement of the shoulder and upper limb. Key muscles associated with the scapula include:

1. Rotator Cuff Muscles:
   - Supraspinatus: Abducts the arm.
   - Infraspinatus: Externally rotates the arm.
   - Teres Minor: Assists in external rotation.
   - Subscapularis: Internally rotates the arm.
2. Other Muscles:
   - Deltoid: Originates from the acromion and spine of the scapula, responsible for arm abduction, flexion, and extension.
   - Trapezius: Elevates, retracts, and rotates the scapula.
   - Rhomboids (Major and Minor): Retract the scapula.
   - Serratus Anterior: Protracts and stabilizes the scapula against the thoracic wall.
   - Pectoralis Minor: Stabilizes the scapula by drawing it anteriorly and inferiorly

Question 3

Joints of scapula

Answer 3

1. Glenohumeral Joint:
   - Formed by the articulation of the glenoid cavity of the scapula and the head of the humerus. It is a ball-and-socket joint that allows for a wide range of motion.
2. Acromioclavicular Joint:
   - The joint between the acromion of the scapula and the clavicle. It allows for limited movement and plays a role in shoulder stability.
3. Sternoclavicular Joint:
   - Although not directly involving the scapula, this joint connects the clavicle to the sternum and indirectly affects scapular movement.

Question 4

Ligaments associated with the scapula

Answer 4

1. Glenohumeral Ligaments: A group of ligaments that reinforce the glenohumeral joint capsule.
2. Coracoclavicular Ligament: Connects the coracoid process of the scapula to the clavicle, providing stability to the acromioclavicular joint.
3. Acromioclavicular Ligament: Reinforces the acromioclavicular joint.
4. Coracoacromial Ligament: Connects the coracoid process to the acromion, forming a protective arch over the shoulder joint.

Question 5

Nerves associated with the scapula

Answer 5

1. Suprascapular Nerve: Innervates the supraspinatus and infraspinatus muscles.
2. Long Thoracic Nerve: Innervates the serratus anterior muscle, crucial for scapular protraction and stabilization.
3. Dorsal Scapular Nerve: Innervates the rhomboids and levator scapulae muscles.
4. Axillary Nerve: Innervates the deltoid and teres minor muscles and provides sensation to the skin overlying the deltoid muscle.

Question 6

Blood vessel of scapula

Answer 6

The blood supply to the scapula is primarily provided by several key arteries that branch from the subclavian artery and the axillary artery. Here are the main arteries involved:

1. Suprascapular Artery: This artery branches from the thyrocervical trunk, which is a branch of the subclavian artery. It supplies blood to the supraspinatus and infraspinatus muscles, as well as the shoulder joint.
2. Dorsal Scapular Artery: This artery typically arises from the subclavian artery or the transverse cervical artery. It supplies the rhomboid muscles and the levator scapulae, as well as portions of the serratus anterior.
3. Circumflex Scapular Artery: This artery branches from the subscapular artery (which itself is a branch of the axillary artery). It wraps around the lateral border of the scapula and supplies the muscles in that region, including the teres major and minor.
4. Thoracodorsal Artery: Also a branch of the subscapular artery, this artery supplies the latissimus dorsi muscle and contributes to the blood supply of the scapular region.

These arteries form an anastomosis around the scapula, ensuring a rich blood supply that supports the muscles and tissues in this area. The vascular network is crucial for the proper functioning of the shoulder girdle and the movements of the upper limb.

Additionally, the axillary artery and its branches, including the subclavian artery, play a significant role in supplying blood to the scapular region. The blood vessels are accompanied by corresponding veins, such as the dorsal scapular vein, which drains the same regions supplied by these arteries.