STERNALIS MUSCLE

What’s the structure labelled 1?

Nipple: A small projection on the breast, containing the opening of the milk ducts in females, playing a key role in breastfeeding.

What’s the structure labelled 2?

Pectoralis Muscle: A large, fan-shaped muscle located on the chest, involved in the movement of the shoulder joint, such as flexion, adduction, and rotation of the arm.

What’s the structure labelled 3?

Serratus Anterior Muscle: A muscle that runs along the side of the chest and helps in the movement of the scapula, playing an essential role in lifting the arm and stabilizing the shoulder blade.

What’s the structure labelled 4?

External Oblique Muscle: A broad, flat muscle on the side and front of the abdomen, important for trunk rotation and flexion, as well as supporting the abdominal wall.

What’s the structure labelled 5?

Rectus Abdominis Muscle: Known as the "six-pack" muscle, this long muscle runs vertically along the abdomen and is responsible for flexing the lumbar spine (bending forward) and stabilizing the core.

What’s the structure labelled 6?

Sternocleidomastoid Clavicular Attachment: This muscle connects the sternum and clavicle to the mastoid process of the skull, helping to rotate and flex the head, as well as assist with forced inspiration.

What’s the structure labelled 7?

Sternalis Muscle: A rare, variable muscle that runs parallel to the sternum and may assist in chest wall movements, though its function is not entirely understood.

What’s the structure labelled 8?

Sternalis Tendon Sternum Attachment: This tendon connects the sternalis muscle to the sternum, potentially aiding in chest wall motion, though its role remains relatively obscure due to the muscle's rarity.