Four major parts of a rib?

Head

The head of a rib is a rounded structure located at the proximal end of the rib. It has two facets for articulation with the thoracic vertebrae:

1. Capitulum: The capitulum is the larger and more medial of the two facets. It articulates with the facet on the body of the corresponding thoracic vertebra.

2. Tubercle: The tubercle is the smaller and more lateral of the two facets. It articulates with the facet on the transverse process of the corresponding thoracic vertebra.

Neck

The neck of a rib is the portion that connects the head to the body. It is a flattened structure that is oriented posterolaterally. The neck is usually quite short, but it is longer in the lower ribs.

Body

The body of a rib is the longest and most substantial portion of the rib. It is a flattened, curved structure that extends from the neck to the costal cartilage. The body of a rib is divided into three regions:

1. Medial region: The medial region of the rib body is the thickest and strongest part of the rib. It is located near the head and neck of the rib.

2. Lateral region: The lateral region of the rib body is thinner and weaker than the medial region. It is located near the costal cartilage.

3. Tubercle region: The tubercle region of the rib body is located near the junction of the medial and lateral regions. It has a roughened surface for the attachment of muscles.

Costal cartilage

The costal cartilage is a thin, flexible structure that connects the sternal end of a rib to the sternum. It is composed of hyaline cartilage and is flexible, allowing for movement of the chest during breathing.