Skeleton of the Thorax and the Human Breast

Vocabulary terms covering the anatomy of the thoracic cage, including the sternum, ribs, and vertebral articulations, as well as the structure and clinical aspects of the human breast.

Osteocartilaginous

The nature of the thoracic skeleton, being composed of both bone (12 thoracic vertebrae, 12 pairs of ribs, sternum) and cartilage (10 pairs of costal cartilages).

Manubrium

The most superior section of the sternum which joins with the clavicles, Rib 1, and the body of the sternum; it features the sternal notch and the sternal angle.

Sternal (jugular) notch

A superior feature of the manubrium where blood pulsing through the aorta can sometimes be seen.

Sternal angle

The junction where the manubrium and body of the sternum meet; it serves as a clinical marker for the second rib and the location of two major heart valves.

Xiphoid process

The most inferior section of the sternum; a clinical marker for the superior liver surface, the apex of the heart, and the central tendon of the diaphragm.

Vertebrosternal (True) ribs

Ribs 1–7, which attach directly to the sternum via their own individual costal cartilages.

Vertebrochondral ribs

Ribs 8–10, which attach to the costal cartilage of Rib 7 rather than directly to the sternum.

Vertebral (Floating) ribs

Ribs 11 and 12, which have no sternal attachment and end in the muscles of the lower lumbar area.

Typical Ribs

Ribs 3–9, which possess standard features including a head, neck, tubercle, angle, and costal groove.

Tubercle

A feature on ribs 1–10 that forms a joint with the transverse processes of the vertebrae.

Costal groove

The location on a rib where the costal Vein-Artery-Nerve (VAN) is situated.

Demifacets

Small superior and inferior articular surfaces on thoracic vertebral bodies 1–9 that allow ribs 2–9 to articulate with two adjacent vertebrae.

Rib 1

The shortest and most flattened atypical rib; it contains grooves for subclavian vessels and lies inferior and posterior to the clavicle.

Lobules

Small oval structures in the breast lined with milk-secreting cells; usually 15–20 are organized into lobes per breast.

Lactiferous duct

The structure that drains milk from the lobules into a lactiferous sinus.

Lactiferous sinus

An area located just deep to the nipple where milk is stored before being released.

Suspensory ligaments

Structures that support the breast from the skin and fascia.

Areola

The darkly pigmented ring of skin surrounding the nipple containing areolar glands that lubricate the nipple during lactation.

Axillary Tail

An extension of breast tissue that reaches into the axilla.

Metastasis

The spread of cancer cells from the primary tumor to other sites, such as lymph nodes or the opposite breast.

Sentinel lymph node

The first node in the chain of lymph nodes draining the breast; it is used to determine if cancer has spread.

Lymphedema

Swelling of a limb distal to the site where lymph nodes were surgically removed.