Skeleton of the Thorax and Human Breast Anatomy

This flashcard set covers the osteocartilaginous structure of the thoracic skeleton, classifications of ribs, anatomical landmarks of the sternum, and the physiological and clinical aspects of the human breast.

Osteocartilaginous

The structural nature of the thoracic skeleton, which is composed of bone ($12$ thoracic vertebrae, $12$ pairs of ribs, and the sternum) and hyaline cartilage ($10$ pairs of costal cartilages).

Hyaline cartilage

The type of cartilage that forms the costal joints, making the thoracic skeleton flexible and slightly moveable during breathing.

Manubrium

The superior section of the sternum that forms joints with the clavicles, the costal cartilages of Rib $1$, and the body of the sternum.

Sternal (jugular) notch

A features located on the superior surface of the manubrium where blood pulsing through the aorta may be visible under certain conditions.

Sternal angle

The clinical marker where the manubrium and body of the sternum meet, used to locate the second rib and the $2$nd intercostal space for listening to heart valves.

Body (of sternum)

The section of the sternum inferior to the sternal angle that forms lateral joints with the costal cartilages of ribs $2$-$7$.

Xiphoid process

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

Vertebrosternal (vertebrocostal) ribs

Also known as "true ribs," these are ribs $1$-$7$ which attach directly to the sternum via their own costal cartilage.

Vertebrochondral ribs

Ribs $8$-$10$ which attach to rib $7$ by an elongated cartilage and have no direct connection 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.

False ribs

A category of ribs consisting of ribs $8$-$12$ that do not have a direct individual attachment to the sternum.

Typical ribs

Ribs $3$-$9$ which share common features including a head, neck, tubercle, angle, and costal groove.

Tubercle

A structure found on ribs $1$-$10$ that forms a joint with the transverse processes of the thoracic vertebrae.

Costal groove

A feature on a rib that serves as the location for the costal Vein-Artery-Nerve (VAN).

Demifacets

Smaller costal facets found on thoracic vertebral bodies $1$-$9$ that allow ribs $2$-$9$ to articulate with both their own vertebral body and the one immediately superior.

Rib 1

An atypical rib that is flattened and the shortest in length, featuring grooves for the subclavian vessels on its superior surface.

Ribs 11 and 12

Atypical ribs that possess single facets on their heads, have no tubercles, and articulate only with their respective vertebral bodies.

Modified apocrine sweat gland

The biological classification of the human breast, which is similar to sweat glands found in the axilla and genital areas.

Lobules

Small oval structures in the breast lined with milk-secreting cells, usually numbering $15$-$20$ per breast and organized into lobes.

Lactiferous duct

The structure that drains milk-secreting cells and empties into a lactiferous sinus just deep to the nipple.

Areola

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

Axillary Tail

An extension of the breast tissue that reaches into the axilla.

Sentinel lymph node

The first node in a chain of lymph nodes draining the breast; its status is used in surgery to determine if cancer has metastasized.

Lymphedema

The swelling of a limb distal to the site where lymph nodes were removed during breast cancer surgery.