Lab 3.2: Thoracic Cage

Vocabulary flashcards covering the anatomy of the thoracic cage, including the sternum, ribs, vertebrae, and associated joints and functions.

Thoracic Cage

The bony structure of the chest consisting of the sternum, ribs, costal cartilage, and thoracic vertebrae.

Sternum

The breastbone, composed of three main parts: the manubrium, the body, and the xiphoid process.

Manubrium

The superior portion of the sternum that articulates with the clavicles and the first pair of ribs.

Xiphoid process

The smallest and most inferior part of the sternum.

Sternal angle

The horizontal ridge where the manubrium joins the body of the sternum.

Jugular notch

Also known as the suprasternal notch; the central indentation on the superior border of the manubrium.

Clavicular notch

The depressions on the manubrium where the sternum articulates with the clavicles.

True Ribs

Ribs $1-7$, which attach directly to the sternum through their own costal cartilages.

False Ribs

Ribs $8-10$, which attach to the costal cartilage of the rib above them (rib $7$) rather than directly to the sternum.

Floating Ribs

Ribs $11-12$, which have no anterior attachment to the sternum or other ribs.

Costa

The anatomical term for a rib.

Costal Cartilage

Bars of hyaline cartilage that connect the ribs to the sternum, contributing to the elasticity of the thoracic cage.

Costal Groove

A groove on the internal surface of the inferior border of a rib that houses the intercostal vein, artery, and nerve.

Costovertebral joint

The articulation between the head of the rib and the vertebral body.

Costotransverse joint

The articulation between the tubercle of a rib and the transverse process of the numerically corresponding vertebra.

Costochondral joint

The joint between the sternal end of the rib and the costal cartilage.

Sternocostal joint

The joint between the costal cartilage and the sternum.

Thoracic Vertebrae ($T1-T12$)

Vertebrae characterized by heart-shaped bodies, long inferiorly projected spinous processes, and costal facets for rib articulation.

Lumbar Vertebrae ($L1-L5$)

Vertebrae characterized by large kidney-shaped bodies, short rectangular spinous processes, and thin tapered transverse processes.

Sacrum

A triangular bone formed by the fusion of five sacral vertebrae ($S1-S5$).

Coccyx

The tailbone, located at the very inferior end of the spinal column.

Superior thoracic aperture

The opening at the top of the thoracic cage, bounded by the first thoracic vertebra, first ribs, and the manubrium.

Inferior thoracic aperture

The large opening at the bottom of the thoracic cage, bounded by the $T12$ vertebra, ribs $11-12$, costal margins, and xiphisternal joint.

Intercostal Space

The space between adjacent ribs, containing intercostal muscles, nerves, and vessels.

Inhalation mechanism

Occurs when the diaphragm and external intercostal muscles contract, increasing the thoracic volume.

Exhalation mechanism

Occurs when the diaphragm relaxes and expiratory muscles (like abdominal muscles) contract, decreasing thoracic volume.