Human Body Anatomy and Body Cavities: Key Concepts and Structures

Body Cavities

Protect delicate organs and allow organs to change shape and size.

Dorsal Cavity

Includes cranial and spinal cavities.

Cranial Cavity

Formed by the skull and houses the brain.

Spinal Cavity

Formed by vertebrae and contains the spinal cord.

Ventral Cavity

Includes thoracic and abdominopelvic cavities, separated by the diaphragm.

Pleural Cavity

Also known as the lung cavity.

Pericardial Cavity

Cavity that surrounds the heart.

Mediastinum

Separates the thoracic cavity into three cavities.

Anatomical Position

Standing upright with arms at sides, palms forward, and feet together.

Anterior

Front; ventral.

Posterior

Back; dorsal.

Superior

Above; towards the head.

Inferior

Below; towards the feet.

Proximal

Closer to where the limb inserts.

Distal

Farther from where the limb inserts.

Medial

Close to the midline.

Lateral

Further from the midline.

Sagittal Plane

Lengthwise left and right portions.

Frontal Plane

Sideways anterior and posterior portions.

Transverse Plane

Horizontal superior and inferior portions.

Oblique Plane

Any diagonal section.

Supine Position

Back facing up.

Prone Position

Face down.

Abdominopelvic Regions

Abdominopelvic Quadrants

Membranes

Flat flexible sheets made of one or more tissues that cover areas in/on the body.

Serous Membranes

Line body cavities and internal organs, secreting serous fluid.

Visceral Layer

Covers the outer surface of organs.

Parietal Layer

Lines the inside of body cavities.

Cytology

The study of cells.

Histology

The study of tissues.

Physiology

The study of function within the body.

Levels of Structural Organization

Includes chemical, cellular, tissue, organ, organ system, and organism levels.

Pelvic Cavity

contains urinary bladder, portions of large intestine, and internal organs of reproduction

Abdominal Cavity

Contains stomach, intestines, spleen, and liver, small, and large intestine.

Superior

toward the head above

Inferior

Towards the feet below