Anatomical position

That of the body standing upright, with the feet at shoulder width and parallel, toes forward. The upper limbs are held out to each side, and the palms of the hands face forward.

Anterior (ventral)

Describes the front or direction toward the front of the body.

Cerebrospinal fluid (CSF)

A colorless fluid produced by the brain that cushions the brain and spinal cord within the posterior (dorsal) cavity.

Coelomic

Cavities that do not open to the outside.

Connective tissue

Type of tissue that serves to hold in place, connect, and integrate the body’s organs and systems.

Cutaneous membrane

Epithelial tissue made up of stratified squamous epithelial cells that cover the outside of the body; skin.

Deep

Describes a position farther from the surface of the body.

Distal

A position in a limb that is farther from the point of attachment or the trunk of the body.

Epithelial membrane

Epithelium attached to a layer of connective tissue.

Frontal plane

Two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions.

Homeostasis

The state of steady internal conditions maintained by living things.

Inferior (caudal)

A position below or lower than another part of the body proper.

Lateral

Describes the side or direction toward the side of the body.

Medial

Describes the middle or direction toward the middle of the body.

Mucous membrane

Epithelial membranes that line the body cavities and hollow passageways that open to the external environment.

Parietal layer

Outermost layer of the pleura that connects to the thoracic wall, mediastinum, and diaphragm.

Pericardium

Membrane that separates the heart from other mediastinal structures; consists of two distinct, fused sublayers: the fibrous pericardium and the parietal pericardium.

Peritoneum

Serous membrane that lines the abdominopelvic cavity and covers the organs found there.

Pleura

The membrane that wraps around the outside of your lungs and lines the inside of your chest cavity.

Posterior (dorsal)

Describes the back or direction toward the back of the body.

Prone

A face-down orientation.

Proximal

A position in a limb that is nearer to the point of attachment or the trunk of the body.

Sagittal plane

Two-dimensional, vertical plane that divides the body or organ into right and left sides.

Serous membrane

One of the thin membranes that cover the walls and organs in the thoracic and abdominopelvic cavities.

Serous space

The very thin, fluid-filled space between the parietal and visceral layers.

Superficial

Describes a position nearer to the surface of the body.

Superior (cranial)

A position above or higher than another part of the body proper.

Supine

A face-up orientation.

Synovial membrane

Thin layer that lines the inner surface of the joint cavity at a synovial joint; produces the synovial fluid.

Tissue membrane

Thin layer or sheet of cells that covers the outside of the body, organs, and internal cavities.

Visceral layer

Innermost layer of the pleura that is superficial to the lungs and extends into the lung fissures.