Introduction to Health Science

The process in which organ systems work to maintain a stable internal environment.

is that of the body standing upright, with the feet at shoulder width and parallel, toes forward.

describes a face-down orientation.

describes a face up orientation.

(or ventral) Describes the front or direction toward the front of the body. The toes are anterior to the foot.

(or dorsal) Describes the back or direction toward the back of the body. The popliteus is posterior to the patella.

(or cranial) describes a position above or higher than another part of the body proper. The orbits are superior to the oris.

(or caudal) describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column). The pelvis is inferior to the abdomen.

describes the side or direction toward the side of the body. The thumb (pollex) is lateral to the digits.

describes the middle or direction toward the middle of the body. The hallux is the medial toe.

describes a position in a limb that is nearer to the point of attachment or the trunk of the body. The brachium is proximal to the antebrachium.

describes a position in a limb that is farther from the point of attachment or the trunk of the body. The crus is distal to the femur.

describes a position closer to the surface of the body. The skin is superficial to the bones.

describes a position farther from the surface of the body. The brain is deep to the skull.

The sagittal plane is the plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into unequal right and left sides, it is called a parasagittal plane or less commonly a longitudinal section.

The frontal plane is the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. The frontal plane is often referred to as a coronal plane. (“Corona” is Latin for “crown.”)

The transverse plane is the plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.

The dorsal (posterior) cavity and the ventral (anterior) cavity are the largest body compartments.

The dorsal (posterior) cavity and the ventral (anterior) cavity are the largest body compartments.

The cranial cavity houses the brain.

The spinal cavity (or vertebral cavity) encloses the spinal cord.

The thoracic cavity is the more superior subdivision of the anterior cavity, and it is enclosed by the rib cage. he thoracic cavity contains the lungs and the heart, which is located in the mediastinum.

The abdominopelvic cavity is the largest cavity in the body. Although no membrane physically divides the abdominopelvic cavity, it can be useful to distinguish between the abdominal cavity, the division that houses the digestive organs, and the pelvic cavity, the division that houses the organs of reproduction.