Anatomical Terminology

OT Dude Academy’s Free NBCOT® Exam Prep Course Medical Terminology, Anatomy, and Physiology Anatomical Terminology

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Anatomical Position

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

Directional Terms

  • Anterior (or ventral) describes the front or direction toward the front of the body. The toes are anterior to the foot.
  • Posterior (or dorsal) describes the back or direction toward the back of the body. The popliteus is posterior to the patella. Dorsal fin.
  • Superior (or cranial) describes a position above or higher than another part of the body proper. The orbits are superior to the oris.
  • Inferior (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 the lowest part of the spinal column). The pelvis is inferior to the abdomen.
  • Lateral describes the side or direction toward the side of the body. The thumb (pollex) is lateral to the digits.
  • Medial describes the middle or direction toward the middle of the body. The hallux is the medial toe.
  • Proximal refers to 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. Close proximity.
  • Distal 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. Distal is distant.
  • Superficial describes a position closer to the surface of the body. The skin is superficial to the bones.
  • Deep describes a position farther from the surface of the body. The brain is deep to the skull.

Body Planes

  • 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.

Body Cavities

The anterior (ventral) and posterior (dorsal) cavities are each subdivided into smaller cavities.

  • Cranial cavity – houses the brain; protected by the bones of the skull and cerebrospinal fluid.
  • Spinal cavity (vertebral cavity) – encloses the spinal cord; protected by the vertebral column and CSF.
  • Thoracic cavity – contains the lungs and the heart; enclosed by the rib cage
    • The diaphragm forms the floor of the thoracic cavity and separates it from the more inferior abdominopelvic cavity.
  • Abdominopelvic cavity – houses the digestive organs, the pelvic cavity, and the reproductive organs; largest cavity in the body; no membrane divides the abdominopelvic cavity.

Tissue Membranes

  • Mucous membranes – line the digestive, respiratory, urinary, and reproductive tracts; coated with mucous gland secretions.
  • Serous membranes – line the body cavities closed to the exterior of the body: the peritoneal, pleural, and pericardial cavities.
  • Cutaneous membrane – the skin; covers the body surface
  • Synovial membranes – line the joint cavities and produce the fluid within the joint.
  • Connective tissue membrane – formed solely from connective tissue. Encapsulate organs and line the movable joints.
  • Epithelial membrane – composed of epithelium attached to a layer of connective tissue, e.g., skin
  • Parietal layers – line the walls of the body cavity
  • Visceral layers – cover the organs (viscera)
  • Serous space – a fluid-filled space that is very thin, between the parietal and visceral layers
  • Pleura – surrounds the lungs in the pleural cavity; reduces friction between the lungs and the body wall
  • Pericardium – surrounds the heart in the pericardial cavity and reduces friction between the heart and the wall of the pericardium.
  • Peritoneum – surrounds several organs in the abdominopelvic cavity. The peritoneal cavity reduces friction between the abdominal and pelvic organs and the body wall.
  1. Betts, J.G., Young, K.A., Wise, J.A., Johson, E., Poe, B., Kruse, D. H., Korol, O., Johnson, J.E., Womble, M. & DeSaix, P. (2013). Anatomy and Physiology. OpenStax. http://cnx.org/content/col11496/latest/[↩]
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