Anatomical Terms and Body Planes

Anatomical Terms

Language of Anatomy

  • Anatomical Position
    • This is a standard position of the body used as a reference.
    • Important for describing locations and relationships in anatomy, especially in the forearm.

Body Planes and Sections

  • Sagittal Plane

    • Cuts the body into right and left parts.
    • If precisely down the middle, termed midsagittal or median cut.

  • Frontal Plane

    • Cuts the body into anterior (front) and posterior (back) sections.

    Frontal Section through Torso

  • Transverse Plane

    • Cuts the body into superior (top) and inferior (bottom) sections.

    Transverse Section through Torso

Body Sections by Plane

  • Sagittal Plane

    • Divides the body into medial and lateral sections.

  • Frontal Plane (also known as the Coronal Plane)

    • Divides the body into anterior and posterior.

  • Transverse Plane

    • Divides the body into superior and inferior.

Directional Terms for Humans

  • Superior / Cranial
    • Refers to a structure being higher in position.
  • Inferior / Caudal
    • Refers to a structure being lower in position.
  • Anterior / Ventral
    • Refers to the front side of the body.
  • Posterior / Dorsal
    • Refers to the back side of the body.

Directional Terms for Cats

  • Posterior / Caudal
  • Dorsal / Superior
  • Inferior / Ventral
  • Anterior / Cranial

Additional Directional Terms

  • Medial
    • Toward the midline of the body.
  • Lateral
    • Away from the midline, toward the side.
  • Intermediate
    • Between a medial and lateral structure.
  • Proximal
    • Closer to the trunk of the body.
  • Distal
    • Farther from the trunk of the body.
  • Superficial
    • Closer to the surface of the body.
  • Deep
    • More internal, away from the body surface.

Important Notes on Directional Terms

  • All directional terms are relative

    • Example: Knees are proximal to feet but distal to thighs.

    • Right and Left

    • These terms are always based on the subject's perspective, not the observer’s.

    • For instance, the heart is slightly on the left side of the median plane.

Anatomical Scenarios

  • Example 1: For a fractured 4th metatarsal, the location of the fracture is described as:

    • Distal end of the 4th metatarsal; right hand.

  • Example 2: For a fractured clavicle, the location is described as:

    • Left clavicle fracture; lateral to the axial skeleton.

Regional Terms

  • Must be familiarized with; see specific pages in the textbook and lab book:
    • Textbook: p. 14
    • Lab book: p. 3 for definitions and p. 11 for illustrations.

Clinical Example

  • A 17-year-old female presents with:
    • 36-hour history of abdominal pain, originating from the periumbilical region and now localized to the right lower quadrant.
    • Associated symptoms: Anorexia, mild fever, one episode of minimal non-bilious vomiting, tender palpation.

Pancreatic Location

  • The pancreas is:
    • An elongated, tapered organ located posterior to the stomach, and between the duodenum and the spleen.
    • Relation to other organs: it is posterior to the stomach and inferior to the gall bladder and liver.

Anatomical Variability

  • Humans exhibit slight variations in anatomy:
    • More than 90% of all anatomical structures match typical descriptions.
    • Possible variations include nerves or blood vessels being misplaced, or small muscles may be absent.
    • Extreme anatomical variations are rare.

Body Cavities

  • Dorsal Body Cavity

    • Consists of:
    • Cranial cavity (contains the brain)
    • Spinal cavity (contains the spinal cord)
    • Cavities are continuous.

  • Ventral Body Cavity

    • Consists of:
    • Thoracic cavity (contains heart and lungs)
    • Abdominopelvic cavity (contains digestive organs)
    • Separation by the diaphragm:
      • Abdominal cavity (digestive viscera)
      • Pelvic cavity (bladder, reproductive organs, rectum)

Thoracic Body Cavity

  • Enclosed by ribs and chest muscles:
    • Contains:
    • Pleural cavity (surrounds lungs)
    • Mediastinum (between pleural cavities)
    • Pericardial cavity (encloses heart within the inferior mediastinum)
    • Superior mediastinum (above heart and between lungs)

Ventral Body Cavity Membranes

  • Parietal Serosa
    • Lines internal body walls.
  • **Visceral Serosa