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