Essential Anatomical Planes, Terms, and Body Cavities

Anatomical Planes

Anatomical planes are imaginary lines drawn through the body in the standard anatomical position. They serve to guide and define the position of organs and structures, providing a universal reference system for describing the human body.

Coronal (Frontal) Plane

This vertical plane divides the body into anterior (front) and posterior (back) sections.

Sagittal Plane

This vertical plane divides the body into left and right sections. A midsagittal (or median) plane specifically divides the body into equal left and right halves.

Transverse (Axial or Horizontal) Plane

This horizontal plane divides the body into superior (upper) and inferior (lower) sections.

Anatomical Directional Terminology

These terms describe the relative positions of body parts, providing a precise language for anatomical descriptions.

General Directional Terms

• Superior (Cephalic or Cranial): Closer to the head or higher part of the body.
• Inferior (Caudal): Closer to the feet or lower part of the body.
• Anterior (Ventral): Toward the front of the body.
• Posterior (Dorsal): Toward the back of the body.
• Medial: Nearer to the midline of the body.
• Lateral: Further from the midline of the body.

Extremity-Specific Terms

These terms are primarily used when describing structures on the limbs:

• Proximal: Closer to the point of attachment of a limb to the trunk.
• Distal: Further from the point of attachment of a limb to the trunk.

Hand and Foot Specific Terms

• Palmar (Volar): The anterior surface of the hand (palm).
• Dorsal (Hand): The posterior surface of the hand.
• Dorsal (Foot - Instep): The superior surface of the foot.
• Plantar: The inferior surface of the foot (sole).

Body Cavities

Body cavities are spaces within the body that contain and protect internal organs. They are broadly divided into dorsal and ventral cavities.

Dorsal Body Cavity

Located on the posterior side of the body, this cavity primarily houses the central nervous system.

• Cranial Cavity

  Formed by the skull bones, it contains the brain.

• Spinal Cavity (Vertebral Canal)

  Formed by the vertebrae, it contains the spinal cord.

Ventral Body Cavity

Located on the anterior side of the body, this larger cavity houses the visceral organs and is further subdivided.

• Thoracic Cavity

  Enclosed by the rib cage, it is superior to the diaphragm. It contains the lungs (within the pleural cavities) and the heart (within the pericardial cavity).

• Abdominopelvic Cavity

  This large cavity extends from the diaphragm to the groin and is divided into two main parts:

  • Abdominal Cavity

    The superior portion, containing most of the digestive organs, kidneys, and spleen.

  • Pelvic Cavity

    The inferior portion, enclosed by the pelvic bones. It contains the bladder, reproductive organs, and rectum.

Abdominal Regions

The abdominal region is often divided into nine imaginary regions to precisely locate organs and describe pain or abnormalities. These regions are defined by two transverse lines (one passing through the inferior costal margins and another through the iliac spines) and two vertical lines (passing through the midclavicular lines).

1. Right Hypochondriac Region
2. Epigastric Region
3. Left Hypochondriac Region
4. Right Lumbar (Flank) Region
5. Umbilical Region
6. Left Lumbar (Flank) Region
7. Right Iliac (Inguinal) Region
8. Hypogastric (Pubic) Region
9. Left Iliac (Inguinal) Region