Anatomical Terminology and Body Planes

Aug 18, 2025

Overview

This lecture covers anatomical terminology, body planes, major body cavities, and regional divisions essential for understanding human body orientation.

Anatomical Nomenclature

  • The sternal, pectoral, and acromial regions refer to areas on the anterior upper body and shoulder.
  • The upper arm is called the brachial region; the forearm is the antebrachial region.
  • The cervical region is the back of the neck; dorsal refers to the back.
  • The olecranon is the back of the elbow, while the gluteal is the buttocks.
  • The femoral region is the thigh, sural is the calf, and calcaneal is the heel.
  • The plantar surface refers to the sole of the foot.

Anatomical Position and Body Planes

  • Anatomical position: body upright, feet forward, palms forward, thumbs lateral.
  • Sagittal (median) plane divides the body into left and right halves.
  • The midclavicular line is a vertical line through the middle of the clavicle, useful for heart auscultation.
  • Transverse/horizontal plane divides the body into superior (upper) and inferior (lower) parts.
  • Coronal (frontal) plane divides the body into anterior (front) and posterior (back) sections.

Body Cavities and Protection

  • Cranial cavity houses the brain; vertebral canal houses the spinal cord, both protected by cerebrospinal fluid.
  • Thoracic cavity (ribs, sternum) protects the heart and lungs.
  • Kidneys are partially protected by floating ribs (11 and 12).
  • Pelvic cavity protects reproductive organs and bladder with the pelvic girdle.
  • Abdominal region is less protected, with mainly soft tissue in the front.

Regional Divisions of the Abdomen

  • Abdomen is divided into nine regions using a tic-tac-toe grid: umbilical (center), epigastric (upper middle), hypogastric/pubic (lower middle).
  • Hypochondriac regions are left/right above the ribs; iliac/inguinal regions are left/right beside the hips.
  • Pain location in the abdomen helps distinguish between digestive and non-digestive issues.

Key Terms & Definitions

  • Anterior — front of the body
  • Posterior (Dorsal) — back of the body
  • Sagittal Plane — divides body into left and right portions
  • Transverse Plane — divides body into upper and lower parts
  • Coronal (Frontal) Plane — divides body into front and back
  • Cavity — a space in the body housing organs

Action Items / Next Steps

  • Review anatomical terms and regional subdivisions from page 13.
  • Memorize the nine abdominal regions and their names.
  • Prepare for questions on body planes and anatomical orientation.