Human Anatomy Overview

Aug 27, 2025

Overview

This lecture introduces fundamental concepts in human anatomy, focusing on structural organization, terminology, body composition, anatomical directions, planes, and cavities to provide a foundational understanding for the course.

Course Structure & Approach

  • The course uses both systemic (system-by-system) and regional (region-by-region) approaches to studying anatomy.
  • Lectures focus on systemic anatomy, while laboratories use the regional approach.
  • Emphasis is on practical, functional anatomy and modern clinical applications.

Levels of Structural Organization

  • Seven levels: chemical/molecular, organelles, cells, tissues, organs, organ systems, and the whole organism.
  • Builds understanding from smallest to largest components of the human body.

Concepts of Form and Function

  • "Form" (structure/morphology) and "function" (physiology) are closely related; form determines function and vice versa.
  • Pathology refers to abnormal structure, and dysfunction refers to abnormal function.

Basic Composition of the Human Body

  • Water makes up 60–70% of body weight; key for chemical reactions (solvent).
  • Minerals/electrolytes (e.g., sodium, potassium, calcium, phosphate) are essential; must be obtained from diet.
  • Major organic molecules: proteins (amino acids, some essential from diet), carbohydrates (sugars, starches), lipids (fats, oils, waxes), vitamins (fat-soluble: A, D, E, K; water-soluble: B complex, C), and nucleic acids (DNA/RNA).

Anatomical Directional Terms

  • Anatomical position: standing, feet slightly apart, arms at sides, palms forward.
  • Directional pairs:
    • Superior/Inferior: above/below.
    • Anterior/Posterior: front/back (also ventral/dorsal).
    • Medial/Lateral: toward midline/toward side.
    • Proximal/Distal: closer/farther from trunk or point of origin (used for limbs).
    • Superficial/Deep: near/beneath the surface.

Body Planes & Sections

  • Coronal (frontal) plane: divides body into anterior/posterior sections.
  • Sagittal plane: divides body into right/left portions (mid-sagittal is equal, para-sagittal is unequal).
  • Transverse (horizontal/cross) plane: divides body into superior/inferior sections.
  • Oblique section: cuts at any angle other than right angles to standard planes.

Body Cavities and Regions

  • Orbital (eye), nasal, buccal/oral (mouth), and otic/auditory (ear) cavities.
  • Dorsal (posterior) cavity: cranial (brain) and vertebral (spinal cord).
  • Ventral cavity: thoracic (heart, lungs), abdominal (digestive/urinary organs), pelvic (urinary bladder, reproductive organs, rectum).
  • Thoracic cavity contains pericardial (heart), pleural (lungs), and mediastinum (center of chest) subcavities.
  • Abdominopelvic cavity can be divided into four quadrants (RUQ, LUQ, RLQ, LLQ) or nine regions (umbilical, epigastric, hypogastric, right/left lumbar, right/left inguinal, right/left hypochondriac).

Key Terms & Definitions

  • Systemic Anatomy — Study of body by organ systems.
  • Regional Anatomy — Study of body by specific regions.
  • Morphology — Study of structure, shape, and form.
  • Pathology — Study of abnormal structure/disease.
  • Electrolyte — Mineral with an electric charge, essential for body functions.
  • Proximal/Distal — Closer to/farther from trunk or origin (mainly limbs).
  • Viscera — Internal organs within body cavities.
  • Anatomical position — Standardized posture for descriptive purposes.

Action Items / Next Steps

  • Review anatomical directional terms and practice identifying them on the body.
  • Watch the orientation video if not already viewed.
  • Read corresponding sections on body planes and cavities in the textbook.
  • Prepare for upcoming lab by familiarizing with anatomical position and directional terms.

Full transcript