Overview of Human Anatomy, Physiology, and Pathophysiology

1. Anatomy

Definition: Study of the structure of living organisms.
Focus: "What is it? Where is it?"
Branches:

• Gross Anatomy: Visible structures (organs, muscles).

• Microscopic Anatomy: Cellular/tissue level (histology, cytology).

• Developmental Anatomy: Changes from conception to adulthood (embryology).

• Regional vs. Systemic Anatomy: Body regions vs. organ systems.

  • Tools: Dissection, imaging (MRI, CT), microscopy.

  • Example: Mapping the heart's chambers and valves.

2. Physiology

Definition: Study of normal functions of living organisms and their parts.
Focus: "How does it work? Why does it work?"
Branches:

• Divided by organ systems (e.g., cardiovascular, neuro, renal physiology).

• Explores mechanisms like homeostasis, metabolism, and signaling.

Key Questions:

• How do muscles contract?

• How do kidneys regulate blood pH?

  • Tools: Biochemical assays, electrophysiology, biomechanics.

  • Example: Studying how nerves transmit electrical impulses.

3. Pathophysiology

Definition: Study of abnormal or disordered physiological processes in disease.
Focus: "How do diseases disrupt normal function?"
Scope:

• Bridges physiology and pathology.

• Examines mechanisms of disease (e.g., inflammation, cell death, genetic mutations).

• Explains symptoms, progression, and complications.

Key Questions:

• Why does hypertension damage blood vessels?

• How does diabetes impair insulin signaling?

  • Application: Foundation for clinical medicine and drug development.

  • Example: Analyzing how atherosclerosis reduces blood flow in coronary arteries.

Key Relationships

Synergy

• Anatomy identifies structural changes (e.g., tumor growth).

• Physiology explains normal operations (e.g., hormone regulation).

• Pathophysiology reveals why a structural flaw (anatomy) causes functional failure (physiology), leading to disease.

Example Integration

A blocked artery (anatomy) → Reduces blood flow (physiology) → Causes tissue ischemia → Leading to myocardial infarction (pathophysiology). This triad forms the cornerstone of biomedical sciences, guiding research, diagnostics, and therapeutics.