Human Anatomy and Physiology Overview

Human Anatomy and Physiology

• Human Anatomy and Physiology (HAP) is the study of the structure (anatomy) and function (physiology) of the human body.
• HAP involves two main principles: anatomy and physiology.
• Anatomy is the branch of science that studies the structure of the body.
  • Subdivisions of Anatomy:
    • Cell Biology/Cytology: Studies the structure of cells.
    • Histology: Studies the structure of tissues.
    • Gross Anatomy: Studies structures visible to the naked eye.
    • Microscopic Anatomy: Studies very small structures.
    • Systemic Anatomy: Studies specific body systems.
    • Radiographic Anatomy: Studies structure with the help of x-rays.
    • Pathological Anatomy: Studies structural changes associated with disease.
• Physiology is the branch of science that studies the function and mechanism of different body parts.
  • Subdivisions of Physiology:
    • Respiratory Physiology: Studies the function of the lungs.
    • Renal Physiology: Studies the function of the kidneys.
    • Immunology: Studies the function of the defense mechanisms.
    • Neurophysiology: Studies the function of the nervous system.
    • Pathophysiology: Studies functional changes associated with disease.
    • Cardiovascular Physiology: Studies the function of the heart and blood vessels.
    • Endocrinology: Studies hormones and their role in body function.

Levels of Structural Organization

• Living things consist of several levels of structural organization:
  • Chemical Level: The lowest level of organization, composed of atoms and molecules, for example, nitrogen, phosphorus.
  • Cellular Level: Atoms and molecules combine to form cells, the basic structural and functional unit of life.
  • Tissue Level: Similar groups of cells combine to form tissues, which are groups of similar cells working together to perform a specific function. There are four basic tissue types:
    • Epithelial Tissue: Covers and protects body surfaces.
    • Connective Tissue: Supports and connects body parts.
    • Muscle Tissue: Responsible for movement.
    • Nervous Tissue: Conducts impulses.
  • Organ Level: Different tissue types combine to form organs, structures that perform a specific function.
  • System Level: Groups of organs that work together form organ systems.
  • Organism Level: The highest level of organization, a complete living being.

Homeostasis

• Homeostasis is the ability of the human body to maintain a stable internal environment.
• This involves regulating and balancing factors such as:
  • pH: The relative acidity or alkalinity of body fluids.
  • Temperature: Maintaining a constant body temperature.
  • Fluid and electrolyte balance: Maintaining the proper levels of water and electrolytes in the body.
• The regulation of homeostasis is governed by feedback systems.