Biomedical Science Notes

Levels of Organisation

  • Levels of Structural Organisation
    • 1. Chemical Level:
    • Composed of atoms and molecules.
    • Essential atoms include Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P).
    • 2. Cellular Level:
    • The smallest functioning units of life.
    • Example: Smooth muscle cell.
    • 3. Tissue Level:
    • Groups of similar cells performing a specific function.
    • Example: Smooth muscle tissue.
    • 4. Organ Level:
    • Structures composed of two or more tissue types.
    • Example: Stomach (epithelial, connective, smooth muscle tissues).
    • 5. System Level:
    • Groups of organs working together.
    • Example: Digestive system (includes esophagus, stomach, liver, etc.).
    • 6. Organismal Level:
    • An individual organism composed of various systems.

Human Body Systems

  • Main Body Systems:
    • Respiratory system
    • Reproductive system
    • Integumentary system
    • Urinary system
    • Skeletal system
    • Digestive system
    • Nervous system
    • Lymphatic system
    • Endocrine system
    • Circulatory system
    • Muscular system

Integration of Body Systems

  • Body systems are interconnected. The function of one system often affects others.
    • Example: The digestive system processes food, while the circulatory system distributes nutrients to the body's cells.

Themes in Physiology

  • Structure and function relationship
  • Molecular interactions and compartmentalization
  • Energy transfer, storage, and usage
  • Information flow coordinating body functions
  • Homeostasis maintains internal stability

Homeostasis

  • Definition: The process of maintaining a stable internal environment in response to changes.
  • Key Components:
    • Receptor (sensor): Monitors physiological variables.
    • Control Centre: Processes information and compares monitored value to a set point.
    • Effector: Adjusts to bring variable back to normal range.
  • Types of Feedback:
    • Negative Feedback: Reverses the effect of the original stimulus (e.g., temperature regulation).
    • Example: Body temperature rises -> sweating -> temperature decreases.
    • Positive Feedback: Amplifies the original stimulus (e.g., blood clotting).
    • Example: Platelet accumulation at a site of injury.

Terminology in Physiology

  • Understanding physiological nomenclature is crucial for mastering new vocabulary.
  • Words formed from prefixes, roots, and suffixes can help decode complex terms.
    • Examples:
    • Cardiology:
      • cardio- (heart) + -logy (study of).
    • Hematology: Study of blood.

Chemical Elements in the Body

  • Major Elements (approx. 96% of body mass):
    • Oxygen (O), Carbon (C), Hydrogen (H), Nitrogen (N)
  • Lesser Elements (approx. 3.6%):
    • Calcium (Ca), Phosphorus (P), Potassium (K), Sulfur (S)
  • Trace Elements:
    • Essential in small amounts, e.g., Iron (Fe), Copper (Cu).

Organic vs Inorganic Compounds

  • Organic: Contain carbon (include molecules like carbohydrates, proteins, lipids).
  • Inorganic: Usually do not contain carbon (include water, salts, and some acids and bases).

Key Takeaways

  • Understanding the structure and function of body systems is paramount in biomedical science.
  • Homeostasis is vital for survival, and physiological terms are foundations for communication in science.
  • The body's composition and molecular interactions underpin all biological processes.