PHYSIOLOGY BASE NOTES

Introduction to Physiology

  • Definition: Physiology is the investigation of the processes or functions of living things (Seeley’s Anatomy and Physiology 13th Ed).
  • Importance: Provides an in-depth understanding of the human body and its functions.

The Human Body

  • 6 Levels of Organization: Organizing principles of the human body:
    1. Chemical Level: Involves atoms and molecules.
    2. Cell Level: Basic structural and functional units containing organelles.
    3. Tissue Level: Groups of similar cells working together; 4 types:
    • Epithelial
    • Connective
    • Muscle
    • Nervous
    1. Organ Level: Composed of two or more tissue types.
    2. Organ System Level: Multiple organs that work together for a common purpose; the human body has 11 organ systems.
    3. Organism Level: The entire living entity.

Characteristics of Life

  • Organization: The hierarchical structure that supports functionality.
  • Metabolism: Chemical reactions that sustain life; energy use for bodily functions.
  • Responsiveness: Ability to detect changes and respond (controlled by nervous and endocrine systems).
  • Reproduction: Creation of new cells, vital for growth and repair.
  • Development: Changes occurring from fertilization to death; includes differentiation of cells to specialized forms.
  • Growth: Increase in cell size and/or number.

Cell Biology

Plasma Membrane

  • Functions:
    1. Cell metabolism and energy use
    2. Synthesis of molecules
    3. Cell communication (chemical and electrical signals)
    4. Reproduction and inheritance (DNA management)
  • Structural Functions:
    1. Barrier to separate intracellular from extracellular fluid.
    2. Encloses cell contents.
    3. Connects cells to the extracellular environment.
    4. Facilitates communication.
    5. Regulates movement of substances.

Plasma Membrane Components

  • Membrane Lipids: Phospholipids form a bilayer; cholesterol adds stability.
  • Membrane Proteins: Integral and peripheral proteins serve various functions.

Membrane Transport Mechanisms

  • Passive Transport: Movement without energy use.
    • Diffusion: Solutes move from high to low concentration.
    • Osmosis: Water moves toward concentration equilibrium.
    • Facilitated Diffusion: Assisted by carrier proteins to help substances cross.
  • Active Transport: Energy-dependent process.
    • Active Transport: Moves substances against a concentration gradient (e.g., sodium-potassium pump).
    • Secondary Active Transport: Utilizes the energy from another gradient.
    • Vesicular Transport: Involves vesicles for bulk transport, includes endocytosis (phagocytosis and pinocytosis) and exocytosis.

Cytoplasm and Nucleus

  • Cytoplasm: Comprises cytosol and organelles; holds components in place.
  • Nucleus: Houses genetic material (DNA); consists of nucleoplasm, nuclear envelope, and nuclear pores.
    (
    Key Structures:
  • Chromosomes: Contain genetic information.
  • Ribosomes: Sites for protein synthesis.
    )

Endoplasmic Reticulum

  • Rough ER: Ribosome-studded, involved in protein synthesis.
  • Smooth ER: Lacks ribosomes; synthesizes lipids and detoxifies.

Golgi Apparatus

  • Modifies, packages, and distributes molecules produced by the endoplasmic reticulum.

Mitochondria

  • Functions:
    • Produces ATP (energy currency of the cell).
    • Site for the citric acid cycle and electron transport chain (aerobic processes).
    • Can increase in number in response to energy demands.

Additional Notes

  • Familiarity with anatomy and physiology is crucial for understanding how the human body systems interact and contribute to overall health and exercise science.