HBS1HBA Module 1 Foundations complete notes

Introduction to the Human Body

• Anatomy & Physiology:

  • Anatomy refers to the structure of the body.

  • Physiology refers to the function of the body.

• The human body is composed of smaller parts organized into larger structures.

• There are 11 distinct body systems, each comprising various organs.

Why Learn About the Body?

• Knowledge of anatomy and physiology is often a course requirement.

• Fundamental for careers in health and benefits personal health understanding.

• Enhances comprehension of diseases, treatments, and health-related news.

Anatomy and Physiology Relationship

• Anatomy and Physiology are interconnected:

  • Human Anatomy: Studies of body structures, including:

    • Gross Anatomy: Larger structures visible without magnification.

    • Microscopic Anatomy: Structures visible only under a microscope.

  • Human Physiology: Examines body functions and interrelation of structures.

• Laboratory experiments are key to understanding body chemistry and functions.

Complexity of Structures

• Levels of Organization:

  • Chemical Level: Atoms and molecules are the simplest building blocks.

  • Cellular Level: Cells are the smallest units of independent life.

  • Tissue Level: Groups of similar cells performing specific functions.

  • Organ Level: Anatomically distinct structure with specific physiological functions.

  • Organ System Level: Groups of organs collaborating for major functions.

  • Organism Level: A complete living being capable of independent functioning.

• Understanding the architecture of the body facilitates comprehension of its systems and functions.

Body Systems

• There are 11 distinct body systems with overlapping organs.

Cellular Structure

• Cell Membrane: Forms a barrier, regulating internal and external environments.

• Cells perform most physiological functions independently.

Cell Membrane Functionality

• Phospholipid Bilayer: Composed of back-to-back phospholipids creating a flexible layer.

• Fluidity: Membrane proteins and lipids are mobile, affecting cell interactions.

• Membrane Proteins:

  • Facilitate cell recognition, act as receptors, perform functions (enzymes, stability).

  • Allow selective permeability, aiding in transport in and out of the cell.

Cell Transport Mechanisms

• Selective Permeability: Cell membranes permit specific materials to cross.

• Transport Types:

  • Passive Transport: Movement without energy (e.g., diffusion).

  • Active Transport: Uses energy (ATP) to move substances against concentration gradients.

  • Vesicular Transport:

    • Endocytosis: Materials enter via membrane folding.

    • Exocytosis: Materials exit via vesicle fusion with the membrane.

Osmosis

• The diffusion of water through a semi-permeable membrane affects cell volume based on solute concentrations.

• Isotonic Solution: No net movement of water; concentrations equal.

• Hypertonic Solution: Water moves out, potentially damaging cells; results from higher external solute concentration.

• Hypotonic Solution: Water moves in, risking cell swelling and rupture.

Cellular Organelles

• Cytosol: Jelly-like fluid containing dissolved nutrients; organelles execute cell functions.

• Organelles: Membrane-bound structures performing specific functions; vary across cell types.

DNA and Proteins

• DNA: Contains genetic instructions crucial for cell functions and protein synthesis.

• Proteins: Determine cell structure and function; essential for most cell activities.

Cellular Differentiation

• Stem Cells: Unspecialized cells with differentiation potential leading to specialized cell types.

• Differentiation Process: Cell specialization based on gene expression: Morphological and physiological uniqueness develops.

Communication Between Cells

• Important for coordinating organism functions and maintaining homeostasis.

• Signaling Mechanisms: Paracrine, endocrine, autocrine, and gap junctions facilitate signaling.

Requirements for Life

• Essential for survival include oxygen, water, nutrients (carbohydrates, lipids, proteins, vitamins, minerals).

• Extreme temperatures or pressure changes can jeopardize life functions.