Introduction to Human Body Systems

Overview of Immune System and Connective Tissues

  • T Cells: Also known as helper cells; play a crucial role in the immune response.

Types of Immunity

  • Active Immunity: Acquired through immunizations (artificial immunity).

  • Lymph Nodes: Filter lymphatic fluid, removing harmful particles and playing a role in the immune system.

Synovial Fluid and Connective Tissues

  • Synovial Fluid: Secretes lubricating fluid between bones, reducing friction in joints.

  • Strongest Connective Tissue: Bone, providing structural support.

  • Liquid Matrix Type Connective Tissue: Blood, essential for transportation of nutrients and waste.

Functions of Lymphatic System

  • Lymphatic System: Circulates lymph, absorbs excess fluid, filters harmful particles through lymph nodes.

  • Antigens: Trigger white blood cell responses and help in identifying blood types.

Mucous Membranes and Gland Functions

  • Mucous Membranes: Found in the respiratory and digestive systems; produce mucus via goblet cells.

  • Endocrine vs. Exocrine Glands:

    • Endocrine Glands: Ductless; secrete hormones into the bloodstream (e.g., thyroid, pituitary).

    • Exocrine Glands: Have ducts; secrete to external surfaces (e.g., sweat glands).

Functions of Adipose Tissue

  • Adipose Tissue: Stores energy, insulates body, and provides cushioning.

Types of Epithelial Tissue

  • Transitional Epithelium: Stretches and returns to original shape; found in the urinary bladder.

  • Types of Epithelial Cells:

    • Squamous: Flat and scale-like.

    • Cuboidal: Cube-shaped.

    • Columnar: Taller, like columns.

  • Classifications:

    • Simple: Single layer (e.g., simple squamous).

    • Stratified: Multiple layers (e.g., stratified squamous).

Blood and pH Levels

  • Blood Type: Determined by antigens on red blood cells (e.g., A, B, AB, O).

  • Acidity and pH:

    • pH below 7.35 is considered acidic.

    • Higher hydrogen ion concentration results in a lower pH.

Homeostasis and Body Systems

  • Homeostasis: Maintaining a stable internal environment despite external changes.

  • Blood Cells: Leukocytes (white blood cells) fight infection; produced in bone marrow.

  • Albumin: Maintains blood volume.

Planes and Body Cavities

  • Transverse Plane: Divides the body into upper and lower parts.

  • Sagittal Plane: Divides the body into right and left parts.

  • Frontal Plane (Coronal): Divides the body into front and back halves.

  • Body Cavities:

    • Mediastinum: Contains the heart.

    • Thoracic Cavity: Contains the lungs.

    • Dorsal Cavity: Contains the brain and spinal cord.

Transport Mechanisms and Solutions

  • Passive Transport: Includes diffusion, osmosis, and filtration.

  • Active Transport: Mechanisms include pumps, exocytosis, and endocytosis.

  • Isotonic Solutions: Maintain cell size; critical for intravenous solutions to prevent red cell lysis or shrinkage.

Blood Functions and Healing Process

  • Blood Coagulation Process:

    • Blood vessels constrict; platelets aggregate at injury site.

    • Prothrombin converts to thrombin, leading to fibrin formation to seal the injury.

Summary of Cellular Functions

  • Ribosomes: Responsible for protein synthesis.

  • Nucleus: Control center of the cell, containing DNA.

  • Cytoplasm: Gel-like substance within the cell.

  • Phospholipid Membrane: Semi-permeable, selectively allows substances in and out of cells.

Final Review

  • Review body regions, functions of various tissues, and general concepts of anatomy and physiology to prepare for the exam.