chapter 5

Section $5.1$: Overview of Tissues

  • Definition: A tissue is a group of similar cells working together to perform a specific function.

  • Histology: The microscopic study of tissue structure.

  • Pathology: The study of how disease changes tissues.

  • Four Main Types:

    1. Epithelial: Coverings and glands.

    2. Connective: Support and protection.

    3. Muscle: Movement.

    4. Nervous: Communication signals.

Section $5.2$: Epithelial Tissue

  • Function: Acts as a barrier or a secretory surface.

  • Anatomy:

    • Apical Surface: Top side facing the environment.

    • Basal Surface: Bottom side attached to the basement membrane.

    • Avascular: Does not have its own blood vessels.

  • Classification:

    • Layers:

    • Simple: 11 layer for diffusion.

    • Stratified: 22 or more layers for protection.

    • Shapes:

    • Squamous: Flat.

    • Cuboidal: Cube-shaped.

    • Columnar: Tall columns.

  • Glands:

    • Endocrine: Release hormones into the blood.

    • Exocrine: Release substances through ducts (e.g., sweat).

Section $5.3$: Connective Tissue

  • Components: Made of cells and an Extracellular Matrix (ECM) (fibers and ground substance).

  • Fibers:

    • Collagen: Provides strength.

    • Elastic: Provides stretch.

  • Main Categories:

    • Connective Tissue Proper: Includes fat (adipose) and tendons.

    • Supportive: Bone and cartilage.

    • Fluid: Blood and lymph.

Section $5.4$: Muscle Tissue

  • Skeletal Muscle: Attached to bones; voluntary movement; striated.

  • Cardiac Muscle: Found in the heart; involuntary; has intercalated discs.

  • Smooth Muscle: Found in organ walls; involuntary; no striations.

Section $5.5$: Nervous Tissue

  • Neurons: Main cells that send electrical signals (action potentialsaction\ potentials).

  • Glial Cells: Support and protect the neurons.

Section $5.6$: Tissue Membranes

  • Mucous: Lines paths open to the outside (e.g., mouth).

  • Serous: Lines internal body cavities to reduce friction.

  • Cutaneous: Your skin.

  • Synovial: Lines moveable joints.

Section $5.7$: Growth and Healing

  • Inflammation: The body's first response to injury (redness, swelling).

  • Healing: Includes blood clotting and the growth of new tissue (sometimes leaves a scar).

  • Aging: Tissues thin, lose elasticity, and heal more slowly.