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4 Main types of tissue

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  • Definition of Tissues:


    Cells grouped to perform a specific function.

  • The 4 Basic Types of Tissues


    :Epithelial tissue, Connective tissue, Muscle tissue, and Nervous tissue.

  • Epithelial Tissue

    • Shape: Tightly packed cells arranged in sheets. Cells can be flat (squamous), cube-shaped (cuboidal),or tall andrectangular (columnar).


    • Function: Protects the body, absorbs nutrients, and releases such as sweat and mucus.

    • Location: Skin, lining of the mouth, stomach, intestines, lungs, and glands.

  • Epithelial Tissue: characteristics


    Avascular (lacks blood vessels), tight cells, and serves to cover, line, and protect.

  • Epithelial Tissue: cell shapes


    • Squamous (flat)

    • Cuboidal (cube-shaped)

    • Columnar or Cylin' (tall/column-shaped)

  • Epithelial Tissue: cell layers


    • Simple: One layer of cells.

    • • Stratified: Multiple layers of cells.

  • Simple Squamous Epithelium


    A single layer of flat, scale-like cells ideal for rapid diffusion and filtration, found in lung alveoli and blood vessel linings.

  • Simple Cuboidal Epithelium


    A single layer of cube-shaped cells specialized for secretion and absorption, found in kidney tubules and glandular ducts.

  • Simple Columnar Epithelium


    A single layer of tall, column-like cells often with microvilli or cilia, specialized for absorption and secretion in the digestive tract.

  • Stratified Squamous Epithelium


    Multiple layers of flat cells designed to protect underlying tissues from abrasion and friction, found in the outer layer of skin.

  • Stratified Cuboidal Epithelium


    Multiple layers of cube-shaped cells providing robust protection and secretion, typically found in large ducts of sweat and salivary glands.

  • Stratified Columnar Epithelium


    Multiple layers of column-shaped cells providing protection and secretion, rarely found in the body (such as parts of the male urethra).

  • Difference between 'Simple' and 'Stratified' epithelial tissues


    'Simple' means a single layer of cells (best for absorption/filtration), while

    'Stratified' means multiple layers of cells (best for protection).

  • Connective Tissue

    • Shape: Cells are usually spread apart within an extracellular matrix (a material surrounding the cells). Itsappearance variesdepending on the type: bone is hard, fat cells are round, and blood cells float in liquid.


    • Function: Supports, connects, and protects body parts. It also stores fat and transports substances,such as oxygen inthe blood.

    • Location: Bones, tendons, ligaments, fat under the skin, cartilage, and blood.

  • Connective Tissue: characteristics


    Vascularized and known as the supporting tissue.

  • connective tissue: composition


    • Fibers: Elastic, Collagen, and Reticular fibers. PNG

    • Ground Substance. (PNG

    • Cells: Fibroblast, Chondroblasts, Osteoblasts, Mast cells, Adipocytes, Macrophages, Mesenchymal cells, and Plasma cells.

  • Loose Connective Tissue: Reticular


    A network of reticular fibers in a loose ground

    substance that forms a soft internal skeleton

    (stroma) supporting other cell types in lymphoid

    organs like lymph nodes, bone marrow, and

    spleen.

  • Loose Connective Tissue: Adipose


    A loose connective tissue dominated by

    adipocytes (fat cells) specialized for energy

    storage, insulation against heat loss, and

    cushioning/protecting organs.

  • Loose Connective Tissue: Areolar


    A gel-like matrix with all three fiber types

    (collagen, elastic, reticular) that cushions organs,

    wraps capillaries, and plays an important role in

    inflammation.

  • Loose Connective Tissue: Mesenchymal


    An embryonic connective tissue characterized by

    star-shaped mesenchymal cells that gives rise to

    all other types of connective tissue later in

    development.

  • Dense Connective Tissue: Dense Regular


    A dense connective tissue with parallel collagen

    fibers and major cell types being fibroblasts,

    providing high tensile strength when pulled in one

    direction (found in tendons and ligaments).

  • Dense Connective Tissue: Dense Irregular


    A dense connective tissue with thickly interwoven,

    irregularly arranged collagen fibers that withstand

    tension exerted in multiple directions (found in

    the dermis of skin and joint capsules).

  • Dense Connective Tissue: Elastic Connective Tissue


    A dense connective tissue containing a high

    proportion of elastic fibers that allows recoil of

    tissue following stretching (found in walls of large

    arteries and bronchial tubes).

  • Muscle Tissue

    • Shape: Skeletal muscle has long, cylindrical fibers with stripes; cardiac muscle has branching,striped cells; smooth musclehas spindle-shaped cells with tapered end


    • Function: Contracts to create movement, pump blood, and move substances through

    • Location: Attached to bones (skeletal muscle), in the heart ), and in the wallsof organs such as the stomachand intestines (smooth muscle).

  • muscle tissue : smooth muscle


    • (Involuntary, non-striated muscle found in walls of hollow organs like the stomach and intestines).

  • muscle tissue : cardiac muscle


    • e(Involuntary, striated muscle found specifically in the heart).

  • muscle tissue: Skeletal Muscle


    (Voluntary, striated muscle attached to bones for movement).

  • nervous tissue

    • Shape: Neurons have a cell body with branching extensions called dendrites and a long extensioncalled an axon. Thesestructures help transmit messages.


    • Function: Receives and sends electrical signals throughout the body. It helps you think, feel,move, and respond toyour surroundings.

    • Location: Brain, spinal cord, and nerves.

  • nervous tissue :components


    Neurons (The primary functional cells of the nervous system responsible for transmitting electrical impulses).