Tissue Structure and Function: General Review

1. Define tissue: A group of cells that are similar in structure and function.

2.     1. Lines body cavities and covers the body's external surface - epithelial

        2. Pumps blood, flushes urine out of the body, allows one to swing a bat - muscular

        3. Transmits waves of excitation - nervous

        4. Anchors and packages body organs - connective

        5. Cells may absorb, protect, or form a filtering membrane - epithelial

        6. Most involved in regulating body functions quickly - nervous

        7. Major function is to contract - muscular

        8. The most durable tissue type - connective

        9. Abundant nonliving extracellular matrix - connective

        10. Forms nerves - nervous

Epithelial Tissue

3. On what basis are epithelial tissues classified? They are classified both by the number of layers (simple or stratified) and by the shape of the cells at the free surface (squamous, cuboidal, or columnar).

4. How is the function of an epithelium reflected in its arrangement? The cells are tightly packed, which allows epithelial tissue to function to form linings or coverings. Also, simple squamous tissues are arrnaged to allow quick diffusion of substances, such as in the lungs. On the other hand, stratified tissues are arranged to help protect surfaces subject to friction, such as the skin.

5. Where is ciliated epithelium found? It lines the trachea and upper respiratory tract.

    What role does it play? The cilia help move substances along the cell surface.

6. Transitional epithelium is actually stratified squamous epithelium, but there is something special about it. How does it differ structurally from other stratified squamous epithelia? The cells are rounded, not flattened, when the tissue is not stretched.

    How does this reflect its function in the body? It allows an organ to be alternatively stretched or not stretched, because the cells can slide over one another. For example, this tissue type lines the urinary bladder.

7.     1. Best suited for areas subject to friction - stratified squamous

        2. Propels substances across its surface - pseudostratified ciliated columnar

        3. Most suited for rapid diffusion - simple squamous

        4. Tubules of the kidney - simple cuboidal

        5. Lines much of the respiratory tract - pseudostratified ciliated columnar

        6. Stretches - transitional

        7. Lines the small and large intestines - simple columnar

Connective Tissue

8. What is the makeup of the matrix in connective tissues? Extracellular matrix is made of nonliving ground substance and fibers secreted by fibroblasts.

9. How are the functions of connective tissues reflected in its structure? The extracellular matrix is specialized for each type of tissue. For example, in bone it is hard and mineralized, in dense fibrous c.t. (tendons & ligaments) it is full of strong fibers, and in blood it is fluid plasma.

10.  1. Attaches bones to bones (LIGAMENTS) and muscles to bones (TENDONS) - dense fibrous c.t.

        2. Forms your hip bone - osseous (bone)

        3. Composes basement membranes; a soft packaging tissue with a jellylike matrix - areolar c.t.

        4. Forms the larynx and the costal cartilages of the ribs - hyaline cartilage

        5. Firm matrix heavily invaded with fibers; appears glassy and smooth - hyaline cartilage

        6. Matrix hard; provides levers for muscles to act on - osseous (bone)

        7. Insulates against heat loss; provides reserve fuel - adipose c.t.

Muscle Tissue

11.  1. Skeletal muscle: A, D, F, I, K, N

        2. Cardiac muscle: A, B, G, H, J, L

        3. Smooth muscle: C, G, H, M, O

Nervous Tissue

12. In what ways are nerve cells similar to other cells? They contain nuclei and have cytoplasm.

    How are they different? Nerve cells (neurons) have long extensions, or cell processes (such as dendrites and axons)

    How does the special structure of a neuron relate to its function? The long cell processes allows a neuron to transmit information over very long distances quickly.

For Review

13.  a. simple columnar epithelium (label: basement membrane, goblet cell (draw it in), free/apical surface

        b.  pseudostratified ciliated columnar epithelium

        c. stratified squamous epithelium (label: free/apical surface, basement membrane)

        d. transitional epithelium

        e. areolar connective tissue

        f. dense fibrous connective tissue (label: extracellular matrix/fibers, fibroblasts)

        g. osseous tissue (bone)

        h. hyaline cartilage (label: extracellular matrix/ground substance, cells)

        i. adipose tissue

        j. smooth muscle

        k. skeletal muscle (label: striations, nuclei)

        l. cardiac muscle

define on p. 254:

        simple: describes an epithelial tissue having one layer of cells

        stratified: describes an epithelial tissue having more than one layer of cells

        squamous: describes an epithelial tissue having flattened ("squashed") cells at the free surface

        columnar: describes an epithelial tissue having tall, narrow cells at the free surface

draw on p. 255:

        glandular tissue (label: free/apical surface, basement membrane, glandular pits)

draw on p. 256:

        blood (label: extracellular matrix/plasma red blood cells, white blood cells, platelets)