Chapter 7

Hyaline Cartilage

Collagen fibers form an imperceptible network, matrix appears smooth

• Supports & reinforces

• Serves as a cushion

• Resists compressive stress

Hyaline Cartilage Location

• Tips of long bones

• Nose

• Trachea

• Larynx

• Ribs

Fibrocartilage

Properties between hyaline and dense regular tissue, strong tensile strength

• Less firm than hyaline

• Absorbs compressive shock

• Predominated by collagen fibers

Fibrocartilage Location

• Intervertebral discs

• Knee joint pads (meniscus)

• Pubic symphysis

Skeletal Muscle

Cells are called muscle fibers, contain multiple nuclei (multinucleated)

• appear striated or banded

• attached to & causes movement of bones

• voluntary muscle

• located throughout the body

Cardiac muscle

striations, one nucleus, many branches, intercalated discs (specialized connections where cardiac cells are joined)

• Involuntary muscle

• Allows heart to pump

• Located in walls of heart

Smooth muscle

no striations, spindle-shaped cells with one nucleus

• One nucleus

• propels substances or objects along internal passage ways

• Located in walls of hollow organs (besides heart, ex: stomach)

Covering and Lining Membranes

Composed of atleast two primary tissue types: epithelium & underlying connective tissue proper layer

3 types:

• Cutaneous membranes

• Mucous membranes

• Serous membranes

Cutaneous membranes

dry membrane, keratinized stratified squamous epithelium (epidermis) attached to dermis

• Skin

• Thin layer of areolar tissue

• Thick layer of dense irregular connective tissue

Mucous Membrane (Mucosa)

Indicates location, not cell composition. Epithelial layer, Non-keratinized stratified squamous, simple & pseudostratified columnar

• moist membranes bathed by secretions

• may secrete mucus

• line body cavities that are open to the exterior

• lamina propria

Mucous Membrane (Mucosa) Location

Digestive, Respiratory, and Urogenital tracts

Lamina propria

Loose areolar connective tissue with glands & vessels

Serous Membranes (Serosae)

Moist membranes found in closed central body cavities. Simple squamous epithelium (mesothelium) & thin areolar connective tissue

• Parietal serosae line internal body cavity walls

• Visceral serosae cover internal organs

• Includes pleurae, pericardium, peritoneum

Tissue repair

When body’s barriers are compromised, inflammatory and immune responses are quickly activated

• Regeneration

• Fibrosis

Regeneration

Same kind of tissue replaces destroyed tissue, restores original function

Fibrosis

Connective tissue replaces destroyed tissue (scar tissue) loses original function

Tissue Repair Step 1

• Tissue & mast cells release inflammatory chemicals

• Dilation of blood vessels (increase blood vessel permeability)

• Leukocytes and clotting proteins seep into area

• Blood clotting occurs & seals off injured area

• Scan forms

Tissue Repair Step 2

• Blood clot is replaced with granulation tissue

• Epithelium begins to regenerate

• Fibroblasts produce collagen fibers to bridge gap

• Any debris in area is phagocytized

Granulation tissue

New capillary enriched tissue

Tissue Repair Step 3

• Scab detaches

• Regeneration: Epithelium thickens and begins to resemble adjacent tissue

• Fibrous tissue matures

• Results in fully regenerated epithelium with underlying scar tissue not visible

• Fibrosis: no regenerative epithelium, scar tissue visible

Tissues that regenerate extremely well

• Epithelial tissues

• Bone

• Areolar connective tissue

• Dense irregular connective tissue

Tissues that regenerate moderately well

• Smooth muscle

• Dense regular connective tissue

Tissues with no regeneration capacities

• Cardiac muscle

• Nervous tissue of brain & spinal cord

Clinical Homeostatic Imbalance

Scar tissue that forms in organs, particularly the heart, can severely impact the function of that organ

• Keloids

Keloids

scarring caused by an excess protein (collagen) in the skin during healing, grow much larger than the wound that caused it, not harmful but can be removed.