Part IV: Nervous Tissue Main component of nervous system Structure: neuron = dendrite + cell body + axon Function: regulates and controls body functions Location in the body: brain, spinal cord, nerves

Part IV: Nervous Tissue 2 Major Cell Types: Neurons Respond to stimuli Transmit electrical impulses Other cells Support, insulate, protect neurons

Tissue Repair Wound healing Two ways: Regeneration: replace destroyed tissue by same kind of cells Fibrosis: form scar tissue (dense fibrous connective tissue) Depends on: Type of tissue damaged Severity of injury

Steps to Tissue Repair: Inflammation Capillaries become very permeable WBC’s and clotting proteins seep into injured area Clot prevents loss of blood (surface dries, forms a scab)

Steps to Tissue Repair: Granulation tissue forms Delicate pink tissue with new capillaries Connective tissue produces collagen fibers Epithelial cells multiply over granulation tissue

Steps to Tissue Repair: Surface epithelium regenerates Surface epithelium thickens Fibrous tissue matures – forms scar tissue

Regenerative Capacity of Different Tissues Extremely Well Moderate Weak Virtually None (mostly scar tissue) Skin epidermis Mucous membranes Fibrous connective Blood Bones Smooth muscle Tendons, ligaments Skeletal muscle Cartilage Cardiac muscle Nervous tissue