Part IV: Nervous Tissue

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:

1. Regeneration: replace destroyed tissue by same kind of cells

2. Fibrosis: form scar tissue (dense fibrous connective tissue)

Depends on: Type of tissue damaged Severity of injury

Steps to Tissue Repair:

1. 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:

2. Granulation tissue forms Delicate pink tissue with new capillaries Connective tissue produces collagen

fibers Epithelial cells multiply over granulation

tissue

Steps to Tissue Repair:

3. 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