Chapter 5: Tissues (Muscle and Nervous)

Four Major Tissue Types

Epithelial
- Functions: protection, secretion, absorption, excretion
- Location: cover body surfaces; cover/line internal organs; form glands
- Distinguishing characteristics: lack blood vessels; cells readily divide; cells tightly packed
Connective
- Functions: bind, support, protect, fill spaces, store fat, produce blood cells
- Location: widely distributed throughout the body
- Distinguishing characteristics: generally good blood supply; cells farther apart than in epithelial tissue; extracellular matrix present
Muscle
- Functions: movement
- Location: attached to bones; walls of hollow internal organs; heart
- Distinguishing characteristics: can contract in response to specific stimuli
Nervous
- Functions: conduct impulses for coordination, regulation, integration, and sensory reception
- Location: brain, spinal cord, nerves
- Distinguishing characteristics: cells communicate with each other and other body parts

Unicellular glands
- Characteristics: single secretory cell
- Example: mucous-secreting cell
Multicellular glands
- Simple glands (ducts do not branch before secretory portion)
- Simple tubular gland: intestinal glands
- Simple branched tubular gland: gastric glands
- Simple coiled tubular gland: merocrine (sweat) glands
- Simple branched alveolar gland: sebaceous gland
- Compound glands (ducts branch repeatedly)
- Compound tubular gland: bulbourethral glands
- Compound alveolar gland: mammary glands

Epithelial membranes are composed of epithelial tissue plus connective tissue; cover body surfaces and line cavities
Types of epithelial membranes
- Serous membranes: line cavities that do not open to the outside; inner linings of thorax and abdomen; cover organs; components: simple squamous epithelium + areolar connective tissue; secrete serous fluid to reduce friction
- Mucous membranes: line cavities and tubes that open to the outside; digestive, respiratory, urinary, reproductive tracts; components: epithelium + areolar connective tissue; goblet cells secrete mucus
Cutaneous membranes: covers body surface; skin; part of the integumentary system
Synovial membranes: not epithelial membranes; composed entirely of connective tissue; line joint cavities

General characteristics: excitable; respond to nervous stimulation; muscle cells (fibers) are contractile; able to shorten and thicken
Skeletal muscle tissue
- Attached to bones
- Striated
- Voluntary
- Long, cylindrical, multinucleated cells
- Stimulated by nerve cells
Smooth muscle tissue
- Non-striated
- Spindle-shaped fibers
- Walls of hollow internal organs and blood vessels
- Involuntary
Cardiac muscle tissue
- Branched cells
- Striated
- Single nucleus
- Involuntary; intercalated discs (specialized intercellular junctions)

Found in brain, spinal cord, peripheral nerves
Neurons
- Main cells specialized for communication via conduction of nerve impulses
- Coordinate, integrate, regulate body functions
- Structure: cell body (soma), dendrites, axon
Neuroglia
- Support and nourish neurons

Skeletal muscle tissue
- Description: long, thread-like cells; striated; many nuclei
- Function: voluntary movements of skeletal parts
- Location: muscles attached to bones
Smooth muscle tissue
- Description: shorter cells; single, central nucleus
- Function: involuntary movements of internal organs
- Location: walls of hollow internal organs
Cardiac muscle tissue
- Description: branched cells; striated; single nucleus
- Function: heart movements
- Location: heart muscle
Nervous tissue
- Description: cells with cytoplasmic extensions
- Function: sensory reception, release of neurotransmitter, conduction of electrical impulses
- Location: brain, spinal cord, peripheral nerves