EPITHELIAL TISSUES

FUNCTIONS:

• Protects from injury
• Acts as a barrier from bacteria
• Secretes mucus
• Prevents drying out

TYPES:

• Squamous - flattened cells, ex. Lining lungs & blood vessels
• Cuboidal - cube shaped cells
• Columnar - rectangular, pillar shaped cells, nucleus at bottom

LAYERS:

• Simple - single layer of cells, ex. capillaries
• Stratified - multiple layers f cells , ex. nose, mouth, skin
• Pseudostratified - LOOKS stratified but is simple because
• each cell touches the basement membrane

JUNCTIONS:

• Tight/Impermeable - membranes join, liquid cannot pass between cells, like a zipper
• Adhesion - give cells strength to withstand mechanical stress (membranes don't touch)
• Communication/gap - when cells must communicate to work together

MUSCLE TISSUE

FUNCTIONS:

• Movement in and of the body
• Produce heat
• Maintain posture

3 TYPES:

• SKELETAL
• SMOOTH
• CARDIAC

1. SKELETAL

• Attached to bones by tendons
• Contracts faster than all other muscle types
• Under VOLUNTARY control
• Fibers are cylindrical and long, multinucleated
• They are STRIATED - light and dark bands (actin and myosin filaments)

2. SMOOTH

• Fibers don't have striations
• NOT under voluntary control - INvoluntary
• Found in the walls of the viscera (internal organs)
• Contract slower, but can maintain contraction longer

3. CARDIAC

• Found in the wall of the heart
• Striated
• INvoluntary
• Fibers are individual that are connected end to end

NERVOUS TISSUE

FUNCTIONS:

• Sensory input
• Integration of data
• Motor output

TYPES:

• Sensory neuron
• Inter neuron
• Motor neuron

3 PARTS OF A NEURON:

• DENDRITE-receives message for the neuron
• CELL BODY-processes messages
• AXON-sends messages to other neurons