CHAPTER 2

Cytology

science of cell structure and function
-depends on body size
-50 to 100 trillion cells, 200 types

Metabolism

cellular function
-nutrients
-oxygen
-ability to eliminate wastes

Cells

the most basic unit of human life
-alive, most reproduce, most live in a liquid environment

Plasma (cell) Membrane

protective barrier on outside of the cell; pliable with small holes (permeability for metabolic processes)

Cytoplasm

in between cell membrane and nucleus
-cytsol
-contains cellular materials (organelles)
-delivers nutrients and waste products

Cytosol

clear, thick, elastic fluid; blood of cell

Nucleus

control center of a cell; controls chemical and reproductive activities

Basal

base

Apical

apex

Exocytosis

moves substances from cytoplasm outside the cell

Passive

doesn't require energy

Active

does require energy

Endocytosis

moves large particles or fluid into the cell

Phagocytosis

moving large particles into cell

Pinocytosis

moving fluid into cell

Mitosis

growth and replacement of damaged or worn cells; 100 billion cells replaced each day

45 days

How long does it take to get a whole new set of skin?

Epidermal, hemopoietic, lining of gastrointestinal tract

What cells do you constantly regain?

Liver and kidneys

What cells do you regain as needed?

Muscle, Nerve

What cells do you never regain?

Hypertrophy

more, stronger, bigger (cellular adaptation)

Atrophy

smaller, weaker (cellular adaptation)

Benign

slow contained growth, better kind; stays in one place

Malignant

rapid growth with possibility of spreading; worse, bigger, more aggressive, spreads faster

Neoplasm

new growth; uncontrolled growth resulting in tumors

Metastasize

cancer gets in body (bloodstream) and spreads

Natural Chemicals
Environmental Pollutants

35% of cancers result from what?
2% of cancers come from what?