Particles tend to move from high to low concentration, or down a concentration gradient.

Ex) Ions moving across cell membranes; neurotransmitters moving between two nerves.

Substances diffuse directly down their concentration gradient through the membrane.

Nonpolar and lipid soluble substances diffuse directly through the membrane. Substances include oxygen and carbon dioxide.

Molecules are transported passively through protein channels down their concentration gradient.

Substances require protein channels (glucose, sugars, amino acids, and ions).

Solutions with the same concentrations of solutes as those found in the cell.

In an isotonic environment, water will diffuse in and out at equal rates.

CELL RETAINS THEIR NORMAL SHAPE.

Solutions with higher concetnration of slutes than in the cell.

CELLS LOSE WATER AND SHRINK.

Ex) Salty water!

Solutions that are more dilute than cells.

CELLS GAIN WATER AND SWELL.

Ex) Distilled water!

Exocytosis and Endocytosis

Moving materials in and out of the cell without using gradients.

Substances are engulfed into the cell.

Phagocytosis, Pinocytosis, and Receptors.

Cell eating (large)

Ex) Bacteria

Mediated Endocytosis

Some integral proteins on the plasma membrane have receptors that recognize and take in hormones, cholesterol, etc.

Epithelial (covering)

Connective (support)

Nervous (control)

Muscle (movement)

1) Covers and lines the body

2) Glandular tissue

Protection

Absorption

Filtration

Secretion

1) cells fit closely together to form SHEETS

2) Has an apical surface (smooth, microvilli, or cilia)

3) Has a basal surface that is attached to a thin supporting sheet called the basal lamina (non cellular, acts as filter)

4) All epithelial sheets rest on connective tissue

5) Avascular (no blood supply) but have lots of nerves

6) regenerate easily if well nourished

It produces and secretes hormones

secrete chemical signals called hormones into the bloodstream where they travel through the body and affect other cells

Secrete their products onto body surfaces or into body cavities

Secretes material into ducts that lead to the body surface

include mucus, sweat, salivary and oil glands

can be multicellular or unicellular

1) Binds body tissues together

2) Supports the body

3) Provides protection

4) Transportation

Vascularized (except tendons, ligaments and cartilage)

Extracellular matrix

1) Mostly water - Absorbs water

2) Adhesion proteins - serves as glue

3) Polysaccharide molecules - as # of molecules goes up, tissues goes from fluid to hard

1) interwoven strands of the protein collagen

2) thick fibers with great tensile strength (it's tough to pull apart)

1) Protein called elastin whose coiled structure allows it to stretch and snap back like a rubber band

2) accounts for the ability of the lungs, arteries, and skin to spring back after they are stretched.

1) a thinner collagen fiber coated with glycoproteins

2) these fibers can branch extensively and form networks for certain organs.

1)irritability

2)Conductivity

3)Responsiveness

Capillaries become very permeable

-introduce clotting proteins

-wall off injured area

Formation of granulation tissue

Regeneration of surface epithelium

All epithelial tissue

Fibrous connective tissue and bone

Cardiac muscle

Nervous tissue within the brain and spinal cord

Ribosome

Rough ER

Golgi Apparatus

released from cell