2. atoms
smallest unit of matter with unique physical and chemical characteristics
there are different atoms =elements (atoms of different sizes and characteristics)
most common elements in body are:
carbon (C), hydrogen (H), oxygen (O), nitrogen (N) and phosphorous (P)
less common are:
Sodium (Na), Chlorine (Cl), Potassium (K) and Calcium (Ca), Phosphate (P)

3. molecules
 atoms are attracted (= chemical bonds) to other atoms to form molecules

4. molecular structure
defines the molecule's functions

5. most common molecule in body
water (60-80%)

6. common organic molecules (covalently bonded carbon backbone)
proteins
lipids or fats
carbohydrates
nucleic acids
List most common elements and molecules in body.

2. Molecules make up organelles and other cellular structures which  make up cells

3. Organelles divide labor and therefore cells become more efficient

2. four major kinds

2. Most organs have more than one function.

3. Selected list of organs (not complete)
Organs in Cavities
Brain, spinal cord
Heart
Lung
Liver, stomach, pancreas, spleen, small intestine, large intestine, gall bladder, urinary bladder, uterus, ovary

Organs not in cavities
kidney, testes, artery, vein, lymph vessel, lymph nodes, bones, muscles, skin, diaphragm

Describe the location (specific cavity if applicable), system and function of all selected organs.

2. Many organs fall into more than one system and work together.

2. postive feedback loop
 response increases with stimulus
 if condition too high, regulation will make even higher
 ex. childbirth, lactation, blood clotting