Interactions of Human Systems
Section 1 - The Human Organism
A. The human body is organized in a series of building blocks that
differ in size and complexity.
B. Life is made up of matter which can be either:
1. elements – made up of only one atom
2. compounds – made up of more than one element and
atoms
C. Life is based on Chemistry happening in the body – inorganic,
organic
1. Inorganic – nonliving things
a. known as micronutrients – needed in small
amounts
b. examples of inorganic substances – minerals and
water (needed in LARGE amounts)
2. Organic – living things
a. known a macronutrients – needed in large
amounts
b. examples of organic substances –
carbohydrates – principal fuel in the body;
made up of carbon, oxygen, hydrogen
lipids – secondary source of fuel in the
body; provides twice the energy as that of
carbs and proteins; made up of fats and oils
proteins – basic building block of cells;
made up of chains of amino acids
nucleic acids – directs all cell activities and
instructs on making proteins; made up of
DNA and RNA
vitamins – work as coenzymes; needed in
SMALL amounts
D. Levels of Organization
1. Cells – smallest functional units in an organisms
2. Tissues – groups of similar cells that do the same sort of
work; helps different parts of the body communicate
3. Organs – different types of tissues that work together
4. Organ systems – group of organs that work together
5. Organism – group of cells, tissues, organs, and organ
systems that are interdependent and work together to
perform life functions