HUMAN ORGAN SYSTEM NOTES:

1.) What are the 4 Levels of Organization in the Human Body? Cells, Tissues, Organs, and Organ Systems
2.) What is a cell? A cell is the smallest unit of structure & function in a living thing.
 3.) What is a tissue?  A tissue is a group of similar cells working together.
 5.) What is an organ system?  An organ system is when 2 or more organswork together to perform an overall function.
 6.) What do multiple Organ Systems form?  Multiple Organ Systems working together form a Multicellular Organism.
7.) How are the different levels of
organization of the Human Body
related?		 - Cells work together to form tissues.
- Tissues work together to form organs.
- Organs work together to form Organ Systems
- Organ Systems work together to form Human
Organisms.
8.) What does the Skeletal System do
for the Human Body?		 The bones provide a frame to support & protect
the Human Body Structures.
- The bones are the organs of the Skeletal
System.
9.) What does the Muscular System do
for the Human Body?		 - The Muscular System works with the Skeletal
System to help humans move.
The muscles contract and pull on the bones to
create movement.
10.) What does the Integumentary System
do for the Human Body?		 Your skin, hair & nails protect the tissue that lies
beneath them.
11.) What does the Lymphatic System do
for the Human Body?		 Returns leaked fluids to blood vessels & helps
get rid of bacteria & viruses.
12.) What does the Endocrine System do for
the Human Body?		 Sends out chemical messages (Hormones) to the
different Body Systems to maintain Homeostasis.
Examples: Thyroid Gland & Pituitary Gland
13.) What does the Exocrine System do for the
Human Body?		 Secretes substances outside the body.
- Excreted substances travel through a duct to an
outside structure.
- Examples: Salivary Gland & Sweat Gland
14.) What does the Urinary System do for the
Human Body?		 Removes wastes from the blood & regulates the
body's fluids.
15.) What does the Digestive System do for the
Human Body?		 Breaks down food you eat into nutrients that you
can absorb.
- Digestion begins when food is mixed with saliva
& chewed in the mouth.
16.) What does the Respiratory System do for
the Human Body?		 The lungs absorb oxygen & release carbon
dioxide.
- Involves inhaling & exhaling.
- Gives oxygen to the blood.
- Provides oxygen for Cellular Respiration to
release energy from food.
17.) What does the Cardiovascular System do
for the Human Body?
(Circulatory System)		 The heart pumps blood through all of the blood
vessels.
- Made of the Heart, Blood & Blood Vessels.
18.) What does the Nervous System do for the
Human Body?

The Nervous System sends & receives electrical messages throughout the body.

- Consists of Brain, Spinal Cord & Nerves.
- Subsystems are Somatic, Autonomic,Peripheral & Central
19.) What does the Reproductive System do for the Human Body?

The Reproductive System enables Humans to create offspring.

- Female produces eggs, nourishes & protects fetus.

- Male produces & delivers sperm.