2.  Flow of blood, nutrients, oxygen and other gases, and hormones to and from cells  Fights diseases  Maintains a stable environment  Also known as the cardiovascular system  Heart, lungs, arteries, veins, coronary and portal vessels

3.  Elastic blood vessel that transports blood away from the heart  Two main types: pulmonary and systematic arteries

4.  Elastic blood vessel that transport blood from various regions of the body to the heart  Pulmonary, systemic, superficial, and deep veins  Size ranges 1 millimeter to 1-1.5 centimeters in diameter  Smallest veins are venules

5.  Extremely small blood vessel in the tissues of the body  Transports blood arteries to veins  Most abundant in tissues and organs are metabolically active  Red blood cells must travel in single order  5-10 microns in diameter  Capillary walls: thin and composed of endothelium

6.  Needed for the formation of a blood clot  Lack a nucleus  Life span of 7-12 days  Prevents excess loss of blood from a wound

7.  Defend against diseases  Larger than red blood cells  Squeeze through openings in the walls of blood vessels  May be irregularly shaped and have a rough surface  Several types of white blood cells

8.  Transport oxygen to cells in all parts of the body  During the formation of a red blood cell, its nucleus and organelles disintegrate  Disk-shaped and concave on both sides

9.  Molecule that actually transports oxygen  Iron-containing protein  Found in a red blood cell

10.  90 percent water  Cells receive nourishment from dissolved substances carried in the plasma  Liquid medium in the bloodstream  Carries hormones and brings waste from the cells to the kidneys or lungs to be removed  Contains variety of proteins

11.  Hemophilia- disorder caused by the absence of one or more of the proteins required for blood clotting  People who have hemophilia excessively bleed when injured and could bleed to death

12.  Heart - A hollow, cone-shaped muscle located between the lungs and behind the sternum (breastbone).  The heart has three layers.  How does blood flow through the heart?  The right and left sides of the heart work together.

13.  Blood enters the heart through two large veins.  As the atrium contracts, blood flows from your right atrium into your right ventricle.  When the ventricle is full, the tricuspid valve shuts.  As the ventricle contracts, blood leaves the heart through the pulmonic valve.

14.  The pulmonary vein empties oxygen-rich blood from the lungs.  As the atrium contracts, blood flows from your left atrium into your left ventricle.  As the ventricle contracts, blood leaves the heart.

15.  Glucagon (glū′k ă -gon) - Glucagon is a naturally occurring hormone that is produced in the pancreas.  The main function of glucagon is to react to a situation where there is a low level of blood sugar present.

16.  Hormones located in plasma (part of the fluids transported to and from the heart)  Hormones help maintain homeostasis  As hormones travel through the bloodstream regulate how the blood flows

17.  The circulatory system is not always perfect.  Examples; Coronary artery disease, hypertension, & rheumatic heart disease.  Hypertension – Technical term for high blood pressure. Blood pressure can be 120 over 80; (TOO HIGH!)  Arteries can burst.