Transport in Humans (Blood and blood vessels) Revision

Across
8.	These structures in certain blood vessels prevent the backflow of blood.
9.	___ blood is blood filled with low levels of oxygen.
10.	This process prevents excessive loss of blood when you are injured.
12.	The red pigment in red blood cells that binds reversibly to oxygen.
15.	White blood cells have ___ shapes.

Down
1.	Humans are ____ organisms, so a transport system is required to transport materials quickly to all parts of the body.
2.	Blood vessel which is only one cell thick.
3.	Membrane-bound fragments of cytoplasm from bone marrow cells.
4.	Blood vessel which transports blood away from the heart.
5.	Red blood cells are destroyed in the _____.
6.	Red blood cells are produced in the ______.
7.	One function of blood is to protect the body against _____.
11.	Pale yellowish liquid which contains 90% water.
13.	Red blood cells are circular, flattened and ____ in shape to increase surface area to volume ratio for faster diffusion of oxygen.
14.	Blood vessel which transports blood back into the heart.