F4 Biology teaching notes Ch 8: 2nd Term NE 9

B		What are the adaptive features of the
		heart for pumping blood? (Book 1B, p. 8-19)

               

Adaptive features	Significance
The heart consists of (25) cardiac muscles	The muscles can contract and relax continuously without fatigue.
The (26) ventricles have a thick muscular wall	provides a strong force of contraction to drive blood over a long distance to all parts of the body
The bicuspid valve, tricuspid valves and (27) semilunar valves	prevent the backflow of blood
(28) Heart tendons	prevent the bicuspid and tricuspid valves from turning inside out

8.5  Blood circulation (Book 1B, p. 8-21)         CE-2008-IB-Q9b

Ø   When blood flows throughout our body in one complete loop, it passes through the heart

    (1) once / twice.

Ø   This type of circulation is called a (2) double circulation (雙循環), which includes:

n  (2) pulmonary circulation

n  (3) systemic circulation

	Pulmonary circulation	(4) Systemic circulation
Pathway	Right atrium → right ventricle → pulmonary artery → (5) lungs → pulmonary veins → left atrium	Left atrium → left ventricle → (6) aorta → all parts of the body except the lungs → venae cavae → (7) right atrium
Change of blood	Becomes (8) oxygenated / deoxygenated	Becomes (9) deoxyggenated

Ø  Most organs receive blood from an artery and drain blood into a vein

Ø  but the liver receives blood from two blood vessels:

n  the hepatic artery (肝動脈)

n  the (7) hepatic portal vein (肝門靜脈) which

links the (8) small intestine to the liver.