Reading Assignment: POHS pp. 1016-1037

Self Quiz: 1-10

Applying Concepts: 2 - 5

Additional thought questions:

1) Given that the force generated by muscle (including cardiac muscle) is proportional to its cross-sectional area (i.e., its thickness), which has thicker (more forceful) walls: Atria or ventricles? Right or left ventricle?

2) How is the heart supplied with blood since the endocardial lining of the heart is impervious to diffusion? Why do the coronary arteries arise from the aorta rather than the pulmonary trunk?

3) If the heart can beat without innervation, why are pace-makers implanted in heart transplantations?

4) Why is "healthy exercise" an oxymoron?

Lecture outline:

Definition and functions of circulatory systems

Diversity of circulatory systems
	type of circulatory systems places constraint on size of organism
	open vs. closed circulatory systems

Vertebrate cardiovascular systems - all closed systems
	"fish" - single atria and ventricle; single (systemic) circuit
	lungfish - 2 atria, 1 ventricle; modified circulation
	amphibians - 2 atria, 1 ventricle; separate pulmonary and systemic circuits
		(dual circuits)
	reptiles (non-archosaurian) - 2 atria and partially divided ventricle; 
		dual circuits
	archosaurs ("ruling reptiles"; birds and crocodiles) - 2 atria and 2 ventricles;
		 dual circuits
	mammals - 2 atria and 2 ventricles; dual circuits
	
	- among tetrapods (vertebrates with 4 limbs) , only birds and mammals lack 
		communications between the pulmonary and systemic systems; 
		associated with high metabolic rate

Human heart as example of mammalian condition
	circulation pattern
	conduction system
		sinoatrial node
		atrioventricular node

The vascular system 
	arteries and veins
	capillaries
	
The lymphaitic system
	dual function:  (1) collects interstitial fluid, (2) immune

Blood - an unusual type of connective tissue
	red blood cells (RBC, erythrocytes)
	white blood cells (WBC, leukocytes)
	platelets
	plasma

Control and regulation of circulation
	autoregulation
	systemic regulation
		hormonal
		nervous

Topics not covered in lecture for which you will be responsible:

	cardiac cycle (systole, diastole)	p. 1022
	EKG	p. 1025
	cardiovascular disease	p. 1030