1. THE CIRCULATORY SYSTEM
9th BIOLOGY
THE CIRCULATORY SYSTEM

2. Functions of the Circulatory System:
Transport of:
Oxygen
Nutrients
Immune cells
Platelets for clotting
Hormones
Heat

3. Blood Vessels:
Arteries- carry oxygen rich blood from the lungs to body cells
Thick smooth muscle layer
High pressure vessels
Veins- carry blood with carbon dioxide from the cells to the lungs
Thinner muscle layer
Low pressure
One way valves to prevent backflow

4. Blood Vessels

5. Capillaries Ultra-thin vessels
Red blood cells go through in a single file
Areas of exchange:
Gases- oxygen and carbon dioxide
Nutrients- fats, glucose, proteins
In kidneys, lungs, intestines and other areas where exchanges need to occur.

6. The Heart Made of cardiac muscle Has 4 chambers
2 atria (upper chambers)
2 ventricles (lower chambers)
Has 4 valves- control flow of blood with each beat

8. The Heart Beat:
Controlled by SA Node (the pacemaker)- bundle of tissues that fire an electrical signal to the AV Node for proper rhythm.
Pulse-
70 beats per minute at rest
Blood pressure-
Amount of pressure exerted against the vessels during heart beat

10. Blood Flow
From heart to the lungs  to body back to heart to lungs, etc.
Picks up oxygen and drops off carbon dioxide(waste product of cellular respiration) at the lungs.
Picks up carbon dioxide from body cells, goes to lungs for carbon dioxide to be exhaled.

12. Blood Components: Red blood cells White blood cells
Carry oxygen via hemoglobin
Made in bone marrow
Have 120 day lifespan
White blood cells
Immune cells that fight infection
Some make antibodies for long-term immunity

13. Blood components, cont. Platelets Plasma
Cell fragments that help with blood clotting
Activate other substances needed for clotting
Plasma
The liquid portion of blood
Carries immune proteins and nutrients
High water content

16. Blood Groups: ABO system
+ or – Rh factor, either it’s present or it’s not.
Alleles are: I A, I B, i
Remember you get one allele from each parent:
IA/ IA or IA/ i = type A
IA/ IB = type AB :universal recipient
IB/ IB or IB/ I = type B
ii = type O : universal donor

18. Circulatory System Disorders
Atherosclerosis- narrowing of the arteries, causing higher blood pressure

19. CHD
Coronary Heart Disease- coronary vessels become clogged with cholesterol and fat deposits, hindering blood flow to the heart muscle itself