1. Chapter 19
Circulatory System

2. Ch 19.1 – Cardiovascular System
A. Cardiovascular system includes your heart, blood and blood vessels
1. Movement of materials into and out of cells occurs by diffusion
2. Movement also occurs by active transport

4. B. Heart – controls blood flow through body
1. Has 4 chambers
a) 2 Atriums –
upper chambers
b) 2 Ventricles –
lower chambers

5. 2. Three types of Circulation: a) Coronary Circulation – flow of blood through chambers in heart b) Pulmonary Circulation – flow of blood in lungs (picks up O2 and drops of CO2) c) Systemic Circulation – flow of blood through blood vessels in rest of body

6. C. Blood Vessels – carry blood to every part of your body 1
C. Blood Vessels – carry blood to every part of your body 1. Arteries – blood vessels that carry blood away from the heart (most contain oxygenated blood) a) Each ventricle is connected to a major artery - right ventricle to pulmonary artery - left ventricle to aorta b) Each time heart beats (contracts) blood is moved into arteries

8. 2. Veins – blood vessels that carry blood back toward the hear (usually deoxygenated) a) Two major veins - Superior Vena Cava: returns blood from head and neck - Inferior Vena Cava: returns blood from lower body b) blood is moved with muscular contractions and one-way valves keep blood moving toward heart (against gravity)

10. 3. Capillaries – microscopic blood vessels that connect arteries to veins

11. Is Our Blood Really Blue?
Deoxygenated blood is darker (more of a deep red to purple)
We see blood vessels through skin as blue b/c that is the only strong enough wavelength of light to penetrate through epidermis and dermis (and then reflect back so we see blue)
Cyanosis – poor circulation can cause localized areas (often fingers) to darken due to tissues lack of oxygen

12. D. Blood Pressure – the force of blood on the walls of the blood vessels 1. BP is highest in arteries and lower in veins a) it rises and falls with every heartbeat b) Normal adult pulse is b/w bpm

13. 2. Measured with 2 numbers a) Systolic BP – first; pressure when ventricles contract pushing blood out of heart (higher #) b) Diastolic BP – second; measures pressure while ventricles are relaxed and filling with blood (lower #) 3. Your brain tries to keep BP constant; sends messages to heart to raise and lower BP by speeding up or slowing down heartrate

14. E. Cardiovascular Disease – leading cause of death in United States 1
E. Cardiovascular Disease – leading cause of death in United States 1. Hypertension – high blood pressure a) when BP is high heart must work harder b) may be caused by stress or plaque build up in blood vessels

15. 2. Atherosclerosis – fatty (plaque) deposits built up on arterial walls which clogs blood flow a) Can occur in any blood vessel but is most dangerous in coronary arteries b) If blood flow is cut off to heart tissue this causes a heart attack (aka myocardial infarction) c) Heart attacks may cause cardiac arrest which is when a heart stops beating/contracting

16. 3. Prevention of Cardiovascular disease a) Eat healthy avoiding too much salt, saturated fat and cholesterol b) Exercise to eliminate excess weight and clear plaque from blood vessel walls

17. Ch Blood
A. Functions of Blood 1. RBC’s carry O2 from lungs to body cells and CO2 from body cells to lungs to be exhaled 2. Carries waste products from cells to kidneys to be removed in urine

18. 3. Carries nutrients from small intestine to cells 4
3. Carries nutrients from small intestine to cells 4. WBC’s fight infections 5. Other molecules in blood clot to heal wounds

19. B. Parts of Blood 1. Plasma – liquid part of blood a) made mostly of water b) has nutrients and minerals dissolved in it c) carries wastes from cells

20. 2. Red Blood Cells (RBC’s) – supply body with O2
[Erythrocytes]
a) Hemoglobin – iron molecule in RBC’s that carries O2 and CO2
b) Life span is 120 days

21. 3. White Blood Cells (WBC’s) – fight infections [Leukocytes] a) Body reacts to invaders by increasing # b) WBC’s enter infected tissues, destroy bacteria and viruses, then absorb the dead cell c) Life span of WBC’s is a few days to months

23. 4. Platelets – irregularly shaped cell fragments a) Release chemicals that form filaments of fibrin which trap blood cells to form a clot b) Life span 5-9 days

24. C. Blood Clotting 1. Platelets stick to wound and release chemicals 2
C. Blood Clotting 1. Platelets stick to wound and release chemicals 2. Chemicals produce threadlike fibers called fibrin that form a sticky net 3. The net traps blood cells to form a clot 4. Skin cells regenerate and fill in the wound

26. D. Blood Types – A, B, AB and O 1
D. Blood Types – A, B, AB and O 1. Based partly on antigens a) chemical ID tags on blood cells b) Type O blood has no antigens – can donate to any type (AKA universal donor)

28. 2. Also based on antibodies a) Proteins in plasma that identify substances that do not belong in the blood and destroy them b) Type AB blood has no antibodies – can receive from any type (AKA universal receiver)

30. 3. Rh factor – another chemical ID tag on cells a) Rh+ has it; Rh- does not b) If people who lack the Rh factor (Rh-) receive Rh+ blood they will produce antibodies against it
Named for rhesus monkey in which it was first discovered

31. E. Blood Diseases 1. Anemia – affects RBC’s
a) hemoglobin molecules not healthy which causes body tissues to not get enough O2
b) caused by large loss of blood or dietary lack of iron

32. 2. Sickle Cell Anemia – affects RBC’s a) body tissues do not receive enough oxygen due to misshapen RBC’s

33. 3. Leukemia – affect’s WBC’s a) Cancer in which WBC’s made in excess but they are immature so do not fight infections properly
Form of cancer b/c cells regenerate too rapidly
Crowding of immature WBC’s make it difficult to have space for production of healthy cells

34. Ch 19.3 – Lymphatic System
A. The lymphatic system (AKA immune system) collects tissue fluid and returns it to the blood
1. Lymph – tissue fluid that has diffused into lymphatic capillaries
a) contains water and dissolved substances
b) contains lymphocytes – type of WBC

35. 2. Lymph is carried through lymph capillaries and vessels to large veins near the heart
3. Lymph is moved by contraction of muscles
4. Lymphatic vessels have valves to keep lymph from flowing backward

37. B. Lymphatic Organs
1. Lymph nodes
a) bean-shaped organs of various sizes found throughout the body
b) filter microorganisms and foreign material from lymphocytes

38. 2. Tonsils
a) organs in throat that protect body from harmful microorganisms that enter through the mouth

39. 3. Thymus
a) makes WBC’s
b) located behind sternum wrapped around
trachea (windpipe)

40. 4. Spleen
b) located behind stomach
a) filters blood to remove damaged RBC’s and harmful microorganisms

41. C. HIV Virus – attacks a type of lymphocyte (WBC) called helper T-cells
1. Healthy people have helper T-cells
2. If a persons helper T count drops below 200 they are diagnosed with AIDS (Acquired Immune Deficiency Syndrome)

42. 3. HIV is spread through body fluids from blood, breast milk and sexual contact (but not tears, sweat, saliva or urine)
4. HIV, like all viruses, have no medicinal cures, however drugs have been developed
to slow the progression of the virus
so people can live longer with this
infection than in years past