1. The Circulatory System

2. Function: Transports nutrients & wastes Contains cells that fight infections Helps maintain body temperature by transporting heat

3. The Circulatory System All organisms must be able to transport nutrients and wastes. Smaller organisms rely on _________ for this movement; humans require an organized circulatory system for the movement of substances through the body. We have a _______ circulatory system, which means our blood is __________________. The human circulatory system includes the heart, the blood vessels, and the blood. diffusion closed contained in vessels

4. I. THE HEART (pp. 943-946) ADD TO NOTES The heart itself is mostly composed of ________ muscle which forms a thick layer of tissue known as the ____________. Humans have a __ chambered heart, divided by a __________ into right and left sides to prevent cardiac myocardium 4 septum Mixing of blood

5. A. Structure ADD TO NOTES 1. Chambers a. Atria (atrium = singular) _______ chambers of the heart that ________ blood. b. Ventricles - _______ chambers of the heart that ________ blood. 2. Valves – Flaps of tissue that keep blood flowing _________________ Upper receive lower pump in one direction

6. B. Pathway of Blood Through the Heart ________  _________  ___________  ____________  ____  ____________  ________  _________  ____  _______ ADD TO NOTES vena cavaright atriumright ventricle pulmonary arterylungpulmonary vein left atrium left ventricleaorta body

7. C. Circulatory Pathways 1. Pulmonary Circulation – The blood entering the right atrium from the body is ____ in oxygen and _____ in carbon dioxide. The flow of blood from the right side of the heart to the _____ and back to the heart is referred to as ___________ circulation. highlow lungs pulmonary

8. C. Circulatory Pathways 2. Systemic Circulation – The blood entering the left atrium from the lungs is _____ in O2 and _____ in CO2. The flow of blood from the left side of the heart to the ______ and back to the heart is referred to as __________ circulation. high low body systemic

10. D. The Heartbeat 1. Stimulus for Contraction Although the brain can change the rate & force of contraction, the heart generates and maintains its own beat. There is a small cluster of cardiac muscle cells in the ______________ referred to as the __________. They trigger an ___________ impulse that stimulates the contraction of cardiac muscle cells. right atrium pacemaker electrical

11. Sinoatrial (SA) node Atrioventricular (AV) node Conducting fibers Contraction of Atria Contraction of Ventricles The Sinoatrial Node

12. D. The Heartbeat 2. The Pulse The powerful contraction of the _________ causes a surge of blood to leave through the _____. This surging action of the blood continues into the ______ that branch off from the aorta. Each contraction of the left ventricle results in another surge of blood in the arteries leading away from the heart. This surge can be felt and is known as the _____. left ventricle aorta arteries pulse

13. Blood Vessels & Blood

15. Blood Vessels Arteries carry blood _____from heart carry oxygen ____blood (except for__________) Have thick elastic walls surrounded by _____muscle ____is the largest artery in the body away rich pulmonary smooth Aorta

17. Blood Vessels Capillaries –________ blood vessels –Walls are only 1 cell thick –This is where the exchange of ______ & _____ takes place smallest nutrients waste

18. Blood Vessels Veins –Collect blood and carry it _____ to the heart –Carry oxygen _______ blood (except for _____________ veins) –Have thinner and less elastic walls –Have _______to keep blood flowing to heart and not _________ –Contraction of _________ muscles help to move blood toward the heart –The ____________is the largest vein in the body back poor pulmonary valves backwards skeletal vena cava

19. Artery vs. Vein

20. Blood Pressure: the force of blood on the walls of the arteries –Falls when the heart ______ –Heart is always under pressure in order to keep blood flowing through it –Regulated by autonomic nervous system –________ also regulate blood pressure by controlling amount of water in blood- when blood pressure is high, more water is__________; this reduces blood volume relaxes Kidneys removed

21. Blood Pressure Blood against the blood vessel’s walls –The systolic pressure refers to the pressure recorded while the ventricles pump the blood. –The diastolic pressure refers to the pressure recorded as the ventricles fill with blood. A normal blood pressure is 120/80

22. Blood Pressure –High blood pressure forces heart to ___________ people more likely to develop heart disease obesity is one cause controlled by weight control, exercise, and diet work harder

23. Blood –Makes up 8% of body – ____ to___ liters –Components of blood 45% = ____ blood cells, ______ blood cells and platelets 55% = plasma –mostly ________- 90% –contains salts, sugars, and plasma proteins 4 6 red white water

24. What does blood contain? 50% Water 45% Erythrocytes 4% Plasma with Substances 1% Leukocytes + Platelets

25. Blood –Plasma proteins Several types of proteins that fight__________, regulate osmotic pressure & help blood ____________ –Red blood cells- erythrocyte- RBC contain ________________- iron containing protein that increases ___________ carrying ability of RBC’s produced in ______bone marrow mature RBC’s have no nucleus so can’t divide live about 120 days – when they die they are destroyed & recycled by spleen infection clotting hemoglobin oxygen red

26. Blood –White blood cells – leukocytes- WBC fewer in numbers than RBC produced in bone marrow live for many months or years more than 20 different types guard against________________, fight_______________, and attack ________________ an increase in the number of WBC’s is an indication the body is fighting an _____________________ – Platelets fragments of cells when blood vessel is injured, platelets become sticky; they cluster around the wound and release a series of chemicals that start a clotting reaction a protein called __________forms a net that traps RBCs and forms a ______ infections pathogens bacteria infection fibrin clot

28. Blood Clotting Break in Capillary Wall Blood vessels injured. Clumping of Platelets Platelets clump at the site and release thromboplastin. Thromboplastin converts prothrombin into thrombin.. Clot Forms Thrombin converts fibrinogen into fibrin, which causes a clot. The clot prevents further loss of blood..

29. DISORDERS ATHEROSCLEROSIS –Fatty deposits called plaque –Builds up in walls of arteries –Obstructs flow –Also a risk if clot breaks free and blocks flow elsewhere

30. Disorders (cont) Heart Attack –Atherosclerosis in coronary artery –Heart muscle begins to die Symptoms –Nausea –Shortness of breath –Severe chest pain IMMEDIATE MEDICAL ATTENTION NECESSARY

31. Disorders Continued Anemia –Caused by either a deficiency of red blood cells or hemoglobin in RBCs. Less oxygen available for cells results in a lack of energy due to decreased ATP production.

32. Disorders (cont) Hypertension –High blood pressure –Hearts works harder than necessary –Increases risk of heart attack or stroke

33. Disorders (cont) Stroke –Blood clot gets stuck in blood vessels leading to brain –Brain cells die due to lack of oxygen Or blood vessel burst –Can lead to paralysis, loss of ability to speak death