Unit 10 The Human Body

1. Unit 10 The Human Body Ch. 37 Circulatory & Respiratory Systems

2. Functions of the Circulatory System • The human circulatory system consists of the heart, a series of blood vessels, & the blood that flows through them

3. The Heart • The heart is made almost entirely of muscle, & is a hollow organ about the size of your clenched fist • Atria - the upper chambers that receive the blood • Ventricles - the lower chambers that pumps the blood out of the heart

4. The Heart • The heart functions as 2 separate pumps • Pulmonary circulation - pathway on the right side that pumps oxygen-poor blood from the heart to the lungs

5. The Heart • Systemic circulation - pathway on the left side that carries oxygen-rich blood from lungs to the heart, & the rest of the body

6. Circulation Through the Heart • Blood enters the heart through the right & left atria • It then flows out from the ventricles to either the body or the lungs • Valves - flaps between the atria & the ventricles, prevent blood from flowing backwards

7. 12 1 6 7 8 5 11 9 2 3 10 1 4

8. Blood Vessels • Aorta - large blood vessel, carries oxygen-rich blood away from heart to the body • As blood flows through the circulatory system, it moves through 3 types of blood vessels: arteries, capillaries, & veins

9. Blood Vessels • Arteries - vessels that carry blood away from the heart to the tissues of the body • They carry oxygen-rich blood

10. Blood Vessels • Capillaries - smallest of the blood vessels • Veins - return oxygen-poor blood to the heart

11. Diseases of the Circulatory System • Cardiovascular diseases, like heart disease & stroke, are among the leading causes of death in the U.S. • High blood pressure & atherosclerosis are 2 of the main causes of cardiovascular disease

12. Diseases of the Circulatory System • Atherosclerosis - condition where fatty deposits, called plaque, build up on the inner walls of the arteries • Can cause heart attacks & strokes

13. Diseases of the Circulatory System • High blood pressure, hypertension, increases the rate of heart attack & stroke • High blood pressure occurs when deposits of fat build up on the artery walls

14. Blood & the Lymphatic System • Blood is a type of connective tissue • It collects oxygen from the lungs, nutrients from the digestive tract, & waste products from tissues • Blood helps regulate body temperature • The components that make up blood help fight infection, & repair damaged blood vessels

15. Blood Plasma • The human body has 4-6 liters of blood, or 8% of the total body mass • 45% of blood consists of cells, that are suspended in the other 55%, plasma • Plasma - 90% water, 10% dissolved gases, salts, nutrients, enzymes, hormones, waste products, & proteins

16. Blood Plasma

17. Blood Cells • The cellular portion of blood consists of red blood cells, white blood cells, & platelets

18. Blood Cells • Red blood cells transport oxygen, are the most numerous, & get their color from hemoglobin • Hemoglobin - iron-containing protein that binds oxygen in the lungs & transports it to tissues throughout the body where oxygen is released

19. Blood Cells • White blood cells are the “army” of the circulatory system - they guard against infection, fight parasites, & attack bacteria • Lymphocytes - a special class of white blood cells, produce antibodies that are proteins that help destroy pathogens

20. Blood Cells • Blood clotting is made possible by plasma proteins & cell fragments called platelets • Platelets - large bone marrow cells that have broken into small fragments

21. The Lymphatic System • A network of vessels, nodes, & organs called the lymphatic system, collects the fluid that is lost by the blood & returns it back to the circulatory system • Lymph - fluid collected by the system

22. The Lymphatic System • The spleen is an organ whose main function is to destroy damaged red blood cells & platelets • T cells (white blood cells) mature in the thymus gland, which produces hormones that promote their development

23. The Lymphatic System

24. What Is Respiration? • At the cellular level, respiration takes place in the mitochondria • It releases energy from the breakdown of food molecules in the presence of oxygen

25. What Is Respiration? • At the level of the organism, respiration means the process of gas exchange - the release of carbon dioxide & the uptake of oxygen between the lungs & the environment

26. The Human Respiratory System • The basic function of the human respiratory system is to bring about the exchange of oxygen & carbon dioxide between the blood, air, & tissues • The respiratory system consists of the nose, pharynx, larynx, trachea, bronchi, & lungs

27. The Human Respiratory System • Pharynx - passageway for both air & food • Larynx - top of trachea, vocal cords • Trachea - windpipe, receives air from pharynx

28. The Human Respiratory System • Bronchi - 2 large passageways in the chest cavity, each leads into 1 of the lungs • Inside the lungs, the bronchi divide into even smaller tubes, called bronchioles • Alveoli - tiny air sacs at the ends of the bronchioles, where gas exchange takes place

29. The Respiratory System

30. Gas Exchange • There are about 150 million alveoli in each healthy lung • Oxygen diffuses across the membrane of the alveoli into the capillaries, wrapped around the outside of the alveoli • At the same time, carbon dioxide diffuses from the blood in the capillaries, into the alveoli, to be excreted

31. Gas Exchange

32. Breathing • Breathing is the movement of air into & out of the lungs • Diaphragm - large, flat muscle at the bottom of the cavity

33. Tobacco & the Respiratory System • The upper part of the respiratory system is able to filter out dust & foreign particles that could damage the lungs • Smoking tobacco damages that protective layer

34. Tobacco & the Respiratory System • Tobacco contains nicotine, carbon monoxide, & tar • Nicotine - a stimulant drug that increases heart rate & blood pressure

35. Tobacco & the Respiratory System • Carbon monoxide is a poisonous gas that blocks the transport of oxygen by hemoglobin in the blood • Tar contains a # of compounds that have been shown to cause cancer

36. Tobacco & the Respiratory System • Smoking reduces life expectancy • Only 30% of male smokers live to age 80, but 55% of male nonsmokers live to that age • Smoking can cause respiratory diseases like: chronic bronchitis, emphysema, & lung cancer

37. Tobacco & the Respiratory System • Chronic bronchitis occurs when the bronchi become swollen & clogged with mucus • Emphysema - the loss of elasticity in the tissues of the lungs, making breathing very difficult

38. Tobacco & the Respiratory System • Lung cancer is deadly because its cells can spread to other locations • By the time lung cancer is detected, it has spread to dozens of other places

39. Tobacco & the Respiratory System • Smoking is also a major cause of heart disease, it constricts, or narrows, the blood vessels • There is a drastic change in body temp. & in circulation immediately after smoking a cigarette