Chapter 20

1. Chapter 20 Respiration & Excretion

2. Ch 20.1 – The Respiratory System A. Functions – supply oxygen to the body 1. Breathing – the movement of the chest that brings air into the lungs and removes waste gases 2. (Cellular) Respiration – oxygen used by cells to release energy from glucose (food) a) waste products of resp. are CO2 & H20

3. B. Organs of the respiratory system 1. Pharynx (throat) – tubelike passageway used by food, liquid and air a) lower end has tissue flap called the epiglottis to prevent food or liquid from entering airway

5. 2. Larynx – small area in neck region below pharynx which houses the vocal cords

6. 3. Trachea – AKA windpipe; tube leading down to lungs held open by rings of cartilage, and lined with cilia and mucous

7. 4. Bronchi – 2 short tubes at the end of the trachea that go into each lung then branch into smaller tubes called bronchioles

8. 5. Lungs – organs at the end of bronchi tubes that contain small clusters of air sacs called alveoli at end of each bronchiole

9. a) Alveoli are surrounded by capillaries which is where gas exchange takes place in the lungs

10. C. Why do you breathe? 1. Signals from brain tell muscles in abdomen to contract and relax a) If oxygen levels in blood decrease and CO2 levels increase your breathing rate increase b) If 02 increases and CO2 decreases your breathing decreases

11. 2. Diaphragm – muscle beneath lungs that contracts and relaxes to move air into and out of lungs

12. The Iron Lung

13. D. Diseases and Disorders 1. Colds, Influenza – viruses that affect the upper respiratory system (nose, mouth, pharynx & larynx)

14. 2. Bronchitis – bacterial infection that irritates the bronchial tubes leading into the lungs; coughing and lots of mucus result as body’s method of removing infection a) Chronic Bronchitis – ongoing from repeated exposure to irritating substances

15. 3. Pneumonia – infection of the alveoli that may be caused by bacteria or virus spreading from upper respiratory system

16. 4. Emphysema – disease of the alveoli which causes them to enlarge then collapse and malfunction a) causes shortness of breath due to lack of oxygen and can often lead to heart problems

17. 5. Lung Cancer – uncontrolled cell growth in lung tissue a) smoking is greatest contributing factor b) tar and other ingredients in cigarette smoke are carcinogens

18. 6. Asthma – disorder in which bronchi tubes contract quickly due to allergic reaction a) may be caused by foreign substance (pollen, smoke, foods etc) or stress b) causes shortness of breath, wheezing or coughing

19. Ch 20.2 – The Excretory System A. Functions – remove body wastes 1. Occurs through integumentary, digestive, circulatory, respiratory and urinary systems

20. B. Urinary System – gets rid of cell wastes that accumulate in the blood and controls blood volume 1. Organs: a) Kidneys – filters blood for waste products and excess water through tubes called nephrons

22. b) Ureters – Tubes that pass urine down from each kidney c) Bladder – elastic organ that collects and holds urine drained from ureters

23. d) Urethra – small tube that passes urine out of the body once bladder is full

24. 2. Hypothalamus – part of the brain that regulates the amount of water in blood a) If blood has too much water, hypothalamus tells kidneys to increase urine production b) If blood has too little water, hypothalamus tells kidneys to decrease urine production

25. C. Other organs of excretion 1. Liver – filters blood and produces a chemical called urea which kidneys pull out and put in urine

26. D. Disease and Disorders 1. Infections – bacterial infections may occur in urethra or bladder a) Urethra and ureters may become blocked interrupting the flow of urine b) May be detected by urine test c) If left untreated bacteria may spread and cause kidney damage

27. 2. Kidney Stones – hard mass developed from crystals forming in the urine

28. 3. Kidney Failure a) A person with one kidney can live normally b) If both fail, the person will need a dialysis machine to filter their blood