1. Respiratory System

2. Respiration The exchange of gases between the body and the outside air
Oxygen is drawn in and delivered to the cells
Carbon dioxide is released

3. Organs of the Respiratory System

4. Journey of a Breath of Air
Ventilation – moving air into and out of the lungs
Nose and Mouth
Mucus and hairs trap any particles in the air
Air is warmed and moistened
Pharynx – Long tube that is shared with the digestive system (esophagus)
Epiglottis closes when you swallow
Larynx – voice box (vocal cords)

5. Journey of a Breath of Air
Trachea – wind pipe
Leads into the chest
Divides into right and left bronchi
Contain cartilage which keeps them from collapsing
Mucus traps any remaining particles
Tiny hairs help move the mucus and particles to where they can be expelled through the throat
Air passes from the Bronchi to the smaller passages called the bronchioles

6. Pulmonary Gas Exchange
Takes places in the alveoli of the lungs

7. Gas Transport
Oxygen is carried from the lungs back to the heart by the circulatory system

8. Peripheral Gas Exchange
Oxygen diffuses into the cells from the capillaries and carbon dioxide diffuses into the capillaries from the cells

9. Gas Exchange and Homeostasis
Some of the carbon dioxide dissolves in the blood and forms carbonic acid to control the pH of the blood
This can get out of whack if we breathe too fast or two slow
As a result breathing must be regulated

10. How does Breathing Occur?
Comes from the contraction of the diaphragm

11. Control of Breathing Controlled by the brain stem
Uses the autonomic nervous system
Brain stem monitors the level of carbon dioxide in the blood
If too high – signals diaphragm to contract more often to get rid of excess carbon dioxide
If too low – the opposite

12. Diseases of the Respiratory System
Asthma – air passages become too narrow and too much mucus
Triggered by allergens, strenuous activity, stress
Pneumonia – alveoli fill with fluid
Coughing, chest pain, difficulty breathing
Infection or injury
Bacterial or viral in nature

13. Diseases of the Respiratory System
Emphysema – walls of the alveoli break down so less gas can be exchanged
Shortness of breath
Usually caused by smoking and is irreversible

14. Cigarette Health Warnings
Larger more prominent warning in September of 2012
Cigarettes are addictive
Tobacco smoke can harm your children
Cigarettes cause fatal lung disease
Cigarettes cause strokes and heart disease
Smoking during pregnancy can harm your baby
Smoking can kill you
Tobacco smoke causes fatal lung disease in nonsmokers
Quitting smoking now greatly reduces serious risks to your health

15. The Digestive System

16. Overview

17. The GI Tract Connects mouth to the anus 30 feet long in adults
Lined with mucus membranes that secrete digestive enzymes and absorb nutrients
Peristalsis is the involuntary muscle contractions that move food along in waves

18. Accessory Organs of Digestion
Food does not pass through them
They secrete or store substances needed digestion
Liver
Pancreas
Gall Bladder

19. Functions of the Digestive System
Mechanical digestion
Physical breakdown of chunks of food
Takes place in the mouth and stomach
Chemical digestion
Chemical breakdown of food into usable smaller nutrients that can be absorbed by the blood
Begins in the mouth and stomach, but takes place mainly in the small intestine
Absorption – nutrients absorbed in the small intestine
Elimination – getting rid of the waste products

20. Digestion as a process Mouth to Stomach
Digestive enzymes released by the salivary glands in the mouth (chemical)
Salivary amylase – starch into sugar
Mechanical digestions
Food passes into the esophagus and then into the stomach
Sphincter controls the entrance of food into the stomach and from moving back up

21. Stomach Chemical and physical digestion
HCl
Kills bacteria in food and give the stomach a low pH needed by the digestive enzymes to work
Pepsin – digests protein
Sphincter opens and partially digested food moves into the small intestine

22. Digestion and Absorption in the Small Intestine
23 feet long in adults
Duodenum – smallest part – most chemical digestion takes place here
Jejunum
Ileum

23. Digestive enzymes of the Duodenum
What it Digests
Where It is Made
Amylase
Carbohydrates
Pancreas
Trypsin
Proteins
Lipase
Lipids
Pancreas, Duodenum
Maltase
Duodenum
Peptidase

24. Liver and Gall Bladder Liver Gall bladder
Produces bile which goes into the duodenum and the gall bladder
Gall bladder
Concentrates and stores bile and then secretes it into the small intestine
Bile breaks up globules of lipids
Enzymes here need a neutral environment
Created by the pancreas secreting bicarbonate

25. Absorption in the small intestine
In jejunum by villi (many capillaries)

26. Large Intestine Cecum Colon – Excess water is absorbed here Rectum
Solid waste eliminated as feces

27. The Excretory System

28. Excretion
The large intestine eliminates solid wastes that remain after the digestion of food
The liver breaks down excess amino acids and toxins in the blood
The skin eliminates excess water and salts in sweat
The lungs exhale water vapor and carbon dioxide

29. Kidneys The main organ of the excretory system
Filters blood to form urine
Nephrons are the structural and functional units of the kidney
There are more than a million nephrons

31. Filtering blood and forming urine
Blood enters through the renal artery and branches into the capillaries
Blood pressure forces some of the water and dissolved substances to enter the Bowman’s capsule
Filtered substances pass to the renal tube
Some substances are reabsorbed and returned to the bloodstream – other substances are secreted into the fluid
Fluid passes through a collecting duct which reabsorbs some water and returns it to the bloodstream
Rest remains in the collecting duct as urine

32. Excretion of Urine Urine enters the ureters
Peristalsis moves it to the bladder
When the bladder is about half full a signal is sent to relax a sphincter muscle which allows the urine to flow into the urethra
Urine passes out of the body through the urethra