1. The Respiratory System
Chapter 17
Section 1

2. Key Concepts What are the functions of the respiratory system?
What structures does air pass through as it travels to the lungs?
What happens during gas exchange and breathing?

3. Key Terms Respiration Cilia Pharynx Trachea Bronchi Lungs Alveoli
Diaphragm
Larynx
Vocal cords

4. Respiratory system functions
How long can without breathing?
Body cells need oxygen and they get it from the air you breathe.
The respiratory system moves oxygen from the outside environment into the body while removing carbon dioxide and water from the body

5. Taking in Oxygen
Oxygen is needed for the energy releasing chemical reactions that take place in your body
Ex. A fire cannot burn without oxygen, cells cannot burn enough fuel to keep you alive without oxygen

6. Respiration vs. breathing
Respiration is the process in which oxygen and glucose undergo a complex series of chemical reactions
Breathing is the movement of air into and out of the lungs
As a result of respiration cells release the energy that fuels growth and other cell processes

7. Removing Carbon Dioxide and Water
Respiratory system eliminates carbon dioxide and some of the water through your lungs

8. Respiratory, digestive, circulatory systems
Respiration could not take place without the digestive and circulatory system
Respiratory system brings oxygen into your lungs
Digestive system absorbs glucose from the food you eat
Circulatory system carries both the oxygen and the glucose to your cells

9. Path of air
Outside environment lungs passes through the following structures-nose, pharynx, trachea and bronchi

10. The Nose Air enters the body Moves into spaces called nasal cavities
Some of the cells lining the nasal cavities produce mucus
Sticky material moistens the air and keeps the lining from drying out
Mucus traps particles such as dust

11. (2)
Cilia are tiny hair like extensions that can move together in a sweeping motion
Cilia sweep the mucus into the throat where you swallow it
Stomach acid destroys the mucus along with everything trapped in it
Some particles can irritate the lining of your nose or throat, you sneeze and the particles shoot out of your nose into the air

12. The pharynx Air enters the pharynx-throat
Pharynx is shared with the digestive system-the nose and mouth connect to the pharynx

13. The trachea From the pharynx air moves into the trachea or windpipe
Run your fingers down the center of your neck-the trachea feels like a tube with a series of ridges, the firm ridges are rings of cartilage that strengthen the trachea and keep it open
Like the nose the trachea is lined with cilia and mucus
Cilia in the trachea sweep upward moving mucus toward the pharynx where it is swallowed
Tracheas cilia and mucus continue the cleaning and moistening of the air that began in the nose

14. (2) Normally only air not food enters the trachea
If food does enter, and block the opening and prevents air from getting to the lungs a person chokes
The epiglottis a small flap of tissue that folds over the trachea sealing off the trachea while you swallow

15. Bronchi and lungs Air moves from the trachea to the bronchi
Lungs are the main organs of the respiratory system
Left bronchus leads into the left lung same for the right side. Right bronchus leads to the right lung
Inside the lungs each bronchus divides into smaller and smaller tubes resembling the branches of a tree

16. (2)
The smallest tubes at the end of the structures look like bunches of grapes-alveoli-tiny sacs of lung tissue for the movement of gases between air and blood

17. Gas exchange
The walls of the aveoli and the capillaries are very thin allowing certain materials to easily pass through them
After air enters an alveolus, oxygen passes through the wall of the alveolus and then through the capillary wall into the blood
Carbon dioxide and water pass from the blood into the alveoli
You lungs can absorb a large amount of oxygen because of the large surface area of the alveoli
The huge surface area of the alveoli enables the lungs to absorb a large amount of oxygen

18. How you breathe How many times do you breath in an average day?
20,000-the rate at which you breath depends on your body’s need for oxygen

19. Muscles for breathing Breathing is controlled by muscles Picture
The lungs in the picture are surrounded by ribs, attached to them are the muscles, at the base is the diaphragm
The diaphragm is a large dome shaped muscle

20. Process of breathing
When you breathe your rib muscles and diaphragm expand or contract your chest-air flows in and out
Inhaling-the diaphragm contracts and moves downward
Exhaling-the rib muscles and diaphragm relax, reducing the size of the chest cavity-decrease in size squeezes air out of the lungs

21. Breathing and speaking
The air that moves out of your lungs as you breathe also helps you speak
The larynx is located in the top part of the trachea underneath the epiglottis