1. Respiratory System Ms. Day AP Biology

2. Circulatory and Respiratory Systems
They work together to help maintain homeostasis in the body.
What do they help to regulate?
Body temp
Heart rate
Breathing rate
O2 and CO2 levels in cells

3. Function of Respiratory and Circulatory Systems
Main job of Respiratory System
Transport gases to and from the circulatory system
What gases?
Get oxygen (O2) into the body and remove waste gases (CO2) out of the body
Main job of Circulatory System
Moves blood to all parts of the body.
These systems work together!

4. Where do the gases come from? Why do we need them?
Cellular Respiration: creates ATP from food
O2 = Needed for cellular respiration to make ATP (energy)
You breath in O2 from air
CO2 = waste product
The overall process is:
Macromolecules + O2  CO2 + H2O + energy (ATP)
Carbohydrates, fats, and proteins can all be used as the fuel, but most useful is glucose.

5. Respiratory and Circulatory Systems
Components of Respiratory
Nose
Mouth
Pharynx
Trachea
Lungs
Diaphragm
Components of Circulatory
Heart
Blood
Blood Vessels
Arteries
Veins
Capillaries

6. Respiratory System (in detail)

7. RESPIRATORY SYSTEM

8. External Respiration Pathway
Respiratory surface = the exchange of gases between the atmosphere and the blood (entirely dependent on diffusion!!!)
Movement of substance from high concentration to low concentration
Mucous membranes are found through the respiratory system thin, warm and moist  needed for diffusion

9. Pathway of Air into the Body
1. Nose/Mouth-external opening to allow entry
Air is filtered, cleaned, warmed, moistened
2. Air moves through pharynx to trachea
Trachea (windpipe) traps the inhaled particles with cilia and mucus
Mucus
traps foreign particles
Cilia
“sweep” foreign material away from lungs then swallowed
Impurities in air, such as dirt and bacteria, are filtered by hair and mucus in the nose.
The air is warmed and moisture is added.

10. Pathway of Air into the Body (continued)
3. Enters a series of tubes
Protected by cartilage to keep tubes firm/open
1st = Enters trachea which branches out into
2nd = two bronchi that also branches out into even smaller tubes called bronchioles
4. Bronchioles end up in air sacs called alveoli, where all exchange of gases occur.
Impurities in air, such as dirt and bacteria, are filtered by hair and mucus in the nose.
The air is warmed and moisture is added.

11. Structure of Alveoli (ends of bronchioles)
Small air sacs covered in mucus
Wrapped in tiny blood vessels called capillaries
300 to 600 million in a pair of lungs
Great deal of surface area
Actual site of gas exchange

12. How do we breath? Involves muscles of the rib cage and the diaphragm
Diaphragm: dome shaped skeletal muscle at the base of the rib cage
Inhale (take air into lungs)
muscles contract, expand rib cage, diaphragm moves down
Exhale (release air from lungs)
muscles relax, contract rib cage, diaphragm moves up

13. Ventilation (Inhalation/Exhalation) Diagram
V P
V P

14. Recall: Gas Exchange 3 principles for gas exchange:
O2 and CO2 are carried by the blood
Opposite directions
Gas moves by diffusion (moves from area of high to low concentration)
Lining of the alveoli must be moist to help gases diffuse

15. Diffusion of gases
Gases always move from areas of high concentration to areas of low concentration
O2 concentration is higher in alveoli than blood
oxygen diffuses into blood
At body cells, O2 concentration is higher in blood
oxygen diffuses out of blood and into cells

16. Gas Exchange O2  alveoli  capillaries  red blood cells
CO2 red blood cells  capillaries  alveoli 
Inhaled oxygen dissolves in the film of moisture on the alveoli cells.
Oxygen then diffuses into a web of capillaries surrounding each alveolus and enters red blood cells, binding with red blood cells.
Carbon dioxide diffuses the opposite way, from the capillaries across into the alveoli. Then the carbon dioxide is expelled back up the trachea, through the nose or mouth out into the air.

17. Hemoglobin and Gas Exchange
Oxygen diffuses into red blood cell (RBC’s) where there is hemoglobin (a protein in RBC)
Hemoglobin contain iron atoms, which bind to oxygen gas

18. Carbon Dioxide Transport
Hemoglobin ALSO helps transport CO2!!
7% of CO2 (in plasma)
transported as dissolved CO2 in blood plasma (water portion of blood)
23% binds to hemoglobin (in RBC’s_
70% (inside RBC’s)
transported in the form of bicarbonate ions (HCO3-)
CO2 (g) + H20 (l)  H HCO3-

19. Oxygen/Carbon Dioxide Transport
O2 diffuses from alveoli to blood
Blood travels to heart and body
In tissues, O2 levels are lower, so RBCs release O2 to cells
In tissues, CO2 levels are higher, so CO2 diffuses from cells to blood
CO2 travels in blood to heart
Heart pumps blood to lungs where CO2 is released
REMEMBER: TOO MUCH CO2 CAUSES BLOOD  ACIDIC!
The altered shape makes it easier for the Hb to give up the oxygen

20. WHY DOES BLOOD BECOMES ACIDIC WITH TOO MUCH CO2?
CO2 causes blood to become ACIDIC because:
CO2 (g) + H20 (l)  H HCO3-
Lots of CO2 indicates lots of cell respiration  need for O2
Control centers in brain regulate
Called Medulla oblongata and pons
Maintain homeostasis by monitoring CO2 level
Main cue is pH change in blood

21. Gas Exchange and the Nervous System
What happens when you exercise?
Start breathing faster
Heart beats faster
Why?
Your muscles cells are running out of oxygen, so the heart and lungs have to work harder to deliver the necessary oxygen
The rate of respiration is controlled by automatic regulators in your brain stem (medulla and pons)
Stimulates nerves in the diaphragm and ribcage to breathe harder and faster

22. Gas Exchange Animation
Complete the quiz questions 1-5 after we’ve watched the animation for review.

23. Health of Respiratory System
Diseases can interfere with gas exchange
Pneumonia
Caused by virus or bacteria, Inflammation of alveoli
Weak and tired due to less oxygen exchange
Bronchitis
Caused by bacteria or virus (cold or flu), Inflammation of bronchi
Cough to clear excess mucus

24. Health of Respiratory System
Asthma
May be allergic, response to stress, etc.
Narrowed breathing passages (bronchi)
Treated with drugs that relax air passages
Emphysema
Lung disorder usually caused by smoking
Alveoli are destroyed and cells can’t get enough oxygen

25. Cancer and emphysema