1. Respiratory System

2. Do Now A student eats a sandwich for lunch:
digested starch  bloodstream  cell  cell organelle  ATP
Identify the molecules used to digest starch.
Identify the molecules produced when starch is digested.
Explain why starch must be digested before it can enter the bloodstream.
Identify the structure in the cell that will produce ATP from the starch building blocks.
State why ATP is important to cells.

3. How does the Respiratory System help maintain homeostasis?
Take in oxygen (O2) for cellular respiration. This allows ATP to be produced and available for life functions.
Excrete carbon dioxide (CO2) as a waste product.

4. Respiratory system consists of two lungs & a system of tubes that carry air from the external environment to internal membranes (alveoli) for gas exchange.
Predict the path air takes to completely enter the lungs

5. The Path Air Takes WHY Air enters through the nasal cavity:
Nose is adapted for warming, moistening and filtering the air
Blood vessels warm cold air
Mucous adds moisture to dry air
Mucous also traps dust and pathogens (sneezed out or swallowed)

6. The Path Air Takes
Air passes from your nose to the pharynx , past the larynx (voice box) and into the trachea (windpipe).
The trachea (windpipe) forks to form two bronchi
Each bronchi branches into many bronchioles (smaller tubes)
The bronchioles end in clusters of tiny sacs called Alveoli (air sacs)

7. Nose  Pharynx  Larynx  Trachea  Bronchi  bronchioles  Alveoli

8. How do we get air to enter our lungs?
The action of your diaphragm and surrounding muscles between your ribs enable you to breath in and out.
Breathing – the alternation of inhaling and exhaling
Is your diaphragm a muscle?

9. How do we inhale and exhale?
Diaphragm contracts and moves downward
Muscles between the ribs move the rib cage up and outward
Exhale:
Diaphragm relaxes and moves up
Muscles between the ribs relax

10. Do Now
What is the name of the tube that air uses to travel to the lungs?
What is the name of the tube that food uses to travel to the stomach?
How does air enter our bodies?
Why must we inhale Oxygen?
Why does our body produce Carbon Dioxide?

11. Inhaled Air *Air breathed in has: Lots of O2 Little CO2
Final destination of inhaled air are the Alveoli sacs in lungs.
Alveoli are thin-walled sacs in the lungs surrounded by a network of capillaries
Capillaries are very thin blood vessels
*Air breathed in has:
Lots of O2
Little CO2

12. Gas Exchange in Alveoli
Inhale
Oxygen diffuses from alveoli into capillaries (blood)
O2 is absorbed
Alveoli
Exhale
Carbon Dioxide diffuses from capillaries (blood) into alveoli
CO2 is excreted
Gases move by diffusion from high to low concentration

13. Diffusion of Gases Capillaries in LUNGS Capillaries in MUSCLE High O2
Low O2
High O2
Low O2
Why?
Low CO2
High CO2
Low CO2
High CO2
Blood
Blood
Body / Muscles
Lungs

14. Gas Exchange Summary Blood going towards lungs from the heart
______ in Oxygen
______ in Carbon Dioxide
Blood going away from lungs towards the heart
______ in Oxygen
______ in Carbon Dioxide
Blood is pumped from the heart to the lungs… why?
Blood goes from the lungs back to the heart… why?

15. What gas do the alveoli pass into the capillaries?
oxygen
What gas do the capillaries pass into the alveoli?
Carbon dioxide

16. Do Now
Organ systems of the human body interact to maintain a balanced internal environment. As blood flows through certain organs of the body, the composition of the blood changes because of interactions with those organs.
State one change in the composition of the blood as it flows through the respiratory system.

18. Control of Respiration
Breathing is usually an involuntary process Partially controlled by an internal feedback mechanism This involves signals being sent to the brain about the chemistry of your blood

19. Feedback Mechanism ___ CO2 = ____ pH (acid) = _____ Breathing rate
Carbon dioxide dissolves in blood increasing acidity (low pH)
Signal sent rib muscles & diaphragm to contract
Person inhales to excrete CO2 and absorb O2

20. Breathing and Homeostasis
Keeping the internal environment of the body balanced
Need to absorb oxygen and excrete carbon dioxide
Need to balance energy (ATP) production
What happens to your breathing when you run?

21. Exercise and Respiration
When you exercise (run, jump…dance) you breathe faster
WHY do you breathe faster?
Breathe faster:
Need –
Bring in –
Excrete –
More ATP / Energy
More Oxygen
Excess Carbon Dioxide

22. How does the Respiratory system help maintain homeostasis?

24. Failure of Homeostasis
Asthma – is a severe allergic reaction in which the constriction of the bronchioles make breathing difficult

25. Bronchitis – is an inflammation of the linings of the bronchial tubes
Bronchitis – is an inflammation of the linings of the bronchial tubes. The air passages become swollen and clogged with mucus causing coughing and difficulty breathing

26. Emphysema – is a lung disorder in which the walls of the air sacs break down and there is less respiratory surface of the lungs.
Often caused by smoking
A failure in the respiratory system leads to an imbalance in energy production