Respiratory System&

Gas Exchange

Lungs

• Central Organ of the Respiratory System

• 2 compartments connect outside environment through the trachea

• Keeps “external” air separate from internal environment

Alveoli

• Tiny air sacs in the lungs

• Increase surface area of lungs

• Surrounded by capillaries

• Responsible for GAS exchange

Oxygen

• Once O2 is absorbed into the blood, it binds to Hemoglobin

• Hemoglobin– Protein found in Red Blood Cells– Delivers oxygen to body

Breathing Process

1. Air passes through nose- Moistened- Warmed- Cleaned

2. Pharynx

3. Larynx

4. Trachea

5. Bronchial tubes - One in each lung

Breathing Process

6. Bronchioles

7. Alveoli

8. Oxygen diffuses across alveolar membranes (thin walls) into capillaries

9. CO2 diffuses from capillaries into alveoli

Circulatory/Respiratory System Cooperation

• Allow oxygen to enter the blood/body without jeopardizing the health of the cells

• Keeps deep body cells away (safe) from external environment

Feedback Systems

• Necessary to retain Homeostasis

• Involve all 3 systems discussed– Respiratory– Circulatory– Nervous

F.S. Example

Breathing Rate During Exercise

1. Processes in body speed up

2. Production of CO2 increases

3. CO2 causes the blood to become more acidic

F.S. Example

Breathing Rate During Exercise

4. Nerve cells detect acidity

5. Cells send signal to respiratory centers of the brain

6. Respiratory centers respond by stimulating the diaphragm and rib muscles to contract more rapidly

F.S. Example

Breathing Rate During Exercise

7. Breathing rate is increased

8. Increases rate O2 brought into body and the rate at which CO2 is released

9. Blood becomes less acidic

F.S. Example

Breathing Rate During Exercise

10.Sensory receptors detect pH change

11. Info is relayed to respiratory centers in the brain

12.Brain signals diaphragm and rib muscles to slow contraction

F.S. Example

• Automatic response– You don’t have to think about your breathing

rate!

• Regulates the acidity of the blood!