30.2 Respiration and Gas Exchange

KEY CONCEPT The respiratory system exchanges oxygen and carbon dioxide.

30.2 Respiration and Gas Exchange

NGSSS

•SC.912.L.14.36 Describe the factors affecting blood flow through the cardiovascular system. (MODERATE)

30.2 Respiration and Gas Exchange

Gas exchange occurs in the alveoli of the lungs.

• Oxygen and carbon dioxide are carried by the blood to and from the alveoli.– oxygen diffuses from alveoli into capillary – oxygen binds to hemoglobin in red blood cells – carbon dioxide difuses from capillary into alveoli

ALVEOLI GAS EXCHANGES

capillaries

alveolus

capillary

co2

o2

Co2 diffusesinto alveolus.

O2 diffusesinto blood.

30.2 Respiration and Gas Exchange

• Red blood cells carries carbon dioxide into the lungs• Hemoglobin is an iron-rich protein that allows more

oxygen to enter red blood cells.• Red Blood Cells carries oxygen away from lungs

30.2 Respiration and Gas Exchange

Gas exchange occurs in the alveoli of the lungs.

• Breathing is regulated by the brain stem.

midbrainpons

medulla oblongata

spinal chord

30.2 Respiration and Gas Exchange

Respiratory diseases interfere with gas exchange.

• Lung diseases reduce airflow and oxygen absorption.– Emphysema destroys alveoli.– Asthma constricts airways.– Cystic fibrosis produces sticky mucus.

30.2 Respiration and Gas Exchange

• Smoking is the leading cause of lung diseases.