Gas Exchange Flashcards
What is gas exchange?
Gas exchange is the process by which oxygen is taken into the body and carbon dioxide is expelled. It occurs in the lungs at the alveoli, where oxygen diffuses into the blood, and carbon dioxide diffuses out of the blood to be exhaled.
Where does gas exchange occur in the human body?
Gas exchange occurs in the alveoli of the lungs. The alveoli are tiny air sacs surrounded by capillaries, where oxygen enters the blood and carbon dioxide exits the blood.
What is the role of hemoglobin in gas exchange?
Hemoglobin is a protein in red blood cells that binds to oxygen, carrying it from the lungs to the body’s tissues. It also transports carbon dioxide from the tissues back to the lungs for exhalation.
How does oxygen diffuse during gas exchange?
Oxygen diffuses from the alveoli (where its concentration is high) into the capillaries (where its concentration is lower) and binds to hemoglobin in red blood cells.
What factors affect the efficiency of gas exchange?
• Surface Area: Larger alveolar surface area increases efficiency.
• Alveolar Wall Thickness: Thinner walls facilitate faster diffusion.
• Concentration Gradient: A greater difference in gas concentrations improves diffusion.
• Ventilation: Proper airflow maintains oxygen levels in the alveoli.
How does breathing contribute to gas exchange?
Breathing brings fresh oxygen into the alveoli (inhalation) and removes carbon dioxide from the alveoli (exhalation), maintaining the concentration gradient needed for gas exchange.
What happens to carbon dioxide during gas exchange?
Carbon dioxide diffuses from the blood (where its concentration is high) into the alveoli (where its concentration is lower) and is then exhaled from the body.
What happens to carbon dioxide during gas exchange?
Carbon dioxide diffuses from the blood (where its concentration is high) into the alveoli (where its concentration is lower) and is then exhaled from the body.
Describe how alveoli are adapted for efficient gas exchange.
• Thin walls (one cell thick) allow rapid diffusion of gases.
• Large surface area enhances gas exchange.
• Moist surface facilitates gas diffusion.
• Rich capillary network ensures efficient transport of gases.
How does exercise affect gas exchange in the body?
During exercise, the body requires more oxygen, and carbon dioxide production increases. The breathing rate increases to enhance gas exchange, and the heart pumps more blood to deliver oxygen faster and remove carbon dioxide more efficiently.
How does gas exchange in fish differ from humans?
Fish use gills for gas exchange. Water flows over the gills, where oxygen is absorbed into the blood and carbon dioxide is expelled. This process is different from humans, who use lungs and alveoli for gas exchange.
What happens during inhalation?
• The intercostal muscles contract.
• The diaphragm contracts and pulls downward.
• More space is created in the chest cavity, increasing the volume.
• Air moves down the trachea to fill the extra space in the lungs.
What happens during exhalation?
• The intercostal muscles relax.
• The diaphragm relaxes.
• Less space is created in the chest cavity, decreasing the volume.
• Air moves out of the lungs due to the decrease in volume.
What happens during exhalation?
• The intercostal muscles relax.
• The diaphragm relaxes.
• Less space is created in the chest cavity, decreasing the volume.
• Air moves out of the lungs due to the decrease in volume.
What is the purpose of respiration in cells?
Respiration transfers chemical energy from glucose to other substances so that cells can use it.
