Gaseous exchange

Question 1

describe the process of gaseous exchange

Answer 1

-gaseous exchange occurs when the alveoli have filled with air
-oxygen moves from the air in the alveoli into the blood in the capillaries
-at the same time, carbon dioxide in the blood moves into the alveoli

Question 2

what characteristic of the capillaries allows gaseous exchange?

Answer 2

one cell thick

Question 3

diffusion

Answer 3

the process of molecules moving from an area of high concentration to an area of low concentration

Question 4

what does the process of diffusion aim to do?

Answer 4

reach a balance

Question 5

describe diffusion after inhalation

Answer 5

-when we breathe in, oxygenated air enters the alveoli
-this means there is a higher concentration of oxygen in the alveoli than in the blood
-this causes oxygen molecules to diffuse into the blood in the capillaries
-at the same time there is a higher concentration of carbon dioxide molecules to diffuse from the capillaries to the air in the alveoli
-this causes carbon dioxide molecules to diffuse from the capillaries to the air in the alveoli

Question 6

what are the characteristics of the alveoli?

Answer 6

-moist thin walls, easy for gas diffusion
-approximately 400 million alveoli in the lungs, provides a large surface area for diffusion to take place
-alveoli and capillaries are close together, gases only have to diffuse across a short distant
-substantial blood supply to the alveoli, so that gas can be carried quickly

Question 7

describe the gaseous exchange of oxygen during exercise

Answer 7

-the muscles need more oxygen during exercise
-as a result, the blood returning from the muscles has a lower concentration of oxygen than normal
-this makes a greater difference the concentration of oxygen between the capillaries and alveoli
-more oxygen therefore has to diffuse into the blood

Question 8

describe the gaseous exchange of CO2 during exercise

Answer 8

-during exercise more carbon dioxide is created in the muscles
-as a result the blood returning from the muscles has a higher concentration of carbon dioxide than normal
-this makes a greater difference the concentration of carbon dioxide between the alveoli and capillaries
-more carbon dioxide therefore has to diffuse into the blood

Question 9

what is the cardiorespiratory system?

Answer 9

the cardiovascular system and respiratory system work together to supply muscles with a continuous supply of oxygen and remove carbon dioxide