Challenges of size B2.2 Flashcards
What are the roles of Stomata and Guard Cells?
Control gas exchange and water loss
What are exchange surfaces?
Exchange surfaces are specialized structures in the body that allow for the exchange of materials between the body and the environment. This can include the lungs, the gut, and the skin.
How does gas exchange happen in the lungs?
Gas exchange occurs at the alveoli in the lungs and takes place by diffusion.
The alveoli are surrounded by capillaries so oxygen and carbon dioxide diffuse between the air in the alveoli and the blood in the capillaries.
Alveoli = Little sacs of air around the lungs, where gas exchange takes place.
What three parts make up the circulatory system?
Blood, Heart & Blood Vessels
Do we have a single or a double circulatory system?
Double - The blood enters the heart twice when pumped around the body in a full circuit.
What happens in the first side of the circulatory system?
In the first one, the heart pumps deoxygenated blood (blood without oxygen)
to the gas exchange surfaces in the lungs to take in oxygen.
The oxygenated blood then returns to the heart.
What happens in the second side of the circulatory system?
In the second one, the heart pumps oxygenated blood around all the other organs of the body. The blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped out to the lungs again.
What is the purpose of valves?
They prevent back flow
How do you view a heart diagram.
The left side on the page, is always the right hand side of the heart.
View it as if it was your own heart.
How does blood pump through the heart?
De-oxygenated blood:
Enters through Vena Cana, into the right atrium, then the right ventricles. Out through the pulmonary artery (to lungs)
Oxygenated blood:
Enters through the pulmonary vein (from lungs)
Left atrium to left ventricle, out through the aorta.
Why is the left side of the heart thicker than the right side?
Left side pushes the blood towards more parts of the body, increasing the pressure in the left hand side of the heart. Thus, needing a larger amount of tissue.
What can be used to make a heart beating if it cannot do so on its own.
A pacemaker
What is the difference between arteries and veins?
Veins take the deoxygenated blood
Arteries take the oxygenated blood.
The eateries have thicker walls to withstand the increased pressure. And has a smaller lumen (hole).
The opposite is true for veins.
What are capillaries?
Capillaries are delicate blood vessels that exist throughout your body. They transport blood, nutrients and oxygen
What is Coronary Heart Disease (CHD), what causes it and what treatment can be given to those who have it?
CHD - Blood vessels supplying the heart and blocked with fatty deposits.
Caused by smoking and regular drinking
Can be treated through bypass surgery and stents which open up the vessels.
