Flashcards in Introduction to the Cardiovascular System Deck (107)
What is true of all living cells?
They are metabolically active
What is the result of living cells being metabolically active?
They use oxygen and nutrients, and produce carbon dioxide and other waste
How can single celled or tiny organisms get oxygen and nutrients?
Directly by diffusion from the environment
What is diffusion?
Random movement that results in an overall movement from high concentration to a low concentration
What is the result in small organisms being able to get oxygen and nutrients directly by diffusion?
They don’t require a cardiovascular system
How many cells are in the human body?
10^14 (100 million)
What is the problem with the human body having so many cells?
Most are far away from a source of oxygen and nutrients, and therefore can’t obtain them from diffusion
Why does the body cells being far away from a source of oxygen and nutrients mean that it can’t get them by diffusion?
Because diffusion is proportional to distance squared, so it works well over short distances, but not larger distances as it takes far longer to travel across
What is the result of large cells being unable to get oxygen and nutrients by direct diffusion?
They need a gas exchange and circulatory system to carry oxygen and nutrients to cells, and carry waste produces away
What does the right heart do?
Pumps blood to the lungs
What happens to blood at the lungs?
Gas exchange takes place and blood becomes oxygenated
What happens to blood once it has become oxygenated?
It passes from the lungs to the left heart
What does the left heart do?
Pumps blood to the body cells
What happens to blood at the body cells?
Oxygen is released
What does deoxygenated blood return to the right heart via?
The kidneys and the gut
Why does blood return via the kidneys?
Why does blood return via the gut?
What is the pulmonary circulation?
The circulation of blood form right heart to lungs, to left heart
Where is blood pumped in the pulmonary circulation?
Why is blood pumped to the alveoli?
So gas exchange can take place by diffusion
What is the systemic circulation?
The circulation of blood form left heart, to body, to right heart
How does blood in circulation travel?
By convective transport (flow)
What is the advantage of convective transport?
It works quickly over long distances
What is essential to allow diffusion to take place?
The mechanism for transporting substances close to cells
What is the distribution system?
Vessels and blood
What is the heart?
Effectively, two pumps
What is the exchange mechanism?
What does blood transport around the body?
How does exchange of substances between the blood and body cells occur?