Flashcards in Introduction to the Cardiovascular System Deck (107)
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1
What is true of all living cells?
They are metabolically active
2
What is the result of living cells being metabolically active?
They use oxygen and nutrients, and produce carbon dioxide and other waste
3
How can single celled or tiny organisms get oxygen and nutrients?
Directly by diffusion from the environment
4
What is diffusion?
Random movement that results in an overall movement from high concentration to a low concentration
5
What is the result in small organisms being able to get oxygen and nutrients directly by diffusion?
They don’t require a cardiovascular system
6
How many cells are in the human body?
10^14 (100 million)
7
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
8
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
9
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
10
What does the right heart do?
Pumps blood to the lungs
11
What happens to blood at the lungs?
Gas exchange takes place and blood becomes oxygenated
12
What happens to blood once it has become oxygenated?
It passes from the lungs to the left heart
13
What does the left heart do?
Pumps blood to the body cells
14
What happens to blood at the body cells?
Oxygen is released
15
What does deoxygenated blood return to the right heart via?
The kidneys and the gut
16
Why does blood return via the kidneys?
Filtering
17
Why does blood return via the gut?
Nutrient acquisition
18
What is the pulmonary circulation?
The circulation of blood form right heart to lungs, to left heart
19
Where is blood pumped in the pulmonary circulation?
Alveoli
20
Why is blood pumped to the alveoli?
So gas exchange can take place by diffusion
21
What is the systemic circulation?
The circulation of blood form left heart, to body, to right heart
22
How does blood in circulation travel?
By convective transport (flow)
23
What is the advantage of convective transport?
It works quickly over long distances
24
What is essential to allow diffusion to take place?
The mechanism for transporting substances close to cells
25
What is the distribution system?
Vessels and blood
26
What is the heart?
Effectively, two pumps
27
What is the exchange mechanism?
The capillaries
28
What does blood transport around the body?
Oxygen
Metabolic substrates
Carbon dioxide
Waste product
29
How does exchange of substances between the blood and body cells occur?
By diffusion
30