CVS Session 1- Intro To The CVS Flashcards Preview

SOPHIE'S ESA 2 > CVS Session 1- Intro To The CVS > Flashcards

Flashcards in CVS Session 1- Intro To The CVS Deck (19)
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0
Q

How does 98% of exchange between capillaries and tissues occur?

A

Via diffusion

1
Q

What is the purpose of the CVS?

A

To supply all cells in the body with their metabolic needs.

2
Q

Which two molecules can diffuse straight through the lipid bilayer?

A

Oxygen and carbon dioxide.

3
Q

Which 3 molecules are hydrophilic and therefore travel down a concentration gradient and diffuse through small pores in capillaries?

A

Lactate, glucose, amino acids.

4
Q

What three factors does the rate of diffusion depend on?

A
  • diffusion resistance
  • area
  • concentration gradient.
5
Q

The greater the conc. gradient the ………… The rate of diffusion.

A

Faster

6
Q

The greater the number of capillaries the ………….the area and the ………… The rate of diffusion.

A

Greater

Greater

7
Q

What is the diffusion resistance dependent on? (3)

A

The nature of the barrier
The nature of the molecule
The path length

8
Q

What is the min and max blood flow in the brain and is there a change?

A

750ml/min (0.75l/min)

No

9
Q

What is the min and max blood flow to the heart. Is there a change?

A

Min- 300ml/min
Max- 1200ml/min
Yes- can increase according to demand.

10
Q

What is the min and max blood flow to the kidneys and is there a change?

A

1200ml/min

No because the kidneys require a constant perfusion in order to carry out their function.

11
Q

What is the min and max blood flow to the gut and liver and is there a change?

A

Min- 1400ml/min
Max- 2400ml/min
It can increase when digestion is required.

12
Q

What is the min and max blood flow to the skin and is there a change?

A

Min- 200ml/min
Max- 2500ml/min
Yes, changes according to thermoregulation

13
Q

What is the min and max blood flow to muscle and is there a change?

A

Min- 1000ml/min
Max- 16000ml/min
Yes it can change according to increased exercise.

14
Q

What is the average cardiac output at rest and during exercise of a 70kg man?

A

Rest- 5L/min

Exercise- 25L/min

15
Q

What is the role of arterioles and pre-capillary sphincters in blood flow regulation?

A

They ensure blood flow is distributed appropriately by restricting flow to easily perfusable parts so that blood is driven to parts that are less easily perfused.

16
Q

What is the role of veins in blood flow regulation?

A

They have capacitance and act as a temporary store of blood.

17
Q

Why are veins able to regulate blood flow in this way?

A

Because they have thin walls that are easily distended or collapsed.

18
Q

What is the percentage breakdown of blood volume in the CVS?

A

67%- veins
17%- heart and lungs
11%- arteries and arterioles
5%- capillaries

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