Physiology- Respiratory part II Flashcards Preview

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Flashcards in Physiology- Respiratory part II Deck (42):
0

When does vasoconstriction occur in pulmonary circulation

When oxygen levels drop

1

Why is it beneficial for lungs to vasoconstrict when there is a drop in oxygen

Forces blood to parts of the lungs that are getting better air flow; keeps blood away from dead space

2

Ventilation/perfusion ratio

Volume of air perfused in alveoli/BF

Amount of air ventilating an area of lung relative to amount of blood flow that area receives

3

Ideal ventilation/perfusion ratio

1.0 (perfect matching)

4

Actual ventilation/perfusion ratio in healthy people

~.8

5

Why healthy people typically have ratios of ~.8

When standing, gravity causes more blood to flow to bottom of lungs

6

What happens to VA/Q when there is blockage of air supply to an area of the lung

Decreases

7

What happens to tidal volume when there is a blockage of air supply to an area of the lungs

Does not decrease, just gets redistributed

8

Embolus

Anything blocking a blood vessel

9

What happens to VA/Q when there is decreased BF to an area of the lungs

Increases (because VA stays the same, but Q decreases)

10

Positive cooperativity

As one oxygen attaches, it makes it easier for others to attach

11

Positive cooperatively is a property of what blood protein?

Hemoglobin

12

Why is it important for hemoglobin to have the property of positive cooperativity?

Allows hemoglobin to load oxygen very rapidly and lose it very rapidly

13

What will happen to the association/dissociation curve of oxygen and hemoglobin in skeletal muscle that is exercising?

It will shift to the right

14

Why is it valuable for the association/dissociation curve of oxygen and hemoglobin to shift to the right during exercise?

Increases the rapid release of carbon dioxide

15

Amount of oxygen released from hemoglobin depends on

Amount of oxygen in tissue (PO2)

16

Three forms of transportation of carbon dioxide

Physically dissolved
Carbamino compounds
Bicarbonate

17

Feedback loop of respiration

Inspiratory cells are self stimulating--> activate muscles of breathing
Inspirational cells--> gradually stimulate expiratory cells--> inhibit inspiratory cells
Pneumotaxic center--> inhibits inspiratory cells

18

What can the respiratory center be altered by

Central and peripheral chemoreceptors

19

What do the chemoreceptors monitor

Oxygen
Carbon dioxide
pH
Carbon dioxide in tissue fluid (PCO2)
Oxygen in tissue fluid (PO2)

20

Where are peripheral chemoreceptors located?

Carotid sinus
Aortic arch

21

Where are central chemoreceptors located?

Medulla

22

Peripheral chemoreceptors are more sensitive to

Oxygen

23

Central chemoreceptors are more sensitive to

Carbon dioxide

24

What will stimulate an increased rate and depth of breathing

Decreased PO2
Increased PCO2
Decreased pH (increased acidity)

25

What is lungs role in acid-base control

Alters carbon dioxide levels

26

Metabolic acidosis

pH below 7.4 due to a metabolic process

27

What will lungs do in response to metabolic acidosis

Increase rate and depth of breathing

28

What will kidneys want to do in response to metabolic acidosis

Get rid of hydrogen ions and conserve bicarbonate

29

Examples of when metabolic acidosis happens

Long term exercise
Diabetes

30

Metabolic alkalosis

pH above 7.4 due to a metabolic process

31

What will kidneys want to do in response to metabolic alkalosis

Conserve hydrogen
Lose bicarbonate

32

What will the lungs do in response to metabolic alkalosis

Not much of an option to conserve carbon dioxide due to need for gas exchange

33

What can cause metabolic alkalosis

Bulimia or chronic vomiting
Antacid abuse

34

Respiratory alkalosis

pH above 7.4 due to respiratory system

35

What will kidneys want to do in response to respiratory alkalosis

Kidneys will not have much of an effect because this is typically an acute situation and the kidneys have slow action

36

What will the lungs want to do in response to respiratory alkalosis

Conserve carbon dioxide

37

What is an example of respiratory alkalosis

Hyperventilation (decreased carbon dioxide, increased constriction....you will pass out)

38

Respiratory acidosis

pH below 7.4 due to respiratory system

39

What will the kidney want to do in response to respiratory acidosis

Lose hydrogen ions
Conserve bicarbonate

40

What will lungs want to do in response to respiratory acidosis

Lose carbon dioxide
...but has difficulty with this due to poor gas exchange, so the body relies mostly on kidney; lungs malfunction

41

What can cause respiratory acidosis

Emphysema
Hypoventilation (drug overdose, head trauma, heat stroke)