Respiration and Breathing 2 Flashcards Preview

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Flashcards in Respiration and Breathing 2 Deck (25):
1

What does blood flow through lungs allow

Transfer of gases to and from the respiring tissues of the body

2

What do gases move according to

They move down a concentration gradient

3

How is pulmonary circulation specialised

Gas composition of blood in pulmonary arteries and veins opposite to those in systemic circulation. Pressures in pulmonary circulation are very low. Pulmonary artery walls are thin and contain little smooth muscle. Pulmonary vascular resistance is low.

4

How do you work out vascular resistance

(input pressure - output pressure)/ blood flow

5

How do you work out alveolar ventilation rate

(tidal volume- dead space) x respiratory rate

6

What is alveolar rate

4 litres per minute

7

What is dead space

150ml

8

What is tidal volume

1/2L

9

What is respiratory rate

11/min when sitting

10

What is blood gas composition regulated by

Changes in alveolar ventilation rate

11

What is hypoventilation

When ventilation is reduced and is not meeting demands. There is not enough O2 and increased conc of CO2 as it id not removed

12

What is hyperventilation

Ventilation is increased above demands. Too deep/ rapid breathing. Oxygen conc increases but is limited by saturation levels. Decrease in conc of CO2

13

Why is hyperventilation dangerous

Decrease in conc of CO2 which increases pH making blood more alkaline

14

What sets the basic rhythm and pattern of breathing

The brainstem

15

How can ventilation be modified

Feedback from higher brain centres (cortex, hypothalamus, limbic system). Feedback from receptors in the lung (stretch, irritants). Feedback from peripheral and central chemoreceptors

16

What does an increase in the arterial partial pressure of CO2 result in

An increase in minute ventilation rate

17

What are sensitive to changes in blood chemistry

Chemoreceptors

18

What are the 2 types of chemorecptors

Peripheral and central

19

Describe peripheral receptors

Acutely sensitive to changes in arterial pressure of CO2. Small increase in PCO2 causes an immediate increase in minute ventilation

20

Describe central receptors

Sensitive to longer-term changes in PCO2

21

Which receptors are sensitive to changes in arterial PO2

Peripheral chemoreceptors

22

What do peripheral chemoreceptors do if arterial PO2 drops

If arterial PO2 drops below 60mmHg minute ventilation rises

23

When are ventilatory responses more sensitve

During hypercapnia and hypoxia

24

What is hypercapnia

When PCO2 is elevated

25

What is hypoxia

When PO2 is reduced