Overview Flashcards Preview

Respiratory Physiology > Overview > Flashcards

Flashcards in Overview Deck (31)
Loading flashcards...
1

What is alveolar surface tension?

Attraction between water molecules at liquid air interface

2

What does this describe: a complex mix of lipids and proteins secreted by alveoli which lowers alveolar surface tension?

Pulmonary surfactant

3

What type of alveoli secretes pulmonary surfactant?

type 2

4

Which forces keep alveoli open?

Transmuralpressure gradient, pulmonary surfactant, alveolar interdependence

5

Which factors promote alveolar collapse?

elasticity of stretched pulmonary connective tissue fibres, alveolar surface tension

6

What division of the ANS causes bronchoconstriction?

parasympathetic

7

What happens to intrapleural pressure during inspiration?

falls

8

What is pulmonary compliance?

measure of effort going into stretching/distending lungs

9

What factors decrease pulmonary compliance?

pulmonary fibrosis, oedema, lung collapse, pneumonia, absence of surfactant

10

What is alveolar dead space?

ventilated alveoli, not adequately perfused with blood

11

If 02 decreases, does vasoconstriction or vasodilation occur in pulmonary arterioles?

vasoconstriction

12

If 02 decreases, does vasoconstriction or vasodilation occur in systemic arterioles?

vasodilation

13

What encircle each alveolus?

capillaries

14

What are alveolar walls made of?

single layer of flattened type 1 alveolar cells

15

How many Haem groups does a Hb molecule contain?

4

16

What is Sao2?

% haemoglobin saturated with 02

17

What can impair O2 delivery?

resp disease, heart failure, anaemia

18

What is cooperativity in Hb?

Binding of one 02 to Hb increasing the affinity of Hb for 02

19

What is myoglobin?

molecule present in skeletal and cardiac muscle which functions as short term storage in anaerobic conditions

20

How many haem groups does myoglobin have per molecule?

1

21

What does the presence of myoglobin indicate?

muscle damage is present

22

How can C02 be transported in the blood?

as solution, or as carbamino compounds, or as bicarbonate (most common)

23

In neural control of respiration, what group of neurons displays pacemaker activity, controls rhythm and where is it found?

Pre-Botzinger complex, found in upper end of medullar resp centre

24

When does active expiration occur and what controls this?

hyperventilation, controlled by ventral respiratory group neurones

25

Is active respiration normal?

No

26

What is apneusis?

Abnormal breathing, prolonged inspiratory gasps and brief expiration

27

What prevents apneusis?

Pneumatoxic centre

28

What is hypercapnia?

too much C02

29

What do central chemoreceptors do?

respond to hydrogen ions in cerebrospinal flui

30

What do peripheral chemoreceptors do?

sense tension of 02 and c02 and H+ in blood. Involved in hypoxic drive and H+ drive of respiration