Overview

Question 1

What is alveolar surface tension?

Answer 1

Attraction between water molecules at liquid air interface

Question 2

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

Answer 2

Pulmonary surfactant

Question 3

What type of alveoli secretes pulmonary surfactant?

Answer 3

type 2

Question 4

Which forces keep alveoli open?

Answer 4

Transmuralpressure gradient, pulmonary surfactant, alveolar interdependence

Question 5

Which factors promote alveolar collapse?

Answer 5

elasticity of stretched pulmonary connective tissue fibres, alveolar surface tension

Question 6

What division of the ANS causes bronchoconstriction?

Answer 6

parasympathetic

Question 7

What happens to intrapleural pressure during inspiration?

Answer 7

falls

Question 8

What is pulmonary compliance?

Answer 8

measure of effort going into stretching/distending lungs

Question 9

What factors decrease pulmonary compliance?

Answer 9

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

Question 10

What is alveolar dead space?

Answer 10

ventilated alveoli, not adequately perfused with blood

Question 11

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

Answer 11

vasoconstriction

Question 12

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

Answer 12

vasodilation

Question 13

What encircle each alveolus?

Answer 13

capillaries

Question 14

What are alveolar walls made of?

Answer 14

single layer of flattened type 1 alveolar cells

Question 15

How many Haem groups does a Hb molecule contain?

Answer 15

4

Question 16

What is Sao2?

Answer 16

% haemoglobin saturated with 02

Question 17

What can impair O2 delivery?

Answer 17

resp disease, heart failure, anaemia

Question 18

What is cooperativity in Hb?

Answer 18

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

Question 19

What is myoglobin?

Answer 19

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

Question 20

How many haem groups does myoglobin have per molecule?

Answer 20

1

Question 21

What does the presence of myoglobin indicate?

Answer 21

muscle damage is present

Question 22

How can C02 be transported in the blood?

Answer 22

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

Question 23

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

Answer 23

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

Question 24

When does active expiration occur and what controls this?

Answer 24

hyperventilation, controlled by ventral respiratory group neurones

Question 25

Is active respiration normal?

Answer 25

No

Question 26

What is apneusis?

Answer 26

Abnormal breathing, prolonged inspiratory gasps and brief expiration

Question 27

What prevents apneusis?

Answer 27

Pneumatoxic centre

Question 28

What is hypercapnia?

Answer 28

too much C02

Question 29

What do central chemoreceptors do?

Answer 29

respond to hydrogen ions in cerebrospinal flui

Question 30

What do peripheral chemoreceptors do?

Answer 30

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

Question 31

What drive is important in acid-base balance?

Answer 31

H+ drive