Respiratory 2

Question 1

gas molecules exert pressure by collisions irregardless of the size. If the partial pressure of oxygen in the blood is lower than the air, what will happen. When will it stop

Answer 1

Diffuse into bloodstream

When equilibrium is reached

Question 2

When is alveolr pressure equal to atmospheric pressure?

Answer 2

When no air is flowing in/out of lungs

Question 3

What is the relationship between dissolving and partial pressure?

Answer 3

The higher the PP, the more it will dissolve

Question 4

What is hypoxia?

Answer 4

Reduced pp O2

Question 5

What is hypocapnia?

Answer 5

Reduced pp CO2

Question 6

What is hypercapnia?

Answer 6

Increased PP CO2

Question 7

Why is alveolar pp O2 lower than air?

Answer 7

Due to mixing with water when inhaled

Question 8

WHat is perfusion?

Answer 8

Blood supply

Question 9

What happens if the ventilation to perfusion ratio is mismatched/

Answer 9

full equilibrium cannot be reached

Question 10

Describe oxygens solubility in plasma

Answer 10

Poor

Question 11

Describe haemoglobin

Answer 11

Iron ion with 4 haem units and globin chain

Question 12

What is the purpose of globin?

Answer 12

Prevent oxygen binding being irreversible

Question 13

What is the oxygen capacity of blood

Answer 13

200 ml per litre

Question 14

What is cooperative binding?

Answer 14

Binding of O2 to haem group increases affinity until saturation point

Question 15

When does the oxygen haemoglobin curve shift right?

Answer 15

Increased temperature
CO2
Acidity
DCG

Question 16

In anaemia animals, how does the percentage saturation of haemoglobin Chang?

Answer 16

It doesn’t

Question 17

The foetal haemoglobin curve is where in comparison to the adult?

Answer 17

Left

Question 18

How is carbon dioxide transported?

Answer 18

Mainly by HCO3
Some by proteins
Few dissolved in plasma

Question 19

What is the equation for H20 and C02

Answer 19

H20 + CO2 —> H2CO3 —> H+ + HCO3-

Question 20

What is chloride shift?

Answer 20

Chlorides move into cell when HCO3- leaves to maintain electrochemical gradient

Question 21

Can protons diffuse out of RBCs? How do they bind?

Answer 21

No

Bind to deoxyhaemoglobin

Question 22

Where do alveolar vessels run?

Answer 22

Alveolar septa

Question 23

Where do extra alveolar vessels run?

Answer 23

Pulmonary arteries/veins

Question 24

Which lung fields are most perfused?

Answer 24

Caudodorsal

Question 25

What happens when lungs are over inflated?

Answer 25

Capillaries are crushed

Question 26

Describe pulmonary vascular difference

Answer 26

Opposite to system resistance | Increased diameter decreases resistnce

Question 27

Does alveolar hypoxia lead to vaso constriction or dilation?

Answer 27

Vasoconstriction

Question 28

What is the equation for pulmonary vascular resistance?

Answer 28

P pulmonary artery - P left atria | Divided by cardiac output

Question 29

How is rhythmic breathing generated and maintained

Answer 29

Pacemaker neurons in medulla oblongata | Central pattern generator provides RR and depth

Question 30

What is the Hering-Beur reflex?

Answer 30

Baroreceptors in lung detect stretch and decrease action potentials to lungs to prevent over inflation

Question 31

Where are central chemoreceptors? What do they monitor?

Answer 31

Brain | Pa CO2 only

Question 32

How do chemoreceptors in the brain detect CO2?

Answer 32

CO2 crosses the BBB | Carbonic anhydride generates HCO3- and H+

Question 33

Where are peripheral chemoreceptors found? What do they monitor?

Answer 33

Carotid and aortic bodies | Monitor Pa CO2, Pa O2 and arterial H+

Question 34

Which nerves innervate the carotid and aortic bodies?

Answer 34

CN IX | CN X