Physiology - Part 2

Question 1

how much oxygen dissolves in each litre of plasma?

Answer 1

3ml

Question 2

how much oxygen does a litre of blood (with haemoglobin) carry?

Answer 2

200ml

Question 3

what is PaO2 determined by?

Answer 3

O2 solubility and the partial pressure of O2

Question 4

what is the O2 demand of resting tissues?

Answer 4

250ml/min

Question 5

how many molecules of oxygen does haemoglobin bind?

Answer 5

4

Question 6

how much oxygen binds to each gram of haemoglobin?

Answer 6

1.34ml

Question 7

what form is the majority of haemoglobin in RBCs in?

Answer 7

HbA

Question 8

what is the major determinant of the degree to which haemoglobin is saturated with oxygen?

Answer 8

partial pressure of oxygen

Question 9

which two types of haemoglobin have a higher affinity for oxygen than normal?

Answer 9

foetal haemoglobin and myoglobin

Question 10

what is anaemia?

Answer 10

anaemia is defined as any condition where the oxygen carrying capacity of the blood is compromised

Question 11

what happens to PaO2 in anaemia?

Answer 11

PaO2 is normal

Question 12

is it possible for red blood cells to be fully saturated with O2 in anaemia?

Answer 12

yes - red blood cells would still be fully saturated with oxygen as PaO2 is normal

Question 13

which way does the haemoglobin saturation curve shift in increased pH?

Answer 13

left

Question 14

which way does the haemoglobin saturation curve shift in decreased pH?

Answer 14

right

Question 15

which way does the haemoglobin saturation curve shift in increased PCO2?

Answer 15

right

Question 16

which way does the haemoglobin saturation curve shift in decreased PCO2?

Answer 16

left

Question 17

which way does the haemoglobin saturation curve shift in increased temperature?

Answer 17

right

Question 18

which way does the haemoglobin saturation curve shift in decreased temperature?

Answer 18

left

Question 19

which way does the haemoglobin saturation curve shift in increased DPG?

Answer 19

right

Question 20

which way does the haemoglobin saturation curve shift in decreased DPG?

Answer 20

left

Question 21

how much greater is the affinity of CO for haemoglobin than O2?

Answer 21

250x

Question 22

what are the symptoms of carbon monoxide poisoning?

Answer 22

hypoxia
anaemia
nausea
headaches
cherry red skin and mucous membranes

Question 23

what is hypoxia?

Answer 23

inadequate supply of oxygen to tissues

Question 24

what are the five types of hypoxia?

Answer 24

hypoxaemic hypoxia
anaemic hypoxia
stagnant hypoxia
histotoxic hypoxia
metabolic hypoxia

Question 25

what is hypoxaemic hypoxia?

Answer 25

reduction in O2 diffusion at lungs either due to increased PO2atmos or tissue pathology

Question 26

what is anaemic hypoxia?

Answer 26

reduction in O2 carrying capacity of the blood due to anaemia (red blood cell loss / iron deficiency)

Question 27

what is stagnant hypoxia?

Answer 27

heart disease results in inefficient pumping of blood to lungs / around the body

Question 28

what is histotoxic hypoxia?

Answer 28

poisoning prevents cells utilising oxygen delivered to them e.g. carbon monoxide / cyanide

Question 29

what is metabolic hypoxia?

Answer 29

oxygen delivery to the tissues does not meet increased oxygen demand by the cells

Question 30

is respiratory acidosis caused by hypoventilation or hyperventilation?

Answer 30

hypoventilation

Question 31

does hyperventilation cause respiratory acidosis or alkalosis?

Answer 31

respiratory alkalosis

Question 32

is alveolar ventilation greater at the base of the lung or the apex?

Answer 32

base

Question 33

is compliance greater at the base of the lung or the apex?

Answer 33

base

Question 34

what is the name of the nutritive circulation in the lungs?

Answer 34

bronchial circulation

Question 35

what is the name of the gas exchange circulation in the lungs?

Answer 35

pulmonary circulation

Question 36

is the flow through the pulmonary circulation high or low?

Answer 36

high

Question 37

is the pressure in the pulmonary circulation high or low?

Answer 37

low

Question 38

what is the average systolic pressure in the pulmonary circulation?

Answer 38

~ 25 mmHg

Question 39

what is alveolar dead space?

Answer 39

alveoli that are ventilated but not perfused

Question 40

what is anatomical dead space?

Answer 40

air in the conducting zone of the respiratory tract unable to participate in gas exchange

Question 41

what is physiological dead space?

Answer 41

alveolar dead space + anatomical dead space