Partial Pressures

Question 1

What is the po2 in alveolar air?

Answer 1

105

Question 2

What is the po2 in venous blood?

Answer 2

40

Question 3

What is the po2 in arterial blood?

Answer 3

105

Question 4

What is the po2 in tissue cells?

Answer 4

40

Question 5

What is the pco2 in atmospheric air?

Answer 5

0.3

Question 6

What is the pco2 in alveolar air?

Answer 6

40

Question 7

What is the pco2 in venous blood?

Answer 7

45

Question 8

What is the pco2 in arterial blood?

Answer 8

40

Question 9

What is the pco2 in tissue cells

Answer 9

45

Question 10

What is the PN2 in atmospheric air?

Answer 10

597

Question 11

What is the PN2 at all other air/blood?

Answer 11

569

Question 12

What is the PO2 in atmospheric air?

Answer 12

160

Question 13

What do partial pressures in alveoli depend on?

Answer 13

Air flow in and out of lungs

Question 14

When is diffusion gradient reduced?

Answer 14

With impaired ventilation

Question 15

What happens if the surface area of alveoli is reduced like on emphysema?

Answer 15

Exchange is impaired

Question 16

What happens when membranes are thickened or swollen or air cells contain excess fluid?

Answer 16

Gaseous exchange is reduced

Question 17

Where are chemo receptors found? 2

Answer 17

In the respiratory centre and in arterial walls

Question 18

Where are peripheral chemoreceptors found?3

Answer 18

In arterial walls. Arch of the aorta and bifurcation of common carotids on each side

Question 19

Where are central chemo receptors found?

Answer 19

In respiratory centre

Question 20

What do central chemo receptors respond to? 3

Answer 20

Changes in partial pressure of co2 in blood and alterations in acidity and CSF

Question 21

What inhibits the stimulation to ventilate? Hypoventilate

Answer 21

A drop in arterial pco2

Question 22

What does an increase in pco2 hypercapnia stimulate?

Answer 22

Chemoreceptors

Question 23

Where are stretch receptors found?

Answer 23

Bronchi and bronchioles

Question 24

What does PH mean?

Answer 24

The power of hydrogen

Question 25

What does the apneustic centre in the pond varolii do?

Answer 25

Cuts out breathing stimulation

Question 26

What does the respiratory centre comprise of? 3

Answer 26

Medullary centre in medulla oblongata.
Pneumotaxic centre in pons varolii.
Apneustic centre in pons varolii.

Question 27

What is hypoxic drive? 3

Answer 27

Co2 in blood is stimulus to breathe.
In COPD patients level of co2 in blood is high so it becomes insensitive to the level of co2.
The co2 drive to stimulate respiration is removed.
Respiratory centre in brain uses hypoxia as stimulus to breathe.