Respiratory failure

Question 1

State volume:
Conducting dead space- anatomical:
Alveolar dead space:
Physiological dead space:

Answer 1

Conducting dead space- anatomical: 150ml
Alveolar dead space: 25ml
Physiological dead space: 175ml

Question 2

What makes up physiological dead space?

Answer 2

Conducting dead space (anatomical)- 150ml
Alveolar dead space- 25ml

150+25= 175ml
Physiological dead space= 175ml

Question 3

Where is greatest resistance to flow?

Answer 3

Segmental bronchi

Question 4

State Poiseuilles Law?

Answer 4

Resistance = 8µl / πr4
Diameter doubles- resistance decreases 1/16
Diameter halved- resistance increases 16x

Question 5

Which bronchus objects more likely get stuck? Why?

Answer 5

Right main bronchus
More vertical

Question 6

Define type 1 respiratory failure?
State what can cause it?

Answer 6

Lung failure- gas exchange failure
Ventilation-perfusion mismatch
Hypoxaemia
High altitude
Pneumonia

Question 7

Define type 2 respiratory failure?
State what can cause it?

Answer 7

Resp system can’t remove CO2- pump failure
COPD
Ventilation failure- hypercapnia

Question 8

What can COPD cause?

Answer 8

Type 2 respiratory failure

Question 9

What can ventilation and perfusion mismatch and pneumonia cause?

Answer 9

Type 1 respiratory failure

Question 10

What responds to irritants, noxious agents and interstitial fluid volume?

Answer 10

Juxtapulmonary receptors

Question 11

List 3 things juxtapulmonary receptors will respond to?

Answer 11

1) Irritants
2) Noxious agents
3) Interstitial fluid volume?

Question 12

What are 3 types pulmonary stretch receptors?
Explain

Answer 12

1) Slowly adapting- inhibit inspiration- smooth muscle respond stretch
2) Rapidly adapting- epithelial cells- respond change and irritates- bronchoconstriction
3) Juxtapulmonary receptors- respond irritants- bronchoconstriction

Question 13

What are 2 layers of pleura on lungs?

Answer 13

Visceral (inner)
Parietal (outer)

Question 14

What is space called between visceral and parietla pleura?

Answer 14

Intrapleural cavity

Question 15

Explain inspiration?

Answer 15

Respiratory muscles expand cavity
Create negative pressure in pleura cavity
Pulls visceral pleura- pulls lungs and decreases pressure
Air rush in lungs- equalise pressure- inspiration

Question 16

In expiration does intrathoracic pressure increase or decrease?

Answer 16

Increase- force air out

Question 17

In inspiration does intrathoracic pressure increase or decrease?

Answer 17

Decrease due to visceral pleura pulling on lungs

Question 18

What is main driver to breathe?

Answer 18

CO2

Question 19

State 2 controls ventilation?

Answer 19

1) Central chemoreceptors- H+ from CO2 diffuse across BBB
2) Peripheral chemoreceptors- H+, PO2, PCO2

Question 20

Where do chemoreceptors fire nerves?
Where to?

Answer 20

Fire to pontine respiratory group
Apneustic- positive firing- respiratory intensity
Pneumotaxic- negative firing- time dependent

Signal to dorsal respiratory group- ventral respiratory group
Stimulate internal intercostals and accessory resp muscles

Question 21

What CN input breathing?

Answer 21

CN IX and X

Question 22

What has positive firing rate?
What has negative firing rate?

Answer 22

Positive- Apneustic
Negative- Pneumotaxic

Question 23

When will air move into lungs?

Answer 23

Atmospheric pressure greater than alveolar pressure

Question 24

State movement oxygen and CO2 in and out respiratory system?

Answer 24

1) Oxygen rich air from environment
2) Nasal cavities
3) Pharynx
4) Trachea
5) Bronchi
6) Bronchioles
7) Alveoli
8) O2 and C02 exchange at alveoli
9) Bronchioles
10) Bronchi
11) Trachea
12) Pharynx
13) Nasal cavities
14) CO2 rich air to environment

Question 25

What When you inhale, your diaphragm muscle contracts and moves downwards, and the intercostal muscles contract and move the ribs upwards and outwards. This increases the volume of the lungs, which reduces the pressure inside and so air moves into the lungs to equalise it. Air that is rich in oxygen moves into the gas exchange system and then the body when you breathe in.

When you exhale, our diaphragm muscle relaxes and moves upwards, and the intercostal muscles relax and move downwards and inwards. This reduces the volume of the lungs, which forces air outwards. Air with more carbon dioxide is then removed when you breathe out.

Question 26

Explain process inhalation?

Answer 26

1) Diaphragm muscle contract- move downwards
2) Intercostal muscles contract- move ribs up and out
3) Increase volume lungs- reduce pressure inside
4) Air moves into lungs- equalise pressure

Question 27

Explain process exhalation?

Answer 27

1) Diaphragm muscle relax and move upwards
2) Intercostal muscles relax- move ribs down and inwards
3) Decrease volume lungs- increase pressure inside
5) Force air out

Question 27

Explain process exhalation?

Answer 27

1) Diaphragm muscle relax and move upwards
2) Intercostal muscles relax- move ribs down and inwards
3) Decrease volume lungs- increase pressure inside
5) Force air out