Respiratory failure Flashcards
State volume:
Conducting dead space- anatomical:
Alveolar dead space:
Physiological dead space:
Conducting dead space- anatomical: 150ml
Alveolar dead space: 25ml
Physiological dead space: 175ml
What makes up physiological dead space?
Conducting dead space (anatomical)- 150ml
Alveolar dead space- 25ml
150+25= 175ml
Physiological dead space= 175ml
Where is greatest resistance to flow?
Segmental bronchi
State Poiseuilles Law?
Resistance = 8µl / πr4
Diameter doubles- resistance decreases 1/16
Diameter halved- resistance increases 16x
Which bronchus objects more likely get stuck? Why?
Right main bronchus
More vertical
Define type 1 respiratory failure?
State what can cause it?
Lung failure- gas exchange failure
Ventilation-perfusion mismatch
Hypoxaemia
High altitude
Pneumonia
Define type 2 respiratory failure?
State what can cause it?
Resp system can’t remove CO2- pump failure
COPD
Ventilation failure- hypercapnia
What can COPD cause?
Type 2 respiratory failure
What can ventilation and perfusion mismatch and pneumonia cause?
Type 1 respiratory failure
What responds to irritants, noxious agents and interstitial fluid volume?
Juxtapulmonary receptors
List 3 things juxtapulmonary receptors will respond to?
1) Irritants
2) Noxious agents
3) Interstitial fluid volume?
What are 3 types pulmonary stretch receptors?
Explain
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
What are 2 layers of pleura on lungs?
Visceral (inner)
Parietal (outer)
What is space called between visceral and parietla pleura?
Intrapleural cavity
Explain inspiration?
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
In expiration does intrathoracic pressure increase or decrease?
Increase- force air out
In inspiration does intrathoracic pressure increase or decrease?
Decrease due to visceral pleura pulling on lungs
What is main driver to breathe?
CO2
State 2 controls ventilation?
1) Central chemoreceptors- H+ from CO2 diffuse across BBB
2) Peripheral chemoreceptors- H+, PO2, PCO2
Where do chemoreceptors fire nerves?
Where to?
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
What CN input breathing?
CN IX and X
What has positive firing rate?
What has negative firing rate?
Positive- Apneustic
Negative- Pneumotaxic
When will air move into lungs?
Atmospheric pressure greater than alveolar pressure
State movement oxygen and CO2 in and out respiratory system?
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
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.
Explain process inhalation?
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
Explain process exhalation?
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
Explain process exhalation?
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
