Gas And Respiration Flashcards
Movement of gases from one compartment to another plays an important role in? (4 points)
- breathing and exchange of alveolar blood gases
- cellular respiration
- equipment used to aid breathing
- physiological responses to altitude and underwater pressure
Passive movement follows what rule?
Standard diffusion rules, always from a higher pressure to a region of lower pressure
If the concentration gradient is larger what is faster?
The diffusion rate
What must gases do in order to diffuse across a biological membrane?
Dissolve in a liquid
Diffusion of oxygen is from…..?
ECF to cells
Diffusion of carbon dioxide is from…?
ICF out of cells
What percentage of oxygen in the blood is dissolved in plasma?
1.5%
How is the majority (98.5%) of oxygen carried in red blood cells?
On haemoglobin
What is Boyle’s law?
The pressure of a gas varies inversely with its volume
What is the primary muscle in inspiration?
The diaphragm
What happens to the diaphragm during expiration?
It relaxes, moves back to its original state
What are the active and passive processes?
Passive - breathing out
Active - breathing in
What happens during the active process (breathing in)?
Chest expands (lung volume increases) —— diaphragm contracts (pressure decreases) = air moves in
What happens during the passive process (breathing out) ?
Chest contracts (lung volume decreases) —— diaphragm relaxes (pressure increases) = air moves out
What are the 2 types of respirators?
- negative pressure ventilator (iron lung)
- positive pressure system
What happens with a negative pressure ventilator?
- helps assist or control breathing
- mimics physiological process of breathing by periodically altering pressure in the chamber
What happens in a positive pressure system?
- oxygen actively pushed into the lungs to create pressure difference
- used when patient cannot breathe alone
- useful for neonates, snoring, sleep apnoea, cardiac failure
What are the mixture of gases in the air?
- nitrogen 78%
- oxygen 21%
- other (carbon dioxide and water etc) 1%
What is the net atmospheric pressure?
760 mmHg
What is Dalton’s law?
Total pressure exerted by a mixture of gases is the sum of the partial pressures of the individual gases
What is the partial pressure of oxygen in the atmosphere?
159 mmHg
What is the partial pressure of carbon dioxide in the atmosphere?
0.15 mmHg
Carbon dioxide has a much higher?
Solubility constant than oxygen - 20x higher
What is Henry’s law?
Increase the partial pressure of a gas then more gas is dissolved
