Gaseous Exchange & Oxygen Dissociation Flashcards
How is oxygen (O2) transported in the blood?
In two ways:
* Within haemoglobin (Hb) as oxyhaemoglobin
* Within blood plasma (approximately 3%)
Oxyhaemoglobin is formed when oxygen binds to haemoglobin in red blood cells.
How is carbon dioxide (CO2) transported in the blood?
In three ways:
* Within haemoglobin as carbamino-haemoglobin (HbCO)
* Within blood plasma (approximately 7%)
* In water
Carbamino-haemoglobin is formed when carbon dioxide binds to haemoglobin.
Define diffusion.
The net passive movement of particles from a region of higher concentration to lower concentration until uniformity is achieved
This process is crucial for gas exchange in the body.
What is particle pressure?
The pressure a gas exerts within a mixture of gases
It plays a key role in the movement of gases during respiration.
What is gaseous exchange?
The movement of gases across a membrane
This process is essential for respiration and occurs across capillary walls.
In which direction do gases move during diffusion?
From areas of high partial pressure (PP) to low partial pressure (PP)
This principle governs the exchange of gases in the lungs and tissues.
What is external respiration?
The exchange of oxygen (O2) and carbon dioxide (CO2) inside the lungs
It occurs between the alveoli and blood capillaries.
What happens to oxygen during external respiration?
Oxygen moves from the alveolus (high ppO2) into the bloodstream (low ppO2)
This is driven by the difference in partial pressures.
What happens to carbon dioxide during external respiration?
CO2 moves from the capillary bed (high ppCO2) into the lungs (low ppCO2)
This exchange is also driven by partial pressure differences.
Define internal respiration.
The process of diffusing oxygen from the blood into the muscle cells
It is essential for cellular metabolism.
What occurs at the muscle cells during internal respiration?
O2 diffuses into muscle cells (low ppO2) from blood capillaries (high ppO2)
CO2 diffuses into blood capillaries (low ppCO2) from muscle cells (high ppCO2)
This process supports energy production in tissues.
How does exercise affect the partial pressure of CO2 in muscle cells?
ppCO2 in muscle cells is higher during exercise
This increase is due to the production of CO2 as a waste product of metabolism.
What is the effect of exercise on the rate of gaseous exchange?
It creates a steeper concentration gradient, resulting in a faster rate of gaseous exchange
This is due to increased O2 usage and CO2 production during exercise.
