Year 1 - Respiratory System Flashcards
What is oxygen needed for?
Aerobic respiration (which releases energy from our food)
What is carbon dioxide?
It is a waste product of respiration, which must be exhaled from the body
What is haemoglobin?
Protein in erythrocytes that transport oxygen
What are ham groups?
Iron-containing molecules in haemoglobin that actually bind oxygen
What can each haemoglobin molecule carry?
Four oxygen molecules
Why do erythrocytes have no nucleus?
To fit in more haemoglobin
Why is the surface area of erythrocyte cell membrane due to the biconcave disc?
For oxygen to diffuse across
Why are erythrocytes tiny and flexible?
So they can squeeze through the narrowest of blood capillaries to deliver oxygen
5% of carbon dioxide…
Is transported dissolved in the plasma
10% of carbon dioxide…
Is transported as carbaminohaemoglobin
85% of carbon dioxide…
Is transported as hydrogen carbonate ions in the plasma
What is carbonic anhydrase?
Enzyme that catalyses the reaction between carbon dioxide and water to form carbonic acid
What does carbonic acid break down and why?
It breaks down into hydrogen carbonate ion and a hydrogen ion because it is unstable
Where do hydrogen carbonate ions go after being formed the erythrocyte?
They diffuse back into the plasma
What is the reaction that forms hydrogen carbonate ions?
They are reversible, which means carbon dioxide can be reformed to be exhaled
What are the lungs?
An organ that exchanges oxygen and carbon dioxide with the blood
What is the trachea?
Allows are to pass to and from lungs
What are the bronchi?
Tubes (right and left) branching off from the trachea and into the lungs
What are the bronchioles?
Airways in the lungs that lead from the bronchi to the alveoli
What are the alveoli?
Tiny sacs, found at the ends of the bronchioles, that are the actual site of gas exchange with the blood
What are the characteristics of the walls of the alveolus?
Is only one cell thick, keeping diffusion short
What are the pleural membranes?
Two membranes surrounding the lungs. The gap between the membranes is filled with pleural fluid.
What are the ribs?
The bones in the chest that protect the heart and lungs.
What is the diaphragm?
Large, flat muscle at the bottom of the thoracic activity that helps with breathing
What is inspiration?
Proper term for breathing in (inhalation)
What is expiration?
Proper term for breathing out (exhalation)
What happens when you breathe in?
The diaphragm contracts and external intercostal muscle contract
What happens when you breathe out?
The diaphragm relaxes and intercostal muscles contract
What is the proper name for “chest cavity”?
Thoracic cavity
Volume increase so the pressure decreases in the thoracic cavity…
To below atmospheric pressure, so air moves in to lungs
Volume decreases, so pressure increases in the thoracic cavity…
To above atmospheric pressure, so air moves out of lungs
What is pulmonary surfactant?
A mixture of phospholipids and proteins that coats the inside of alveoli, breaking the water layer’s surface tension and thus preventing alveoli from collapsing towards the end of exhalation
What is the feature of water that means pulmonary surfactant is needed?
High surface tension
What is ventilation rate?
Number of breaths per minute
More carbon dioxide is generated by aerobic respiration when we…
Exercise
What is the unconscious trigger for an increase in ventilation rate?
A rise in blood carbon dioxide concentration
What does a rise in blood carbon dioxide concentration lead to?
It leads to a fall in pH (more acidic), which leads to an increase in our ventilation rate
Why does the higher ventilation rate will return carbon dioxide concentration to normal?
So the ventilation rate can go back down to normal (negative feedback)
