Section 3: Gas Exchange in Humans Flashcards
(31 cards)
What happens in respiration?
Food is oxidised such as glucose to get energy
What do cells need to respire aerobically?
A continuous supply of oxygen
What is ventilation?
The movement of air in and out of the lungs
What is a more general term for ventilation?
Breathing
How has the trachea adapted to keep its airway clean?
They have a thin layer of cells, which release mucus and they have cilias
What is the purpose of mucus?
To collect dirt particles and bacteria
What do cilias do?
They beat backwards and forwards to sweep the mucus towards the mouth and not the lungs
How does smoking impact the cilias?
It kills them which stops this protection mechanism from fully working
How is ventilation able to work?
By the change in air pressure. Air goes to places of low concentration.
When we breathe, what happens to our thorax?
The thorax changes the volume of it. This alters the pressure in it which causes air to go in or out of the lungs.
What happens when we breathe in?
Our ribs are moved by intercostal muscles. This outer intercostals contract, pulling the rib up. Also, the diaphragm contract, making it a flatter shape. This increases the volume of air and drops the pressure inside the thorax. Air then enters the lungs.
What happens when we breathe out?
Our external intercostal muscles relax, while the internal intercostals contract which pulls the rib down and in. The diaphragm relaxes which means it goes to its regular dome shape. The volume of the thorax decreases so the pressure is raised. Pressure forces the air to go out.
What do our lungs absorb into our blood and what does it remove from it?
It absorbs oxygen and removes carbon dioxide
How is the alveoli adapted to do its job efficiently?
They have a structure which makes the blood close to the air, they have a very large surface area and their walls are one cell thick
What is the concentration level of oxygen in the alveolus?
It is very high; it diffuses into the blood
What is the concentration level of carbon dioxide in blood?
It is very high; it diffuses into the lungs
How does smoking upset the air passages?
They disrupt air passages being free and having a large surface area
How does smoking impact pregnant woman?
She will deprive her unborn fetus of oxygen. This stunts growth and development, which makes the baby lighter and smaller.
How are cilias destroyed when people smoke?
The chemicals in cigarette smoke destroys them
How do smokers develop smokers cough?
As their cilias are destroyed, the mucus is not being swept away to the mouth. This clogs up the lungs and forces them to cough.
How does smoking impact the rate of mucus being secreted from the lungs?
The smoke irritates the lining of cells in the thorax
How does smoking damage the wall of the alveoli?
The smoke damages the walls of alveoli, which breaks down and fuse together, forming enlarged, irregular air spaces
How does smoking make the alveoli inefficient for gas exchange?
When the damaged walls of the alveoli break down and fuse together, this greatly reduces the surface area for gas exchange
How does emphysema impact the volume of oxygen being pumped per red blood cell?
The blood of a person with emphysema carries less oxygen
