Respiration and the respiratory system Flashcards
(31 cards)
What is the function of the respiratory system in mammals?
To provide cells with the oxygen needed for aerobic respiration and remove waste products produced during the process to prevent build up
Do all animals have a respiratory system?
No, small animals do not have one as they absorb oxygen through their skin.
What would happen if we absorb oxygen through our skin?
The cells deep inside our body would die before any oxygen would have a chance to reach them as diffusion is only effective over small distances.
What happens as animals get larger?
- Their surface area to volume ratio reduces so supply can not meet demand
- Larger animals tend to be more active so a greater oxygen supply is required due to needing more energy.
What features are in the respiratory system?
- Nasal cavity
- Trachea
- Bronchus
- Bronchiole
- Rib cage
- Lungs
- Alveoli
- Intercoastal muscles
- Diaphragm
How is ventilation carried out?
By movements of your ribcage and diaphragm
What happens during inspiration?
Breathing in, fresh air is provided to the alveoli
What happens during expiration?
Breathing out, removes air from the lungs
What happens when you breathe in?
Your intercoastal muscles contract pulling your ribs upwards and outwards and your diaphragm muscles contract flattening it from its usual dome shape.
This increases volume of your thorax as the same volume of air is now in a bigger space, the pressure inside your thorax drops.
Pressure inside the thorax is now lower then the pressure of air outside your body, resulting in air moving into your lungs
What happens when you breathe out?
Your intercoastal muscles relax, dropping your ribs down and in. When the diaphragm relaxes it’ll curve back into your thorax.
The volume of the thorax decreases, this increases pressure inside the thorax so air is forced out of your lungs.
What is the process of inspiration using a bell jar model?
- The rubber sheet is pulled down
- Volume of bell jar (representing thorax) increases
- The pressure inside the bell jar and the balloons decrease
- Pressure inside balloons is now lower then the pressure of the air outside of the body and air moves into balloons
What is the process of expiration using a bell jar model?
- The rubber sheet is pulled up
- Volume of bell jar (representing thorax) decreases
- The pressure inside the balloons is now higher then the pressure of air outside of the bell jar, air moves out of the balloons
What is the limitation of a bell jar model?
Whilst they’re helpful to illustrate a biological process, they cannot represent the process perfectly
What do the bronchi branch into inside the lungs?
Into smaller tubes called bronchioles
What is at the end of every bronchiole?
A group of alveolis
What is the function of alveolis?
The sites of gas exchange
Are alevolis adapted to gas exchange effectively?
Yes, they have a large surface area, thin walls and moist lining. These adaptations minimise the rate of diffusion of oxygen and carbon dioxide
What gases are exchanged in the alveolus?
Oxygen is absorbed into the blood and carbon dioxide is released from the blood
What happens to blood leaving the alveolus area?
It is high in oxygen and low in carbon dioxide
What carries carbon dioxide in the blood?
Blood plasma
What absorbs oxygen in the alveolus?
Red blood cells
What experiment demonstrates the difference between inhaling and exhaling?
Using a ‘huff and puff’ apparatus with lime water to detect carbon dioxide
What does lime water do in the presence of carbon dioxide?
Changes from clear to milky
What do the mucus and cilia do?
Help protect the respiratory system as they form the cleaning mechanism of the respiratory system
