Respiratory System Flashcards
Describe passage of air into lungs
- Air enters the body and is warmed as it travels through the mouth and nose.
- It then enters the trachea.
- The trachea divides into two bronchi. One bronchus enters each lung.
- Each bronchus branches out into smaller tubes called bronchioles. Air travels through these bronchioles.
- At the end of the bronchioles, the air enters one of the many millions of alveoli where gaseous exchange takes place.
Two main parts of breathing - explain process
Two important structures for breathing and briefly explain
Two important structures for breathing are the diaphragm and intercostal muscles.
The diaphragm is a sheet of muscle that separates the chest (or thoracic) cavity from the rest of the body.dome shaped
The intercostal muscles are found between the ribs and they control rib movement.
Inspiration (breathing in)
The diaphragm contracts and moves downwards. The intercostal muscles contract and move the ribs upwards and outwards. This increases the size of the chest and decreases the air pressure inside it which sucks air into the lungs.
Expiration (breathing out)
The diaphragm relaxes and moves back to its domed shape. The intercostal muscles relax so the ribs move inwards and downwards under their own weight. This decreases the size of the chest and increases the air pressure in the chest so air is forced out of the lungs.
Two main parts of breathing - explain process
Two important structures for breathing and briefly explain
Two important structures for breathing are the diaphragm and intercostal muscles.
The diaphragm is a sheet of muscle that separates the chest (or thoracic) cavity from the rest of the body.dome shaped
The intercostal muscles are found between the ribs and they control rib movement.
Inspiration (breathing in)
The diaphragm contracts and moves downwards. The intercostal muscles contract and move the ribs upwards and outwards. This increases the size of the chest and decreases the air pressure inside it which sucks air into the lungs.
Expiration (breathing out)
The diaphragm relaxes and moves back to its domed shape. The intercostal muscles relax so the ribs move inwards and downwards under their own weight. This decreases the size of the chest and increases the air pressure in the chest so air is forced out of the lungs.
Explain gas exchange
How and where does it occur
Gas exchange occurs at the alveoli in the lungs and takes place by diffusion. The alveoli are surrounded by capillaries so oxygen and carbon dioxide diffuse between the air in the alveoli and the blood in the capillaries.
Diffusion
- Movement of gas from an area of high concentration to an area of low concentration.
- High concentration of oxygen in the alveoli and a low concentration of oxygen in the blood, so oxygen diffuses from the alveoli into the blood.
- High concentration of carbon dioxide in the blood and a low concentration in the alveoli, so carbon dioxide diffuses from the blood into the alveoli.
- Both oxygen and carbon dioxide are capable of combining with an iron-rich protein in the blood called haemoglobin. Haemoglobin carries oxygen to be exchanged at the working muscle and carbon dioxide to be exchanged at the lung.
Three main measures of Lung volume
Vital capacity
- is the maximum amount of air that can be breathed out after breathing in as much air as possible. Taking part in regular aerobic exercise has been shown to increase a person’s vital capacity.
Tidal volume
- is the amount of air breathed in with each normal breath. The average tidal volume is 0.5 litres (500 ml).
Total lung capacity
- is the total amount of air that the lungs can hold after the biggest possible breath in. The average total lung capacity is about 6 litres (6000 ml).
Respiratory system - BBC Edexcel test questions - Edexcel
1
Where in the respiratory system does gas exchange take place?
Alveoli
Trachea
Bronchioles
2
Which of the following contracts to cause inhalation of breath?
Lung
Diaphragm
Bronchus
3
Where would you find the intercostal muscles?
In the lung
Below the diaphragm
Between the ribs
4
What percentage of the air breathed out is oxygen?
21%
18%
16%
5
Which of these gases can the protein haemoglobin carry?
Ammonia and methane
Nitrogen and hydrogen sulphide
Oxygen and carbon dioxide
6
Which term is used to describe the movement of gases from an area of high concentration to an area of low concentration?
Contraction
Diffusion
Evaporation
7
Which lung volume can be defined as “the amount of air breathed in with each normal breath”?
Vital capacity
Total lung capacity
Tidal volume
8
Which gas is produced by the muscles during exercise as a waste product that needs to be transported and removed?
Oxygen
Carbon dioxide
Lactic acid
9
For the average adult, what measurement would we expect for total lung capacity?
1 litre
6 litres
10 litres
10
During the first ten minutes of a hockey match, what would you expect to the tidal volume of a midfielder to do?
Remain constant
Decrease
Increase
Check score
1.alveoli
2. Diaphragm
3. between ribs
4. 16%
5. Oxygen and Co2
6. Diffusion
7.tidal volume
8.carbon dioxide
9 6 l
10.incease
