Respiratory System Flashcards
What do goblet cells (layer of cells covering turbinal bones) make?
A liquid containing mucus and water
What are cilia? What do they do?
Hair like projections, they waft mucus containing dust and bacteria to the back of the throat so that it does not block up the lungs
What happens to swallowed mucus?
It goes into the stomach and the bacteria in it is killed
What is the function of the Epiglottis?
It shuts when food is swallowed to prevent it from going down the trachea
What keeps the trachea open at all times?
It is stiffened by rings of cartilage
Why are the cartilage rings āCā shaped?
Because it allows for the oesophagus to expand when food goes down it
Where is the voice box located?
Under the epiglottis
What is another name for the voice box?
Larynx
What is inside the voice box?
Vocal cords
How do vocal cords make noise? How is the pitch of the sound determined?
They vibrate when air passes over them. The looser and slower they vibrate the lower the pitch, the tighter and faster they vibrate the higher the pitch
Describe the structure of the trachea (its branches)
It branches out into the left and right bronchi (singular; bronchus) which then divide into bronchioles that end in alveoli
What process occurs in the alveoli?
Gaseous exchange
What is the diameter of an alveoli?
0.25mm
What is the total surface area of alveoli?
70m2
What makes the alveoli well adapted for gaseous exchange?
- One cell thick walls (0.001mm)
- Excellent transport system
- They are moist
- Large surface area (70m2)
- Blood capillaries closely wrapped around each alveoli
Definition of breathing
The process of moving air in and out of the lungs
Another name for breathing
Ventiliation
What 2 sets of muscles help us breathe?
Intercostal muscles and the diaphragm
What happens to the volume of the thorax/lungs during inspiration?
It increases
What happens to the volume of the thorax/lungs during expiration
It decreases
What happens to the pressure of the air in the thorax/lungs during inspiration?
It decreases
What happens to the pressure of the air in the thorax/lungs during expiration?
It increases
During inspiration what do the external intercostal muscles and diaphragm do?
They contract;
1. The external intercostal muscles pull the ribs up and out
2. The diaphragm flattens
During expiration what do the external intercostal muscles and diaphragm do?
They relax;
1. The external intercostal muscles pull the ribs down and in
2. The diaphragm returns to its dome shape
What happens during coughing?
- Coughing is breathing out more forcefully. 2. Internal intercostal muscles contract more strongly forcing the ribs to drop down further. 3. The muscles of the abdomen wall contract. 4. The lungs are made smaller than usual.
What is coughing for?
To get rid of excess mucus containing bacteria
Volume of lungs in females and males
Females = 4.5
Males = 5.5
What is tidal air? How many litres is it?
The amount of air that is breathed in and out with each normal breath. 0.5 litres
What is vital capacity? How many litres is it?
The maximum amount of air you can inhale or exhale. 4-5 litres
What is residual air? How many litres is it?
The air that cannot be exhaled. 1-1.5 litres
What is the normal adult breathing rate?
16-18 times a minute
What is breathing controlled by?
The respiratory centre located in the medulla
What does the respiratory centre/medulla detect?
CO2 levels
What happens if there is an excess of CO2 levels?
The medulla sends a message to the intercostal muscles and diaphragm to contract faster causing the person to breathe faster. This removes CO2 from the lungs and takes O2 into the lungs
