The Respiratory System Flashcards
What are the 3 parts of the nasal cavity?
cilia
mucous membranes
blood capillaries
Why is cilia present in the nasal cavity?
They are the filter - remove dust
Why are mucous membranes present?
To moisten the air
Why are blood capillaries present?
To warm the blood at the surface
What is the pharynx made of and what is its function?
Made of muscle
Narrow - helps push out food and other particles
What is the epiglottis and what is its function?
A flap of tissue/cartilage
Prevents food entering the trachea - choking
What is another name for the trachea?
Windpipe
What is the trachea made of?
Rings of cartilage
What is the function of the trachea and in relation to its structure?
Connects throat to lungs
Rings of cartilage - avoids collapsing
What is the bronchi?
An airway leading into the lungs - branches off further
What is the main role of the bronchi?
Guide air into the alveoli
Explain the structure of the bronchioles:
Made of smooth muscle - not cartilage
What are the main functions of the bronchioles?
Connects the bronchi and alveoli
Explain the structure of the alveoli:
Air sacs covered in capillaries
one cell thick
What is the main function of alveoli?
Gaseous exchange
What are the 3 respiratory muscles?
Internal intercostals
External intercostals
Diaphragm
What do the internal intercostals do when you breathe out during exercise?
They pull the rib cage down and in
Contract
What do the external intercostals do to our rib cage?
They pull the rib cage up and out
What do your internal intercostals do when you are breathing out at rest?
They relax
Natural recoil brings the rib cage down and in
What happens to the diaphragm when it is contracting?
It flattens
What happens to the diaphragm when it is relaxing?
It changes into a dome shape
When is the diaphragm contracting?
When breathing in
When is the diaphragm relaxing?
When breathing out
What is the thoracic cavity?
Chamber of the chest
protected by thoracic wall
Separated from the abdominal cavity by the diaphragm
What kind of process is expiration at rest?
Passive process - natural recoil
What kind of process is expiration during exercise?
Active process - intercostals contract to pull rib cage down and in
What is the benefit of the internal intercostals contracting during exercise?
Exhale air quicker
Remove air from lungs quicker
Remove CO2 from lungs faster
What type of process is inspiration?
An active process - always
What is the part of the brain stem involved in the neural control of breathing?
Medulla Oblongata
What is sent from the medulla oblongata?
Signals or neurones - tell the intercostal muscles to contract or relax
When will the medulla oblongata send these neurones?
When a signal has come that more oxygen is required by the muscles - removal of CO2 is key
Is breathing voluntary or involuntary
An involuntary process caused by impulses in the brain stem
What is the definition of diffusion?
Gases move from an area of high partial pressure to an area of low partial pressure
Describe how oxygen moves at the lungs:
Oxygen moves from the alveoli into the blood capillaries
Describe how carbon dioxide moves at the lungs:
Moves from the blood capillaries into the alveoli to be breathed out
What is a diffusion gradient?
Difference in partial pressure creates a gradient
Diffusion happens because of a gradient
What is diffusion rate?
The speed of the transfer of gases across the membrane
When will a faster diffusion take place?
When there is a steep diffusion gradient
Why does blood that arrives back to the alveoli have less oxygen during exercise than at rest?
The muscles have used more oxygen during exercise so there is less being brought back
Why is the partial pressure of oxygen in the alveoli higher during exercise?
The person is breathing faster and deeper and therefore is bringing more oxygen into their lungs
What happens during neural control when the chest cavity increases in size after a signal has been sent?
Pressure is put on the pulmonary stretch receptors = mechanoreceptors
What are mechanoreceptors?
Measure how far your lungs have contracted
Why is measuring the contraction of the lungs important?
Feed info back to brain - they know whether to keep increasing breathing or to now go to expiration and reduce the breathing rate
What does the medulla oblongata regulate?
Stimulates resp. muscles depending on the body’s demands for oxygen
What happens during exercise to the medulla oblongata?
Impulses are sent more frequently
breathing rate and depth increases
What else do the nerve impulses stimulate during exercise?
They pull the rib cage down and in (not natural recoil during exercise)
How is energy created - the chemical control of breathing?
Glucose and oxygen = energy
What bi products are produced during energy production?
Heat
Water
Carbon dioxide
Lactic acid
What happens if there is high levels of CO2 in the blood?
The blood becomes acidic
What are chemoreceptors?
Measure the level of CO2/acidity within the blood
Where are chemoreceptors found?
At the aortic arch
Carotid arteries
Where do the chemoreceptors send info about acidity levels in the blood?
To the medulla oblongata
What will happen if the blood is to acidic and has to much CO2 present?
There will be an increase in breathing rate and depth to get rid of CO2
What will happen if there is low levels of CO2 and acidity in the blood?
There will not be an increase in breathing rate or depth
What will happen if the CO2 levels and acidity levels in the blood are beginning to decrease?
There will be a decrease in breathing rate and depth
What is meant by the term ‘breathing rate’?
The number of breaths you take in one minute
What is the average breathing rate per min at rest?
12 breaths per min
What is the average breathing rate during exercise?
30-40 breaths per min
What is tidal volume?
Volume of air moved in and out of the lungs in one breath (depth of the breath)
What is the average tidal volume?
500cm3
What is minute volume?
Volume of air moved in and out of the lungs in one minute
What is the equation for working out minute volume?
Breathing rate x tidal volume = minute volume
What is residual volume?
Volume of air that is remaining in the lungs after maximal expiration
What is the average residual volume?
1.2 litres
What is vital capacity?
The amount of air that can be forced out of the lungs after maximal inspiration
What is the average vital capacity?
48000cm3
What is the total lung capacity?
Volume of air in the lungs after maximal inhalation
How is total lung capacity calculated?
Vital capacity + Residual volume = Total lung capacity
What is inspiratory reserve volume?
Volume of air that could be inhaled after normal breath
What is the expiratory reserve volume?
Volume of air that could be forced out of the lungs after a normal breath
