Respiratory System Flashcards
What is Tidal Volume?
Volume of air breathed in or out per breath
Increase during exercise
What is Inspiratory Reserve Volume (IRV)?
Volume of air that can be forcibly inspired after a normal breath (tidal volume)
Decreases during exercise
What is Expiratory Reserve Volume (ERV)?
Volume of air that can be forcibly expired after a normal breath (tidal volume)
Slightly decreases during exercise
What is Residual Volume?
The amount of air that remains in the lungs after maximal expiration.
Remains the same during exercise
What is Minute Ventilation?
Volume of air breathed in or out per minute.
Big increase during exercise
What is partial pressure?
The pressure exerted by an individual gas when it exists within a mixture of gases.
What is breathing frequency?
The number of breaths per minute (breaths per minute)
Minute ventilation formula
Minute ventilation =
Breathing frequency x Tidal Volume
What structures are in the respiratory system?
• Lung
• Heart
• Diaphragm
• Trachea
• Bronchi
• Pulmonary Arteriole
• Bronchioles
• Alveoli
• Pulmonary Vein
Explain gas exchange at the alveoli
At the alveoli oxygen diffuses from a highly concentrated area ,where it has a high partial pressure, to an area of low concentration (the blood) where the partial pressure is lower.
CO2 diffuses in the other direction.
Why is gas exchange at the alveoli efficient?
• Large number of alveoli
• Large number of capillaries
• Thin membrane between alveoli and capillary
Explain gas exchange at the muscles
At rest there is a small arteriovenous difference. When exercising, there is a arteriovenous difference, which increases the pressure gradient for gas diffusion.
What happens to gas exchange pressure gradient during exercise?
As exercise intensity increases, there is a larger pressure gradient between the CO2 and O2 levels at the sites of gas exchange.
Explain dissociation of oxyhemoglobin
In a high partial pressure of oxygen (the lungs), oxygen binds more readily to haemoglobin.
As this partial pressure decreases (exercising muscles) oxygen is more readily released.
As exercise intensity increases, the partial pressure of oxygen decreases and so oxygen is easily released from haemoglobin.
What is the respiratory control centre?
The respiratory control centre of the brain is made up of the inspiratory control centre and the expiratory control centre.
These two centres work together to regulate breathing at rest and during exercise without conscious thought.
They require different receptors to send them information in order to control breathing rate.
How do neural factors regulate breathing rate?
The respiratory centres regulate breathing rate by increasing or decreasing respiratory muscle activation through sympathetic or parasympathetic stimulation.
What receptors is neural stimulation dependent on?
• Proprioceptors
• Baroreceptors
• Thermoreceptors
What do thermoreceptors do?
Detect changes in temperature
What do Baroreceptors do?
Detect changes in blood pressure.
What do Proprioceptors do?
Detect movement, tension and force.
What do chemoreceptors do?
Detect changes in blood acidity.
What is sympathetic vs parasympathetic system?
Sympathetic is fight or flight responses
Parasympathetic is rest and digest responses
How do chemical factors regulate breathing rate?
Chemoreceptors in the aorta and medulla oblongata detect changes in blood pH level.
As CO2 increases, breathing rate increases as a result of stimulation from the inspiratory control centre.
How do hormonal factors regulate breathing rate?
Breathing rate can be increased by the release of the hormone adrenaline from the adrenal glands
Impacts of smoking on respiration
Increased:
- Risk of asthma
- Risk of bronchitis
- Risk of lung cancer
- Risk of asthma attack during exercise
- Risk of cardiovascular disease
- Risk of emphysema
Decreased:
- Movement of oxygen through airways
- Transportation of oxygen in blood
- Cardiovascular endurance
- Ability to be active
- Intensity if exercise can be tolerated
Damaged alveoli
Tidal volume definition
The amount of air normally breathed in/out with each breath
What is tidal volume typical resting value?
500ml
Minute ventilation typical resting value
6.0 L/min
Residual volume typical resting value
1200ml
Expiratory reserve volume typical resting value
1200ml
Inspiratory reserve volume typical resting value
3100ml
What happens to tidal volume during exercise?
Tidal volume increases during exercise
What happens to minute ventilation during exercise?
Minute ventilation increases during exercise
What happens to residual volume during exercise?
Residual volume remains almost the same but may decrease slightly during exercise
What happens to expiratory reserve volume during exercise?
Expiratory reserve volume decreases during exercise.
What happens to Inspiratory reserve volume during exercise?
Inspiratory reserve volume decreases during exercise.
