Respiratory System Flashcards
Which area does air move between?
An area of high pressure to and area of low pressure
How does pressure difference affect diffusion?
The greater the pressure difference, the faster air will flow so the faster the rate of diffusion
What will happen when the volume of the thoracic cavity is increased?
The pressure in the lungs will decrease
What will happen when the volume of the thoracic cavity is decreased?
The pressure in the lungs will increase
What is tidal volume?
The volume of air breathed in or out per breath
How does tidal volume change during exercise?
Increases
What is inspiratory reserve volume?
The volume of air which could be forcibly inspired in addition to tidal volume
How does IRV change during exercise?
Decreases
What is expiratory reserve volume?
The volume of air which could be forcibly expired in addition to tidal volume
How does ERV change during exercise?
Decreases
What is residual volume?
The volume of air which must remain in the lungs after maximal expiration
How does residual volume change during exercise?
It remains the same
What is minute ventilation?
The volume of air inspired or expired per minute - breathing rate x tidal volume
How does minute ventilation change during exercise?
Increases
What is vital capacity?
The maximum amount of air that can be breathed out after breathing in as much air as possible - total capacity - reserve volume
How does vital capacity change during exercise?
Decreases
What is the pathway of air?
Nose/mouth
Pharynx
Larynx
Trachea
Lung
Right bronchus
Left bronchus
Bronchiole
Alveoli
Diaphragm
What are the muscles used in inspiration during rest?
Diaphragm
External intercostals
What are the muscles used in inspiration during exercise?
Diaphragm
Scalenes
External intercostals
Sternocleidomastoid
Pectoral is major/minor
What are the muscles used in expiration at rest?
Diaphragm
External intercostals
What are the muscles used in expiration during exercise?
Internal intercostals
Abdominals
What are some reasons for effective gas exchange?
Large diffusion gradients - these increase during exercise
Capillary membrane is one cell thick so diffusion distance is short
Narrow capillaries - increasing the opportunity for gas exchange to occur
Large network of capillaries - increasing the opportunity for gas exchange to occur
Myoglobin - higher affinity for oxygen than haemoglobin so promotes oxygen dissociation
What does a greater partial pressure lead to?
Greater rate of diffusion
How does oxygen gases exchange occur in the alveoli?
Partial pressure of oxygen is higher in the alveoli than in the capillary so oxygen diffuses out into the capillary
How does carbon dioxide gaseous exchange occur at the alveoli?
The partial pressure of carbon dioxide is greater in the capillaries than in the alveoli so carbon dioxide diffuses into the alveoli
How does oxygen gaseous exchange occur at the muscles?
The partial pressure of oxygen in the capillary is greater than in the muscle cell so oxygen diffuses into the muscle cell
How does carbon dioxide gaseous exchange occur at the muscles?
The partial pressure of carbon dioxide in the muscle cell is greater than in the capillaries so carbon dioxide diffuses out into the capillaries
What are the 3 factors that regulate pulmonary ventilation (breathing)?
Neural control
Chemical control
Hormonal control
Where is pulmonary ventilation controlled?
Respiratory Control Centre (RCC) - in the medulla oblangata
Contains the ICC and ECC
What hormone controls the hormonal regulation of PV during exercise?
Adrenaline
How does adrenaline play a role in the hormonal regulation of PV during exercise?
Adrenaline is pumped into the blood after being made in the adrenal glands
The adrenaline causes breathing rate to increase in preparation for exercise to take in more oxygen and remove more carbon dioxide
What is used in the chemical regulation of PV?
Chemoreceptors
What do chemoreceptors detect?
An increase in blood acidity
Why does blood acidity increase during exercise?
Due to an increase in carbonic acid (dissolved CO2 in blood) concentration and lactic acid production
Where are chemoreceptors found?
Carotid artery
Aortic arch
How do chemoreceptors react to an increase in blood acidity?
They send impulses to the ICC to increase ventilation until blood acidity has returned to normal
This is done by -
RCC sends impulses down the phrenic nerve to stimulate more inspiratory muscles (sternocleidomastoid, pectoralis minor, scalenes) to increase depth and rate of breathing
How do the sympathetic and parasympathetic nervous systems play a role in PV?
Sympathetic - will prepare body for exercise so will increase breathing rate
Parasympathetic - lower breathing rate
What is the role of baroreceptors during exercise?
Detect a change in blood pressure before sending information to the RCC to increase breathing rate during exercise
What is the role of proprioreceptors during exercise?
Detect an increase in muscle movement and provide feedback to the RCC to increase breathing rate during
What is the order for neural/chemical control for increased inspiration during exercise?
Receptors ➡️ medulla oblangata ➡️ phrenic nerve ➡️ inspiratory muscles
What is the order for neural/chemical control of expiration during exercise?
Receptors ➡️ medulla oblangata ➡️ intercostal nerve ➡️ expiratory muscles
How does smoking affect oxygen transport?
Carbon monoxide from cigarettes combines with haemoglobin in red blood cells much more readily than oxygen (higher affinity) - reduces the oxygen carrying capacity of blood
What are some damaging impacts of smoking?
Irritation to the trachea and bronchi
Reduces lung function and increases breathlessness by swelling and narrowing of the lung’s airways
Damages cilia (causes a mucus build up)
Damages alveoli
Can cause COPD (chronic obstructive pulmonary disease) due to a reduction in the efficiency of gas exchange
