1.2 Respiratory system Flashcards
Explain the term ‘respiration’
Taking in of oxygen and removal of CO2
Identify the pathway air travels when inhaled
Air drawn into the body through the nose, pharynx, larynx, down the trachea, and into left and right bronchus and finally the alveoli.
Describe the structure of an alveoli
Alveoli is designed for gaseous exchange, therefore:
- Walls are one cell thick = short diffusion pathway
- Extensive capillary network = good blood flow
- Large surface area = greater uptake of oxygen
BOG = Big sa, One cell thick, Good blood supply
Explain what is meant by ‘diffusion’
The movement of gas molecules from an area of high concentration to low concentration.
Explain what is meant by the term ‘gaseous exchange’
The movement of oxygen from air into the lungs so it can diffuse into the blood and be transported.
The removal of CO2 from the blood so it can diffuse into the lungs and be expired.
Air is a mixture of gases. Air will always move from an area of high to low concentration via diffusion. The greater the concentration gradient the faster air will flow. For inspiration, the pressure needs to be lower in the lungs than in the atmosphere. For expiration, the air pressure needs to be higher in the lungs than the atmosphere.
Air is a mixture of gases. Air will always move from an area of high to low concentration via diffusion. The greater the concentration gradient the faster air will flow. For inspiration, the pressure needs to be lower in the lungs than in the atmosphere. For expiration, the air pressure needs to be higher in the lungs than the atmosphere.
At rest, approximately how many litres of air is inspired and expired per breath
0.5 litres
Explain the term ‘Tidal volume’
The volume of air inspired or expired per breath
Explain what is meant by Inspiratory and Expiratory reserve volume (IRV & ERV)
IRV: volume of air forcibly inspired after normal breath
ERV: volume of air forcibly expired after normal breath
Explain the term ‘residual volume’ and identify its importance
Residual volume is the volume of air that remains in the lungs after maximal expiration. We can never totally empty our lungs when we exhale as air is needed to prevent the lung from collapsing.
Explain the term ‘minute ventilation’
The volume of air inhaled/exhaled per minute.
What is used to measure the volume of air an individual breaths in and out?
Spirometer
How could diffusion occur at a faster rate?
The steeper the concentration gradient (difference between concentration gradient at high and low areas) the faster diffusion occurs.
What is meant by the term pulmonary ventilation?
Breathing
What factors are involved when it comes to regulating pulmonary ventilation during exercise?
Neural control (brain + nervous system)
Chemical control
Hormonal control
How do poor lifestyle choices natively impact the respiratory system?
Smoking causes irritation of the trachea and bronchi. Causes breathlessness due to swelling and narrowing of the lungs airway. Mucus builds up due to damaging of cilia resulting in smokers cough. Damage alveoli and reduce efficiency of gaseous exchange.
Describe the function of the ‘Cilia’?
Hair like protection to sweep away particles in the lungs
Identify what controls breathing and state its location
Respiratory control centre in the Medulla Oblongata
Describe the process of inspiration
The intercostal muscles contract, raising the ribs up and outwards, while the diaphragm is forced downwards.
Describe the process of expiration
Diaphragm extends upwards and ribs collapse
Identify what the body requires to produce energy?
The body requires a continuous supply of oxygen to produce energy. Oxygen is used to break down food to release energy. Carbon dioxide is produced as a waste product which the body needs to remove.
Identify how lung volumes change during exercise
Lung volumes during exercise:
Tidal volume + increase
Minute ventilation + increase
IRV - decrease
ERV - decrease
Residual volume = stays the same
Briefly explain the pathway taken by oxygen and CO2 during diffusion
Oxygen: alveoli, blood, muscles
CO2: muscles, blood, alveoli
(Reverse order)
What percentage of oxygen makes up air?
21% of oxygen makes up air
Explain what an alveoli is responsible for
Exchanging gas between the lungs and the blood which occurs via diffusion.
Explain what is meant by ‘partial pressure’
The pressure exerted by a gad when it exists within a mixture of gases
Explain what is meant by ‘concentration gradient’
Explains how gases flow from an area of high to low concentration. The steeper/bigger the difference, the faster this occurs.
Oxygen will diffuse into the ___ from the ___ until the ___ pressure is ___ in both
Oxygen will diffuse into the alveoli from the blood until the partial pressure is equal in both
Briefly explain how diffusion occurs at the muscle
The partial pressure of oxygen has to be lower at the muscle than in the blood for diffusion to occur. Oxygen will diffuse from the blood into the muscle until equilibrium is reached.
Describe how neural and chemical regulation of pulmonary ventilation occurs
The nervous system controls pulmonary ventilation through two system: the sympathetic and parasympathetic systems. They have opposite effects as they activate different chemicals.
Sympathetic: prepares the body for exercise which increases breathing rate.
Parasympathetic: lowers breathing rate
Identify where the respiratory centre is located?
Medulla Oblongata in the brain
Identify and explain the areas the respiratory centre consists of
The respiratory centre consists of the inspiratory and expiratory centre.
The inspiratory centre is responsible for inspiration and expiration.
The expiratory centre stimulates the expiratory muscles during exercise.
Describe the function of the inspiratory centre
The inspiratory centre sends nerve impulses via the phrenic nerve to the inspiratory muscles (diaphragm and external intercostals) to cause them to contract. This stimulation acts for around 2 seconds and then impulses stop and passive expiration occurs due to elastic recoil of the lungs.
Describe the function of the expiratory centre
Send signals and stimulates the expiratory muscles during exercise
Describe the process of ‘cellular respiration’
A metabolic reaction that takes place in a cell to obtain energy from fuel (glucose)
During exercise, blood ___ increases due to the increase in the___ concentration of CO2 and production of ___.
During exercise, blood acidity increases due to the increase in the ___ concentration of ___ and production of lactic acid.
Where are chemoreceptors located?
Carotid artery
Describe the function of chemoreceptors
Detect changes in blood chemistry such as an increase in CO2 or lactic acid during exercise. Chemoreceptors send impulses to the inspiratory centre to increase ventilation until blood acidity is back to its normal state.
Chemoreceptors send impulses/information to the inspiratory centre to increase pulmonary ventilation during exercise. What takes place for this information to be acted upon?
The respiratory centre sends impulses down the phrenic nerve to stimulate more inspiratory muscles: scalenes, pectoralis minor. As a result, the rate and depth of breathing increases.
Identify what causes pressure changes within the lungs
The contraction of muscles cause for pressure changes
Identify the muscles being used during the inspiration ventilation phase
Diaphragm, external intercostals, scalenes, pectoralis minor, sternocleidomastoid.
Identify the muscles being used during the expiration ventilation phase
Internal intercostals, abdominals
The nervous system controls pulmonary ventilation through the use of what systems?
Sympathetic and parasympathetic
Describe the function of the respiratory centre
Located in the Medulla oblongata, controls the rate and depth of breathing using both neural and chemical control
Describe the role of the proprioceptors in the regulation of pulmonary ventilation
Chemoreceptor - detects chemical changes in the blood (CO2/lactic acid) to increase breathing rate
Baroreceptor - detects changes in blood pressure to increase/decrease breathing rate
Proprioceptor - detects changes in muscle movement/stretch to increase breathing rate
Briefly explain the pathway taken by neural/chemical control for inspiration
Receptors > Medulla > Phrenic nerve > diaphragm & external intercostals
Identify and explain how hormones regulate pulmonary ventilation during exercise
The hormone Adrenaline acts as a stimulant made in the adrenal gland of the kidney. It is transported in the blood to increase breathing rate. It could be released in anticipation of exercise (just before exercise) to increase oxygen and CO2 exchange.
