the respiratory system Flashcards
what is respiration
the taking in of oxygen and the removal of oxygen
what does respiration include
ventilation- getting air in and out of the lungs
external respiration- gaseous exchange between the lungs and blood
transport of gases
internal respiration- exchange of gases between the blood in the capillaries and the body cells
cellular respiration- metabolic reactions and processes that take place in a cell to obtain energy from fuels such as glucose
what is the passage of air
nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli
nearly perfectly lobbed the ball back again
- air drawn into body through nose
- passes through pharynx onto larynx, then down to trachea
- into the right and left bronchus
- air moves through each bronchus and they subdivide into secondary bronchi
- get progressively thinner and branch into bronchioles and then respiratory bronchioles
- lead into the alveoli
what are the alveoli responsible for
the exchange of gases between the lungs and the blood, occurs via diffusion
what is diffusion
movement of gas molecules from an area of high concentration to an area of low pressure
structure of alveoli to help gaseous exchange
- one cell thick, thin walls= short diffusion pathway
- big surface area= greater oxygen uptake
- good blood supply
what is gaseous exchange
movement of oxygen from the air into the blood and carbon dioxide from the blood into the air
what does the greater difference in pressure mean
the faster the air will flow
- in order to get air into lungs(inspiration), pressure needs to be lower here than in the atmosphere
- to get air out (expiration) air pressure needs to be higher in the lungs than the atmosphere
what will increasing and decreasing the thoracic, chest cavity do
increase =reduce the pressure of air in the lungs
decrease= increase the pressure of air in lungs, forcing it out
- muscle contractions causes this
what are the muscles used during inspiration at rest and during exercise
rest:
- diaphragm
- external intercostals
during exercise:
- Pectoralis minor
- sternocleidomastoid
- scalenes
- external intercostals
- diaphragm
what are the muscles used in expiration at rest and during exercise
rest:
- passive: diaphragm and external intercostals just relax
during exercise:
- internal intercostals
- abdominals
what happens to the ribcage and diaphragm wen inhaling and exhaling
inhaling:
ribcage moves upwards and outwards, diaphragm contracts and is pulled flat
exhaling:
ribcage falls, diaphragm relaxes and rises to dome-shaped position
what is lung volumes
movement of air into and out of the lungs
what is tidal volume
volume of air breathed in or out per breath
increase during exercise
what is the formula to calculate minute ventilation
number of breaths (per min) x tidal volume = minute ventilation
minute volume = volume of air breathed in or out per minute
big increase during exercise
what is inspiratory reserve volume
volume of air that can be forcibly inspired after a normal breath
decrease during exercise
what is expiratory reserve volume
volume of air that can be forcibly expired after a normal breath
slight decrease during exercise
why will exercise have an effect on these volumes
becuase more oxygen is required so our depth of breathing increases, meaning tidal volume increases becuase we are using more of our inspiratory reserve volume and expiratory reserve volume
wht is residual volume
the amount of air that remains in the lungs after maximal expiration
can never totally empty our lungs becuase there is still some air in the alveoli, bronchi, trachea as these are held open permanently by rings of cartilage
remains the same during exercise
how can volume of air we breathe in and out be measured
using a spirometer
spirometer trace
tidal volume is the small middle bit
expiratory is from tidal volume to residual
vital capacity is from expiratory to inspiratoy
insoiratory is from big lines from tidal volume
when does minute ventilation change
more demanding the physical activity is, the more breathing increases to meet the extra oxygen demand
gaseous exchange at the alveoli
partial pressure of oxygen in alveoli is higher than partial pressure in capillary blood vessels
becuase oxygen has been removed by the working muscles so its concentration in the blood is lower ans therefore so its partial pressure
difference in partial pressure is concentration/diffusion gradient
bigger the gradient, faster diffusion will be
oxygen diffuses from the alveoli into the blood until the pressure is equal in both
diffusion pathway of oxygen
alveoli –> blood –> muscles
diffusion pathway of carbon dioxide
muscles –> blood –> alveoli
gaseous exhange at the muscles
partial pressure of oxygen has to be lower at the tissues than in the blood for diffusion to occur
lower partial pressure allows oxygen to diffuse from the blood into the muscle until equilibrium is reeached
partial pressure of carbon dioxude in blood is lower than in the tissues so diffusion occurs and carbon dioxide moves into the blood to be transported to the lungs
what are the 3 factors involved in the regulation of pulmonary ventilation during exercise
- neural control
- chemical control
- hormonal control
what is pulmonary ventilation
breathing
neural control
involves brain and nervous system
works with chemical control to regulate breathing
when blood acidity is high, brain is informed and send impulses through nervous system to increase breathing
chemical control
blood acidity
works with neural control to regulate breathing
impact of poor lifestyle choices in respiratory system : smoking
- cause irritaion of the trachea and bronchi
- reduces lung function and increases breathlessness caused by swelling and narrowing of the lungs airways
- cigarette smoke damages the cells lining the trachea, bronchi and bronchioles
- cilia are damaged mucus cannot be pushed out so builds up in lung passages= smoker cough
- smoking can damage alveoli as their walls break down and join together forming larger air spaces than normal
- reduces efficiency of gaseous exchange
- increase risk of COPD (chronic obstructive pulmonary disease)
- affects oxygen transport as the carbon monoxide from cigarettes combines with haemoglobin in red blood cells much more readily than oxygen
- reduces oxygen carrying capacity of the blood, increases breathlessness during exercise
sympathetic nervous system
prepares body for exercise
increse breathing rate
parasympathetic nervous system
lower brathing rate
where is the respiratory centre located
in the medulla oblongata
controls rate and depth of brathing and uses nearul and chemical control
what happens if there is an increase in concentration of carbon dioxude
stimulates respiratory centre to increase respiratory rate
two parts in respiratory centre
inspiratory centre= inspiration and expiration
- sends impulses via phrenic nere to inspiratory muscles to cuase them to contract
expiratory centre = expiratory muscles during exercise
inspiratory centre
barorecptors- detect decrease in blood pressure
chemorecpetors- detect increase in blood acidity
propriorecpetors- detect an increase in muscle movement
stretch receptors- prevent over-inflation of lungs by sending impulses to expiratory centre
respiratory centre
phrenic nerve- disaphragm and external intercostals= increase breathing rate
intercostal nerve- abdominals and internal intercoastals= increase expiration
order of neural/chemical control for insoiration
receptors–medulla-phrenic nerve-disphragm and external intercotals
order of neural/chemical control for expiration
receptors-medulla-intercostal nerve- abdominals and internal intercostals
hormonal regulation of pulmonary ventilation during exercise
adrenaline made in adrenal f=gland, transported in the blood and effects nervous system
just before exercise brain sends impulse to the adrenal gland which pump adrenaline into the b;ood in the anticipation of increased need for oxygen and carbon dioxide exchange. breathing rate increases in preparation for exercise and demnad to take in more oxygen and remove more carbon dioxide
