respiratory system Flashcards
what happens at inspiration at rest?
its an active process
diaphragm and external intercostal muscles contract
ribs move up and out
volume of thoracic cavity increases
pressure inside lungs decreases
air rushes in
what happens at expiration at rest?
passive process
diaphragm and external intercostal muscles relax
ribs move down and in
volume of thoracic cavity decreases
pressure inside lungs increases
air rushes out
what happens at inspiration during exercise?
still an active process
scalenes, sternocleidomastoid and pectorals major contract as well as the diaphragm and external intercostals
ribs move up and out further
volume increases further
pressure decreases further
air forced in more rapidly
what happens at expiration during exercise?
becomes an active process
internal intercostal muscles and rectus abdomen contract
diaphragm and external intercostals still relaxed
ribs more down and in further
volume decreases further
pressure increases further
air forced out more rapidly
what directly stimulates the RCC?
receptors
what are the two areas of the RCC?
the inspiratory centre and the expiratory centre
what does the inspiratory centre do?
it sends impulses to stimulate nerves
which nerves stimulate which muscles from the RCC?
intercostal nerve, stimulates the external intercostal muscles to contract.
phrenic nerve, stimulates the diaphragm to contract
what happens at rest in the inspiratory and expiratory centre?
the inspiratory centre sends impulses.
the expiratory centre is inactive during rest as expiration is passive process at rest
what does the inspiratory centre do during exercise?
increases stimulation of the diaphragm and external intercostals. also stimulates the additional muscles (scalenes, sternocleidomastoid, pectoralis major). increased force of contraction and depth of inspiration.
what happens in the expiratory centre during exercise?
it stimulates internal intercostals, rectus abdominals and obliques. causes a forced contraction which reduces the duration of inspiration.
where does internal respiration occur?
in muscle tissue and capillary
where does external respiration occur?
in the alveoli and capillary
what is particle pressure (PP)?
the pressure that one gas will exert within a mixture of gases
whats the process of the respiratory system (5 parts)?
nasal cavity to the
trachea to the
bronchi to the
bronchioles to the
alveoli- where gaseous exchange occurs
what’s the process of internal respiration?
PP of oxygen is high in the capillary and low in the muscle so goes down the PP gradient from capillary to muscle
PP of CO2 is low in the capillary and high in the muscle therefore goes down the PP gradient from the muscle to capillary
what’s the process of external respiration?
PP of oxygen is low in the capillary and high in the alveoli so travels down the PP gradient then to left atrium
PP of CO2 is high in the capillary and low in alveoli so travels down the PP gradient then to the lungs and then expired
what’s breathing rate (f)?
the number of times you breathe per minute
what’s tidal volume (TV)?
volume of air inspired and expired per breath
what’s minute ventilation (VE)?
volume of air inspired and expired per minute
how can you work out minute ventilation (VE)?
VE=TV x f
what’s the resting breathing rate for an untrained athlete?
12-15 breathes/min
what’s the maximal breathing rate for a untrained athlete?
40-50 breathes/min
what’s the resting breathing rate for a trained athlete?
11-12 breathes/min
what’s the maximal breathing rate for a trained athlete?
50-60 breathes/min
what’s the resting tidal volume for an untrained athlete?
0.5L
what’s the maximal tidal volume for an untrained athlete?
2.5-3L
what’s the resting tidal volume for a trained athlete?
0.5L
what’s the maximum tidal volume for a trained athlete?
3-3.5L
what is the resting minute ventilation for an untrained athlete?
6-7.5L/min
what’s the maximal minute ventilation for an untrained athlete?
100-150L/min
what’s the resting minute ventilation for a trained athlete?
5.5-6L/min
what’s the maximal minute ventilation for a trained athlete?
160-210L/min
what happens to external respiration during exercise?
-skeletal muscles are using a greater amount of oxygen and therefore creating a large amount of CO2 as a bi-product
-deoxygenated venous blood returning to the right atrium has a high PP of CO2 and low PP of oxygen
-alveolar air has a high PP of oxygen and low PP of CO2
-creates a steeper PP gradient for both oxygen and CO2 at the alveoli-capillary membrane resulting in quicker and greater gaseous exchange
-also ensures haemoglobin is fully saturated
what happens to internal respiration during exercise?
greater oxygen dissociation in muscle tissues during exercise is required to increase the supply to the working muscles
-oxygen dissociation curve shifts to the right
what is the bohr shift?
oxygen-haemoglobin dissociation curve shifts to the right during exercise
what are the 3 factors that have an effect at shifting the dissociation curve to the right?
- increase in blood and muscle temperature
- decrease in pH within the muscle
- increase in PP of CO2
what does the oxygen-haemoglobin dissociation curve inform us about?
that amount of oxygen that has saturated haemoglobin
what is saturates/ associated haemoglobin?
haemoglobin that is fully bound or loaded with oxygen
what is dissociation?
oxygen unloading from haemoglobin
what happens to breathing rate during exercise?
-increases in proportion to exercise until we reach our maximum
-will plateau during sub-maximal exercise due to the supply of oxygen meeting the demand from the working muscles
what happens to tidal volume during exercise?
-initially increases in proportion to exercise intensity at sub maximal intensities up to 3L
why does tidal volume plateau at sub maximal exercise?
because breathing intensity increases to maximal values so doesn’t allow enough time and requires too much muscular effort for maximal inspirations or expirations
what is anticipatory rise caused by?
hormonal action of adrenaline stimulating the RCC
how does minute ventilation change during exercise?
-rapid rise due to neural stimulation of the RCC for f and TV increases
-in sub maximal exercise, VE plateaus which represents steady state exercise as demands are being met
what happens to minute ventilation once exercise stops?
-there’s a rapid decrease in VE due to the cessation of proprioreceptors and decreased chemoreceptor stimulation
-there is then a slowing decrease down to resting values
