respiratory system Flashcards
inspiration - rest
- external intercostals contract
- diaphragm contracts
- ribs + sternum move up and out
- volume of thoracic cavity increases
- pressure in lungs decreases
IC - RCC
inspiration - exercise
- external intercostals, diaphragm, sternocleidomastoid, pectoralis MINOR = contract with MORE FORCE
- ribs + sternum move up and out FURTHER
- thoracic cavity volume increases MORE than at rest
- pressure in lungs decreases MORE than at rest
IC - RCC
expiration - rest
- external intercostals relax
- diaphragm relax
- ribs + sternum move down and in
- thoracic cavity decreases
- pressure in lungs increases
EC - RCC
expiration - exercise
- ex intcost, diaphragm = relax
- internal intercostals + rectus abdominis contract
- ribs + sternum move down and in with GREATER force
- thoracic cavity volume decreases MORE than at rest
- pressure in lungs increases MORE than at rest
EC - RCC
respiratory regulation
- The Respiratory Control Centre (RCC) receives information from the sensory nerves
- sends direction through motor nerves
- to change the rate of respiratory muscle contraction
two centres within RCC:
- Inspiratory centre (IC)
- Expiratory centre (EC)
IC - RCC
Inspiratory centre:
- stimulates inspiratory muscles to contract at rest + during exercise
EC - RCC
Expiratory centre:
- inactive at rest
- BUT will stimulate additional expiratory muscles at rest + during exercise
how is our breathing regulated?
- our breathing frequency increases as we exercise to meet the rising demands for o2 supply + removal of co2
- medulla oblongata - ICC + ECC
- regulated through neural + chemical controls
neural:
- proprioceptors
- thermoreceptors
- baroreceptors
chemical:
- chemoreceptors
medulla oblongata - regulation of breathing
the section of the brain which contains the respiratory control centre
within the RCC there is:
- inspiratory control centre (ICC) = controls rate + depth of inspiration = cr, pr, tr
- expiratory control centre (ECC) = controls rate + deth of expiration - br
chemical control
chemoreceptors (cr):
- detect changes in blood pH in aorta + medulla oblongata
- stimulate ICC to increase inspiration when co2 levels increase + o2 levels decrease
neural control - pr
proprioceptors:
- detect changes in join movement
- stimulate ICC to increase inspiration when moving
neural control - tr
thermoreceptors:
- detect changes in blood temperature which occur during exercise + increase respiratory rate
neural control - br
baroreceptors:
- stretch receptors
= detect stretch of lungs which accompanies exercise
= stimulates ECC to increase expiration
tidal volume
the volume of air inspired or expired per breath (resting, approx. 500ml)
minute ventilation
the volume of air inspired or expired per minute
TV x f (resting, approx 6-7.5l)
tidal volume x breathing rate
breathing rate response to exercise
- breathing rate increases in proportion to the intensity of exercise
- until we reach our max of around 50-60 breaths/ min
- in sub-maximal, steady-state exercise, breathing rate can plateau
- due to the supply of o2 meeting the demand from working muscles
tidal volume response to exercise
- depth of breathing = tidal volume
- TV/ depth of breathing increases initially
- in proportion to exercise intensity at sub-maximal intensities
- then reaches a plateau during sub-maximal intensity
- cus increased BR towards maximal intensities
= doesn’t allow enough time
= requires too much muscular effort for maximal expirations/ inspirations
minute ventilation response to exercise + recovery
response to exercise + recovery is a combo of TV + BR:
VE = minute ventilation
VE increases proportionally with exercise intensity = TV + BR will increase
minute ventilation response to exercise + recovery = SUB-MAXIMAL INTENSITY EXERCISE
during sustained sub-maximal intensity exercise:
- VE will plateau as reach comfortable steady state
= supply meeting demand for o2 delivery + waste removal
minute ventilation response to exercise + recovery = LIGHT INTENSITY EXERCISE
- initial anticipatory rise in VE prior to exercise due to release of adrenaline
- a rapid increase in VE at the start of the exercise due to increased BR + TV to increase o2 delivery + waste removal in line with exercise intensity
- a steady state VE throughout the sustained intensity exercise as O2 supply meets demand
- initially rapid + then more gradual decrease in VE to resting levels as recovery has less o2 demand dramatically reduced
minute ventilation response to exercise + recovery = MAXIMAL INTENSITY EXERCISE
- VE doesn’t plateau as exercise intensity continues to increase
- growing demand for O2 + waste removal which VE must meet
- TV will plateau + further increase in VE is from continues rise in BR
in recovery:
- rapid decrease followed by a slower decrease to resting levels
- BR + TV will decrease = important to do this gradually
- active recovery maintains VE providing the continued need for O2 for aerobic energy production + removal waste products
association
the combining of oxygen with haemoglobin to form oxyhaeomglobin
dissociation
the release of oxygen from haemoglobin for gaseous exchange
how many o2 can haemoglobin carry?
haemoglobin (protein) able to carry 4 o2 molecules
Bohr Shift
the steeper the diffusion gradient, the more readily available o2 dissociates from haemoglobin + diffuses across the membrane due to:
- increased temperature
- increased CO2
- increased lactic acid production
- increased carbonic acid production
