respiratory system Flashcards
describe what happens during inhalation at rest
-external intercostals contract, pulling ribs up and out
-diaphragm contracts and flattens
-thoracic capacity volume increases
-lung air pressure fills below atmospheric air pressure
-air is inhaled
describe what happens during inhalation at exercise
-external intercostals contract more than at rest, pulling ribs up
-recruited the muscles: sternocleidomastoid, scalene and pectoralis major
-diaphragm contracts with more force than at rest
-thoracic capacity volume increases more than at rest
-lung air pressure decreases below atmospheric air pressure more than at rest
-more air is inhaled than at rest
what happens during exhalation at exercise
-external intercostals relax
-internal intercostals and rectus abdominus contract
-diaphragmrelaxes back to dome
-thoracic capacity volume decreases faster than at rest
-lung airpressure increases faster than at rest
-air is forced out faster than at rest
what happens during gaseous exchange at rest (external)
a diffusion gradient is created by there being a high PPO2 in alveoli and low PPO2 in capillaries. Also a high PPCO2 in capillaries and low PPCO2 in alveoli.
what happens during gaseous exchange at rest (internal)
a diffusion gradient is created by there being a high PPO2 in capillaries surrounding muscles and low PPO2 in muscles. Also a high PPCO2 in muscles and low PPCO2 in capillaries surrounding muscles
what happens during gaseous exchange at exercise (external)
a larger diffusion gradient is created by there being a higher PPO2 in alveoli and lower PPO2 in capillaries. Also a higher PPCO2 in capillaries and lower PPCO2 in alveoli.
what happens during gaseous exchange at exercise (internal)
a larger diffusion gradient is created by there being a higher PPO2 in capillaries surrounding muscles and lower PPO2 in muscles. Also a higher PPCO2 in muscles and lower PPCO2 in capillaries surrounding muscles
What is partial pressure
The pressure of a gas tells us how much oxygen is available
Higher O2 in blood means higher partial pressure
What does the disassociation curve describe
How much of the O2 is going to be saturated with haemoglobin in the blood
What happens when the disassociation graph plateaus
Increased partial pressure means a smaller increase in saturation
What is the Bohr shift
haemoglobin has a lower affinity for oxygen at working muscles, giving up oxygen more easily
What determines the direction which the curve shifts on a disassociation graph
An increase in partial pressure of carbon dioxide will shift the curve to the right, whereas a decrease in partial pressure of carbon dioxide shifts the curve to the left.
What affect does the Bohr shift have on the blood
Increases CO2 levels And Decreases pH which causes a reduced affinity of haemoglobin for O2
what is oxyhaemohlobin
haemoglobin carrying oxygen in blood
what is tidal volume
the amount of air breathed in with each normal breath
what muscles are recruited during inhalation during exercise
sternocleidomastoid
scalene
pectoralis major
what muscles are contracted and relaxed during exhalation during exercise
-external intercostals are relaxed
-internal intercostals and rectus abdominus are contracted
what happens during neural control of breathing
chemoReceptors to IC detect chemical changed, baroreceptors detect lung stretch to EC. Inspiratory centre stimulates motor neurones to increase depth of breathing. Phrenic nerve stimulates diaphragm to contract more strongly. Intercostal nerves stimulate external intercostals to contract with more force 5. Recruitment of the Sternocleidomastoid, scalenes, pectoralis minor, internal intercostals, rectus abdominis
what are the receptors in the RCC
inspiratory centre
expiatory centre
what do the receptors sending info to the RCC detect
chemoreceptors- chemical changes
proprioreceptors- movement
thermoreceptors- temp changes
baro receptors- lung stretch
what is the equation for minute ventilation (VE)
VE= frequency x tidal volume
what does VE stand for
minute ventilation
what is the unit for breathing frequency (f)
breath/min
what is the unit for tidal volume (TV)
L/breath
what is the unit for minute ventilation (VE)
L/min
why is resting VE lower for a trained person
as their respiratory system is more efficient which means it’s better at taking oxygen out of the air. this explains why the breathing frequency is lower for the trained person
why is tidal volume greater for a trained person at maximal exercise
as of the strength of the inspiratoire muscles
why is breathing frequency at maximal exercise higher for a trained person
as of the strength of the expiratory muscles like the internal intercostals
what effect does exercise have on the dissociation curve
-curve moves to the right
-haemoglobin at tissues is saturated with oxygen
-the 75% released has dissociated and gone into the muscle
what is the dissociation curve like at rest
-in haemoglobin at resting tissues 75% is saturated with O2
-25% of haemoglobin has given O2 to the tissues(this is dissociation)
-100% of haemoglobin is saturated with oxygen at lungs
what does a decrease in pH do to the oxygen dissociation curve
causes a shift to the right
what does an increase in pH do to the oxygen dissociation curve
causes a shift to the left
what are three factors that mean blood acidity increases
-increase CO2
-increased production of lactic acid
-increased oxygen consumption
how does an increased of temp effect oxygen dissociation curve
causes a shift to the right
bohr shift means that athletes can produce energy at higher intensities… when
aerobically
when does oxygen associate with haemoglobin faster
if other oxygen molecules have done so first
what is the effect of decreases temperature on oxygen dissociation curve
shift to the left
explain the role of the sternocleidomastoid in respiration during exercise
-contraction of sternocleidomastoid during inspiration causes rib cage to move up and out
-relaxation of sternocleidomastoid during expiration allows rib cage to move down
explain how neural control increases heart rate
-inspiration centre stimulates nerves to increase depth of breathing
-phrenic nerve stimulates diaphragm to contract more strongly
-intercostal nerves stimulate external intercostals to contract with more force
-recruitment of sternocleidomastoid, scalene, pectoralis minor
how does the dissociation of oxygaemogkobin affect oxygen diffusion at working muscles during exercise
-Bohr shift takes place
-increase in carbon dioxide so decrease in pH
-causing a reduced affinity of haemoglobin for O2
-so more oxygen available for diffusion to the muscle
