Module 5: Respiratory System Flashcards
what is minute ventilation
amount of air exchanged (in and out) in one minutes
what is alveolar ventilation
amount of tidal volume reaching alveoli
what is perfusion
the supply of blood in the lungs. total volume is 500ml
what happens in the systemic circulation if there is high carbon dioxide
capillaries with high CO2 stimulates arterioles to dilate, increase blood supply to capillaries
what happens in pulmonary circulation when there is high CO2
high CO2 in capillaries stimulates arterioles to constrict, reduce blood supply to capillaries
how is forced different to quiet breathing in terms of muscles involved
only diaphragm contracts in quiet breathing, external (inhalation and internal (exhalation) intercostals also involve in forced breathing
how is forced different to quiet breathing in terms of energy cost
energy cost lower in quiet breathing, fewer muscles used exhalation passive in quiet breathing
in inhalation and exhalation does the atmospheric pressure change
no
what is needed to move air into the lungs (alveolar pressure)
alveolar pressure needs to decrease relative to atmospheric
what is needed for exhalation (alveolar pressure)
alveolar pressure needs to increase relative to atmospheric pressure
how much of the inhaled air reaches the alveoli per breath
tidal volume - airway volume
what happens if minute ventilation increases (O2 and CO2)
increases oxygen intake, increase CO2 excretion
what does O2 do
diffuses into cell, diffuses into mitochondria, used in mitochondria
what does CO2 do
produced in mitochondria, diffuses out, diffuses out of cell
diffusion of gas is proportional to
pressure differences between two areas, surface area, solubility of molecule
which is more soluble CO2 or O2
CO2 more soluble
which has higher pressure CO2 or O2
O2
what is haemoglobin to oxygen
an oxygen carrier/buffer
difference in haemoglobin in arterial and venous
arterial haemoglobin has 4 oxygens while venous usually has 3
when tissues are metabolically active they produce more
CO2, heat, acid
Why is Co2 produced
to break down carbs, fats and to regenerate ATP
what is CO2 carried as in blood
bicarbonate
how is bicarbonate produced
reaction catalysed by carbonic anhydrase in red blood cells. H+ dissociates from H2CO3 to form HCOc-
in tissues what produces ATP and CO2
metabolism
What happens to CO2 in tissues
it diffuses from tissues to blood where most of it is converted to bicarbonate
what happens if H+ is increased (pH decreases)
bicarbonate binds acid to increase pH, then forms water and CO2, increased ventilation removes excess CO2
what happens If H+ decreases (pH increases)
reduced ventilation, increase blood CO2
what receptors detect CO2
central receptors
what receptors detect O2
peripheral receptors
