Gas Exchange in Respiration Flashcards
what is the tidal volume
the volume breathed in and expired.
how do gases move along pressure gradients
downward. from high to low
on average, how many ml/min of oxygen are consumed
250
on average, how many ml/min of carbon dioxide are expired
200
what is the partial pressure of oxygen
150mmHg
is partial pressure of oxygen in the blood greater before going into the lungs are after
after
what do pressure gradients show
the direction of movement of oxygen and carbon dioxide in the respiratory system
what is the partial pressure
pressure a gas exerts in a particular environment, taking into account if the environment is wet or dry
what must the sum of partial pressures of a gas be equal to
total pressure
what do pressure changes in the environment depend on
weather patterns and the time of day
what is barometric pressure
the pressure outside the body
what is the equation to calculate partial pressure
fraction of the gas in the gas mixture times by the barometric pressure
what is the pressure of water vapour in the body
47mmHg
how many ml of air breathed in per breath on average at rest
500ml
how many ml of air remains in the airways after expiration
150ml
describe the respiratory tree
trachea
bronchi
non respiratory bronchioles
respiratory bronchioles
alveolar ducts
what happens at each division of the respiratory tree
increase in number, an increase in surface area
do the conducting airways participate in gas exchange
no
what are the respiratory airways
bronchioles with the alveoli where gas exchange occurs, from the terminal bronchioles to the alveoli
what is a respiratory unit
basic physiological unit of the lung consisting of respiratory bronchioles, alveolar ducts and alveoli
how many alveolar sacs in average adult
300-400 million
describe alveoli
polygonal
type 1 and type 2 epithelial cells
what feature of alveoli encourages gas exchange the most
its close connection with capillary networks
describe type 1 epithelial cells in alveoli
97% of surface area of alveoli.
primary site of gas exchange
describe type 2 epithelial cells of the alveoli
septal cells
3% surface area
produce pulmonary surfactant (this reduces surface tension)
alveolar macrophages remove debris
describe the key features of alveolar
large surface area of 100m2
very thin walls
good diffusion characteristics
what are the blood supplies of the lungs
pulmonary circulation
bronchial circulation
describe pulmonary circulation
brings deoxygenated blood from the heart to lung and oxygenated blood from lungs to the heart and then the rest of the body