Respiratory system Flashcards
what does the respiratory system consist of?
ventilation, external respiration, internal respiration + cellular respiration
what is ventilation?
breathing air in and out of the lungs
what is external respiration?
gaseous exchange between the lungs and blood
what is internal respiration?
gaseous exchange between the capillaries and body cells
what is cellular respiration?
metabolic reactions that take place in a cell to obtain energy from fuels (glucose)
what is diffusion?
the movement of gas molecules from an area of high partial pressure to an area of low partial pressure
what are the structures of the alveoli and their functions?
-walls are one cell thick= short diffusion pathway
-extensive capillary network= good blood supply to transport gases away
-huge surface area= allows greater uptake of O2
explain the mechanics of breathing, during inspiration at rest and during exercise.
-diaphragm= contracts and is pulled down/flat
-ribcage= moves up and out
-muscles at rest= diaphragm + external intercostals
-muscles during exercise= diaphragm, external intercostals, sternocleidomastoid, scalenes and pectoralis major
-volume= increases
-pressure- decreases
-air= rushes in
explain the mechanics of breathing during expiration at rest and during exercise.
-diaphragm= relaxes and rises to dome-shape
-ribcage- moves down and in
-muscles at rest= diaphragm and external intercostals passively
-muscles during exercise= internal intercostals + abdominals
-volume= decreases
-pressure= increases
-air=rushes out
what is tidal volume?
the volume of air inspired and expired per breath
what is minute ventilation?
the volume of air inspired or expired per minute
== number of breaths per minute X tidal volume
what is inspiratory reserve volume?
the volume of air that can be forcibly inspired after a normal breath
what is expiratory reserve volume?
the volume of air that can be forcibly expired after a normal breath
how does exercise affect lung volumes?
TV= increases as more O2 required so depth of breathing increases
IRV+ERV= decreases as more used up by TV
minute ventilation= increases as more air is inspired/expired per minute to meet O2 demand
residual volume= stays the same
what is a spirometer?
the measurement of volume of air breathing in + out