C2: Functions of respiratory system Flashcards
what are the intercostal muscles?
-group of muscles that are located in between ribs and help move thoracic cavity
what are the external intercostal muscles responsible for?
-forced and quiet inhalation
-raise and expand the chest cavity
what are the internal intercostal muscles responsible for?
-forced exhalation
-they depress the ribs and decrease space in the chest cavity
what is the diaphragm?
-dome shaped sheet of muscle and tendon
-main muscle of respiration
-fibrous tissue that separates thoracic cavity and abdomen
contract- up and out
relaxed- down and in
what is meant by mechanism of breathing?
how it works
if the volume in the TC increases what happens to the pressure?
decreases
whats boyles law?
volume increase= pressure decrease
volume decrease=pressure increase
what happens during inspiration(breathing in) in general?
-volume of TC increases so pressure in lungs decreases.
-Atmospheric air is therefore at higher pressure so air is forced in the body
what happens during expiration(breathing out) in general?
-TC returns to original size
-decrease in volume= increase in pressure
-pressure in lungs is higher than atmospheric air pressure do air is forced out
why does it depend on pressure whether or not air is forced in or out?
because pressure always ‘diffuses’ to where there is less pressure
what do external muscles do?
-pulls the muscle out
what do internal muscles do?
-pull the muscles in
what happens in gas exchange?
-blood becomes oxygenated
-diffusion of oxygen into RBC and removal of CO2
where does gas exchange happen?
in alveoli and capillaries
how are capillaries suitable for gas exchange?
-they are narrow(1 cell thick) and so slow blood flow so gas exchange happens more often
what are the 4 stages of gas exchange?
-Pulmonary Ventilation
-Pulmonary Gas exchange
-Gas transport
-Systemic Gas exchange
what happens during pulmonary ventilation?
oxygen is inhaled into the alveoli
what happens during pulmonary gas exchange?
the oxygen is moved from the alveoli into the capillaries
what happens during gas transport?
oxygen is moved around the body via the blood stream
what happens during systemic gas exchange?
-diffusion of oxygen into working muscle cells and removal of CO2
-O2 molecules bind to haemoglobin which transports in body via erythrocytes.
where does external respiration occur?
-between alveoli and pulmonary capillaries
explain what happens in external respiration
-There is a high concentration of CO2 in the capillaries and a low concentration in the alveoli, so CO2 diffuses into alveoli
-There is a higher concentration of O2 in the alveoli than the capillaries so O2 diffuses into the capillaries
Where does internal respiration occur?
-between systemic capillaries and skeletal muscles
what are the 4 different types of lung volumes?
-tidal volumes
-vital capacity
-residual volume
-total capacity
what is tidal volume?
the amount of air that moves in or out of the lungs with each respiratory cycle.
what happens to the tidal volume as we exercise?
increases bc more air is breathed in
value of tidal volume?
500ml
what is vital capacity?
the maximum amount of air that can be exhaled after maximum inhalation
what happens to vital capacity due to exercise?
-increases from a lot of aerobic respiration leading long term adaptations like more alveoli and capillaries.
-no changes from single sessions tho
value of vital capacity?
5000ml
what is residual volume?
-the amount of air left in the lungs after full exhalation
-But kept slightly inflated
what is the job of residual volume?
to keep the lungs inflamed so they don’t collapse
value of residual volume?
1000ml
what is total capacity?
vital capacity+residual volume= 6000ml
what can be used to help remember the mechanics of breathing?
M-muscles
V-volume
P-pressure
A-air
using MVPA what happens during inspiration at rest?
M-Diaphragm contracts(flattens) and external intercostal muscles contract
V-increase in volume of TC
P-Air pressure in lungs decrease
A-air forced into lungs
using MVPA what happens during inspiration during exercise?
M-diaphragm contracts(flattens) and external intercostal muscles.Latissimus dorsi, Pectoral minor and sternocleidomastoid are contracting
V- increase in volume due to more muscles contracting
P-air pressure decreases
A- air is forced in
using MVPA what happens during inspiration during exercise?
M-diaphragm contracts(flattens) and external intercostal muscles.Latissimus dorsi, Pectoral minor and sternocleidomastoid are contracting
V- increase in volume due to more muscles contracting
P-air pressure decreases
A- air is forced in
using MVPA what happens during expiration at rest?
M-diaphragm relaxes back to dome shape and intercostal muscles relax
V-TC reduces in volume
P-increase pressure in lungs
A-air is forced out
using MVPA what happens during expiration during exercise?
M-diaphragm relaxes and returns to dome shape.Abdominal muscles contract pushing against the diaphragm.Intercostal muscles contract
V-decrease in lung and TC volume
P-increase pressure in lungs
A-air forced out of lungs
what is the diaphragm made up of?
-fibrous muscle tissue and tendons
