respiratory system Flashcards
(23 cards)
what is the function of the nose
air enters the body through the nostrils
contains many blood vessels close to the surface causing it to be warm
warms and moisten air
lining produces mucus which traps dust and bacteria
contain cilia which waft mucus to throat away from lungs
what is the function of the pharynx
allows air to pass from nose to trachea
also transports food from mouth to oesophagus
what is the function of the epiglottis
small flap of tissue which blocks opening of glottis when food is being swallowed
opens to allow air to enter the glottis
opening at the top of trachea
what is the function of the trachea
long tube which allows air to enter the lungs when breathing in
c shaped rings of cartilage keep the trachea open to allow unobstructed movement of air
function of the bronchus
2 bronchi
left bronchus leads to left lung
right bronchus leads to right lung
allow air to pass from trachea into lungs
contains rings of cartilage
what is the function of the bronchioles
bronchi branch into smaller tubes called bronchioles which get very narrow towards the ends
no rings of cartilage
contain smooth muscle which allow them to widen when needed
what is the function of alveoli
tiny sac like structures at the end of bronchioles
each alveolus is surrounded by a dense of network of capillaries which is needed for gaseous exchange
alveoli are the gaseous exchange surface in humans
numerous alveoli provide large surface for gaseous exchange
about 150 million in each lung
what is the function of the pleural membranes
secrete pleural fluid which lubricates lungs
reducing friction when lungs expand and contract
what is the function of the diaphragm
dome shaped membrane
lungs rest on this membrane
shape is altered during breathing
what is the function of the ribcage
protect the lungs and the other organs within the chest cavity
what is the function of the intercostal muscles
internal and external intercostal muscles are found in pairs between the ribs
antagonistic when one contracts the other relaxes
bring about movement of ribcage needed for breathing
explain the process of gaseous exchange across alveoli
air rich in oxygen enters alveoli during inhalation
deoxygenated blood in capillaries (rich in co2 and low in 02) passes next to alveoli in lungs
higher concentration of o2 in alveoli than o2 in blood causes o2 to diffuse across alveolar wall and capillary wall into blood down its concentration gradient
o2 diffuses into red blood cells which it binds to haemoglobin to form oxyhaemoglobin which is bright red in colour
how is co2 transported out of the lungs
co2 is transported as hydrogen carbonate salts in blood
the low concentration on co2 in alevoli stimulates carbonic anhydrase enzyme in the blood to break down the hydrogen carbonate salts and release co2
co2 diffuses down its concentration gradient out of blood across capillart wall across alveolar wall into alveoli
co2 enters alevoli is then removed from lungs during
list 4 ways in which alveoli adapted for gaseous exchange
thin walls – walls of alveoli are only 1 cell thick making diffusion of gases easy
rich blood supply – each capillary is surrounded by a dense network of capillaries which bring a continuous supply of blood for gaseous exchange to occur
large surface area – there are millions of alveoli in each lung and there are two lungs
this provides an enormous SA for gaseous exchange to take place
moist – there is a lining of moisture inside each alveolus in which gases diffuse increasing efficiency of gaseous exchange
what are the properties of all gaseous exchange surfaces
large surface area
thin
moist
define breathing
physical or mechanical process which involves movements of the ribcage, intercostal muscles, diaphragm and lungs
necessary to bring oxygen into the lungs and remove carbon dioxide from the lungs
what would happen without breathing
no oxygen available for cells to use in respiration and carbon dioxide produced by cells in respiration would remain in the body where it would become toxic to cells
what is breathing in called
inspiration or inhalation
what is breathing out called
expiration or exhalation
compare oxygen in inhaled air and exhaled air
20.93
16.4
compare carbon dioxide in inhaled air and exhaled air
0.03
4.1
compare nitrogen in inhaled air and exhaled air
78
78
compare water in inhaled air and exhaled air
variable
usually higher than inhaled air
