Studied by 2 peoplewhat is the function of this system
to continually supply oxygen and remove carbon dioxide
what are the main parts of the system
air passages, respiratory surfaces and respiratory muscles
describe the nasal cavities
passages line swith ciliated mucosa and have 3 bony shelves (conchi) and senosry neurons
what does ciliated mucosa do
the mucus traps foreign particles and the cilia beat to move the mucus and particles along
what do conchi do
increase surface area of nasal cavities so they can humidify, warm and filter air
describe the pharynx (throat)
the passage from the nasal cavities and mouth to the trachea
it is muscular and lined with mucosa (stratified epithelium)
has 2 upper opens which lead to ear via eustachian tubes
carries food and air
describe the larynx (voice box)
links pharynx and trachea
made of cartilage
vocal cords (flaps of connective tissue) span across it
thyroid attached to it
describe the trachea (wind pipe)
duct from larynx to lungs
c shape cartilage rings keep it open all the time
connective tissue and smooth muscle between rings
lined with ciliated mucosa
describe bronchi
trachea splits into 2 primary bronchi
primary split into secondary then tertiary (27 times total)
narrower bronchi have less cartilage and more smooth muscle
lined with mucosa
describe bronchioles
narrow bronchi tubes which lead to alveolar sacs
only smooth muscle so they can constrict when muscle contracts
describe the lungs
deep in chest cavity
made of alveoli
covered in pleura
describe alveoli
spherical sacs surrounded by simple epithelial and capillaries for gas exchange and have a moist lining
describe pleura
a membrane surrounding the lungs which secretes pleural fluid into the pleural cavity
what brings blood to and from the lungs
pulmonary arteries and veins
describe the steps when we inhale
diaphragm and intercostals contract
chest moves up and out
chest cavity and lung volume increases and pressure decreases
air follows pressure gradient from high outside to low inside
describe steps when we exhale
diaphragm and intercostals relax
chest moves in and down
chest cavity volume decrease and pressure increases
air follows pressure gradient from high inside to low outside
what does pleural fluid do
adheres lungs to cavity wall so they move simultaneously when chest expands or contracts
where does gas exchange occur
between alveolar air and blood in lung capillaries
describe steps of gas exchange
inhaled air containging 02 diffuses from inside alveoli into blood
02 follows concentration gradient from high in air to low in blood
02 chemically combines with haemoglobin
C02 in blood diffuses into alveolar air from blood, following concentration gradient
what must gases do before they diffuse
dissolve in moist film of alveoli
how is the 02 and C02 concentration gradient maintained
the continual flow of blood and breathing
where does 02 go from after diffusing
97% becomes oxyhaemoglobin
3% dissolves in blood plasma
where does C02 go
70% becomes bicarbonate ions (HC03-)
22% becomes carboaminohaemoglobin (HbNHC00H)
8% dissolves in blood plasma
what is the exchangable equation for carbon dioxide
CO2 + H20 → OR <- H2C03 → OR <- H+ + HC03-
Note
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