gas exchange Flashcards
(29 cards)
example of cutaneous gas exchange
Salamander
* needs to keep skin moist at all times (limits the environments it can occupy)
* skin is thin, rich in blood vessels, wrinkled to increase surface area
* environments with low oxygen like swamps
* vulnerable to absorbing toxins
properties of gas exchange surfaces
- thin tissue layer
- permeability
- large surface area
- moist
- concentration gradient
adaptations to maintain a steep concentration gradient
- dense network of blood vessels
- continuous blood flow
- ventilation
- mammals can separate oxygenated and deoxygenated blood w double circulatory system
how do fish breathe
- water comes in from mouth
- it gets pushed through a part of gills called filaments
- lot of capillaries around the gills and there gas exchange occurs
double circulatory system
to go around the body once, blood needs to pass heart twice, helps ensure that respiring cells receive highly oxygenated blood
respiratory system parts
nasal cavity
buccal cavity
pharynx
epiglottis
larynx
trachea
bronchus
bronchioles
alveoli
nasal cavity function
allows air to enter respiratory system
* warms air
* filters for pathogens and allergens
buccal cavity function
works with nasal cavity to be the primary filter for pathogens
pharynx role
the throat
air coming in from nose and mouth passes through
epiglottis
a flap of cartilage that covers trachea when swallowing
> prevents food from entering the trachea (henkitorvi)
larynx
a hollow tube that air passes through to enter trachea
* contains vocal cords
trachea
windpipe that carries air to lungs
* produces mucus (traps dust, debris and bacteria)
bronchus and bronchioles
parts of lungs that increase surface area
alveoli and alveolar fluid
alveoli = sacs w large surface area across which oxygen and CO2 are exchanged between air and blood
cells in alveoli = type II pneumocytes - secrete alveolar fluid
* moistens
* reduces surface tension of alveoli (helps prevent collapse during exhalation)
* contains surfactant to which gases can dissolve into before diffusing across alveoli and vessel to blood
inspiration
- diaphragm contracts, out and down
- rib cage up and out as external intercostals contract and internal relax
- thoracic cavity increases
- lung pressure decreases
air moves down pressure gradient into lungs
expiration
- diaphragm relax, up and in
- both muscles relax and rib cage in and down
- thoracic cavity decreases
- lung pressure increases
air moves down pressure gradient out of the lungs
adaptations of mammalian lungs for gas exchange
- alveolar fluid
- highly branched bronchioles
- extensive capillary beds around alveoli
- many alveoli
total lung capacity
the maximum amount of air that can be inhaled
tidal volume
the amount of air that moves in and out in normal ventilation
forced vital capacity
the volume of air that can be forcibly exhaled
residual volume
air remaining in lungs that cannot be exhaled
inspiratory reserve
additional volume of air that can be inhaled after taking a normal breath
expiratory reserve
the additional volume of air that can be exhaled after exhaling normally
factors that can affect lung capacity in humans
age
body composition
sex
respiratory disease
level of exercise
