gas exchange Flashcards
relationship of the SA to volume ratio in larger organisms
bigger the organism have a smaller SA to volume ratio
gas exchange of a single celled organism
direct diffusion of oxygen
:very high SA:vol allows absorption through membrane
gas exchanged of ft worm
direct diffusion if oxygen : flat which is a short diffusion distance
b/c SA:vol
gas exchange of small mammal
lungs and circulation
high SA:vol which loses more heat per gram of body
: faster rate of respiration
: move oxygen needed
: to maintain a constant body temp
gas exchange of a large mammal
lungs and circulation
small SA:vol : loses lots of of heat per gram of body
: slower rate of respiration
: uses less of oxygen
what does efficiency of gas exchange systems depend on (3)
high surface area
short diffusion distance
high concentration gradient
how does gas exchange of insects
air enters through spiracles
O2 diffuse down concentration gradient along the trachea
trachea are closely. surrounded by cellsO2 diffuses into cells => ventilation helps to maintain high con gradient (also water loss)
how water loss is reduced in insects
body is covered by a waxy cuticle to reduce evaporation
insects can close spiracles
gas exchange in fish (5)
filaments and lamellae have big SA which increases efficiency of diffusion
thin epithelium => short diffusion pathway
counter current flow = blood and water move in opposite directions which maintains a high conc gradient | water is always next to blood with a lower conc of O2
Circulation of blood replaces blood that is saturated with O2
Ventilation
gas exchange in dicalytlodenous plants
mesophyll is where gas exchange of CO2 for photosynthesis happens and is spongy = large SA
gases diffuse in/out
stomata = gap between 2 guard cells
guard cells can open/close to reduce water loss
gas exchange in xenophobic plants
(adaptations) (5)
curled leaf
stomata in sunken pit as a microenvironment prevents water from making high conc gradient
hairs in epidermis as water vapour buil up which decrease the wat diffusion gradient
thick waxy cuticle as reduces evaporation
fewer stomata
how does stomata open and close
if plant has lots of water= cells are turgid
if plants has little water = cells are flaccid
flaccid guard cells can close stomata
structure of gas exchange in humans
(label)
diffusion distance in gas exchange in humans
alveoli and capillary have thin epithiliums
which mean a short diffusion pathway => fast rate of diffusion
adaptations of efficient gas exchange
high surface area: (about alveoli)
lots of them be have folded membrane
close to many capillaries = fast diffusion
concentration gradient:
ventilation brings in air with high conc of O2 to replace air with low conc
circulation replaces blood high on O2 with blood low on O2
maintains a high conc gradient = fast diffusion
what are the things shown on spirometer trace
tidal volume
volume of air breathed in or out per breath at rest
breathing rate
no. of breaths per minute
pulmonary ventilation
the total volume of air breathed in one minute
oxygen consumption
volume of oxygen used per minute
equation of pulmonary ventilatin
tidal volume * breathing rate
effect of excercise on
a) tidal vol
b) breathing rate
c) pulmonary ventilation
d) oxygen consumption
increase (deeper breath)
increase (faster breath)
increase (breathe more air)
increase (more respiration)
what is inspiration
diaphragm contract => flatttens
external intercostal muscles contract =>rings move up and out
icrease the volume of thorax
decreases the pressure in the thorax
air moves in from high to low pressure
what is expiration
diaphragm relaxes => becomes domed
external intercostal muscles relax => rib cage moves down and in
decreases the volume of htorax
increases the pressure in thorax
air moves out from high to low pressure
