transport in animals Flashcards
what does the respiratory system transport
air
what does the circulatory system transport
blood
steps of the circulatory system
- ventilation (bulk flow)
- diffusion at the respiratory surface
- circulation (bulk flow)
- diffusion into tissues to the mitochondria
what equation is used to describe the factors that affect the rate of diffusion across a respiratory system
Fick Equation
partial pressure
the pressure due to each gas in a mixture of gases
for gases we must think in terms of ____ gradients rather than ____ gradients
partial pressure, concentration
pressure gradients ____ flow, resistance ____ flow
generate, impedes
gas exchange occurs only at the…
alveoli
which parts of the lungs are part of the “dead space”
- trachea
- bronchi
- bronchioles
after gas exchange occurs, what is the approximate composition of gases at the alveoli
lower oxygen and higher carbon dioxide than air
the atrium is ___-walled and contracts ___
thin, weakly
the ventricle is ___-walled and contracts ___
thick, strongly
systole phase of cardiac cycle
- contraction
- pressure increases
diastole phase of cardiac cycle
- relaxation
- pressure decreases
valves insure what kind of flow
unidirectional
where are valves located
- at entrance to atrium
- between atrium and ventricle
- at exit of ventricle
why is pressure change in the arteries much smaller than in the heart?
arteries are stretchy
how does the heart ensure blood gets back to the heart despite low pressure in veins
- valves in the veins to prevent backflow
- skeletal muscles help pump blood
as altitude increases, total pressure…
decreases
why do we need hemoglobin
- oxygen is not very soluble in water
- when oxygen is bound to hemoglobin, it no longer contributes to the overall concentration of oxygen in the plasma OR the partial pressure
- allows for more oxygen to dissolve in the plasma
- more oxygen can be carried
