exam 1 class 8 Flashcards
(34 cards)
does gas exchange in the lungs move down or up conc. gradient?
down
what happens when arterial blood reaches the tissue capillaries
gradient is reserved
what is the main factor that affects atmospheric oxygen content
altitude
does partial pressure increase or decrease s you go from sea level to higher altitudes
decreases
low alveolar ventilation
hypoventilation
lower than normal values of fresh air in the alveoli and less blood oxygen level
hypoxia
factors affecting alveolar gas exchange
1. oxygen reaching the lungs ->
composition of inhaled air
factors affecting alveolar gas exchange
2. alveolar ventilation ->
- airway resistance
- ability of lung to stretch
- rate and depth of breathing
CNS depression does what ?
slows ventilation rate and decreases depth of breathing
causes of CNS
depression
alcohol poisoning and
drug overdoses
The transfer of oxygen from alveoli to blood requires diffusion across the barrier created by__________________
type I alveolar cells and the capillary endothelium
factors affecting aveolar gas diffusion
3. gas diffusion between air and blood
- surface area
- diffusion distance
- barrier permeability
- concentration gradient
factors that make alveolar gas exchange much harder?
- decrease in amount of alveolar SA available
- increase in thickness of the alveolar capillary exchange barrier
- increase in diffusion distance between the alveolar air space in the blood
factors affecting alveolar gas exchange
4. Adequate perfusion of
the alveoli
how good
is the blood capillary
network
how much of O2 in blood is transported as bound hemoglobin
98%
how much of O2 is transported as dissolved in blood plasma
2%
one hemoglobin molecule has the potential to bind to
4 oxygen molecules
Hemoglobin bound to oxygen is called
oxyhemoglobin (HbO2)
The absolute
concentration of
dissolved gases also
depends on?
the solubility, ⍺, of oxygen
in water
factors affecting alveolar gas exchange
3. gas diffusion between the blood and air
- surface area
-diffusion distance - barrier permeability
- concentration gradient
what gives red blood cells their color
hemoglobin
3 ways carbon dioxide is transported
- cellular respiration (exhaled)
- to much CO2 can alter pH
- to much CO2 can depress CNS function and lead to death
elevated CO2
hypercapnia
pH disturbance by to much CO2
acidosis