Lecture 12 Flashcards
Dalton’s Law of Partial Pressures
total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture
the partial pressure of each gas is directly proportional to its percentage in the mixture
Henry’s Law
-when a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure
-the amount of gas that will dissolve in a liquid also depends upon its solubility
Solubility and p. pressure of key gases in respiration
CO2 in respiration
Percentage of O2 saturation in various places in the body
Percentage of CO2 in various places in the body
the amount of gas reaching the alveoli
ventilation
the VENOUS blood flow reaching the alveoli
perfusion
in other words, the best perfusion ideally goes to the alveoli that have the best ventilation at any given moment
ventilation-perfusion coupling
if PCO2 in alveoli is high
dilate the bronchioles servicing those alveoli constrict the CO2 loaded blood vessels [arterioles]
if PCO2 in alveoli is low
constrict the bronchioles servicing those alveoli dilate the CO2 loaded blood vessels [arterioles]
In internal respiration, pressure and diffusion gradents are
reversed from external
PO2 in tissues is always _____ than the systemic arterial blood
Lower
BLANK carries oxygen in blood
hemoglobin
Each hemoglobin binds how many oxygen molecules?
4
the hemoglobin-oxygen combination is called
oxyhemoglobin
hemoglobin that has released oxygen is called
reduced or deoxyhemoglobin
when all four hemes of the molecule are bound to oxygen
saturated hemoglobin
when one to three hemes are bound to oxygen
partially saturated hemoglobin
Max saturation of O2 in blood
98%
How much O2 in blood?
20% by volume, 20ml per 100ml of blood.
How much O2 is released as blood flows thru capillaries?
5ml
How much oxugen is unloaded during one systemic circulation?
20-25%
Factors that increase O2 unload from Hb are higher in lungs or tissues?
Tissues
biproduct of RBC metabolism that helps unload Os from Hb
2,3-biphosphoglycerate
can 2,3BPG bind to HbF(etal)?
No
cells metabilizing glucose, ^ CO2 and H+, causing acidosis (v pH), weakening of Hb O2 bond
Bohr effect
Working tissues increase factors that make O2 offloading easier
yes
NO
N2O