BIO 3302 Lecture Notes - Lecture 21: Metabolic Alkalosis, Respiratory Acidosis, Rainbow Trout
15 Dec 2016
School
Department
Course
Professor
POP
AVT goes up (non
-
mammalian ADH) reabsorption of water from distal tubule
-
Water uptake across pelvic patch
-
Bladder reabsorption and reduce filtration at glomerulus
-
A frog becomes dehydrated ( blood osmo rises) hat is the hormonal response? What responses are triggered by hormone?
Accumulate lactic acid that’s released into blood stream and caused metabolic acidosis
-
Sim effect in diving animals when recovering from anaerobic dive.
○
pH changes with addition of acid in blood
-
Walls of stomach secrete acid
○
Can also have alkalosis
-
CO@ levels go up and get acid respiradosis bc interact with water and release H+ and increase pH
-
Respiratory alkalosis by hyperventilating, increase O2 intake.
-
Recall CO2+ H2O HCO3-+ H+
•
Respiratory compensation
–
adjustments of PCO
2
(via breathing)
•
Metabolic compensation
–
direct adjustments of H
+
and/or HCO
3-
(via gills, kidney or skin)
•
To correct an acidosis ([H
+
] too high)
•
Compensation for acid
-
base disturbances
-
ACID BASE DISTURBANCES
Co2 levels fall when breathing a lot
Blowing off co2 and lowering proton
levels and brief alkalosis.
LEC 19
-
Acid Base Balance
November 24, 2016 1:14 PM
ANIMAL PHYS Page 1
“Blow off” CO
2
: CO
2
HCO
3
-+ H+= hyperventilating (lowering H+ levels)
○
Accumulate HCO
3-
and/or excrete H
+
○
To correct an acidosis ([H
+
] too high)
•
Retain CO2: CO2 HCO3-+ H+
○
Excrete HCO
3-
and/or accumulate H
+
○
To correct an alkalosis ([HCO
3
-
] too high)
•
Increase pH, respiratory acidosis
Excrete bicarbs via urine to compensate
No low o2 levels driving you to breathe.
□
Decrease breathing?
The hyperventilation experienced by a human at high altitude
○
Metabolic alkalosis
Vomiting and lose acid in stomach, make more acid and add to stomach
Constant addition of bicarbs to body
To fix:
Prolonged, severe vomiting (hint
–
acid is added to the stomach in digestion)
○
Respiratory acidosis
Will slow breathing, accumulate CO2
Increase ventilation but high o2 stimulus so not likely
□
Correction: acid secreting cells
Exposure of a rainbow trout to hyperoxic water (high O
2
water)
○
Describe the acid
-
base disturbance caused by each of the following situations as (1) an acidosis or alkalosis and (2)
metabolic or respiratory. How could each one be corrected?
•
Acid
-
base disturbances
–
a bit of practice
-
Differ in reliance on respiratory compensation
•
Differ in primary organ for metabolic compensation
•
Alter ventilation
○
During acidosis, HCO
3
-
is retained by enhancing HCO
3
-
reabsorption by the nephron
□
Rely on HCO
3-
adjustment via the kidney
○
Tetrapod's
•
•
Compensation for acid
-
base disturbances: tetrapod's vs fish
-
ANIMAL PHYS Page 2
Water breathers tend not to use respiratory compensation and rely on metabolic at gill
-
Kidney is supporting role
-
Co2 in animals already very low bc envt low o2 levels
•
Breathe a lot and body co2 levels very low
•
Increase vent, not much room to further lower co2, so rely on metabolic•
Metabolic occurs through acid secreting MEC and base secreting MR cell also for cl uptake.
•
Gill more impt in metabolic compensation.
-
They can be in conflict.
•
Na uptake can interfere with lowering basicity.
•
Maintain acid
-
base and ion balance.
-
Why must N
2
be excreted?
-
-
Nitrogenous base of DNA and amino acids
•
N removed to get a carbon skeleton to make other molecules•
Need to get rid of this.
○
Leaves behind n2 which is bad bc forms nh3 which is a neurotoxin
•
Where does n2 come from?
-
NITROGEN EXCRETION
ANIMAL PHYS Page 3
Document Summary
Avt goes up (non-mammalian adh) reabsorption of water from distal tubule. Accumulate lactic acid that"s released into blood stream and caused metabolic acidosis ph changes with addition of acid in blood. Sim effect in diving animals when recovering from anaerobic dive. Co@ levels go up and get acid respiradosis bc interact with water and release h+ and increase ph. Blowing off co2 and lowering proton levels and brief alkalosis. Recall co2 + h2o hco3- + h+ Respiratory compensation adjustments of pco2 (via breathing) Metabolic compensation direct adjustments of h+ and/or hco3- (via gills, kidney or skin) Blow off co2: co2 hco3- + h+ = hyperventilating (lowering h+ levels) Describe the acid-base disturbance caused by each of the following situations as (1) an acidosis or alkalosis and (2) metabolic or respiratory. The hyperventilation experienced by a human at high altitude. No low o2 levels driving you to breathe. Prolonged, severe vomiting (hint acid is added to the stomach in digestion)
