BIOM2015 Lecture Notes - Lecture 10: Osmotic Concentration, Water Balance, Osmosis
Saturday, 19 May, 2018
Kidney L02
How do we control GFR?
-since lying down and standing up changes our bp and maintaining constant bp is very
important
-heavy exercise increase blood going increase pressure increase production bp
increases maintain we can cause afferent arteriole to constriction becomes narrow
harder to go glomerulus decrease net filtration brings back to normal
Reabsorption
-why do we push everything out kidney and reabsorb it?
-we do not have transporter to deal with foreign substance
-we create electrical gradient from pushing Na+ out using active transport involving
ATP
-We push Na+ out the ECF
-anions can then be reabsorbed through passive diffusion since electrical gradient is
created
-osmotic gradient is build up and H2O can be reabsorbed
Secretion
- wants to reduce concentration
- K+ ion should be low in blood; excitable cells need correct conc. of K+ and Na+ to get
action potential; is found high in ICF e.g. neurones and muscles;it is a hormonal control
from aldosterone in distal and collecting duct
- organic ions
-Hydrogen and bicarbonate important for maintaining pH (too much acidity secrete H
+)
Na/K pump use ATP move molecules across gradient
-against conc gradient; goes through channel which is inserted to luminal membrane;
K+ diffuse to lumen and secrete; using ATP to drive the process and secreted
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Document Summary
Since lying down and standing up changes our bp and maintaining constant bp is very important. Heavy exercise increase blood going increase pressure increase production bp increases maintain we can cause afferent arteriole to constriction becomes narrow harder to go glomerulus decrease net ltration brings back to normal. We do not have transporter to deal with foreign substance. We create electrical gradient from pushing na+ out using active transport involving. Anions can then be reabsorbed through passive diffusion since electrical gradient is created. Osmotic gradient is build up and h2o can be reabsorbed. Hydrogen and bicarbonate important for maintaining ph (too much acidity secrete h. Na/k pump use atp move molecules across gradient. Against conc gradient; goes through channel which is inserted to luminal membrane; K+ diffuse to lumen and secrete; using atp to drive the process and secreted. Transports are not selective; they depending on the charge.
