Volume Regulation: Renal Mechanism To Adjust pH Flashcards
What is responsible for regulating ECF osmolairty?
What about ECF volume?
What is the same, what is different?
Osmolarity: Hypothalamic osmoreceptors (firing AP), vasopressin secretion, aquaporins in collecting duct, water reabsorption.
Volume: volume sensors, kidney, saves or excretes Na+
Same: Na+ is the principle extracellular solute.
Different: osmolarity of ECF is kept constant, volume of ECF depends on amount of extracellular solute.
Do we have a good pathway to excrete when in excess or retain when in drought? What is the pathway?
When in drought.
What is the rate limiting step of RAAS? (Renin-Angiotensin-Aldosterone System)
Renin.
What enzyme is required to make angiotensin 1 into angiotensin 2?
ACE
What does angiotensin 2 do? (2)
aldosterone stimulates Na+ reabsorption in the
cortical collecting duct by stimulating expression of what two proteins?
What is the opposite pathway of RAAS? Why is it the opposite?
Responds to too much volume.
Increased blood volume causes increased stretch. Which these stretch sensitive cells release ANP.
Comparing ANP and RAAS, how do these systems manipulate:
1. GFR
2. Na+ reabsorption
3. ECF volume
4. Blood pressure
Low blood flow to the kidney increases renin secretion and causes pathological increases in RAAS activity.
What are the two pathology’s we need to know, that make the kidney have low blood flow.
Heart failure causes unhelpful expansion of what? (Why will be a different FC.)
RAAS pathway.
Heart failure, along with many other pathology’s, increase RAAS activity. Why is this bad?
What drugs are a mainstay for treatment of heart failure and hypertension? (2). What activity of what molecule do they block?
Reducing RAAS activity limits proteinuria in chronic kidney disease. Explain how this works.
What other glomerular disorders are treated with drugs that block RAAS? (2 specific, 1 broad)
Define buffer.
buffer: a molecule
that reversibly
binds H+ to resist
changes in the pH
What are buffers in the body?
How is HCO3- (major buffer in plasma) reabsorbed from kidney? 5 steps.
What is the importante reaction taking place in this process?
(What’s the vital enzyme here!)
Where does fine-tuning of acid base regulation occur in the kidney?
What happens in Acidosis?
What happens in Alkalosis?
I’m wrong for innvervating smooth muscle. It’s autonomic nervous system and a parasympathetic neuron.
During bladder filling, sphincters stay ________.
Smooth muscle _______.
Contracts
Relaxes
Urination is a reflex that can be facilitated or inhibited by what?
What reflex initiates “needing to pee”. What fires in response? What stops firing in response?
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