Concentrating Urine PP#3 Flashcards
What system is a mechanism for controlling blood pressure and fluid volume?
Renin Angiotensin System
A fall in BP releases what?
Renin
Renin converts angiotensinogen into _________?
Angiotensin 1
Where is angiotensin 1 converted to angiotensin 2?
Lungs
What substance converts angiotensin 1 into angiotensin 2?
ACE
Angiotensin 2 is a potent ________?
Vasoconstrictor
How does angiotensin 2 work?
- Directly on kidneys to cause salt and water retention
- Stimulates Aldosterone
What 3 things stimulate the renin angiotensin system?
- Drop in BP
- Drop in fluid volume
- Increase Beta 1
Where is angiotensin made?
Liver
Where is renin made?
Juxtaglomerular apparatus of the Kidney
What 3 things inhibit Renin angiotensin system?
- increase in BP
- Increase in fluid volume
- Decrease in Beta 1
4 components of juxtaglomerular apparatus
- Afferent smooth muscle
- Efferent Smooth Muscle
- Mesangial cells
- Macula Densa Cells
Macula densa cells detect what?
Sodium in the distal tubule
What is the most potent vasoconstrictor known?
Angiotensin 2
5 roles of angiotensin 2
- Vasoconstriction
- Increased aldosterone
- Increased ADH
- Increased thirst
- Feedback inhibition of renin
Aldosterone acts where?
Distal tubules and collecting ducts
2 Aldosterone functions?
Decrease K
Increase Sodium
What does aldosterone stimulate?
Na / K ATPase pump
What is Conn’s syndrome?
Too much aldosterone
What causes Conn’s syndrome?
Aldosterone secreting tumors
Most dangerous effect of Conn’s syndrome
Hypokalemia
What does hypokalemia cause?
Hyperpolarization of nerve and muscle cells
Why is it important to be able to concentrate urine?
Maintain osmolarity for proper cell function
The human kidney can produce a max urine concentration of what?
1200-1400 mosm
