Renal 8 Flashcards
Effects of Angiotensin 2
Increased Cardiac output
Increased Na+ Reabsorbtion
Thirst
Increased vasopressin secretion
Increased peripheral vasoconstriction
Stimulus: Low blood pressure
Thirst is controlled by
Hypothalamus
What are the sources of increasing thirst
Increased blood osmolarity
Decreased blood volume
Decreased blood pressure
Dry mouth
Behavioural mechnaisms for salt intake
increased aldosterone
increased angiotensin 2
Avoidance behaviours
Helps prevent dehydration
CV system responds
To blood volume and blood pressure
Renal responds to
Blood volume and blood osmolarity
increase osmolarity and increase blood volume
When eating salty popcorn. Ingesting more salt than water. Ingestion of hypertonic saline
How do kidneys resolve increase osmolarity and increased blood volume
By excreting hyperosmotic urine
Increased volume and no change in osmolarity
If salt and water are ingestes equally to isotonic solution
Increase volume and decreased osmolarity
Simply drinking pure water
Kidneys cannot excrete pure water
No volume increased osmolarity
Kidneys created concentrated urine
Thirst is triggered
Eating salt without drinking water, increases ECF osmolarity
No change in volume decreased osmolarity
if you are sweating. can lead to hypokalemia or hyponatremia
Decrease volume Increased osmolarity
Dehydration. due to excessive excersie or sweating or diarrhea
Can result in inadequate perfusion (decreased blood volume) and cell dysfunction
You want to increase water intake
Decrease volume no chnage osmolarity
Hemorrhage
Need blood transfusion
Decrease volume Decrease dehydration
May be due to incomplete dehydration
Dehydration is due to
Decreased blood pressure and increased osmolarity
Dehydration is restored by
- Conserving fluid to prevent additional loss
- Trigger cardiovascular reflexes to incrase blood pressure
- Stimulate thirst so normal fluid volume and osmolarity can be restored
ANP release in stimulated by
Increased blood volume
Renin - angiotensin is stimulated by
Decreased blood volume
Increase in osmolarity
Inhibits aldosterone release
What senses dehydration in CVVCC
Cartoid and aortic baroreceptors
how does CVCC respond to dehydration
Heart rate goes up as SA node controls shifts from parasympathetic to sympathetic.
2. Force of ventricular contraction increases from sympathetic stimulation
3. Sympathetic input to arterioles increases peripheral resistance (Vasoconstriction)
4. Sympathetic vasoconstriction of afferent arterioles in kidney decreses GFR, coserving fluid
5. Increased sympathetic activity at granular cells increases renin seretion
Direcr responses of Low blood pressure
Decreases blood pressure directly decreases GFR
Paracrine feedback at macula densa cells causees granular cells to release renin
Granular cells respond to decreased blood pressure by releasing renin
Decreased blood pressure, and increased osmolarity and increased ang 2 stimulate vasopressin and the thirst centers at hypothalamus
ANG 2 reinforces CV response
Results of blood pressure mechanisms
- Rapid attmept by the CVCC to maintain blood pressure
- Restoration of volume by water conservation and fluis intake
- Restoration of normal osmolarity by decreased na+ reabsorbtion and increased water reabsorbtion and intake
pH of solution
Is a measurement of H+ Concentration