Long term control of BP Flashcards
What are the 3 hormone systems that control plasma volume in the kidney?
Renin-angiotensin-aldosterone system
Antidiuretic factor (ADH, vasopressin)
Atrial natriuretic peptide
Which organ has the biggest long term control/influence on blood pressure?
Kidney
What are the functions of the kidney?
Excretion of waste products Maintenance of ion balance Regulation of pH Regulation of osmolarity Regulation of plasma volume
What does the Na+ transport determine in the kidneys?
The size of the osmotic gradient
What does the permeability of the collecting duct determine?
Whether water follows that osmotic gradient or not
Therefore control how much water is lost in urine/how much retained
What happens to plasma volume when collecting duct is very permeable?
Lots of reabsorption of water to little urine so conserve plasma volume
Where is renin produced?
Juxtaglomular of kindey ( granule cells )
What triggers the production of renin?
- Decrease in distention of the afferent arterioles
- Decreased delivery of Na/Cl through tubule
- Activation of the sympathetic nerves to juxtaglomular
What is the function of renin?
Converts angiotensinogen into angiotensin 1
What is the function of angiotensin converting enzyme?
Converts angiotensin 1 into angiotensin 2
What is the function of angiotensin 2?
- stimulates the release of aldosterone from adrenal cortex.
- Increased release of ADH from pituitary
- Is a vasoconstrictor
What does the release of aldosterone cause in the loop of henle?
An increase in Na reabsorption in the loop of Henle
What does the ADH effect in the collecting duct?
It increases water permeability of the collecting duct
Therefore reduces diuresis and increases plasma volume and increases sense of thirst
It also causes vasoconstriction therefore increasing MAP
What does vasoconstriction increase ?
It increases TPR
What type of feedback system are all 3 hormone systems?
Negative feedback system
