Lecture 1- Regulation of Body Fluid Osmolality Flashcards
Controls of AVP: Nausea
stimulate AVP
Controls of AVP: Atrial Natriuretic Peptide
Inhibit AVP: heart is under too much pressure
Controls of AVP: Angiotensin II
Stimulate AVP
Controls of AVP: Nicotine
Stimulate AVP
Controls of AVP: Ethanol
Inhibits AVP; leads to more water loss
What is osmoreceptor control?
Osmoreceptor control is the receptors that control the release of ADH from the shrinking/swelling of the cell. These osmoreceptors are located in the anterior hypothalamus.
What is the level of osmolarity that the osmoreceptors like to keep themselves at?
275-290 mOsm/kg H20
Remember the two things that control the release of the AVP form posterior pituitary?
osmotic control and blood volume control
What are the low pressure receptors for the blood volume and where are they located?
Low pressure receptors are located in the atrium and the large pulmonary vessels
(pulmonary makes sense because it is on the low pressure right side of the heart)
What are the high pressure receptors for the blood volume ?
Aortic Arch and the Carotid Sinuses
What is the pathway for the control?
receptors–> brainstem–> AVP secretory cells of the supraoptic and paraventricular cells of the hypothalamus–> posterior pituitary gland
What is the after effect of bradykinin on the secretion of AVP?
Bradykinin first lowers the blood pressure which causes the decrease in Blood Pressure. This leads to the release of AVP from the posterior pituitary gland. Later increasing the BP.
What about the effect of histamine on AVP?
Histamine will increase the Blood Pressure and thus change the osmolarity which will cause no secretion/ decreased secretion of AVP.
-Osmoreceptors will swell up!
What effects does AVP on the nephron?
It increases the reabsorption of NaCl in the:
- thick ascending limb of the Henle’s Loop
- distal tubule
- cortical portion of the collecting duct
