A patient has a decrease in blood flow in her kidney.

Question

    Which renal structure detects the decrease in blood flow?  

     Which neurotransmitter will be released? 

     What renal structure will be affected and how?

Answer 1

renal blood flow dynamics is very complex. but to give a basic idea, nephron is basic structure of kidney.

the main regulator of renal flow is renin angiotensin aldosterone system among others.

most important is RAA system ( renin angiotensin aldosterone system ).

when there is low blood flow due to any reason, say blood loss, hemorrhage, etc

nephron, basic unit of kidney, releases renin hormone.

Renin acts on angiotensin 1 produced from lungs and changes it to angiotensin 2.

angiotensin is another hormone that is carried to kidneys where it dilates afferent arterioles (afferent means where blood enters nephron) and constricts efferent arterioles (efferent means where blood leaves kidneys).

so more blood remains in kidneys which maintains blood flow and flomerular filtration rate (ie kidney keeps making urine)

other hormones involved include:

ANP (atrial natriuretic peptide)

BNP (B natriuretic peptide)

they are released by heart in response to increased volume of blood and increased urine production to decrease blood volume.

i will give a brief summary but would recommend the following video, start from 2 minute and 40 seconds. thanks, https://www.youtube.com/watch?v=SrEzYv4M7C0.

if you wanna read, https://www.ncbi.nlm.nih.gov/books/NBK470410/