Physiology Review

What is the function of ACE?

Convert Angiotensin I into Angiotensin II

What causes renin secretion?

Low blood pressure or volume, increased beta 1 activation

Will increased Angiotensin II increase MAP?

Yes

Will increased Angiotensin II increase Na+ reabsorption?

Yes

Will increased Angiotensin II increase aldosterone levels?

Yes

What is the purpose of renin

controls formation of angiotensin

What are the 2 types of nephrons?

Juxtamedullary (15%) and Cortical (85%)

What is the most abundant type of nephron?

Cortical

Which nephron is close to the medulla and has a long loop of Henle?

Juxtamedullary

What does the macula densa do?

Sense filtrate flow and send paracrine signals to afferent arteriole

What does activation of the sympathetic nerve fiber do?

Constriction of the afferent arteriole and stimulate renin secretion from juxtaglomerular cells

What do juxtaglomerular cells respond to?

NE, blood pressure, macula densa

Constriction of the afferent arteriole will have what effect on filtration rate?

Decrease

Constriction of the efferent arteriole will have what effect on filtration rate?

Increase

Which two starling forces oppose filtration?

Pbs and πgc

What is the filtered load equation?

GFR x [Plasma]

What is the theoretical equation for excreted load?

Filtered load + secreted - absrobed

What is the measurable equation for excreted load?

Volume x [urine]

If filtered load is greater than excreted load, is it net reabsorption or secretion

Net reabsorption

If excreted load is greater than filtered load, is it net reabsorption or secretion

Net secretion

What effect does caffeine have?

Dilate afferent arterioles

Which starling force is determined by plasma proteins?

πgc

A kidney stone would have what effect on GFR?

Decrease

A urinary tract blockage would affect which starling force?

Pbs