Principles Of Renal Function

Question 1

Fluid and solute balance in body

Answer 1

Water intake + metabolic production = renal production + GI excretion + evaporation

Gain and loss must be equal over time
Positive balance: net increase of substance in the body
Negative balance: net decrease of substance in body
Does not mean concentration inc/dec

Question 2

To evaluate balance

Answer 2

Look at vol and concentration of urine
Kidneys bring tubular fluid close to plasma to allow exchange
Most renal disorders involve problems with filtration, blood flow, tubular flow, or transport

Question 3

Essential structure of a nephron

Answer 3

For every tube there is a blood vessel
Afferent arteriole -> glomerular capillaries -> efferent arteriole -> peritubular capillaries (including vasa recta) -> renal vein

Arterial portal system: each nephron has its own supply, vessels of single nephron are a series system and vascular supplies are in parallel

Question 4

Specialization of glomerular capsule and Bowmans capsule

Answer 4

Favor filtration

Ions, small molecules, and some peptides (plasma w/o protein)

Question 5

Glomerular filtration rate

Answer 5

Amount of fluid that filters is determined by Starling factors

Normal kidney only segment in which net filtration occurs is from glomerular capillaries into Bowmans capsule

Question 6

Controlling solutes and water

Answer 6

Steady state that occurs is not necessarily at the normal or healthy condition, body may be volume expanded or contracted

Width measures volume, height measures osmolarity in Darrow-Yannet diagram
Osmolarity in ICF and ECF same

Question 7

Loss or gain of solutes without change of ECFV produces

Answer 7

Euvolemic osmolarity changes