Kidney overview
What are the main functions of the kidneys?
regulating volume & composition of body fluids, removing metabolic waste, excess water, & electrolytes, control rate of RBC production, regulate BP, regulate calcium absorption
which nephron is most important in production of concentrated urine?
juxtamedullary
What are the two types of control?
intrinsic & extrinsic control
What does ADH do?
antidiuretic hormone increases water reabsorption which increases BP & ADH release
What is the structural/functional unit of the kidney?
Nephron
What are the three main parts of urine formation?
filtration, absorption, secretion
True or false: increased filtration = increased urine output which decreases BP
true
What does ANP (atrial natriuretic peptide) do?
decrease sodium which decreases blood vol. & BP (released in response to increased blood vol. & BP)
The urinary system works closely with what body system?
reproductive system
True or false: glomerular filtration is a passive process, flowing down the concentration gradient
true
Myogenic intrinsic control refers to sensing increases & decreases in?
blood pressure, INC = constrict afferent arterioles restricting blood flow to glomerulus & protect it, DEC = dilation to increase blood flow
what does PTH (parathyroid hormone) do?
Increases calcium reabsorption which allows body to keep more calcium to act on DCT
What are the two classes of nephrons? **bonus, which one makes up 85% of nephron
1. juxtamedullary
2. cortical, 85%
What lines the tubule & senses salt content of filtrate?
Macula Densa
true or false: Neural extrinsic control involves the parasympathetic system & releases ADH
False, sympathetic system, at rest -> blood vessels dilated & autoregulation continues, when symp. driven release norepinephrine & epinephrine to vasoconstrict (INC BP + blood vol., DEC filtration)
What does aldosterone do?
keep sodium to increase BP & decrease potassium (targets collecting ducts & distal DCT-> promoting sythesis of sodium & potassium channels)
what is the proper order of blood flow in kidney arteries?
renal -> segmental -> interlobar -> arcuate -> interlobular
what is the anatomical structure that transports urine out of the body?
urethra
1. direct stimulation by symp. NS
2. stimulation by activated macula densa cells when filtrate NaCl concentration is low
3. reduced stretch of cells in nephron
What does ADH inhibitor do?
allows for more excretion of water