Chapter 26 Urinary system

what is the function of the urinary system?

it removes waste from your blood in the form of urine

what is the function of kidneys?m

regulates blood ionic composition

blood pH

blood volume

what structures make up the urinary system?

kidneys

renal pelvis

ureters

bladder

urethra

what is a nephron?

a functional unit that consists of the renal corpuscle and real tubule

What are the 2 nephrons?

cortical and juxtamedullary

what are the basic process used by kidneys?

filtration and reabsorption

filtration

uses nephron to filtrate

reabsorption

movement of water and solutes from tubule back to plasma

secretion

water and hydrogen ions pass from the capillaries into the renal tubule

what are the 3 basic functions performed by nephrons?

filtration

reabsorption

secretion

what is the filtration membrane and factors that promote it

glomerular and blood pressure/volume

what are factors that control glomerular filtration?

capillary hydrostatic pressure

Bowmans space oncotic pressure

what is the equation for net filtration?

NFP= GBHP-CHP-BCOP

list 3 types of regulation for GFP

renal autoregulation

neural regulation

hormonal regulation

route for tubular reabsorption

solutes are reabsorbed across the wall of nephron into interstitial fluid

route for tubular secretin

solutes are secreted across the wall of nephron into the filtrate

tubular reabsorption mechanism

osmosis

tubular secretion

active transport and passive diffusion

paracellular

passive fluid leakage between cells

transcellular

directly through the tubule cells

primary active transport

uses ATP like Na and K pump

secondary active transport

driven by ions electrochemical gradient

obligatory water reabsorption

90% water follows the solutes that are reabsorbed

facultative water reabsorption

10% regulated by ADH

what happens during reabsorption in PCT?

water and solutes within PCT are transported into the blood stream causing it to be isomotic

symporters

move substances in same direction

antiporters

move substances in opposite direction

what is a nephron loop ?

something that conserves water for the organism and produces highly concentrated urine

DCT duct

short tubule that regulate extracellular fluid volume and electrolyte homeostasis

collecting duct

collects urine through it to the pelvis through ureters

principal cells

reabsorb Na and secretes K

intercalated cells

reabsorb HCO3 and secretes H

what is the homeostatic regulation of tubular reabsorption and secretion

ADH and aldosterone

5 hormones that affect the extent of Na, Cl, Ca2, and H2o

angiotensin II

ADH

aldosterone

ANP

PTH

dilute urine

osmolarity in the tubule

concentrated urine

osmotic gradient is created

how does ADH affect urine concentration?

high ADH causes concentrated urine and low causes diluted urine

countercurrent exchange

energy is used to create an osmotic gradient that enables reabsorption of water

how does female and male urethras differ?

female is short and male is long

how could kidney functions be evaluated?

blood urea nitrogen

plasma creatine

renal plasma clearance

characters of urine?

pale yellow

odorless

pH of 4.5-8.0

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affects of kidneys with agin

shrunken kidneys

filtering less blood

decreased blood flow