urinary system

urinary system functions

1. maintain osmotic balance

2. remove waste

nephron — filtration

fluid from the blood enters the glomerulus into the bowman’s capsule

filtrate is most concentrated

nephron — reabsorption

certain filtrate components are returned from the nephron to the body

nephron — secretion

transfer of substances from the blood to the nephron to be excreted

passive transport

movement of substances from high to low concentration

does not require ATP

diffusion, facilitated diffusion, osmosis

active transport

movement of substances from low to high concentration

requires ATP

A. bowman’s capsule

B. proximal convoluted tubule

C. loop of Henle (descending & ascending)

D. distal convoluted tubule

E. collecting duct

proximal convoluted tubule

reabsorption of water, salt, and glucose

secretion of waste (hydrogen, ammonium)

descending loop of Henle

water reabsorption due to hypertonic interstitial fluid

ascending loop of Henle

salt reabsorption due to hypertonic filtrate

aquaporins

channels that regulate transport of water

found in descending loop of Henle

distal proximal tubule

reabsorption of water and salt

secretion of wate (hydrogen, ammonium)

collecting duct

reabsorption of water and salt

controlled by hormones