Regulation of Water and Electrolytes

Vocabulary

acid

substance that lowers pH in the blood by increasing the levels of hydrogen ions

base

substance that increases blood pH by removing hydrogen ions

blood filtration

passive process involving the transfer of water and soluble components, such as nutrients, electrolytes, and waste, from the blood into the glomerular capsule of the nephron

buffer

solution that resists changes in blood pH

collecting duct

duct in the kidney that collects the fluid produced by the nephron. This structure determines the final concentration of urine.

cortical nephron

nephron found in the outer region of the renal cortex with a nephron loop that does not descend very far into the renal medulla

distal convoluted tubule

final segment of the nephron where ion concentrations are modified through secretion and reabsorption

electrolyte

chemical that dissociates in water and becomes positively or negatively charged

glomerular capsule

closed, cuplike structure of the nephron where blood filtration occurs

glomerulus

capillary bed located in the kidneys where blood filtration occurs

juxtamedullary complex

point of contact between the end of the ascending limb of the nephron loop and the afferent arteriole. This complex allows self-regulation of the glomerular filtration rate in the renal corpuscle.

juxtamedullary nephron

nephron located in the inner region of the renal cortex containing a nephron loop that descends deep into the renal medulla

nephron

primary structure in the kidney that produces urine by filtering blood and modifying the filtrate

nephron loop

section of the nephron that dips down into the renal medulla and functions to create a concentration gradient in the renal medulla

osmoregulation

process of regulating osmotic pressure of body fluids by controlling the transport of salt and water across cellular membranes

osmotic pressure

minimum amount of pressure applied to a solution that would prevent pure water from entering the solution through a semipermeable membrane

proximal convoluted tubule

segment of the nephron that receives the initial filtrate from the glomerular capsule and modifies the filtrate through the processes of reabsorption and secretion

reabsorption

transport of materials from the nephron into the blood

secretion

transport of a substance from the blood into the nephrons