Bio Ch. 44

osmoregulators that must obtain water from the environment

reduces water loss compared to other nitrogenous wastes, but requires more metabolic energy to produce

ammonia

The urethra is identified by the letter

renal pelvis....ureter....urinary bladder

Filtrate is formed as fluid is forced through the walls of the glomerulus and, initially, collects in the structure indicated by the letter

renal arteries

cortex

nephron

the insects

useful substances must be selectively reabsorbed

filtration

secretion

sodium chloride, glucose, water and amino acids

more...water

urea (and other nitrogenous wastes)

active transport

ADH secretion, dehydration due to inadequate water intake, sweating, eating salty food

aldosterone release, blood loss, severe diarrhea

diabetes insipidus, alcohol consumption, caffeine consumption

more concentrated urine

collecting duct

regulate water and electrolyte balance in terrestrial vertebrates

renal corpuslce>proximal tubule>loop of Henle>distal tubule>collecting duct

higher pressure in glomerular capillaries than in surrounding Bowman's capsule

renal corpuscle, proximal tubule, and loop of Henle

loop of Henle

ADH causes the collecting duct to increase water reabsorption by the surrounding tissue under conditions of dehydration

solute concentrations and balances the gain and loss of water

movement of water across a selectively permeable membrane

isoosmotic with their surroundings and do not regulate their osmolarity

energy to control water uptake and loss in a hyper osmotic or hypo osmotic environment

gain of water and salt ions from food through mouth; excretion of salt ions from gills; osmotic water loss through gills and other parts of body surface; excretion of salt ions and small amounts of water in scanty urine from kidneys

gain of water and some ions in food; uptake of salt ions by gills, osmotic water gain through gills; excretion of salt ions and large amounts of water in dilute urine from kidneys

salt uptake in gills and water excretion in urine

expend energy to maintain osmotic gradients

seawater in a tidal pool

type of wastes, quantity of waste products

ammonia need access to lots of water

the less toxic urea; produced in the liver and carried to the kidneys

pros: less toxic, requires less water cons: energetically expensive

uric acid

relatively nontoxic and does not dissolve readily in water

energetically expensive produce than urea

uric acid

an animal's evolutionary history, habitat, environment of the animal egg

the animal's energy budget

nitrogenous waste excreted as ammonia

pump out salts to keep tissue at 500 mOsm/L.

solute movement between internal fluids and the external environment

urine by refining a filtrate derived from body fluids

function in both excretion and osmoregulation

salts, glucose, amino acids, vitamins, nitrogenous wastes, and other small molecules

interstitial fluid and then capillaries

secreted into the filtrate

materials to be excreted become concentrated

channels formed by aquaporin proteins

high osmolarity of the interstitial fluid, which is hyper osmotic to the filtrate

salt but not water; filtrate becomes increasingly dilute

K+ and NaCl concentrations of body fluids, the controlled movement of ions contributes to pH regulation

filtrate through the medulla to the renal pelvis

body fluids

conserve water is a key terrestrial adaptation

produced only using energy to transport solutes against concentration gradients

NaCl and urea

filtrate volume decreases but its osmolarity remains the same

the loop of Henle maintains a high salt concentration in the kidney

the osmotic gradient between the medulla and cortex

through the osmolarity gradient, and more water exits the filtrate by osmosis

collecting duct as it traverses the inner medulla

enables the kidney to produce urine that is hyper osmotic to the blood

key to water conservation in terrestrial animals

long loops of Henle

relatively short loops

conserve water by excreting uric acid instead of urea

only optical nephrons but also excrete nitrogenous waste as uric acid

salt in their distal tubules and excrete large volumes of dilute urine

to freshwater fishes

hypo osmotic compared with their environment; their kidneys have small glomeruli and some lack glomeruli entirely; filtration rates are low, and very little urine is excreted

high enough to develop hyper osmotic urine

urea, which is less toxic than ammonia

nervous and hormonal control

permeability of the collecting duct epithelium to water; water osmolarity increases, this triggers the release of ADH, which helps to conserve water

complex feedback circuit that functions in homeostasis

juxtaglomerular apparatus (JGA) to release the enzyme renin

of the peptide angiotensin 2

raises blood pressure and decreases blood flow to the kidneys; stimulates the release of the hormone aldosterone, which increases blood volume and pressure

water reabsorption, but only RAAS will respond to a decrease in blood volume

opposes the RAAS; ANP is released in response to an increase in blood volume and pressure and inhibits the release of renin

the transport epithelium in the ascending loop of Henle is relatively impermeable to water

an increase in aquaporin channels in collect duct