CH_44_Excretion_and_Osmoregulation_Gibbons-1

Osmoregulation

The balance of uptake and loss of water and dissolved solutes in organisms.

Osmosis

The movement of water down its gradient across a selectively permeable membrane.

Osmolarity

The solute concentration of a solution.

Isoosmotic

Two solutions with the same osmolarity.

Osmoconformers

Organisms that are isoosmotic with their surroundings and do not regulate their osmolarity.

Osmoregulators

Organisms that expend energy to control water uptake and loss in a hyperosmotic or hypoosmotic environment.

Stenohaline

Organisms that can only survive within a narrow range of salinities.

Euryhaline

Organisms that can survive in a wide range of salinities.

Hyperosmotic medium

An environment where the solute concentration is higher than that of the organism's body fluids.

Hypoosmotic medium

An environment where the solute concentration is lower than that of the organism's body fluids.

Excretory Processes

Processes of filtration, reabsorption, secretion, and excretion in excretory systems.

Protonephridia

Excretory organs consisting of a network of tubules that excrete waste and osmoregulate.

Metanephridia

Excretory organs found in many invertebrates that function in osmoregulation.

Malpighian Tubules

Excretory structures in insects that remove waste and conserve water.

Nephron

The functional unit of the kidney involved in filtration, reabsorption, and secretion.

Antidiuretic hormone (ADH)

Hormone that increases water reabsorption in the kidneys during dehydration.

Filtration

The process whereby body fluids pass through structures to remove unwanted material.

Reabsorption

The reclaiming of valuable solutes from the filtrate back into the body.

Secretion

The addition of nonessential solutes and wastes to the filtrate.

Homeostasis

The maintenance of a stable internal environment in an organism.

Aquaporins

Protein channels in cell membranes that facilitate the transport of water.

Urine Concentration

The process by which the kidneys concentrate urine, leading to water conservation.

Filtration Pressure

The hydrostatic pressure that drives fluid and solutes from blood into the renal tubules.

Countercurrent Multiplier

A system in the kidneys that increases the osmolarity of the medulla to enhance water reabsorption.

Proximal Tubule

The segment of the nephron where a majority of solute and water reabsorption occurs.

Loop of Henle

A U-shaped section of the nephron that plays a critical role in urine concentration.

Distal Convoluted Tubule

The nephron segment that further modifies filtrate through secretion and reabsorption.

Collecting Duct

The final segment of the nephron where urine is concentrated and transported to the renal pelvis.

Renal Cortex

The outer region of the kidney involved in processing blood and producing urine.

Renal Medulla

The inner region of the kidney that contains structures involved in the concentration of urine.

Kidney Stones

Solid formations in the kidneys that can cause obstruction and pain during excretion.