Osmoregulation, Excretion, and Circulatory Systems

Vocabulary flashcards related to osmoregulation, excretion, circulatory systems, and plant transport mechanisms.

Osmoregulation

The process of balancing the uptake and loss of water and solutes in organisms.

Osmoconformers

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

Osmoregulators

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

Nitrogenous wastes

Byproducts of the breakdown of proteins and nucleic acids, which vary among animals as ammonia, urea, or uric acid.

Ammonia

Highly toxic nitrogenous waste excreted mainly by aquatic animals, requiring large amounts of water for excretion.

Urea

Less toxic nitrogenous waste excreted by most terrestrial mammals, requiring less water than ammonia for excretion.

Uric acid

Relatively nontoxic nitrogenous waste excreted by insects, land snails, and birds, often as a paste to minimize water loss.

Nephron

The functional unit of the kidney, organized for stepwise processing of blood filtrate.

Filtration

The process of filtering body fluids in the excretory systems to form urine.

Reabsorption

The process of reclaiming valuable solutes from filtrate in the excretory systems.

Secretion

The process of adding nonessential solutes and wastes to the filtrate in excretory systems.

Excretion

The process of releasing processed filtrate, containing nitrogenous wastes, from the body.

Antidiuretic hormone (ADH)

Hormone that regulates water balance by increasing water reabsorption in kidney collecting ducts.

Renin-angiotensin-aldosterone system (RAAS)

Hormonal system that regulates blood pressure and fluid balance in the body.

Atrial natriuretic peptide (ANP)

Hormone that opposes the RAAS by inhibiting renin release and Na+ reabsorption.

Closed circulatory system

A type of circulatory system where blood is confined to vessels distinct from interstitial fluid.

Alveoli

Small air sacs in lungs where gas exchange occurs.

Hemoglobin

Respiratory pigment in red blood cells that binds oxygen for transport.

Transpiration

The process by which water is absorbed by plant roots and evaporates from leaves.

Stomata

Pores on the leaf surface that regulate gas exchange and water loss.

Phloem

Type of plant tissue that transports sugars from sources to sinks.

Xylem

Type of plant tissue that transports water and minerals from roots to shoots.