Osmoregulation and Excretion

Vocabulary flashcards based on lecture notes about osmoregulation and excretion in animals, covering topics such as osmoregulators, osmoconformers, and kidney function.

Osmoregulation

The regulation of solute concentrations and the balancing of water gain and loss.

Osmoconformers

Animals that are iso-osmotic with their surroundings and do not regulate their osmolarity.

Osmoregulators

Animals that expend energy to control water uptake and loss in a hyper-osmotic or hypo-osmotic environment.

Osmolarity

The solute concentration of a solution, which determines the movement of water across a selectively permeable membrane.

Hypo-osmotic

A solution with a lower concentration of solutes.

Hyper-osmotic

A solution with a higher concentration of solutes.

Countercurrent Exchange

The process by which fluids in two adjacent vessels flow in opposite directions, allowing for efficient exchange of substances.

Excretion

The elimination of metabolic wastes from the body.

Transport Epithelia

Epithelial cells specialized for moving particular solutes and water in controlled amounts in specific directions.

Nitrogenous Waste

Nitrogenous breakdown products of proteins and nucleic acids, such as ammonia, urea, and uric acid.

Ammonia

A toxic nitrogenous waste product excreted by many aquatic animals.

Urea

A less toxic nitrogenous waste product excreted by mammals, most amphibians, sharks, and some bony fishes.

Nephron

The functional unit of the mammalian kidney.

Filtration

The process of filtering blood and collecting filtrate in the nephron.

Reabsorption

The process of reclaiming valuable substances from the filtrate and returning them to the body fluids.

Secretion

The process of extracting other substances, such as toxins and excess ions, from body fluids and adding them to the contents of the excretory tubule.

Urine

The fluid that leaves the system and the body after filtration, reabsorption, and secretion.

Homeostasis

The maintenance of a relatively constant internal environment within narrow limits.

Osmosis

The movement of water from a region of higher concentration to a region of lower concentration across a selectively permeable membrane.

Anhydrobiosis

The process where aquatic invertebrates in temporary ponds lose body water and survive in a dormant state.

Kidney

The organ responsible for filtering blood, reabsorbing essential nutrients, and excreting waste as urine in mammals.

Renal Cortex

The outer region of the kidney where nephrons are located.

Renal Medulla

The inner region of the kidney organized into cone-shaped structures called renal pyramids.

Renal Artery

The vessel that carries blood into the kidney for filtration.

Renal Vein

The vessel that carries filtered blood away from the kidney.

Cortical Nephron

A type of nephron with a short loop of Henle primarily located in the renal cortex.

Juxtamedullary Nephron

A type of nephron with a long loop of Henle that extends deep into the renal medulla, important for concentrating urine.

Glomerulus

The initial structure of the nephron where filtration occurs, consisting of a glomerulus enclosed within Bowman's capsule.

Bowman's Capsule

A cup-like structure that surrounds the glomerulus and receives filtrate from the blood.

Proximal Tubule

The portion of the nephron responsible for reabsorbing water, ions, and nutrients from the filtrate.

Loop of Henle

The U-shaped part of the nephron between the proximal and distal tubules; responsible for concentrating urine.

Distal Tubule

The portion of the nephron responsible for further reabsorption of ions and water, helping to maintain pH and electrolyte balance.

Collecting Duct

A duct that collects urine from multiple nephrons and transports it to the renal pelvis.

Peritubular Capillaries

Small blood vessels that surround the nephron tubules and participate in reabsorption and secretion.

Vasa Recta

Specialized capillaries that run parallel to the loops of Henle in juxtamedullary nephrons, helping to maintain the concentration gradient in the medulla.

Urinary Bladder

A temporary reservoir for urine before it is eliminated from the body.

Urethra

The tube through which urine is excreted from the body.

Renal Pelvis

The central collecting region of the kidney from which urine flows into the ureter.

Ureter

The tubes that carry urine from the kidneys to the urinary bladder.

Afferent Arteriole

Blood vessel carrying blood to the glomerulus.

Efferent Arteriole

Blood vessel carrying blood away from the glomerulus.

Marine Fish Osmoregulation

Marine fish perform osmoregulation by drinking water and excreting salt ions through their gills.

Freshwater Fish Osmoregulation

Freshwater fish perform osmoregulation by excreting large amounts of dilute urine and uptaking salt ions through their gills.

Antidiuresis

A condition where the collecting ducts are permeable to water, leading to water reabsorption and concentrated urine.

Diuresis

A condition where the collecting ducts are not permeable to water, leading to water remaining in the filtrate and dilute urine.

Euryhaline

Animals that can tolerate a wide range of salinities.

Countercurrent Multiplication

A process in the loop of Henle where Na+ and Cl- are actively pumped from the ascending loop into the medullary fluid, concentrating the urine.

Solvent

A liquid substance capable of dissolving other substances.