Homeostasis
Balancing and rebalancing of physiological processes that maintain stability in the normal internal state of the body in response to disturbance.
Osmoregulators
An organism that is able to adjust their internal osmolarity through excretion and absorption of ion.
Osmoconformers
An organism that does not actively adjust their internal osmolarity and have fluids isotonic to their environment.
Euryhaline
An organism that can tolerate a wide range of salinities.
Stenohaline
An organism that can only tolerate a limited range of osmolarity.
Convection
Transfer of heat by flow of air.
Radiation
Transfer of heat by electromagnetic waves and emission of heat.
Conduction
Transfer of heat by contact with another surface.
Evaporation
Transfer of heat by the change of a substance from a liquid to a gas.
Metabolic water
Water produced inside a living organism through their oxidation of energy-rich materials.
Simple Diffusion
A type of diffusion used by Deuterostome echinoderms to excrete waste via water vascular system across the thin layers of their tube feet and papulae.
Direct Diffusion
A type of diffusion used by Protostome cnidarians with high water contents in their body to excrete waste through their epidermis or gastrodermis.
Contractile Vacuole
A cell structure that is not a true excretory organ but is used for water balance and excretion since many wastes dissolve in water.
Protonephridia
An excretory system common to flatworms and rotifers wherein fluid enters through flame cells and is moved to tubule cells where water and solutes are resorbed. Then, wastes are expelled through excretory pores.
Metanephridia
An open system excretory organ common to annelids and mollusks.
Antennal Glands
An organ located in the head of crustaceans, the end sac collects fluid from the blood.
Malpghian Tubules
An organ located at the juncture of the midgut and hindgut that serves as a site of resorption of important solutes and water.
Archinephros
First form of kidney found in embryo of hagfish. It is the ancestral condition of the vertebrate kidney.
Pronephros
Second form of a kidney that is functional in adult hagfish, some bony fish species, embryonic fishes, and amphibians while for embryonic reptiles, mammals and birds, this is a fleeting form of kidney. Humans start with this.
Mesonephros
Third form of a kidney that is short-term in embryonic lampreys, fishes, amphibians, reptiles, birds and mammals.
Metanephros
Fourth possible form of a kidney developed from Mesonephros that is functional for adult reptiles, birds and mammals. Humans have this kidney.
Opisthonephros
Fourth possible form of a kidney developed from Mesonephros that is functional for adult lampreys, fishes, and amphibians.
Kidney
The principal organ that is retroperitoneal (attached to back of body) and regulates volume and composition of internal fluids.
Nephron
The microscopic functional unit of the kidney that performs filtration of fluids (blood) and electrolyte concentration.
Renal Capsule
Part of a kidney that serves as covering, protection which helps encase the kidney. It is made of fibrous tissues for sheathing.
Cortex
Part of a kidney where most nephrons are located and filtration of blood occurs via the renal corpuscles.
Medulla
Part of a kidney that is located in the deepest portion and functions to control salt and water balance of animals via tubules.
Cortical Nephron
Type of nephron located almost entirely in the renal corpuscle in the cortex. (Superficial). Has a shorter loop of Henle.
Juxtamedullary Nephron
Type of nephron located low in the renal cortex near the medulla. (Deep). Has a longer loop of Henle that extend deeply into the renal medulla
Glomerulus
A ball of capillaries surrounded by Bowman's capsule in the nephron and serves as the site of filtration in the vertebrate kidney.
Peritubular Capillaries
A type of blood vessel associated with the cortical components of the nephron which resorbs water and materials from glomerular filtrate, secretes ions and excess water into proximal convoluted tubule.
Vasa Recta
A type of blood vessel associated with the medullary components of the nephrons. Has a descending and ascending portion.
Descending Vasa Recta
Part of the vasa recta which resorbs sodium chloride and urea into the blood while secreting water.
Ascending Vasa Recta
Part of the vasa recta which secretes sodium chloride and urea into the interstitium while resorbing water.
Renin-Angiotensin System
A system that controls loss of water and sodium as well as concentrating the urine. It is associated with blood pressure regulation by modulating blood volume, sodium reabsorption, potassium secretion, water reabsorption, and vascular tone.
Poikilotherm
Pertains to organisms whose body temperature fluctuates in response to environmental temperature.
Homeotherm
Pertains to organisms whose body temperature is regulated independently of changes in environmental temperature.
Ectothermy
Type of body temperature regulation that relies on behavioral adaptation to exploit temperature changes in the environment. Metabolic heat is lost as quickly as it is gained.
Endothermy
Type of body temperature regulation in which metabolic heat generated is retained to maintain a high stable internal temperature.
Thermogenesis
Generation of internal heat through shivering and non-shivering mechanisms.
Torpor
State of decreased physiological activity in an animal like birds to save energy.
Hibernation
Response to extreme cold in which animals depress their metabolism, cardiovascular and respiratory weight which allows them to survive on stored body fat.
Aestivation
Response to extreme heat in which animals burrow themselves underneath the ground to conserve as much moisture.