Animal Physiology: Osmoregulation and Excretory Systems

Vocabulary flashcards covering osmoregulation, excretory systems, and related concepts in aquatic and terrestrial animals.

Osmoregulation

The regulation of body fluids, including water and electrolyte content in animals.

Aquatic Environment

External environment, which could be water and the salts that are dissolved in water (e.g., lakes, shallow marine scenarios, large rivers).

Tissue Fluid

Fluid found within the bodies of organisms that bathes the cells and allows for the maintenance of homeostasis of electrolytes and fluid.

Diffusion

The process by which solutes move from an area of high concentration to an area of low concentration.

Osmosis

The movement of water from an area of low solute concentration to an area of high solute concentration.

Osmotic Pressure

The pressure generated by the movement of water from one location to another through a semi-permeable membrane due to differences in solute concentration.

Isosmotic

The osmolarity of an organism's internal fluid matches that of the external environment.

Hyperosmotic

An organism has a higher solute concentration internally than its outside environment.

Hypoosmotic

An organism has a lower solute concentration than its external environment.

Hyperosmotic regulators

Freshwater fishes that regulate internal condition even though it doesn’t match the external condition. This involves physiological mechanisms to maintain osmolarity expending energy to regulate ion pumps.

Isoosmotic invertebrates

Ocean invertebrates organisms thought to reflect the ancestral condition. Their osmolarity is the same as ocean water, requiring little energy for osmoregulation.

Recolonization event

Ocean bony fish evolved from freshwater fishes that recolonized to the marine environment. Meaning during the shift into saltwater, the osmolarity remained at .3 to .5 osmolarity

Salt Glands

Specialized glands in marine vertebrates that remove excess salt consumed through their diet. Requires energy-dependent ATP

Brackish Water

The interface where fresh water and marine water mix, resulting in varying salinity levels. Typically found at the mouths of rivers.

Osmotic Conformers

Invertebrates that their internal osmolarity changes with the salinity of the external environment (e.g. marine mussel).

Osmotic Regulators

Invertebrates that can maintain a stable internal osmolarity despite changes in the external environment (e.g. blue crab).

Kidneys

Are the primary organs in the mammalian excretory system. They filter blood, modify filtrate, and produce urine.

Nephron

The smallest functional unit of the kidney responsible for filtering blood and modifying filtrate.

Glomerulus

A network of capillaries within the nephron where blood is filtered under high pressure.

Bowman's Capsule

The structure within the nephron that collects filtrate from the glomerulus.

Proximal Convoluted Tubule

The first region of the nephron tubule where the filtrate passes after being collected by Bowman's capsule.