Excretion, osmoregulation, and temperature regulation

Osmosis

Diffusion of water through a selectively permeable membrane

Isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

-eg cytoplasm

Hypertonic solution

A solution in which the concentration of solutes is GREATER than that of the cell that resides in the solution

Hypotonic solution

A solution in which the concentration of solutes is LESS than that of the cell that resides in the solution

Osmoregulation

balance of salt and water in the body

Isosmotic

animals at same total solute concentration as surroundings

hypoosmotic

animal at lower concentration than surroundings

hyperosmostic

animal at higher concentration than surroundings

Osmoconformers

An organism that allows its internal salt concentration to change with the salinity of the surrounding water

stenohaline

animals that cannot tolerate substantial changes in external osmolarity

Euryhaline

animals that can survive large fluctuations in external osmolarity

Hyperosmotic regulator

an aquatic animal that maintains a blood osmotic pressure higher than the osmotic pressure of the water in which it lives

Osteichthyans

bony fish

Chondrichthyans

sharks and rays

-retain urea in blood to raise osmolarity

-isosmotic

Urea

major nitrogenous waste excreted in urine

How is water gained?

it is gained by drinking and eating

How is water lost?

is it lost by evaporation, excretion of wastes

How is water conserved?

is it conserved by concentrated urine and behavioural strategies

ammonia

nitrogenous waste is excreted in the form of ammonia and takes a large amount of water

Uric acid

nitrogenous waste produced by insects, birds, and reptiles

-non-soluable and non toxic

What is the simplest excretory system?

Protonephridia (in flatworms) is the simplest system

Protonephridia

Excretory system consisting of flame cell bundles that remove waste and where diffusion occurs

-present in flatworms

metanephridia

Excretory system of body segments carrying nephridia that manage waste and materials

-present in earhtworms

Nephridia

organs that remove metabolic waste inside metanephridia

what are Antennal glands?

paired excretory organ crucial for osmoregulation (maintaining fluid balance) and nitrogenous waste elimination located in the head of crustations

Malpighian tubules

Excretory system of insects that excrete metabolic wastes into the hindgut and are responsible for osmoregulation. Surround the gut

glomerular filtration (bowman's capsule)

1st step of urine formation, where blood plasma is filtered through the glomerulus, a network of capillaries within the kidney, to remove waste products, excess water, and other substances

-Kidney uses osmolarity to make excretion more efficient

-Osmolarity of kidney affects rate of dissolved solutes (eg middle of kidney higher dissolved solutes)

-Osmotic pressure increases the closer to the center of kidney

Glomerulus

A ball of capillaries surrounded by Bowman's capsule that are responsible for the selective ultrafiltration of plasma and the clearance of small solutes

tubular reabsorption

process of reclaiming water and solutes from the tubular fluid and returning them to the blood

retains:

-amino acids

-glucose

-ions

-water

Tubular secretion

substances are moved from the peritubular capillaries into the renal tubular lumen

-ions are moved

antidiuretic hormone (ADH)

hormone that controls permeability of collecting duct to water

-inhibited by alcohol

Endotherm

metabolism generates heat to maintain a stable body temperature

Ectotherm

Organism's body temperature is dependent on environmental factors