Excretory System

Osmoregulation

This is the balancin the uptake and loss of water and solutes

Osmosis

process by which water enters and leaves cells

Osmolarity

unit of measurement for solute concentration

moles of solute per liter of solution (mOsm/L)

what is the unit for osmolarity

200 mOsm/L - Blood; 1000 mOsm/L

What are some common osmolarity values?

Osmo-conformers

Composed of mostly marine animals, all are iso-osmotic

Osmoregulators

They expend energy to control water uptake or loss

Marine Invertebrates - osmo-conformers; Marine Vertebrates - osmoregulators

The difference between marine invertebrates and vertebrates

By drinking almost no water

How do freshwater animals maintain water balance?

Anhydrobiosis

What adaptations do animals have that go into a dormant state when water is lost in the surroundings?

Amonia, Urea, and Uric acid

What are the different nitrogenous wastes?

Filtration, Reabsorption, Secretion, and Excretion

What are the functions of the excretory system?

Filtration

Filtering of body fluids

Reabsorption

reclaiming valuable solutes

Secretion

adding of non-essential solutes and wastes to the filtrate

Excretion

processed filtrate containing nitrogenous wasts is released from the body

Protonephridia

a network of dead-end tubules connected to an external opening; Ex. Flatworms

Flame Bulb

cap at the end of the tubules in Protonephridia

Metanephridia

consist of tubules that collect coelomic fluid and produce dilute urine for excretion; Ex. earthworm

Malpighian Tubules

removes nitrogenous wastes from hemolymph in insects and other terrestrial arthropods

Kidneys

main excretory organs of vertebrates

Salt, Glucose, Amino acids, Vitamins, Nitrogenous wastes, and other small molecules

What does the filtrate from the Bowman's capsule contain?

Proximal tubules -> Loop of Henle -> Distal Tubule -> Collecting Duct

What is the pathway of filtrate?

Proximal tubules

site for reabsorption of ions, water, and nutrients

Descending Limb of Loop of Henle

Reabsorption of water via aquaporins

Ascending Limb of Loop of Henle

filtration of remaining salts

Distal tubule

Regulates K+ and NaCl concentration of body fluid

Collecting Duct

Reabsorbs solutes and water

Yes

Is urine hyperosmotic to body fluids

Dry Environment - Longer loops of Henle; Fresh water - short loops

The difference between mammals in a dry environment and fresh water

Antidiuretic Hormone (ADH) or Vasopressin

What regulates the osmolarity of our blood?