Daily Warm-up March 18thCompare the endocrine and nervous systems

HW: -Read 32.3 and 32.4

Turn in:-Test corrections if haven’t already

OsmoregulationProcess by which animals control solute

concentrations in interstitial fluid and balance water gain and loss

Breakdown of nitrogenous compounds creates ammonia (toxic)Excretion- process that rids the body of toxic

metabolites

Osmosis and OsmolarityAll animals need to balance water uptake and

loss

Osmosis?

Osmolarity= total solute concentration expressed as molarity (moles of solute per liter of solution)milliOsmoles per liter (mOsm/L)

SituationsIsoosmotic

Hyperosmostic

Hypoosmotic

Osmoregulatory Challenges and MechanismsOsmoconformer-

*All are marine animals

Osmoregulator-? Allows animals to live in environments

uninhabitable to osmoconformers

Consider Marine vs. FreshwaterMarine environment very dehydrating- what

should happen to the fishWhat about freshwater?

Nitrogenous WastesMost metabolic wastes need to be dissolved in

water to be excreted through the body

Ammonia (NH4+) is toxic because it interferes with

oxidative phosphorylation

Some animals are able to excrete it directly

Others have to convert it to other forms before excretionUrea and uric acid

Ammonia, Urea, or Uric Acid?Ammonia needs lots of water to be tolerated

when releasedAquatic

Most vertebrates need to use urea so as not to lose the amount of water required to release ammoniaVery low toxicity

Uric acid- paste, requires very little water lossLizards, snails, birdsMuch more energetically expensive than urea!

Excretory ProcessMost osmoregulation and removal of

nitrogenous wastes use transport epithelia

Kidney in vertebrates- water balance and blood pressure

Homeostatic Regulation of Kidneys

Nervous and hormonal systems help control

Key hormone: Antidiuretic hormone (ADH)

ADH release increases number of aquaporins in kidney cellsIncrease reabsorption of water

ADH and Dehydration

Blood osmolarity rises from sweating or eating salty foods

Increase in ADH

Increase in aquaporins

Increase in water reabsorption

Concentrated urine bc losing less water

RAAS Renin-

Aldosterone-Angiotensin System

Deals with blood volume when lose a lot