Osmoregulation in Animals

Chapter 44

Osmoconformers vs. Osmoregulators

How does a salmon survive?

Usually osmoregulation uses about 5% of metabolism.

Osmoregulation in extreme saline conditions: up to 30%

Key functions of osmoregulation

Get rid of nitrogeneous wasteWhat are the

advantages/disadvantages of types of waste?

Retain waterHow does the

kangaroo rat survive?

Processes

Filtration

Reabsorption

Secretion

Excretion

Gets rid of waste; yet retains key materials!

Mammalian Excretory System

Functional Unit: Nephron99% of water is

reabsorbed!

1000 L pass through kidney to make 1.5L of urine each day!

Describe how the filtrate changes…

Key Concept: Active transport drives the passive

transport of water

Hormonal BalanceTwo systems:

What is the stimulus for each system?What hormones are involved?How do hormones cause a response?

ADH

RAAS

Reviewing HormonesMini Case Study: Alcohol inhibits ADH. A

college student was binge drinking. The student passed out and friends just figured they’d let him “sleep it off.” Knowing what you know about the feedback and osmoregulation, why is this a bad choice?

Compare and ContrastOsmoregulation in saltwater vs. freshwater fish!

Compare and Contrast the Following Excretory

OrgansName of Structure

Organisms How structure works

Protonephrida

Metanephridia

Malphigian Tubules