BI 231 - Human Physiology and Anatomy
Homeostasis and Osmosis Study Guide

Compiled by Pat Bowne, Sherry Dollhopf,and Justin LaManna, 2007-11


Human physiology and anatomy deals with the structure and function of the human body. Physiology in particular is the study of how the human body maintains homeostasis. We will begin our study by examining mechanisms of maintaining homeostasis. We will also begin to look at osmosis and membrane transport at the cellular level and how they are important in maintaining body fluid levels.

Before class, make sure you:

Can describe the general structure of eukaryotic cells and their membranes.

Can explain the difference between solutes and solvents

Can define lipids, proteins, and sugars

Tutorials and reading assignment: Review the basics of osmosis by doing the osmosis tutorial and quiz at:

Chapter 1, pages 4-10 (sec. 1.2)
Chapter 6, pages 131-155
What you should know for the assessment:

Be able to explain homeostasis, negative feedback mechanisms, and positive feedback mechanisms.

Be able to DESCRIBE and DIAGRAM the events involved in negative and positive feedback mechanisms.

Be able to USE the concept of osmosis to predict the movement of water and/or solutes across cellular membranes in human physiology examples.

Be able to MODEL the movement of water around the body as solutes move between compartments

Be able to APPLY osmosis to explain specific situations in case studies

Homeostasis and osmosis terms to memorize

Practice Questions

1. ANSWER these questions for a situation in which there is too little water in the blood.
Step 1 Why is it important that blood water content (osmolality) is maintained in a normal range?
Step 2 How could you develop too little water in the blood?
Step 3 How do you think the receptor cells will notice?
Step 4 Where do you think the control center is?
Step 5 What might be the effector that can add water to the blood?
Step 6 How do you think it will add water?
Step 7 When the water has been added, what will happen to the receptor cells? What will the effector do?

2. After Hurricane Rita, doctors were talking about the fear of cholera in New Orleans . Cholera is a disease in which the body pumps electrolytes (ions) into the large intestine, and they are lost in the feces as diarrhea. What will happen to body water? Why?

In the old days, they used to give water to drink to replace the lost water. Is this a good idea or not?

Practice question with example answer

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