Homeostasis

Compare and contrast negative and positive feedback loops

We will:

Understand the process of homeostasis in the human body

I will:

Today's Objectives

Homeostasis in Cells

THE CELL (or plasma) MEMBRANE!

• The cellular (or plasma) membrane is responsible for controlling substances entering and leaving its boundaries.

• Hypertonic, Isotonic, and Hypotonic situations/solutions

• Balance & Equilibrium

• Water soluble and insoluble substance control

Homeostasis

Keeping "normal" conditions for survival

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​Proper functioning of systems

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​Maintaining Equilibrium

Homeostasis

Negative Feedback Loop

​-Nothing bad about this system

​-Simply moves back to a "normal" state

-Ex. If your body temperature rises to 103 degrees (F), and then returns to 98F hours later, that is movement in a "negative" direction...but totally normal!​

Open Ended

What is another example of a "negative feedback mechanism" in your body?

Homeostasis

Positive Feedback Loop

This mechanism results, usually, in a permanent change

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It also is a push to a "completion" of something. Ex. pregnancy

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​It's a change in the SAME direction, unlike NF, whereas the change goes back the other way

Multiple Choice

Which of those examples was a POSITIVE feedback loop?

• The pregnant woman

• Cut on arm

• Blood pressure

• Running a fever

-Detects the change (stimulus)
-Sends information to control center (brain)

-Ex. Your body begins to heat up when you walk outside and its 105 degrees!!

​Receptor

-The reaction to the stimulus from the brain

-You brain sends a response or solution to the effector

-Ex. Walking outside and it's 105 degrees...how does your body respond?

Effector

Homeostasis

Multiple Choice

What would your "control center" be?

• The effector

• your brain

• the receptor

• your immune system

Open Ended

Describe a recent experience you had with homeostasis in the past 24hrs:

Compare and contrast negative and positive feedback loops

We will:

Understand the process of homeostasis in the human body

I will:

Today's Objectives