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

​

​Proper functioning of systems

​

​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!​

Homeostasis

Positive Feedback Loop

This mechanism results, usually, in a permanent change

​

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

​

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

-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

Compare and contrast negative and positive feedback loops

We will:

Understand the process of homeostasis in the human body

I will:

Today's Objectives