science homework

Introduction: In biology, a feedback mechanism is a physiological loop that brings the body either toward or away from the normal, steady state. The feedback mechanism, also referred to as a feedback loop, either amplifies a certain biological pathway or inhibits it. These pathways most commonly return the body to homeostasis.

Title: Observing Feedback Mechanisms in Excretion

Aim: To observe excretory feedback control

Apparatus: hormone levels data, pencil, graph paper

Methods/Procedure:

· collect blood hormone level data for a patient who is thirsty
· record their levels of ADH, over a period of time
· discuss the relationship between increase in thirst [over time] and ADH production
· draw a graph to show the levels of ADH in the plasma as thirst increases

Results: ______________________________________________________

Plasma ADH (pg/ml)

Time (mins.)

0.5

0

0.5

1

2

2

4.5

5

5

6

6

7

9

10

11.5

13

Discussion:

· Discuss the function of ADH
· Define osmoregulation
· What is feedback control?
· Why are feedback mechanisms important?
· Discuss negative vs. positive feedback
· What trends do you identify from the graph?
· hints: what is the relationship between thirst and increased ADH? Is this an example of negative or positive feedback?

Conclusion:

ADH Feedback Mechanism ORR

LAYOUT:

All sections of lab completed /1
Methodology [past tense/ passive voice] /1

RESULTS:

Graph cuts more than half the page /1
Graph has appropriate title /1
Axes labeled [w/ units] /1
Suitable intervals /1
Correctly plotted points [1/2 pt. ea.] /4

/10

ADH Feedback Mechanism A/I

DISCUSSION:

Discuss the function of ADH /1
Define Osmoregulation /1
What is feedback control? /1
Why are feedbacks important? /1
Negative vs. positive feedback /2
Identify trends from the graph? /2

CONCLUSION:

Related to the aim /1
Brings closure to the lab /1

/10