1. Aim: What isAim: What is
homeostasis?homeostasis?
Do Now: On your paper.Do Now: On your paper.
Notes are inNotes are in yellowyellow..

2. Words to know…Words to know…
Maintain – keep up.
Constant – the same.
Internal – inside the body.
Environment – surroundings of the
body.

3. What is Homeostasis?What is Homeostasis?
Body cells work best if they have the
correct
Temperature
Water levels
Glucose concentration
Your body has mechanisms to keep
the cells in a constant environment.

4. What is Homeostasis?What is Homeostasis?
The maintenance of a
constant environment
in the body

5. In Other Words...In Other Words...
The weather report from inside your
body is ALWAYS THE SAME.

6. Controlling body temperatureControlling body temperature
• All mammals and birds maintain a
constant body temperature.
 Human beings have a body
temperature of about 98.6 ºF.
 If your body is in a hot environment
your body temperature is 98.6 ºF
 If your body is in a cold environment
your body temperature is still 98.6 ºF

7. What mechanisms are there toWhat mechanisms are there to
cool the body down?cool the body down?
1. Sweating

8. Sweating
The
skin

9. What mechanisms are there toWhat mechanisms are there to
coolcool the body down?the body down?
2. Enlargement of the blood vessels
 There are capillaries underneath
your skin that expand if hot.
 This brings the blood closer to the
surface of the skin so more heat can
be lost.
 This is why you look red when you are
hot!

10. If the
temperature
rises, the blood
vessel dilates
(gets bigger)
This means more heat is lost from the surface of the skin

11. What mechanisms are there to coolWhat mechanisms are there to cool
the body down?the body down?
3. Panting
Similar to sweating

12. Panting

13. What mechanisms are there toWhat mechanisms are there to
warm the body up?warm the body up?
1.Shrinking of the blood vessels
 The capillaries underneath your skin
get constricted (smaller).
 This takes the blood away from the
surface of the skin so less heat can
be lost.

14. If the
temperature
falls, the blood
vessel constricts
(tightens)
This means less heat is lost from the surface of the skin

15. What mechanisms are there toWhat mechanisms are there to
warm the body up?warm the body up?
1.Goosebumps
 The hairs trap a layer of air next to
the skin which is then warmed by
the body heat
 Does NOT work in humans. Why?

17. • Shivering
 Shaking muscles generate
heat
What mechanisms are there toWhat mechanisms are there to
warm the body up?warm the body up?

18. Wrap-Up!
Turn to the chapter 2 word wall on page 53.
Record at least two “new to you” words that we used in class today.

19. Aim: How doAim: How do
disease and stressdisease and stress
affect homeostasis?affect homeostasis?
Do Now: On your paper.Do Now: On your paper.
Notes are inNotes are in yellowyellow..

20. Controlling Glucose levels
• Your cells also need an exact level of
glucose in the blood.
 This is regulated by 2 hormones from
the pancreas called:
Insulin
Glucagon

21. If there is
too much
glucose in the
blood, Insulin
converts some
of it to
glycogen
Insulin
Glucose in the blood
Glycogen

22. If there is
not enough
glucose in the
blood,
Glucagon
converts some
glycogen into
glucose.
Glycogen
Glucagon
Glucose in the blood

23. DiabetesDiabetes
People with diabetes do not produce
enough insulin.
When they eat food, the glucose
levels in their blood cannot be
reduced.
Diabetics sometimes have to inject
insulin into their blood. They have to
be careful of their diet.

24. The glucose in
the blood
increases.
Glycogen
Glucose in the blood
But there is no
insulin to
convert it into
glycogen.
Glucose
concentration
rises to
dangerous
levels.
Insulin

25. Time
Glucose
Concentration
Meal eaten
Insulin is
produced and
glucose levels
fall to normal
again.
Glucose levels
rise after a
meal.

26. Time
Glucose
Concentration
Meal eaten
Insulin is not
produced so
glucose levels
stay high
Glucose levels
rise after a
meal.

27. Ben’s Bad Day
http://ats.doit.wisc.edu/biology/ap/ho/t1.htm

28. Wrap-Up!
Turn to the chapter 2 word wall on page 53.
Record at least two “new to you” words that we used in class today.

29. Aim: What is the metric
system, and why do we use it?
Notes are in Yellow.
Do Now: On
your paper
30ºC = 86 ºF
35 km = 21 miles

30. What Type of Measurement do
we Normally Use in the USA?
• The “English System”
• Why don’t we use this
system in science?
• Too complicated, no logic

31. How Complicated Is It?
• 12 inches in a foot
• 3 feet in a yard
• 16 ½ feet in a rod
• 120 feet in a furlong
• 2 pints in a quart
• 4 quarts in gallon
• 2 gallons in a peck
• 4 pecks in a bushel

32. WTFudge?
• There is no logic so you can’t
guess the relationship.
• If you want to use the English
System, you have to memorize
the relationships and multiply or
divide to do conversions
• Luckily, the metric system is
MUCH easier!!!

33. How is the Metric
System Easier?
• In the metric system, everything
is based on units of 10.
• Every type of measurement uses
the same beginning prefixes.
• We can do conversions
WITHOUT doing math, just by
moving the decimal point right or
left.

34. What is the Basic
Unit for Length?
Meter abbreviated as m
• How long is a meter?
• A meter is about a yard. (39.37
inches - a yard is 36 inches)

35. What is the Basic
Unit for Volume?
Liter abbreviated as L
• How much is a liter?
• A liter is about a quart.
(1.06 quarts)

36. What is the Basic Unit
for Mass/Weight?
Gram abbreviated as g
• How much is a gram?
• A gram is very light –
about the weight of a
paperclip! (0.035 ounces)

37. • Would a meter stick be good enough
unit to measure a hair?
• No, it’s too big
• If you wanted to measure the
distance from the earth to the sun,
would a meter stick be a good way to
measure the distance?
• No, it’s too short
• Need smaller and larger units
Using the Metric System

38. Use Prefixes to Make Units
Bigger or Smaller
• Centi – what does this mean?
• 1/100 or 0.01 -makes unit smaller
• Milli – what does this mean?
• 1/1000 or 0.001 -makes unit smaller
• Kilo – what does this mean?
• 1000 - makes unit larger

39. Conversions are EASY! Let’s Practice!
• A) 9 0 g = _____ kg
• B) 3.0 L = _____ mL
• C) 5.0 m = _____ cm
0 0 0 0 0 0 0.009.

40. Conversions are EASY! Let’s Practice!
• A) 9 0 g = _____ kg
• B) 3 0 L = _____ mL
• C) 5.0 m = _____ cm
0.0 0 0 0 0 0.009
.0 0 0 0 0 0. 3000

41. Conversions are EASY! Let’s Practice!
• A) 9 0 g = _____ kg
• B) 3 0 L = _____ mL
• C) 5 0 m = _____ cm
0.0 0 0 0 0 0.009
0 0 0 0 0 0. 3000
0 0 0 0 0 0. . 500

42. Wrap-Up!
Turn to the chapter 2 word wall on page 53.
Record at least two “new to you” words that we used in class today.

43. Aim: What are microscopes
and how do we use them?
Do Now: on your paper
Notes are
in RED.

44. Types of Microscopes
Optical Microscope: Uses lenses to
magnify an object.
Dissecting Microscope: Magnifies
objects that are too thick for other
types. Used to look at whole
organisms.
Electron Microscopes: Gets much
higher resolutions. Very expensive
and only used at universities

45. In high school, the
microscope that you will be
using is the optical
microscope.

46. Which type of microscope?
A.
B.
C.

47. Robert Hooke- 1663
Was using a primitive simple microscope –
consisted of a few lenses
Looked at a piece of cork
He saw a bunch of little boxes in the cork
Made up the word “cell” since he thought each
box looked like a room in a monastery
(which were called “cells”)

48. Antony van
Leeuwenhoek- 1673
Ground Lenses together- more efficient than
Hooke
Looked at pond water and saw organisms that he
called “animicules” (tiny animals)
Now we use the word
“microorganisms.”
Was the first
person to observe muscle fibers,
bacteria, sperm cells, and blood
flow in capillaries.

49. Some Things to Remember
NEVER use the course- adjustment knob when
you are on the highest power. You could break
the slide or the microscope!
Microscopic things are measured in microns.
1 millimeter = 1000 microns.
In a microscope, the field of view is flipped.
If your organism moves up, it will move down in
your field of view. If your organism moves
left, it will move right in your field of view.

50. Low Power vs. High Power

51. Body tube
Revolving
Nosepiece
Objective
Lenses
Stage Clips
Diaphragm
Light Source
Ocular
Lens /
Eyepiece
Arm
Stage
Coarse
Adjustment
Fine
Adjustment
Base

52. Wrap-Up!Turn to the chapter 2 word wall on page 53.
Record at least two “new to you” words that we used in class today.

53. Aim: How do we determine how
big an object is when we look at
it under the microscope?
Do Now: Review from yesterday.
Figure A represents a cell as viewed by a student using the 10X ocular
and the 10X objective of a compound light microscope. Figure B
represents the same cell as seen with a different objective. The
magnification of the objective used to observe the cell shown in figure
B is most likely
A. 4X C. 40X
B. 60X D. 100X
Notes are in purple.

54. Magnification
To determine your magnification…you
just multiply the ocular lens by the
objective lens
Example: The ocular is 10x and the
objective is 40x, so 10 x 40 = 400
Object is 400
times larger than
it is in real life.

55. How do we determine the size
of objects under a microscope?
1. Focus your microscope-
make sure that you can
see your slide subject!
2. Take out a CLEAR ruler
with millimeters on it.
3. Place the ruler on top
of your slide.
4. Count how many
millimeters there are in
your field of view.
5. Estimate how big your
object is.

56. Converting from mm to
µm
There are 1000 micrometers (µm) in 1 millimeter (mm)
State how many µm wide the following objects are.
A skin cell is 0.71 millimeters across.
A human hair is 1.45 millimeters across.
A pollen grain is 0.05 millimeters across.
Answers:
710 µm
1450 µm
50 µm

57. How big is this object, in µm?
Our object

58. Internet Activity!!
http://virtualurchin.stanford.edu/microscope.htm

59. Wrap-Up!Turn to the chapter 2 word wall on page 53.
Record at least two “new to you” words that we used in class today.