Anatomy Exercise 3 The Microscope

Front 1

Compound Microscope

Back 1

Precision instrument where the magnification is achieved through the interplay of two lenses - the ocular and objective.

Front 2

Objective lens

Back 2

Magnifies the specimen to produce a real image that is projected to the ocular.

Front 3

Ocular lens

Back 3

Magnifies the real image to produce the virtual image that the eye sees

Front 4

Total Magnification

Back 4

Equal to the power of the ocular lens multiplied by the power of the objective lens used

Front 5

Resolution

Back 5

Ability to discriminate two close objects as separate.

Front 6

Resolving Power

Back 6

- Determined by the amount and physical properties of the visible light that enters the microscope

- More light delivered to the objective lens, the greater the resolution

- Size of the objective lens opening decreases with increasing magnification, allowing less light to enter the objective - thus it may be necessary to increase the light at higher magnifications

Front 7

Components of the Miscroscope

Back 7

Base

Substage light

Light control Knob

Stage

Mechanical Stage

Condenser

Iris diaphragm lever

Adjustment Knobs (Coarse and Fine)

Head

Arm

Nosepiece

Objective Lenses

Ocular Lens(es)

Front 8

Base

Back 8

Bottom of microscope. Provides sturdy flat surface to support and steady the microscope

Front 9

Substage light

Back 9

Located in the base. The light from the lamp passes directly upward through the microscope

Front 10

Light control knob

Back 10

Located on the base or arm. Allows you to adjust the light intensity

Front 11

Stage

Back 11

Platform that the slide rests on while being viewed

Front 12

Mechanical stage

Back 12

Holds the stage in position for viewing and has two adjustable knobs that control the precise movement of the slide

Front 13

Condense

Back 13

Small nonmagnifying lens located beneath the stage that concentrates the light on the specimen

Front 14

Iris diaphragm lever

Back 14

Shutter within the condenser that can be controlled by a lever to adjust the amount of light passing through the condenser.

Front 15

Coarse adjustment knob

Back 15

Allows you to make large adjustments to the height of the stage to initially focus your specimen

Front 16

Fine adjustment knob

Back 16

Used for precise focusing once the initial coarse focusing has been complete

Front 17

Head

Back 17

Attaches to the nosepiece to support the objective lens system.

Front 18

Arm

Back 18

Vertical portion of the microscope that connects the base and the head

Front 19

Nosepiece

Back 19

Rotating mechanism connecting to the head that carries 3-4 objective lenses.

Front 20

Objective lenses

Back 20

Attached to the nosepiece. Usually a compound light microscope has four objectives

- Scanning (4x)

- Low Power (10x)

- High Power (40x)

- Oil immersion (100x)

Front 21

Ocular lens(es)

Back 21

Located in the eyepieces at the superior end of the head.

Front 22

Microscope Field

Back 22

- Decreases with increasing magnification

Front 23

Diameter of field A * Total magnification of field A = Diameter of field B * Total magnification of field B

Back 23

How to calculate field diameter?

Front 24

Meter (m)

Centimeter (cm)

Millimeter (mm)

Micrometer (um)

Nanometer (nm)

Back 24

Metric Units of Length

Front 25

10-2 m

Back 25

1 cm =

Front 26

10-3 m

Back 26

1 mm =

Front 27

10-6 m

Back 27

1 um =

Front 28

10-9 m

Back 28

1 nm =

Front 29

Depth of Field

Back 29

- Thickness of the plane that is clearly in focus

- Greater at lower magnifications

- Decreases as magnification increases

Front 30

Wet Mount

Back 30

- A method to prepare cells for viewing under a microscope where the specimen is mixed with physiological saline and stained