Unit 3 - Cells and the Human Body: Lesson 1 - Microscopes

A set of vocabulary flashcards covering microscope types, parts, magnification, and proper usage based on the Unit 3 lecture notes.

Microscope

An instrument used to magnify (enlarge) small objects, allowing the observer an extremely close view of minute structures.

Optical (light) microscope

A type of microscope that uses light and a system of lenses to magnify an object; it is easy to use, inexpensive, and can view live specimens at low magnification.

Electron microscope

A powerful microscope that uses electrons rather than light, can magnify up to $1,500,000 imes$, and provides detailed 3D images of surface and interior structures.

$$0.2\,\text{nm}$$

The resolution limit of an optical microscope due to the wavelength of light.

Eyepiece (Ocular)

The part of the microscope you look through at the top; standard versions typically have a magnifying power of $10\times$.

Eyepiece Tube

The part that holds the eyepieces in place above the objective lens.

Objective Lenses

The primary optical lenses on a microscope which range from $4\times$ to $100\times$.

Nosepiece

The rotating part that contains the objective lenses, typically including $4\times$, $10\times$, $40\times$, and $100\times$ objectives.

Coarse Focus knob

The larger knob used for initial focusing of the specimen.

Fine Focus knob

The smaller knob used to achieve high resolution (clear focus).

Stage

The platform where the specimen to be viewed is placed, often moved using mechanical stage knobs.

Stage Clips

Used to hold a slide in place when the microscope does not have a mechanical stage.

Aperture

The hole in the stage that allows light to pass through from below.

Illuminator

The light source typically located in the base of the microscope.

Condenser

A component used to collect and focus light from the illuminator onto the specimen.

Iris Diaphragm

A component that controls the amount of light reaching the specimen.

Condenser Focus lever

A lever moved left to right to control the amount of light from the iris diaphragm.

Magnification

The amount of visual enlargement of an object, expressed as values such as $X2$, $X4$, or $X10$.

Total Magnification

Calculated by multiplying the eyepiece power ($10\times$) by the objective lens power (e.g., $4\times \times 10 = 40\times$).

$$15\,\mu\text{m}$$

The approximate size given for Prokaryotic cells in the size range chart.

$$2\,\text{nm}$$

The thickness of a DNA helix.

Microscope Transportation

To safely move the instrument, the dominant hand holds the arm and the other hand supports under the base.

Starting Settings

The stage should be all the way down and the nosepiece should be turned to the lowest objective lens.