A&P Lab 3: The Light Microscope

cytology

study of cells

histology

study of tissues

gross anatomy

structures large enough to see with the naked eye

light microscope

also called optical microscope, uses visible light and lenses to magnify an object

simple microscope

single lens

compound microscope

light passes through a series of lenses; will be used in lab

frame of a microscope

head, arm, base

head

upper part of frame, supports lenses, also called body tube

arm

vertical part of frame, connects head and base

light switch

turns light source on and off

rheostat

adjusts intensity of light, also called light intensity knob

base

bottom part of frame, contains light source

light source

found within the base, illuminates the specimen

before using the microscope...

clean lenses with lens paper, plug in microscope, and make sure rheostat is on its minimum position

ocular lenses

the eyepieces provide upright virtual image, 10x magnification

revolving nosepiece

supports objective lenses, rotates to change objective lens

slide clips

hold slide in place on stage

mechanical stage

platform for slide to sit on

mechanical stage adjustor knob

moves stage forward, back, left, or right

fine focus knob

used for precision focusing

coarse focus knob

raises or lowers the stage

objective lenses

create real upside down image, 4 strengths

scanning lens

4x magnification

low power lens

10x magnification

high power lens

40x magnification

oil immersion lens

100x magnification

condensor

lens below the stage, concentrates light onto the specimen

iris diaphragm

adjusts contrast, opens and closes to regulate the amount of light reaching the condenser

resolution

capability of human eye/device to distinguish finer details of an object

field of view

area of the slide that is visible to you when looking through the microscope

parfocal objectives

need little or no fine adjustment when moving from one to the other objective

when viewing the letter 'e', what was unusual about its appearance?

the letter is upside down and flipped over

when you moved the stage to the right, which direction did the 'e' move?

to the left

when you moved the stage forward, which direction did the 'e' move?

down

wet mount

suspends a specimen in a liquid, usually water or a stain, and covers it with a coverslip

nucleus

contains cell's DNA

cytoplasm

semisolid substance of a cell

trachea

organ in respiratory system

the field of view is largest when the ______ lens is being used

scanning power

plasma membrane

the outer boundary of the cell

resolution of human eye

0.14 mm (140 micrometer)

resolution of light microscope

0.0002 mm (0.2 micrometer)

how to measure field of view

use ruler or stage micrometer

working distance

distance between front objective lens and surface of cover glass, when object is in sharp focus

ocular micrometer

needs to be calibrated with stage micrometer at each magnification

stage micrometer

1 mm scale divided into 100 divisions, each division = 0.01 mm (10 micrometers)