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histology (E1 Woods) > Microscopy > Flashcards

Flashcards in Microscopy Deck (25):
1

Who produced the first operational compound microscope with a magnification of 30x

Janssens

2

Who described cork and other cells and introduced the term cell

Hooke

3

What did Bichat do?

recognized 21 kinds of membranes (tissues) but did not use microscope

4

who formed the cell theory

Mirbel, Turpin, Virchow

5

Who came up with the free cell formation theory

Schleiden

6

what is the free cell formation theory

cell is essential unit of the living organism (idea that cells arise by budding from the nucleus)

7

Define refraction of light

bending of light waves

8

what is the equation for refractive index

velocity of light/velocity of light inside transmitting medium

9

what does the degree of bending depend on in optics

Refractive Index
angle at which light strikes surface

10

what is refractive power

measure of how much a lens bends light waves. measures in diopters

11

define focal point

point through which all parallel rays of light will pass after passing through each part of the lens

12

define focal length

distance from the center of the lens to the focal point

13

name characteristics of real image

object is outside focal point
real image is inverted
real image can be projected onto a screen
real image differs in size from the object

14

name characteristics of virtual image

object is placed inside the focal point
virtual image is not inverted
virtual image cannot be projected onto a screen
virtual image can be magnified

15

define resolution

ability of a microscope to distinguish 2 small points as separate points

16

what are the components of a compound optical (light) microscope

light source
condenser
stage
objective lens
ocular lens

17

what are the pros of compound optical (light) microscopes

ability to magnify
ability to resolve structural detail

18

what are the cons of compound optical (light) microscopes

specimen must be thin
relatively little contrast in the unstained specimen

19

what do phase contrast microscopes do

converts phase shifts in light passing through a transparent specimen to brightness changes in the image

20

what is phase contrast microscopes particular useful for examining

unstained cells and tissues
living cells
(used more for research than medical application)

21

what do fluorescence microscopes do

detects molecules that emit light of wavelengths in the visible range when exposed to a UV light source

22

give examples of how fluorescence microscopes are used

detection of antigens or antibodies in immunochemical staining procedures
detection of fluorescent tracers injected into animals or cells

23

what microscope allows for the reconstruction of 3D images

confocal scanning microscope

24

name some advantages of confocal scanning microscopes

very thin optical images of the specimen are created
out of focus images are subtracted from the image by the computer program
computer can make 3D reconstructions of the specimen by stacking individual images

25

what are the components of transmission electron microscopes

cathode
heated tungsten filament
anode
series of electromagnets: condenser lens, objective lens, projection lens
specimen holder
viewing screen and photographic film