Histology

Question 1

cytology

Answer 1

The study of the structure and function of cells

Question 2

histology

Answer 2

The study of tissues/web. Now encompasses Cytology as the study of microscopic anatomy of cells

Question 3

organology

Answer 3

study of microscopic association of organs

Question 4

pathology

Answer 4

study of diseased/abnormal cells, tissues, and organs

Question 5

Principle of Complementarity of Structure and Function

Answer 5

“function always reflects structure” . physiology always reflects anatomy.

Question 6

levels of structural organization of human body from simple to complex

Answer 6

chemical-> cellular level-> tissue level-> organ level-> organ system level-> organismal level

Question 7

primary tissue types

Answer 7

epithelial tissue, muscle tissue, connective tissue and nervous tissue

Question 8

resolution

Answer 8

the distance that two objects must be separated from each other in order to be distinguished as two distinct objects

Question 9

human eye
light microscope
SEM
TEM
Atomic force microscopy

Answer 9

human eye - 0.2 mm
light microscope- 0.2 micrometers
SEM- 2.5 nm
TEM-0.05 nm/1.0 nm
atomic force microscopy - 50.0 pm

Question 10

Resolution dependent on

Answer 10

1. optical system
2. wavelength light source
3. specimen thickness
4. quality of fixation
5. staining intensity

Question 11

Steps for Light Microscopy

Answer 11

1. Acquire Tissue or cells
2. Fixation
3. Processing
4. Embedding
5. Sectioning
6. Staining

Question 12

Fixation of tissues

Answer 12

fix tissues with a fixative (formalin) in order to stop metabolism, enzyme activity, and to fix proteins. Want to preserve morphology.

Question 13

Processing

Answer 13

1. Dehydration- replace water with alcohol
2. Clearing- clear with xylene (misc. w/ alcohol and paraffin)
3. Infiltration- infiltrate with liq. wax

Question 14

embedding

Answer 14

Orient tissue in cassette in correct orientation w/ liquid wax. Move the tissue from the hot liquid to the cool section so that it can harden

Question 15

Problems with Standard Technique for Light Microscopy

Answer 15

1. Time
2. Solvent dissolves lipids
3. Shrinkage of tissues

Question 16

How to solve time factor

Answer 16

use cryostat to fix the tissue (rapidly freeze). *Can monitor enzymatic activity because proteins are not cross-linked

Question 17

How to avoid dissolving lipids

Answer 17

Need TEM. Perform double-fixation with gluteraldehyde and osmium tetroxide to preserve structure. Os. tetroxide binds to phospholipids

Question 18

shrinkage of tissues

Answer 18

Use TEM: Perform double-fixation and then submerge into liquid plastic rather than wax.

Question 19

Acidic Dyes

Answer 19

carry a net negative charge and bind with eosinophilic cell/tissue components (those with a net positive charge)
Pink. Eosin dye

Question 20

Basic dyes

Answer 20

carry a net positive charge and bind with basophilic cell/tissue components (those that carry a net negative share) Blue. Hematoxylin dye

Question 21

Fluorescence miscroscopy

Answer 21

probe with UV light and emit light of wavelengths that humans can see

Question 22

phase-contrast microscopy

Answer 22

lens system that determines refractive indexes and changes in light speed as light passes through specimen. Can detect speed of light as passes through specimens and produces an indirect image

Question 23

brightfieqld microscopy

Answer 23

light enters through bottom of microscope. Requires stain in order to view specimens

Question 24

histochemistry and cytochemistry

Answer 24

localize cell structures by using enzyme activities and marker compound (use cryostat).

Question 25

immunohistochemistry

Answer 25

can determine location of macromolecule (antigen/protein) with antibody and then secondary antibody