Histology of tissues Flashcards
The function of Objective lenses
Bends light to magnify the image
What is the Scanning Electron Microscope?
It is used to create a 3D image of a specimen’s surface as a focused beam of electrons is passed over the gold-coated surface.
The collection of electrons to make the image is done by a computer software
Purpose of Sectioning
A microtome is a machine with a thin steel or glass blade used to cut the solidified specimen.
Light Microscopy
This microscopy technique is used to shine light through specimens to examine it.
What are some drawbacks to using TEM?
Requires heavy metal staining/shadowing
Time-consuming and labor-intensive
What are the 2 interacting components in the tissue?
Cells and the Extracellular Matrix (ECM)
What is used to collect/ create an image in TEM?
Fluorescent plate collects the electrons that pass through the ultrathin specimen
What are the two types of electron microscopes?
Transmission Electron Microscope (TEM)
Scanning Electron Microscope (SEM)
What are the Mechanical components in light microscopy?
FaMsLs
Focus adjustments
Mechanical stage
Light source
What is the role of the extracellular matrix?
To support cells and the fluid that transports nutrients to the cells, and carries away their catabolites and secretory products.
Function of condenser
Concentrates the light through the specimen
Purpose of Staining
This is used to visualize structures in the cell easier.
Acidophilic stains are acidic stains that colorize basic (+ve charge or alkaline) structures in the cell
eg. eosin
Basophilic stains are used to colorize acidic (-ve charge)structures in the cell
eg. Hematoxylin
Purpose of mounting
Each section is applied to a glass slide
What is an Electron microscope?
Uses electron beam instead of light to examine specimens and create an image
What is a Transmission Electron Microscope?
It produces 2D images of an ultrathin section by capturing electrons that have passed through it
What is the maximum magnification of the Electron microscope?
150,000 X
What are the 4 major tissue types in adults?
Connective
Muscle
Nerve
Epithelial
What is the resolution of a light microscope?
~0.1 micrometers
(0.1 x 10-6)
What is TEM useful for?
Studying the cells interior
Purpose of clearing
Treatment with Xylene makes the specimen transparent
List steps to prepare a specimen
Fred Designs Clean Ember Sections Mounting Stains
- Fixation
- Dehydration
- Clearing
- Embedding
- Sectioning
- Mounting
- Staining
What are the optical components?
COO
Condenser
Objective lenses
Ocular lenses
Purpose of embedding
Plastics such as paraffin are sometimes used for embedding because they allow thinner sections to be made as they provide support so the specimen isn’t too distorted from cutting.
What is the realistic resolution of the Electron microscope?
2 x 10-9 m or 2 nm
Function of ocular lenses
Further magnifies the image
Purpose of Dehydration
Used to remove any water from the specimen using alcohol baths
Define tissue
A collection of cells with similar function and structure
Purpose of fixation
Alters the chemical composition of the specimen and slows deterioration by treating it with a chemical fixative ie formalin
Protein crosslinking and denaturation may take place
What does resolution mean?
The ability for a lens to reveal two individual points as being separate
