W1 - Intro to Histology Flashcards
Does haematoxylin/eosin bind to +ve/-ve tissue components?
Haematoxylin - negative, eosin - positive
Is haematoxylin a basic/acidic dye?
Basic
Is eosin a basic/acidic dye?
Acidic
What 3 -ve things does haematoxylin bind to?
Nuclear chromatin, cytoplasmic RNA, certain extracellular proteins (e.g. cartilage)
What 2 +ve things does eosin bind to?
Most extracellular protein fibres and cytoplasmic proteins
What colour is haematoxylin in a microscope image?
Blue (shows nuclei)
What colour is eosin in a microscope image?
Pink/red (rest of cell)
What tags does immunohistochemistry use to identify proteins?
Antibodies
What colours indicate immunohistochemistry?
Blue and brown
How to tell the difference between HP and LP on a H+E stain?
HP is when you can see the individual cells/nuclei, LP you will see the large sections/general layers of the tissue
What is the difference between what SEM and TEM show?
SEM - outside 3D structures, TEM - inside 2D images
What is the definition of a tissue?
A group of cells that have a similar structure and function
What are the five types of tissue?
Blood, epithelia, nervous, muscle, connective
What is the definition of an organ?
Collection of tissues that perform a specific function together
Nervous, muscular, cardiovascular and skeletal systems are the 4 main systems. What are the other 6?
Lymphatic, urinary, digestive, endocrine, reproductive, respiratory
What does the skeletal system create for the muscular system?
Structure and anchor points for the muscles
What does the nervous system do?
Coordinates bodily functions by creating a communication network
What is the function of the lymphatic system?
Regulates the body’s defences
What does the urinary system do?
Eliminates waste and balances electrolites
Why are the digestive and respiratory systems important?
Provide energy
What is the job of the endocrine system?
Regulates hormones
What is the definition of a system in biology?
Group of organs working together to carry out a function
What is the definition of a cell?
The fundamental unit of human life
What normal look like is…
Histology
What disease looks like is…
Pathology
How normal functions is…
Physiology
Where is the additional magnification in a microscope that’s not always considered?
In the eyepiece (x10)
What is LP and HP on a light microscope?
LP = x4, HP = x40
List the steps of tissue embedding
Dehydration, clearing, infiltration w/ wax
What does clearing tissues with a solvent thats miscible with alcohol and paraffin wax do?
Removes alcohol and allows tissue to be infiltrated with the paraffin wax
What feature of the solvent allows the purpose of clearing to occur?
It is miscible with both the alcohol and the paraffin wax
What stain is used on resin sections?
Toluidine blue
What are the 3 steps after embedding?
Sectioning, mounting, staining
How thick are the sections cut using a microtome?
0.004mm thick (4 micrometres)
What occurs during mounting?
Sections floating on water bath are picked up onto glass slides
What does it mean for a tissue to be impregnated?
Complete removal of clearing reagents by replacing with paraffin wax/another embedding medium
