Cellular Patholgy Flashcards
What are the 4 types of primary tissue?
- Connective
- Epithelial
- Muscle
- Nervous
What is histology?
Study of tissues of the body an how these tissues are arranged to constitute organs
Involves all aspects of tissue biology to correlate the tissue structure with its function
What is a tissue?
Tissues are groups of similar cells that come together to perform a common function
What is cytology?
Involves looking at individual cells/ clusters of cells
What are the 6 steps of tissue preparation?
- Fixation
- Dehydration
- Clearing
- Embedding
- Sectioning
- Staining
Describe fixation
Critical step in preservation of sections
Tissues are pressed as close to the natural state as possible for examination
Describe dehydration
Series of alcohol solutions of ascending concentrations
Describe clearing
Clear the tissue to allow paraffin wax to embed into the tissue
Describe embedding
For light microscopes- paraffin
Electron- epoxy resin
Describe sectioning
Light- 5-15um thick
Electron- ultra thin section using a diamond knife (0.05-0.09um)
What is H&E staining?
Haematoxylin and Eosin
Haemotoxylin to react with anionic components
Eosin to react with cat ionic components
What is PAS staining?
Periodic Acid Schaffer
For CHO’S and carb rich molecules
Stains them magenta/ pink
Why does Mallory’s Trichrome stain do?
Stains collagen blue
What does Masson’s Trichrome stain do?
Differentiates smooth muscle (stains red) from tissue collagen
(blu/green)
What is the basis of immunohistochemistry?
IHC is the specificity of a reaction between an antigen and antibody
How does autoradiography work?
- Radioactive compound binds to the tissues
- Tissue is placed next to film
3.reaction produced by radioactivity is quantified and localised
What is the epithelium?
Structure that lines and covers all pars of the body and separate the organs in the body, it has no direct supply and is supported by connective tissue
What’s are the 2 types of epithelium?
Proper-covers the whole body and organs
Glandular- secretes hormones, digestive juices and sweat
List the function of the epithelial tissues
- Protection
- Sensory
- Secretions
- Absorption
- Excretion
How are the different types of epithelial tissue classified?
- Cell shape at surface
- No of cell layers
- Transitional epithelium
- Pseudostratified epithelium
What are the 4 types of epithelia?
Squamous
Cuboidal
Columnar
Pseudostratified
Describe simple squamous epithelium and their function
One layer of smooth surface flat cells attached to the basement membrane where cell width is larger than the height
Function- Exchange barrier and lubrication
What is the typical location of simple squamous epithelium?
Linguini of the heart
Body cavities
Bowman’s capsule
Describe stratified squamous epithelium and their function
Several layers of cells (deepest layer of cells only), squamous being the superficial layer and they can be keratinised/ non-keratinised
Function- Protection and barrier to dehydration + infection
Where can stratified squamous cells be found?
Esophogous
Vgaina
Epidermis (keratinised)
Describe simple cuboidal epithelium and their function
One layer of cuboidal cells in which the cell height= width= depth attached to the basement membrane
Nucleic are typically spherical and apical surfaces may have microvilli
Function- absorption and secretion barrier
Where are simple cuboidal epithelia found?
Surface of the ovaries
Kidney tubulars
Thyroid follicles
Describe stratified cuboidal epithelia and their function
2-3 layers of cells where the basal layer is attached to the membrane
Function- barrier and conduit (channel)
Where are stratified cuboidal epithelia generally found?
Sweat glands and ducts
Exocrine glands
Anorectal junction
Describe simple columnar epithelium and their function
Layer of columns cell attatched to absent of membrane, where the cell height is larger than the width
The nuclei are typically oval and the surface my be specialised depending on location
Function- Absorption and secretion
Where are simple columnar epithelial found?
Stomach
Intestines
Gallbladder
Describe stratified columnar cells and their function
2/3 layers of cells in the superficial layers
Not a common type of epithelium
Function- barrier and conduit (channel)
Where are stratified columnar epithelial cells found?
Exocrine glands
Anorectal junction
Describe transitional epithelia and their function
Staratifed epithelium that line the urinary tract
Surface cells are often dome shaped (aka umbrella cells)
Function- Barrier and dispensable property
Where are transitional epithelium cells found?
Renal calyces
Ureter
Bladder
Describe psuedostratifed epithelium and their function
Layer of cells that vary in shape, size and height
Most are columnar but some are short basal
Pseudo= false
Functions- Secretion, conduit and absorption
Where are psuedostratified cells found?
Trachea
Bronchi
Male reproductive tract
How are glandular epithelium classified?
Exocrine- Secrete ONTO a surface: Merocrine, Aprocrine and holocrine
Endocrine- Secrete products INTO connective tissues that can then enter the bloodstream: Paracrine and Autocrine
What is the classification of exocrine glands based on?
- Number of cells- uni/ multi cellular
- Type of secretion- serous, mucus or mixed
How are multicellular cells sub-classified?
- Shape of secretary cells- tubular, alveolar, tube alveolar
- Presence/ absence of branching duct- simple= unbranched, compound= branched duct