A detailed introduction to provide a foundation into understanding histology and histological components. These notes are a basic summary of histology to grasp the fundamental key elements of this topic.
Samenvatting Histologie (Pawlina) volgens blokboek Biomoleculen (B1BI)
Alles voor dit studieboek
(3)
Geschreven voor
University of the Witwatersrand (wits)
Anatomy (ANAT2021)
Alle documenten voor dit vak (16)
Verkoper
Volgen
tiffanyjanewilton
Voorbeeld van de inhoud
DEFINING HISTOLOGY
• Histology- Study of tissues and arrangement into organs
• Tissue = cells + extracellular matrix (ECM)
▪ Cells
– Major compartments = nucleus & cytoplasm(with organelles)
▪ ECM
– Structural network surrounding cells
– Influences cellular communication and function
– Contain fibres (collagen/elastic) and ground substance (proteoglycans, glycoproteins and
glycosaminoglycans)
• Structure is related to function!
HISTOLOGICAL TECHNIQUES
→ The routinely prepared hematoxylin and eosin–stained
section is the specimen most commonly studied.
• Haematoxylin
– Basic dye
– Stains acidic structures basophilic
– Colour: purple/dark blue
– Basic dyes react with anionic components of cells and tissue (components that carry a net negative
charge).
– A basic dye carries a net positive charge on its colored portion and is described by the general
formula [dye+ Cl− ].
– Anionic components include the phosphate groups of nucleic acids, the sulfate groups of
glycosaminoglycans, and the carboxyl groups of proteins.
– The ability of such anionic groups to react with a basic dye is called basophilia
– Hematoxylin is not, strictly speaking, a basic dye. It is used with a mordant (i.e., an intermediate link
between the tissue component and the dye).
– Tissue components that stain with hematoxylin also exhibit basophilia.
• Eosin
– Acidic dye
– Stains acidic structures eosinophilic
– Colour: pink
– An acidic dye carries a net negative charge on its colored portion and is described by the general
formula [Na+ dye−].
– Acidic dyes react with cationic groups in cells and tissues,
particularly with the ionized amino groups of proteins.
– The reaction of cationic groups with an acidic dye is
called acidophilia.
– Reactions of cell and tissue components with acidic
dyes are neither as specific nor as precise as reactions
with basic dyes
,→ A limited number of substances within cells and the extracellular matrix display basophilia.
• heterochromatin and nucleoli of the nucleus (chiefly because of ionized phosphate groups in nucleic
acids of both)
• cytoplasmic components such as the ergastoplasm (also because of ionized phosphate groups in
ribosomal RNA)
• extracellular materials such as the complex carbohydrates of the matrix of cartilage (because of
ionized sulfate groups).
→ Staining with acidic dyes is less specific, but more substances within cells and the extracellular matrix
exhibit acidophilia.
• most cytoplasmic filaments, especially those of muscle cells
• most intracellular membranous components and much of the otherwise unspecialized cytoplasm
• most extracellular fibers (primarily because of ionized amino groups).
→ Fixation, usually by a chemical or mixture of chemicals, permanently preserves the tissue structure for
subsequent treatments.
→ Specimens should be immersed in fixative immediately after they are removed from the body.
→ Fixation is used to:
• terminate cell metabolism,
• prevent enzymatic degradation of cells and tissues by autolysis (self-digestion),
• kill pathogenic microorganisms such as bacteria, fungi, and viruses
• harden the tissue as a result of either cross-linking or denaturing protein molecules.
Voordelen van het kopen van samenvattingen bij Stuvia op een rij:
Verzekerd van kwaliteit door reviews
Stuvia-klanten hebben meer dan 700.000 samenvattingen beoordeeld. Zo weet je zeker dat je de beste documenten koopt!
Snel en makkelijk kopen
Je betaalt supersnel en eenmalig met iDeal, creditcard of Stuvia-tegoed voor de samenvatting. Zonder lidmaatschap.
Focus op de essentie
Samenvattingen worden geschreven voor en door anderen. Daarom zijn de samenvattingen altijd betrouwbaar en actueel. Zo kom je snel tot de kern!
Veelgestelde vragen
Wat krijg ik als ik dit document koop?
Je krijgt een PDF, die direct beschikbaar is na je aankoop. Het gekochte document is altijd, overal en oneindig toegankelijk via je profiel.
Tevredenheidsgarantie: hoe werkt dat?
Onze tevredenheidsgarantie zorgt ervoor dat je altijd een studiedocument vindt dat goed bij je past. Je vult een formulier in en onze klantenservice regelt de rest.
Van wie koop ik deze samenvatting?
Stuvia is een marktplaats, je koop dit document dus niet van ons, maar van verkoper tiffanyjanewilton. Stuvia faciliteert de betaling aan de verkoper.
Zit ik meteen vast aan een abonnement?
Nee, je koopt alleen deze samenvatting voor €2,70. Je zit daarna nergens aan vast.