What is the importance of histology?

What is the importance of histology?

Histology is the study of how tissues are structured and how they work. Knowing what a normal tissue looks like and how it normally works is important for recognizing different diseases. It also helps in figuring out what causes certain diseases, how to treat those diseases, and whether the treatment has worked.

What is tissue in histology?

A tissue is a functional aggregation of similar cells and their intercellular materials that combine to perform common functions. An organ is an anatomically discrete structure (e.g. heart, skin) with 1 or more functions. Four tissues are considered basic or primary: epithelial, connective, muscular and nervous.

What is the important of tissue?

Tissues are important because of the following reasons: (i) They divide the work labour in multicellular organisms. (ii) They get organised to form different organs and organ systems. (iii) They provide a higher efficiency to multicellular organisms by improving their organisation.

What is the importance of tissue preparation in histological study?

Slide preparation begins with the fixation of your tissue specimen. This is a crucial step in tissue preparation, and its purpose is to prevent tissue autolysis and putrefaction. For best results, your biological tissue samples should be transferred into fixative immediately after collection.

What is the purpose of tissue fixation?

The broad objective of tissue fixation is to preserve cells and tissue components in a “life-like state” or as little alteration as possible to the living tissue, and to do this in such a way as to allow for the preparation of thin, stained sections.

What is the purpose of tissue processing?

DEFINITION : Tissue processing: The aim of tissue processing is to embed the tissue in a solid medium firm enough to support the tissue and give it sufficient rigidity to enable thin sections to be cut, and yet soft enough not to damage the knife or tissue.

What are the steps in tissue processing?

Overview of the steps in tissue processing for paraffin sections

1. Obtaining a fresh specimen. Fresh tissue specimens will come from various sources.
2. Fixation. The specimen is placed in a liquid fixing agent (fixative) such as formaldehyde solution (formalin).
3. Dehydration.
4. Clearing.
5. Wax infiltration.
6. Embedding or blocking out.

How do you fix a histology tissue?

Summary

1. Fixation must be performed immediately after surgery/dissection.
2. Fix tissue in 10% neutral buffer formaldehyde (NBF) solution or freshly prepared 4% paraformaldehyde solution.
3. Cut tissue into smaller pieces (max.
4. Fixation must be performed for no more than 24-36 hours depending on the size of tissue.

What are disadvantages of automatic tissue processing?

Disadvantages include inability to cut thin sections, storage of blocks in alcohol and speed of technique (which can take several weeks or months). This is harder than paraffin wax and has a lower melting point (46-48oC). Good for cutting hard tissues since it does not crumble.

What are advantages of automatic tissue processor?

The device can handle larger number of tissues, process more quickly and produces better quality outcome. Advantages of automated tissue processor – Saves time, decreases human error, effective fluid circulation, Temperature can be adjusted and vacuum/pressure can also be incorporated.

What factors affect tissue processing?

Factors Affecting Tissue Processing

• Tissue size (biopsy versus resection)
• Tissue thickness.
• Tissue density.
• Lipid content in tissue.

Why dehydration of tissue is important?

Dehydration is simply the removal of water from aqueous-fixed tissue. Since most fixatives are aqueous, this step is necessary to prepare the tissue for embedding in non-aqueous media like paraffin. In this step, the alcohol penetrates tissue quickly and the water is replaced with alcohol. …

How do you fix tissue?

Fixation of tissues can be achieved by chemical or physical means. Physical methods include heating, micro-waving and cryo-preservation (freeze drying). Heat fixation is rarely used on tissue specimens, its application being confined to smears of micro organisms.

What is the importance of trimming the tissue block?

The purpose of trimming is to create an even, flat surface in the area of interest in the tissue so that the histologists to not have to face (cut with the microtome) into the paraffin block as deeply when trying to get the first good sections for a slide.

What is the most important step in tissue processing?

FIXATION. Fixation of tissues is the most crucial step in the preparation of tissue for observation in the transmission electron microscope. Fixation consists of two steps: cessation of normal life functions in the tissue (killing) and stabilization of the structure of the tissue (preservation).

How long does Tissue processing take?

In general, the whole process takes around six hours and is usually set up to run overnight.

What is the importance of tissue impregnation?

Impregnation (infiltration) is the process whereby the clearing agent is completely removed from the tissue and replaced by a medium that will completely fill all the tissue cavities thereby giving a firm consistency to the specimen, and allowing easier handling and cutting of suitably thin sections without any damage …

What is clearing in tissue processing?

Introduction. Clearing is an essential step in histopathology processing for light microscopy. The purpose of clearing is to remove dehydrating agents from tissues and to prepare the tissues for impregnation with the embedding agent. Xylene is the clearing agent used most commonly worldwide.

Why is sectioning tissue important?

Using serial sections allows the 3D structure of the tissue to be visualized. This is especially important in determining whether an abnormality is an artifact of preparation or a pathologic process.