Histology
At the end of Histology you will be able to:
explain the relation between the shape and the function of cells
explain how cells together form a tissue, with the digestive system as an example.
analyze histological preparations using light microscopy.
draw the structure and organelles of the cell, and explain their role in functioning of the cell.
Manner of analysis: light and electron microscopy. Light microscope: resolution: 0.2 micrometer. Electron
microscope: Transmission EM: 0.2 nanometer.
Microscope slide preparation:
- Fixation: stabilization of structure: Formalin
- Imbedding in paraffin
- Cutting of slices: 50 nm-7 µm
- Cytological staining: Overview staining: Cytochemical: identify specifics in the cell (e.g. proteins,
DNA, sugars, etc)
There are four basic types of tissue.
There are ± 200 different cell types, these are organized in tissues (structures with discrete structural and
functional properties). These tissues (cells working together) can be classified in 4 basic types of tissue:
Epithelial Covers exposed surfaces, lines internal passageways and chambers,
tissue and forms glands (produces glandular secretions).
Epithelia line all passageways that communicate with the outside
world.
Functions: provide physical protection, control permeability (any
substance that enters or leaves you body must cross an epithelium),
provide sensation (neuroepithelium), produce specialized secretions
(gland cells).
Connective Fills internal spaces, provides structural support for other
tissue tissues, transports materials within the body and stores energy.
Muscle Is specialized for contraction and includes the
tissue skelet mucles of the body, the mucles of the heart,
and the muscular walls of hollow organs
Nervous Carries information from one part of the body to another in the
tissue form of electrical impulses.
These basic tissue types are functionally organized/ combined in organs (e.g. liver, hart, gut).
Embryonic origin: cell types that are part of the same basic tissue type can look much different. What these
cells share is the same embryonic origin.
, Epithelial tissue
Able to recognize and name different types of epithelia
Able to explain the relation between shape and function of different types of epithelia
Able to name cellular characteristics, and associated functions, of epithelia
Able to name intracellular connections, and associated functions, between epithelial cells
An epithelium is a tissue existing of cells that are tightly connected to each other. It is derived from one of
the three primary germ layers (ecto-, endo- of meso-derm). There are two types: covering epithelia (e.g.
skin) and glands (invagination of epithelial layers). Epithelia are layers of cells that cover external or line
internal surfaces. Glands are structures that produce fluid secretions. They are either attached to or derived
from epithelia.
An epithelium is classified based on its embryonic origin, morphology and cell organisation:
- Ecto-, endo-, or mesodermal
- The shape of the cells
- Number of cell layers (strata)
Cell shapes Cell layers
Simple epithelium = really thin, fragile (secretion, absorption, e.g. Gas-exchange
Transitional: changes between of the lungs). All cells have the same polarity, so distance from the nucleus to
squamous and cuboidal. basement membrane does not change from one cell to the next.
Stratified epithelium = generally located in areas that are exposed to mechanical
of chemical stresses (e.g. skin surface).
At the end of Histology you will be able to:
explain the relation between the shape and the function of cells
explain how cells together form a tissue, with the digestive system as an example.
analyze histological preparations using light microscopy.
draw the structure and organelles of the cell, and explain their role in functioning of the cell.
Manner of analysis: light and electron microscopy. Light microscope: resolution: 0.2 micrometer. Electron
microscope: Transmission EM: 0.2 nanometer.
Microscope slide preparation:
- Fixation: stabilization of structure: Formalin
- Imbedding in paraffin
- Cutting of slices: 50 nm-7 µm
- Cytological staining: Overview staining: Cytochemical: identify specifics in the cell (e.g. proteins,
DNA, sugars, etc)
There are four basic types of tissue.
There are ± 200 different cell types, these are organized in tissues (structures with discrete structural and
functional properties). These tissues (cells working together) can be classified in 4 basic types of tissue:
Epithelial Covers exposed surfaces, lines internal passageways and chambers,
tissue and forms glands (produces glandular secretions).
Epithelia line all passageways that communicate with the outside
world.
Functions: provide physical protection, control permeability (any
substance that enters or leaves you body must cross an epithelium),
provide sensation (neuroepithelium), produce specialized secretions
(gland cells).
Connective Fills internal spaces, provides structural support for other
tissue tissues, transports materials within the body and stores energy.
Muscle Is specialized for contraction and includes the
tissue skelet mucles of the body, the mucles of the heart,
and the muscular walls of hollow organs
Nervous Carries information from one part of the body to another in the
tissue form of electrical impulses.
These basic tissue types are functionally organized/ combined in organs (e.g. liver, hart, gut).
Embryonic origin: cell types that are part of the same basic tissue type can look much different. What these
cells share is the same embryonic origin.
, Epithelial tissue
Able to recognize and name different types of epithelia
Able to explain the relation between shape and function of different types of epithelia
Able to name cellular characteristics, and associated functions, of epithelia
Able to name intracellular connections, and associated functions, between epithelial cells
An epithelium is a tissue existing of cells that are tightly connected to each other. It is derived from one of
the three primary germ layers (ecto-, endo- of meso-derm). There are two types: covering epithelia (e.g.
skin) and glands (invagination of epithelial layers). Epithelia are layers of cells that cover external or line
internal surfaces. Glands are structures that produce fluid secretions. They are either attached to or derived
from epithelia.
An epithelium is classified based on its embryonic origin, morphology and cell organisation:
- Ecto-, endo-, or mesodermal
- The shape of the cells
- Number of cell layers (strata)
Cell shapes Cell layers
Simple epithelium = really thin, fragile (secretion, absorption, e.g. Gas-exchange
Transitional: changes between of the lungs). All cells have the same polarity, so distance from the nucleus to
squamous and cuboidal. basement membrane does not change from one cell to the next.
Stratified epithelium = generally located in areas that are exposed to mechanical
of chemical stresses (e.g. skin surface).
