There are really good and very usefull histology lectures , notes and lectures about Histology. Histology subjects and ppt. power point presentation slides available below links:
The Cell histology
Histotechniques Lecture Notes histology
Epithelium histology
Loose Connective Tissues histology
Blood and Blood Vessels histology
Lymphatic System histology
Bone histology
Dense Connective Tissue and Cartilage histology
Muscle histology
Nervous System histology,
Sensory Systems histology
Integument histology
Digestive System I histology
Digestive System II histology
Respiratory System histology
Urinary System histology
Female Reproductive System histology
Male Reproductive System histology
Endocrine System histology
Histology power point slides and lectures
brain histology
l Nerve cells/neurons
Oligodendrocytes, Astrocytes, Ependymal cells,
Microglia Special glial cells - (CNS)
2 Glial cells|
Schwann cells, Satellite/Capsule cells,
Enteric (gut) glia - (PNS)
3 Blood vessels
4 Connective tissue enclosing sheaths
ELEMENTS OF NERVOUS SYSTEM
NEURONS : Pseudounipolar:one process branching into two a short way from the cell soma, e.g., dorsal-root ganglion cell
Bipolar cells processes come off from opposite poles of the cell, and the cell then assumes a spindle shape
Multipolar cells :
stellate or star-like, pyramidal with apical and basal dendrites, Purkinje with a plump body tapering to an espalier-oriented dendritic tree
NEURONS
Neuron , Axis-cylinder process = Axon
Protoplasmic processes = Dendrites
Body of the nerve cell = Soma
Nerve Cell
Neuron
Neuron
Body of the nerve cell = Soma
Soma contains a large central nucleus with little chromatin. The nucleolus is prominent because the neuron has to synthesize organelles and cytoplasm to fill its long processes
Around the nucleus is the perikaryon with:
(a) Nissl bodies/granules - basophilic, cytoplasmic structures are concentrations of granular ER.
(b) Neurofilaments - a variety of intermediate filament - are aggregated into neurofibrils visible in the cytoplasm after silver impregnations.
(c) Surrounding the nucleus are elements of the Golgi apparatus, mitochondria, lysosomes, and microtubules. Actin filaments move vesicles in the zone directly under the neuron's plasmalemma.
(d) Pigment is sometimes present, e.g., melanin in substantia nigra neurons, and lipofuscin in old neurons.
(e) Cell membrane has specialized receptive areas, the subsynaptic membranes of synapses.
Synapses
A junction that mediates information transfer from one neuron:
To another neuron
To an effector cell
Presynaptic neuron – conducts impulses toward the synapse
Postsynaptic neuron – transmits impulses away from the synapse
Cell to Cell Conduction: the Synapse
Cell to Cell Conduction: the Synapse
Electrical synapses: gap junctions
Very fast conduction
Example: cardiac muscle
Chemical synapses
Pre synaptic terminal
Synthesis of Neurotransmitters (L-glutamate, GABA, dopamine, serotonin, acetylcholine, noradrenaline and glycine OR "minor" transmitters such as cholecystokinin, endogenous opioids, somatostatin, substance P …)
Ca2+ releases Neurotransmitters
Synaptic cleft
Postsynaptic cell: Neurotransmitter receptors
Astrocytes :Protoplasmic astrocytes: large, star-shaped with many processes, some of which attach pedicels to blood vessels or the basal lamina under the pia mater; have cytoplasmic filaments and microtubules; are common in grey matter.
Fibrous astrocytes: similar to protoplasmic astrocytes, but have more filaments and glycogen, and lie in the white matter
Astrocytes
Fibrous Astrocytes (Objective 40x)
Astrocytes in BBB
Astrocytes:
Provide physical support to neurons
Clean up carcasses of dead neurons
Provide controlling chemicals to neurons
Play important role in providing nourishment to neurons
Oligodendrocytes
= oligodendroglia: plump cell body with fairly dense cytoplasm and a darker nucleus and fewer, shorter processes than an astrocyte; common in white matter, but some are perineuronal Provide physical support to neurons Produce myelin sheath that insulates axons
Microglia
(a) derived from mesenchyme via bone marrow;
(b) potentially phagocytic;
(c) dispersed throughout the brain;
(d) a small elongated cell with many short processes and a dark nucleus.This is the ramified or resting microglial cell, which becomes round and phagocytic as a reactive microglial cell (Gitter cell), when responding to damage
Clean up CNS debris
Play role of immune system in brain
(similar to microphages in blood)
Functions: Ependymal cells lining ventricles, and covering the choroid plexus, they are typically cuboidal and often have cilia
Ependymal cells : Form a relatively permeable barrier between CSF and the tissue fluid that surrounds the cells of the CNS. In certain region of the brain ependymal cells possess cilia, the beating of which help to circulate the CSF. Modified ependymal cells contribute to the formation of the choroids plexus which is a capillary knot that protrudes into a brain ventricle, and is involved in the synthesis of cerebrospinal fluid.
Cerebral neocortex :
The number of layers to be clearly seen depends on the particular area of the cerebral cortex and the criteria of the investigator. Thus Cajal worked with an 8-layered scheme, whereas Brodmann adopted 6 - today's choice. Even so, in the motor region only 5 are to be easily made out.
Cerebral Cortex
I: plexiform (molecular): dendrites and axons of cortical neurons making synapses; neuroglia and rare horizontal cells
II: outer granular: dense population small pyramidal cells and stellate cells [small neurons]; various axons and dendritec connections
III: (outer) pyramidal cell: moderate size; increasing size deeper
IV: inner granular: densely packed stellate cells
V: ganglionic or inner pyramidal: lg pyramidal cells (including Betz cells) and smaller numbers of stellate cells and small neurons
VI: multiform (fusiform) cell: numerous small neurons, small pyramidal cells, stellate cells, especially superficially and fusiform cells in deeper part.
Cerebral Cortex
I: plexiform
II: outer granular
III: (outer) pyramidal cell
IV: inner granular
V: ganglionic or inner pyramidal
VI: multiform (fusiform) cell
bone histology subjects
Bone Growth: Interstitial and Oppositional bone growht observed in histology science.
Bone Function: Mineral homeostasis and Hemopoiesis.
Key Special Words and simple definitons: Bones is a topic of Histology. If you learn histology, also you will learn something about bones tissue histology, and bone cell structure, bone layers.
Mineralization
Calcification
Ossification
Hardness
Tensile strength
Volkmann’s canal
Haversian canal
Lacunae
Osteon
Trabeculae
Epithelium
Epithelium
Types of epytheliums
The epithelia are tissues made from cells closely juxtaposed, without the interposition of fiber or ground substance (which distinguishes them from connective tissue). The cells are linked to each other through intercellular junctions. They are not vascularisés with the exception of vascular streaks (cochlea, the production of endolymph). The input of nutrients and export of waste is done in conjunction with connective tissue underlying through a basement membrane, which rests epithelium (if a fabric has joined cells but not basal, this is not an epithelium, such épendymocytes). In this type of tissue, cells are often polarized (the two opposite ends are different morphologically and biochemically), although there are some epithelia where this polarity is difficult to distinguish (liver tissue). There are the apical region of the cell and basal region which is attached to the basal lamina.
They meet two physiological functions not exclusive of each other: function coating and glandular function.
The presence of specific intermediate filament Cytokeratin allows their identification by immunohistochemical methods.
histology topics
Quick study
For some operations still requires the surgeon during the operation on the information collected tissue for its further approach. In this case, a part of the sample in about 10 minutes as a quick cut processed.
Stabilization tissue by freezing (about -20 ° C), depending on fabric
Production of a 5-10 micron thick cut on cryostat
Pulling of the cut on a coated glass slides
DB-fast staining, Paragon staining or other quick-staining
Findings
histology and technic
Before a pathologist / biologist the fine details of a patient sample / evaluate an experiment may be the tissue processing a detailed assessment. These methods can take as Histotechnik together and are largely from laboratory histological biomedical analysts or (V) by MTA.
The tissue processing laboratory in histodiagnostischen includes the following terms:
Fixation to stabilize the tissue (Hauptfixans: 4% neutral buffered formaldehyde solution)
macroscopic examination of meaningful cut tissue districts. In the pathology and medical activities pertaining to the diagnostic process.
Drainage and impregnation of the fabric with liquid paraffin
Einblocken of the tissue in paraffin wax, paraffin cuboid is produced, which includes the tissue.
In modern Histologielaboren the Gewebsstückchen in so-called "Einbettkassetten" laid.
In these tissue sample through the drainage and Einparaffinierung. Then the cassette serves as a base block and can thus in the so-called quick-release frame, with the most modern microtomes are, to be fixed.
Manufacture of 2-5 microns thick slices on microtomes
Pulling on the cuts (coated) glass slides
Histologic staining
The processing of tissue FFPE (formalin-fixed paraffin-embedded tissue), including the Hämatoxylin-eosin staining, the world-wide routine method of Pathology and lasts an average of one to two days from adoption of the samples to the findings. In contrast to the clinical laboratory, many chemical steps carried out by hand. Especially the production cut at microtomes requires great skill.