Histology is the science of the microscopic structure of cells, tissues and organs. Nervous Tissue DR. DEVI 1 16-4-19 2. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. Nervous tissue histology - slideshare.net For oligodendrocytes, the rest of the cell is separate from the myelin sheath as a cell process extends back toward the cell body. These glial cells appear similar to epithelial cells, making a single layer of cells with little intracellular space and tight connections between adjacent cells. The central axons are so thin that they appear as purple dots in the middle of the lighter-colored circles of myelin. Together these organs provide the ability of reproduction and sexual intercourse. The name glia comes from the Greek word that means glue, and was coined by the German pathologist Rudolph Virchow, who wrote in 1856: This connective substance, which is in the brain, the spinal cord, and the special sense nerves, is a kind of glue (neuroglia) in which the nervous elements are planted. Today, research into nervous tissue has shown that there are many deeper roles that these cells play. Examine the gray matter on each side of the sulcus using first low and then high power. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. Tissues join together in different arrangements to form our body organs. Different regions of the nervous system have distinct histological characteristics that make them easily recognizable, under the microscope. The cells are laid down on top of dense irregular connective tissue, the basement membrane (BM). Axon diameters can be as small as 1 to 20 micrometers. Unipolar cells are exclusively sensory neurons and have two unique characteristics. Within the medulla, most axons will cross over to the opposite hemisphere of the brain from which they originated a process called decussation and then continue within the white matter of the spinal cord, before synapsing with interneurons and lower motor neurons, in the grey matter of the spinal cord. White mater 4. It has a similar role as the nervous system, working in tandem with it to maintain homeostasis of the body. Ana 211 (Histology of Nervous tissue).pptx - Academia.edu Review diagrams illustrating the morphology of neurons in your textbooks. ("1" in the orientation figure) a polymorphic layer containing many nerve fibers and small cell bodies of interneurons, ("2" in the orientation figure) a middle pyramidal cell layer containing hippocampal pyramidal cells. Neurons are specialized cells that contain a body (soma) and one or more processes (dendrites, axons). Slide NP004N hippocampal region coronal section luxol blue View Virtual Slide [orientation]. The inner edge wraps around the axon, creating several layers, and the other edge closes around the outside so that the axon is completely enclosed.Myelin sheaths can extend for one or two millimeters, depending on the diameter of the axon. They also have cilia on their apical surface to help move the CSF through the ventricular space. The function of myelin will be discussed below. In the above image, we can observe only the relatively large, triangular-shaped cell bodies of the pyramidal cells with clearly visible nuclei, parts of the dendrites, and the beginnings of axons. Both will appear grey to the naked eye and under the microscope, due to their lack of myelin. Note that sacral levels of the cord (levels S2-4) also contain visceral motor neurons in the lateral horn, but these are parasympathetic. The projections connect at the dendrites and are so extensive that they give the microglial cell a fuzzy appearance. The dendritic tree and axon of each Purkinje cell can only be seen in thicker sections stained with special silver stains. Above the temporal (ventral or inferior) horn of the lateral ventricle the lateral geniculate nucleus is present. Work for the lab This website is a great way to view the tissues. Satellite cells are found in sensory and autonomic ganglia, where they surround the cell bodies of neurons. Click on launch activity 2. Lectures | General Histology PPT - Histology of Nervous Tissue PowerPoint Presentation, free Nervous tissue is made of cells (neurons and glial cells) and extracellular matrix. Basic nervous tissue staining mechanisms and classification of nervous tissue elements will be discussed. These include epithelial cells, fibroblasts, neutrophils, erythrocytes, keratinocytes, chondrocytes just to name a few. Peripheral nerves are analogous with neural tracts of the CNS. In general, where in the brain can grey matter be found? The testes produce male gametes (spermatozoa) via the process of spermatogenesis. Muscle attaches to bone via tendons; bundles of dense regular connective tissue made out of many collagen type I fibers. T and B lymphocytes are born and raised in the thymus and bone marrow, respectively. Histology Complete and Basic Tissues. Author: Most of the nuclei visible in the granular layer belong to very small neurons, granule cells, which participate in the extensive intercommunication involved in the cerebellums role in balance and coordination. It consists of small, spindle-shaped mesenchymal cells and ground substance with sparse collagen and reticular fibers. Look at the margins of the ventricle at higher magnification and note that it is entirely lined by ependymal cells. The epidermis is a keratinized stratified squamous epithelium mostly made out of keratinocytes. Use the virtual slide of the hippocampal region to study the ependymal cell lining of the choroid plexus. The integumentary system consists of the skin and skin appendages. Title: PowerPoint Presentation Author: Jennifer Ann Jost Last modified by: Jeff Keyte Created Date: 10/29/2003 10:25:53 PM Document presentation . Connective tissue proper is further subdivided into loose connective tissue, mostly found in internal organs as supporting tissue stroma, and dense connective tissue, which can be regular (tendons, ligaments) or irregular (dermis of the skin, organ capsules). Aspects of peripheral nerve embryology and clinically . Just medial (to the right) of the tail of the caudate, note the choroid plexus slide NP004N View Image, which consists of highly convoluted and vascularized villi covered by ependymal cells which are specialized for the production of cerebrospinal fluid, or CSF. Skeletal muscle consists of long cylindrical-shaped muscle cells with multiple, peripherally located nuclei and a cytoplasm filled with myofibrils. Slide NP004N hippocampal region, coronal section, luxol blue View Virtual SlideSlide 13270astrocytes,Gold-stainingView Virtual Slide. Most of the respiratory tract is lined by respiratory mucosa; a pseudostratified columnar ciliated epithelium with mucus producing goblet cells. . Histology (6th ed.). Study with Quizlet and memorize flashcards containing terms like Afferent, efferent, visceral and more. Describe the organization and understand some of the basic functions of regions of the: Observe the 3-layered organization of the, Outer plexiform (molecular) layer: sparse neurons and glia, Outer granular layer: small pyramidal and stellate neurons, Outer pyramidal layer: moderate sized pyramidal neurons (should be able to see these in either, Inner granular layer: densely packed stellate neurons (usually the numerous processes arent visible, but there are lots of nuclei reflecting the cell density), Ganglionic orinner pyramidal layer: large pyramidal neurons (should be able to see these in either, Multiform cell layer: mixture of small pyramidal and stellate neurons. Nervous tissue consists of two cells: nerve cells or neurons and glial cells, which helps transmit nerve impulses and also provides nutrients to neurons. Additional sub-classifications are possible, based on the cell specializations. Pyramidal cells in the cerebral cortex act as upper motor neurons, which then synapse with the lower motor neurons that are in direct contact with muscles to initiate contraction. Multiple muscle cells are bound by connective tissue into fascicles, and multiple fascicles join to form a muscle belly. Learning anatomy is a massive undertaking, and we're here to help you pass with flying colours. A few other processes provide the same insulation for other axon segments in the area. Cells come together with extracellular matrix (a jelly-like fluid) to form the four types of tissues found in the human body: epithelial, connective, muscle and nervous. For example, a multipolar neuron that has a very important role to play in a part of the brain called the cerebellum is known as a Purkinje (commonly pronounced per-KIN-gee) cell. Sensory reception is a peripheral function (those dendrites are in the periphery, perhaps in the skin) so the cell body is in the periphery, though closer to the CNS in a ganglion. A longitudinal section of a nerve looks very different than a transverse section: In a longitudinal section of a nerve (Figure 9), the axons stain darker and are visible as purple lines. thyroid, ovaries, suprarenal) and individual hormone-secreting cells found in many organs of the body (e.g. Like a few other parts of the body, the brain has a privileged blood supply. The outer cerebellar cortex, shown in Figure 8, is tightly folded and has three distinct layers: Purkinje cells are typically arranged in a single row between the exterior molecular and interior granular layers. Histology of Nervous Tissue - PowerPoint PPT Presentation - PowerShow ("3" in the orientation figure) a molecular layer containing dendrites of the pyramidal cells. PPT - Histology PowerPoint presentation | free to download - id: 4617df The accessory genital glands include the prostate, seminal vesicles and bulbourethral glands. The cerebellum is the part of the brain responsible for integrating input from the sensory organs to coordinate the precise, voluntary movements originally initiated in the cerebral cortex. 48 Spinal CordWhite Matter (Spinal Cord)View Virtual EM Slide In this field you see several oligodendrocytes, the cells that make myelin in the CNS, surrounded by numerous myelinated axons of various size, cut in cross section. Some sources describe a fourth type of neuron, called an anaxonic neuron. Also found in CNS tissue is the oligodendrocyte, sometimes called just oligo, which is the glial cell type that insulates axons in the CNS. Histology - Histology. The nervous system is responsible for all our. adipose tissue, gastrointestinal tract, cardiovascular system). Electron microscopy (EM) is a more modern form of microscopy that provides a much higher magnification and high resolution images. Blotting technique is a method of localizing and quantifying proteins, DNA and RNA. Slide 66a View Virtual Slide shows a section of thoracic spinal cord. Unlike the highly organized cerebellar cortex, the cerebral cortex appears to be less well-organized when viewed with the light microscope. With the exception of the unipolar sensory ganglion cells, and the two specific bipolar cells mentioned above, all other neurons are multipolar. 49 Motor nerve cell - Ventral Horn of Rabbit Spinal Cord, MultipolarMotor Neuron Cell BodyView Virtual EM Slide Motor Neuron Cell Body. Reading time: 28 minutes. Click on the white box with the question mark on it 4. Reviewer: To visualize this dendritic tree, an osmium stain can be used. Pia mater 2. Get an overview of the different types of epithelial tissue: Connective tissue connects, separates and supports the body organs. The four main types of stains used in histology are empirical, histochemical, enzyme histochemical and immunohistochemical. It relays sensory input to other neurons in the spinal cord. Neurons. PPT - INTRODUCTION TO HISTOLOGY PowerPoint Presentation, free download Mucoid connective tissue is a fetal tissue present in the umbilical cord. Nonetheless, it is loosely stratified into layers containing scattered nuclei of both neurons and glial cells. If you were to look at some bones on a skeleton, youd see a greyish rigid mass with some bumps and depressions. 1. The cells of Clarke's nucleus then relay this information via axonal projections that extend all the way up into the cerebellum (hence the reason why the cells are so large) where it is processed to allow for coordinated movement. It is this myelin, a lipid-rich sheath covering axons, that causes white matter to be lighter in color than grey matter. While their origin is not conclusively determined, their function is related to what macrophages do in the rest of the body. In the hippocampus orientation Image, observe: In the dentate gyrus orientation Image, observe: The "hilus" is the region where the head of hippocampus abuts the dentate gyrus. The entirety of the lungs is externally lined by pleura, a thin epithelial layer made of squamous cells with a thin underlying layer of connective tissue.Learn more about the upper respiratory tract and the lower respiratory tract. Everything absorbed through the alimentary tract passes through the special discontinued capillaries of the liver before going anywhere else. This is the final course in the series that will explore special stains used in the clinical histology laboratory. Neurons are usually described as having one, and only one, axona fiber that appears as a long cord emerging from the cell body and projects to target cells. The cells of the genital ducts and glands produce secretions to support this process. Test yourself on cardiac muscle tissue with the following quiz. This method is based on the ability of single stranded DNA or RNA to merge with a complementary strand and build a hybrid which is then detected due to the label. Gordana Sendi MD Correct answer 2. Cerebral cortex 3. Pyramidal cells and olfactory cells are two other examples of neurons named for these classifications which will be discussed later. How is this different in the spinal cord? Alveoli are the primary site of gas exchange. These cells contain contractile filaments (myofibrils) called actin (thin) and myosin (thick). Nervous tissue contains two basic categories of cells: neurons and support cells (glia). Ependymal cells, which are uniquely located lining the ventricles of the brain the central canal of the spinal cord, are one notable exception. However, if you take a much closer look, youll see that the histology of bones, is a whole other story. Skin glands include sweat glands (apocrine and eccrine) and sebaceous holocrine glands, both are important in regulating body temperature. Contents Neuron Nerve cell processes Synapses And impulse transmission The neuroglia Myelin sheath 2 3. Some cutting edge research suggests that certain neurons in the CNS do not conform to the standard model of one, and only one axon. This traps and removes any inhaled dust, bacteria or foregn substances. All cells are enveloped by a semipermeable two-layered membrane, which serves as a dynamic medium for the cells interaction with the external environment. Histology guide: Definition and slides | Kenhub As such, nerves do not contain neural cell bodies. Which are classified as grey matter? When viewing the microscopic anatomy of the ovary, we can see that it consists of a surface germinal epithelium (capsule), ovarian follicles (cortex) and connective tissue (capsule, cortex medulla). Neurons of the cerebral cortex are of varying shapes and sizes, but the most obvious arepyramidal cells. Learn more about the histology of the upper and lower digestive tract. Myelin, however, is more than just the membrane of the glial cell. Histology. This Power point presentation will allow students to practice the skill of identifying tissue types from 25 histology slides. PPTX Histology of Nervous Tissue Nervous system ppt #2 - Liberty Union High