nervous tissue histology ppt

The accessory genital glands include the prostate, seminal vesicles and bulbourethral glands. There is a lot more to know about the female reproductive system. Histology. Want to create or adapt books like this? In these slides you will not be able to discern the amazing dendritic tree that extends from the Purkinje cell bodies into the molecular layer, nor will you be able to see their axons, which extend down through the granular layer into deeper parts of the cerebellum. What is the distinction between the CNS and the PNS? It also helps us understand the relationship between structure and function. Glial cells, or glia, are known to play a supporting role for nervous tissue. Neurons are important, but without glial support they would not be able to perform their function. The spleen on the other hand, filters blood. within limits that maintain life. Name thefunction of the cell marked by the black arrow. 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. This is done by the use of a complementary nucleotide probe, which contains a radioactive or fluorescent label. Wheaters functional histology: A text and colour atlas. Use the virtual slide of the hippocampal region to study the ependymal cell lining of the choroid plexus. The choroid plexus is a specialized structure in the ventricles where ependymal cells come in contact with blood vessels and filter and absorb components of the blood to produce cerebrospinal fluid. 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. Edinburgh: Churchill Livingstone. Very little can pass through by diffusion. The endocrine system is a set of tissues that secrete hormones directly into the bloodstream. Grey matter is composed mainly of unmyelinated cell bodies and dendrites, and appears grey in color. Read more. It is specialized tissue found in the central nervous system and the peripheral nervous system. Nervous or the nerve tissue is the main tissue of our nervous system. Other methods include histochemistry, immunocytochemistry, hybridization techniques, tissue culture and many others. Smooth muscle tissue appears non-striated because of the less orderly arrangement of their filaments. The white matter contains nerve fibers (axons) entering and exiting the gray matter, and traveling up and down the spinal cord, linking it to the brain. The cells here arepreganglionic sympathetic neurons whose axons terminate in either sympathetic chain ganglia or the "visceral" (or "pre-aortic") ganglia associated with the major branches of the abdominal aorta (e.g. Because of this, only specific types of molecules can enter the CNS. The perikarya of large somatic motor neurons slide 065-2 View Image located in the ventral horn of the cord innervate the skeletal muscles of the limbs and trunk, which are embryologically derived from somites (hence, somatic muscles). When responding to a foreign threat, immune system cells can activate non-specific inflammation or progress to a specific immune response. The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). Those processes extend to interact with neurons, blood vessels, or the connective tissue covering the CNS that is called the pia mater (Figure 4). The PNS is all neural tissue outside of the CNS, i.e. Click on human from the drop down list 5. Remember, a nerve is a bundle of axons, running in parallel, in the PNS. Pia mater 2. At low magnification, differentiate inner gray from outer white matter and identify dorsal and ventral horns of the gray matter. Oligodendrocytes have processes that reach out to multiple axon segments, whereas the entire Schwann cell surrounds just one axon segment. Nutrient molecules, such as glucose or amino acids, can pass through the BBB, but other molecules cannot. The lipids are essentially the phospholipids of the glial cell membrane. They include hair follicles, skin glands and nails. Scattered in the cytoplasm are the characteristic clusters of ribosomes and rough ER termed Nissl bodies or Nissl substanceslide 066aView Image. They have rectangular bodies and many dendrite like projections stemming from their shorter sides. True unipolar cells are only found in invertebrate animals, so the unipolar cells in humans are more appropriately called pseudo-unipolar cells. At one end of the axon are dendrites, and at the other end, the axon forms synaptic connections with a target. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. adipose tissue, gastrointestinal tract, cardiovascular system). Gordana Sendi MD They are organized into lobules, with each lobule containing a parenchyma of seminiferous tubules and a connective tissue stroma. Depending on the number of layers, epithelial tissue is classified into simple (single layered) or stratified (multi-layered). Upon maturation, they are released into the blood, lymph and into secondary lymphoid organs, where they work alongside immune system support cells to carry out a detailed surveillance of potential threats. Work for the lab This website is a great way to view the tissues. Neuroglia. The small gap in the myelin sheath that occurs between adjacent Schwann cells is called a node of Ranvier. 10:10 - 12:05 Muscle Tissue ppt | pdf WEEK 2 Monday, August 22. Organelles can be membranous (mitochondria, Golgi apparatus, endoplasmic reticulum) or non-membranous (ribosomes, nucleolus, centrioles). The PNS encompasses all nervous tissue outside of bony structures, and includes all peripheral and cranial nerves, plexuses, and ganglia. 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). Note that sacral levels of the cord (levels S2-4) also contain visceral motor neurons in the lateral horn, but these are parasympathetic. The nervous system is responsible for all our. The primary purpose of this article is to evaluate the histology of peripheral nervous tissue. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. There are more tissues on the website than you are responsible for. While their origin is not conclusively determined, their function is related to what macrophages do in the rest of the body. Myelin is a fatty substance that makes the axon appear white. In general, where in the brain can grey matter be found? Lymphatic vessels drain lymph (interstitial fluid) from all the extracellular spaces in the body. In the PNS, myelin is produced by Schwann cells, which wrap around the axon. Last reviewed: November 28, 2022 At the end of the axon is the axon terminal, where there are usually several branches extending toward the target cell, each of which ends in an enlargement called a synaptic end bulb. Grounded on academic literature and research, validated by experts, and trusted by more than 2 million users. Examine the gray matter on each side of the sulcus using first low and then high power. In addition to the dorsal and ventral horns, two structures especially obvious in the thoracic cord are the dorsal nucleus of Clarke and the lateral extension of the ventral horn. Dendrites of Purkinje cells extend deep into the molecular layer, while the axons of Purkinje cells cross the granular layer and join other nerve fibers in the interior white matter of the cerebellum. In the peripheral nervous system, the larger diameter axons are surrounded by a lipid-rich myelin sheath formed by the Schwann cells (Wheater's pg. Because the axon hillock represents the beginning of the axon, it is also referred to as the initial segment. Schwann cells are different than oligodendrocytes, in that a Schwann cell wraps around a portion of only one axon segment and no others. They are responsible for the electrical signals that communicate information about sensations, and that produce movements in response to those stimuli, along with inducing thought processes within the brain. ("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. The tissue is sectioned thinly enough so that light can pass through it. Fetal tissues are classified into two types: mesenchyme and mucoid (mucous) connective tissue. It acts as insulation, much like the plastic or rubber that is used to insulate electrical wires. as white matter? There are two types of EM: transmission electron microscopy, which requires very thin sections of tissue, and scanning electron microscopy, which uses larger pieces of tissue and produces 3-dimensional images. Register now There are many neurons in the nervous systema number in the trillions. . Bipolar cells have two processes, which extend from each end of the cell body, opposite to each other. Still deeper is the white matter slide 077 View Image of the cerebellum, which contains nerve fibers, neuroglial cells, small blood vessels, but no neuronal cell bodies. Deep to the gray matter of the cerebral cortex is the white matter that conveys myelinated fibers between different parts of the cortex and other regions of the CNS. The ventral spinal cord. Basic nervous tissue staining mechanisms and classification of nervous tissue elements will be discussed. The lateral extension of the ventral horn slide 065-2 contains relatively large, multipolar visceral motor neurons of the intermediolateral cell column that extends from levels T1 through L2 of the spinal cord. 3. Electron microscopy (EM) is a more modern form of microscopy that provides a much higher magnification and high resolution images. I would honestly say that Kenhub cut my study time in half. Some of the proteins help to hold the layers of the glial cell membrane closely together.The appearance of the myelin sheath can be thought of as similar to the pastry wrapped around a hot dog. Wednesday, August 24. Like the spleen and lymph nodes, the immune cells in this tissue can mount an immune response against foreign invading material. Other staining techniques such as Masson trichrome, alcian blue, reticulin stain and others are sometimes used to demonstrate specific tissue components not seen on a H&E stain. These cells have a single, long, nerve tract entering the bottom of the cell body. Nueron ppt naseemmeeran 139 views . Nervous tissue consists of two cells: nerve cells or neurons and glial cells, which helps transmit nerve impulses and also provides nutrients to neurons. Diffuse lymphoid tissues and lymphatic nodules are non-encapsulated accumulations of lymphoid tissue found in locations such as the alimentary, respiratory and genitourinary tracts. The lymphatic system consists of a network of vessels and lymphoid organs. Eroschenko, V. P. (2017). One or more cell processes may also be seen emerging from the neuronal perikaryon. Recall thatSchwann cells are the glial cells responsible for myelination in the peripheral nervous system. The layers of the blood-air barrier comprise of type I pneumocytes, basement membrane and endothelial cells of the capillaries. The material presented details the chemistry, diagnostic application, and staining protocols for special stains used to . Which are classified as grey matter? White mater 4. The most used tool today for examining cells, tissues and organs is optic (light) microscopy. The information we provide is grounded on academic literature and peer-reviewed research. Some well-known lymphatic nodules include; the tonsils, Peyers patches and vermiform appendix. Did you know that there are special cardiomyocytes in your heart that spontaneously generate impulses to initiate heartbeats? Histology of Nervous TissueNervous system ppt #2. Access to the supplemental resources for this session is password-protected and restricted to University of Michigan students. 1. Slide NP004N hippocampal region coronal section luxol blue View Virtual Slide [orientation]. nervous tissue is derived from embryonic neuroectoderm The nervous system is divided anatomically into: Central Nervous System (CNS), consisting of the brain and spinal cord. These layers of myelin are many times thicker than the diameters of the axons. Examine the layered organization of the cerebral cortex usingslide 76stained withluxol blue/cresyl violet[orientation](which stains white matter tracts and cell bodies) ortoluidine blue and eosin[orientation](TB&E, toluidine blue stains the nuclei and RER of cells whereas eosin stains membranes and axon tracts). The central axons are so thin that they appear as purple dots in the middle of the lighter-colored circles of myelin. Neurons in the dorsal horn are essentially interneurons that project to other regions of the CNS (e.g., motor neurons in the spinal cord or sensory input to the brain), so they have much smaller overall volume and therefore much less metabolic demand compared to motor neurons which project to target muscles that may be more than a meter away. Neurons are the primary type of cell that most anyone associates with the nervous system. How. Since tissues are relatively colorless, the magnifying properties of the optic microscope are not sufficient for proper visualization of a specimen; therefore staining techniques described above are coupled with optic microscopy. Later in this sequence, you will learn how the hippocampus and dentate gyrus function in what is known as the "limbic system" to integrate inputs from many parts of the nervous system into complicated behaviors such as learning, memory, and social interaction. Any of those processes can function as an axon depending on the conditions at any given time. They are stabilized by ligaments, flexible fibrous bands made of dense regular connective tissue. Nicola McLaren MSc Do you know why some structures stain blue (basophilic) and others pink (eosinophilic)? It relays sensory input to cerebral cortex. 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. Other blotting techniques include Southern blot, Western blot, Far-Western blot, Southwestern blot, Eastern blot, Far-Eastern blot, Northern blot, Reverse Northern blot and Dot blot. Epithelium is classified by both its cellular morphology and the number of cell layers. New York, NY: McGraw-Hill Education. Thus are essential for maintaining homeostasis of the body. They are considered part of the mononuclear phagocytic system and will proliferate and become actively phagocytic in regions of injury and/or inflammation. 5 Nervous system The introductory part of the chapter is adapted from BC OpenStax Anatomy and Physiology book under the CC BY license. Based on morphology, epithelial cells can be either squamous (flat), cuboid (cube) or columnar (rectangular). Kind of like border police, it controls everything that comes in or out of the cell. It is composed of densely packed epithelial cells with only a little extracellular matrix (ECM). The dendrites receive neural input from other neurons viasynapses (or they are specialized to receive sensory stimuli), and they transmit neural information toward the perikaryon (Law of Dynamic Polarization). Muscle cells have a specialized type of smooth endoplasmic reticulum called sarcoplasmic reticulum, which stores calcium ions. Unipolar cells are exclusively sensory neurons and have two unique characteristics. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. normal functioning and disorders of the nervous. Aspects of peripheral nerve embryology and clinically . The alimentary canal is a tube extending from the mouth to the anus that serves as a channel for food and water to be digested, their nutrients absorbed and indigestible portions excreted. Read more. This preserves it into the same state that it had when it was in the body, and thus, keeps it from degrading. If you are a University of Michigan student enrolled in a histology course at the University of Michigan, please click on the following link and use your Kerberos-password for access to download lecture handouts and the other resources. As cells are generally colourless, they need to be stained so that they can be easily viewed under the microscope. Nervous tissue contains two categories of cellsneurons and neuroglia. It consists of small, spindle-shaped mesenchymal cells and ground substance with sparse collagen and reticular fibers. Some neurons are named on the basis of those sorts of classifications (Figure 3). All cells are enveloped by a semipermeable two-layered membrane, which serves as a dynamic medium for the cells interaction with the external environment. Once urine is formed from the ultrafiltrate, it travels through the excretory pathway of tubes, all of which are lined by transitional epithelium with the exception of some parts of the urethra. Histology. This actually causes problems with drug delivery to the CNS. This system delivers oxygenated blood from the heart to the tissues, and returns deoxygenated blood from the tissues back to the heart and lungs. Vocal cords are housed in the larynx, formed by two folds of mucosa, each containing a supporting ligament (vocalis ligament) and a skeletal muscle (vocalis muscle). Pulmonary capillaries come into close contact with the alveoli, forming the blood-air barrier. The other major glial cell type you should know about are microglia which are small cells derived from blood monocytes. A key difference between myelin and the insulation on a wire is that there are gaps in the myelin covering of an axon. The three-dimensional shape of these cells makes the immense numbers of connections within the nervous system possible. As the name implies, the cell body is shaped somewhat like a pyramid, with a large, branching dendrite extending from the apex of the pyramid toward the cortical surface, and with an axon extending downward from the base of the pyramid. The neuron shown is a multipolar neurons. Thompson, Ph.D. Histology of Nervous Tissue Despite the complexity of organization, there are only two functional cell . Because information flows through the neuron from dendrites or cell bodies toward the axon, these names are based on the neurons polarity (Figure 2). For Schwann cells, the outermost layer of the cell membrane contains cytoplasm and the nucleus of the cell as a bulge on one side of the myelin sheath. Neuroglia. Histology of Nervous Tissue Feature of nerves tissue Type of cell: neuron & neuroglia General feature of neuron Type of Expert Help Tissue preparation, tissue staining, microscopy, hybridisation. Table 2 outlines some common characteristics and functions. Thoroughly learn the parts of a cell using our diagrams and cell quizzes! Here you will see the Purkinje cell bodies slide 077 View Image. Review diagrams illustrating the morphology of neurons in your textbooks. Correct answer 2. 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. Review the organization of the spinal cord using your atlas. Specialized connective tissue includes the blood, reticular, cartilage, bone and adipose tissue. It relays sensory input to cerebellar cortex. As a muscle contracts, its tendon transmits the force to the bone, pulling on it and causing movement in the associated synovial joint. All Rights Reserved. 2. Histology - Histology. For now, focus just on the morphology of these regions and observe the presence of three distinct layers rather than the six layers found in the cerebral cortex (evolutionarily speaking, the three-layered organization is considered to be "older," so this type of cortex is also known as "archicortex" whereas the "newer" six-layered cerebral cortex is "neocortex"). Bones articulate with other bones by way of joints, which can be synovial, fibrous or cartilaginous. Nervous tissue is composed of two types of cells, neurons and glial cells. 138, 7.18). All cells contain cytoplasm, are surrounded by a membrane, and contain a variety of structures and organelles. Tissuesare classified into four basic types: epithelium, connective tissue (includes cartilage, bone and blood), muscle, and nervous tissue. Friday, August 26 The gray matter contains relatively more neuronal and glial perikarya, as well as non-myelinated (e.g. Learn more about the histology of the upper and lower digestive tract. Luv ya! between a tract and a nerve? This is the reason why people with extensive burns are in life-threatening danger. Peripheral nerves are bundles of myelinated nerve fibers (axons) wrapped in connective tissue (endo-, peri- and epi- neurium). This is a tapering of the cell body toward the axon fiber. The excretory system includes the kidneys, ureters, urinary bladder and urethra. Also note these columnar cells lining the ventricles of the brain. What anatomical feature explains this phenomenon? The projections connect at the dendrites and are so extensive that they give the microglial cell a fuzzy appearance. These bulbs are what make the connection with the target cell at the synapse. Aside from finding efficacious substances, the means of delivery is also crucial. It consists of neurons and supporting cells called neuroglia. The name suggests that it has no axon (an- = without), but this is not accurate. The proteins are then exposed to labeled artificial antibodies that bind to the protein of interest and catalyse a chemiluminescent reaction, in which light is emitted as a result of a chemical reaction allowing visualization of the protein. After preparation, the tissue is stained. Epithelial tissue can cover external surfaces (skin), line the inside of hollow organs (intestines) or form glands. They are separated into four categories: muscular, nervous, epithelial and connective. In these slides, dorsal happens to be "up," but you should be able to tell dorsal and ventral horns based on morphology and the cells present rather than the orientation. The axons of pyramidal cells will descend through the interior white matter of the cerebrum into the three parts of the brainstem: the midbrain, the pons, and the medulla. It is the axon that propagates the nerve impulse, which is communicated to one or more cells. Body tissues are collections of cells, grouped in the body according to structure and function. Based on the number of processes, neurons are classified into multipolar, bipolar and unipolar. Correct answer 1. Nerve tissue consists of 2 principal types of cells: neurons and supporting cells. Histology of Nervous Tissue PROF. DR. FAUZIAH OTHMAN DEPT OF HUMAN ANATOMY Feature of nerves tissue Type of cell: neuron & neuroglia General feature of neuron Type of The BBB also makes it harder for pharmaceuticals to be developed that can affect the nervous system. Ependymal cells line each ventricle, one of four central cavities that are remnants of the hollow center of the neural tube formed during the embryonic development of the brain, as well as the central canal of the spinal cord. The ECM of nervous tissue is rich in ground substance, with little to no protein fibers. The lighter-colored layers on both sides of the axon are myelin. In this electron micrograph, note some of the features you saw in ventral horn motor neurons with the light microscope, such as the large, pale nucleus, prominent nucleolus, Nissl bodies, dendrites and axon. In addition to pyramidal cells, other nuclei seen in these sections may belong to other neurons or to glial cells also present in the cortex. Figure 1, Figure 4, and Figure 5 show the myelin sheath surrounding an axon segment, but are not to scale. The nervous system can be organized in several different ways. Description: Chapter 11 Histology of Nervous Tissue J.F. The spinal cord contains a butterfly-shaped area of grey matter surrounded by an outer layer of white matter. 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. Together these organs provide the ability of reproduction and sexual intercourse. Histology: An overview: want to learn more about it? The product is the magnifying power of the objective (4x, 10x, 20x, 40x or 100x) multiplied by the power of the ocular lenses (10x). Controls and integrates all body activities. Mescher, A. L. (2013). Nervous tissue is made of cells (neurons and glial cells) and extracellular matrix. Neurons are the primary type of cell that most anyone associates with the nervous system. DNA is condensed and coiled up into chromosomes. Pharmaceutical companies are challenged to design drugs that can cross the BBB as well as have an effect on the nervous system. Both respond immunologically to foreign material in the fluid passing through. system is called neurology. Here, the tissue of interest is immersed in a fixative solution. . It will also benefit the publication of several new topics (Hematology, Pathogen ID, and Gross Anatomy). Afferent nerves carry information from sensory organs to the brain, while efferent nerves carry motor impulses from the brain to the muscles.Taking location into account, the nervous system can be divided into the central nervous system (CNS) and the peripheral nervous system (PNS). Water and some other small particles, like gases and ions, can enter. Did you know that chronic alcoholics have a lot more smooth endoplasmic reticulum concentrations in their hepatocytes? Next, the tissue is embedded with paraffin wax, which firms the tissue enough permit thin slices. Cardiomyocytes contain actin and myosin filaments just like other muscle cells, but they have some special structural and functional properties. The cardiovascular system consists of the heart and blood vessels (arteries, arterioles, capillaries, venules, veins). Since tissues are normally colourless, applying a dye to the tissue section allows the cells and their components to be seen under a microscope. The dorsal nucleus of Clarke slide 066a View Image is in the dorsal horn and contains relatively large, multipolar neurons that receive proprioceptive information from dorsal root ganglion cells that are innervated by muscle spindles in the trunk and lower limb. There are six types of glial cells. Each gap is called a node of Ranvier and is important to the way that electrical signals travel down the axon. They are large, easily distinguishable, and have an extensive dendritic tree that is not visible in typical histology. All rights reserved. The name means cell of a few branches (oligo- = few; dendro- = branches; -cyte = cell). 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. 1. For example, nerves can be classified based on their function. The study of. All content published on Kenhub is reviewed by medical and anatomy experts. Peripheral nerves are analogous with neural tracts of the CNS. At a microscopic level, a nephron consists of a renal corpuscle and a series of tubules. The basic functional unit of the kidney is the nephron. Multiple muscle cells are bound by connective tissue into fascicles, and multiple fascicles join to form a muscle belly. The main effector cells of the lymphatic system are the immune system cells. The digestive system consists of the alimentary canal and its associated organs (tongue, teeth, salivary glands, pancreas, liver and gallbladder). Spermatozoa pass from the testis into the epithelial lined epididymis and ductus (vas) deferens via efferent ductules, then into the ejaculatory duct, which merges with the urethra. Slide NP004N hippocampal region, coronal section, luxol blue View Virtual SlideSlide 13270astrocytes,Gold-stainingView Virtual Slide. It is permeable to oxygen, carbon dioxide and other gases, allowing for the occurrence of gas exchange. The Schwann cells (in the peripheral nerves) and the satellite cells (in the ganglia) are glial cells (supporting cells) of the PNS. Neurons are the basic functional units of nervous tissue. 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. 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. Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). Slide of tissue is followed by slide of tissue with correct answer. The nucleus is considered to be the brain of the cell. Pancreatic serous acini secrete digestive enzymes which break down fat, carbohydrates and proteins.

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