Be able to identify tissues in the nervous system (nerves, cell bodies and ganglia, and white vs. gray matter in the spinal cord, cerebellum, and cerebrum). The edges of this loose enclosure extend toward each other, and one end tucks under the other. On a longitudinal section, cardiomyocytes appear branched, joined together by specialized junctions called intercalated discs which allow them to quickly exchange electrical impulses and work as a syncytium. The dendrites are projections that branch many times, forming small, tree-shaped structures protruding from the cell body that provide locations for other neurons to communicate with the cell body. ("6" in the orientation figure) a molecular layer containing dendrites of the granule cells. This is done by the use of a complementary nucleotide probe, which contains a radioactive or fluorescent label. The central axons are so thin that they appear as purple dots in the middle of the lighter-colored circles of myelin. Type II pneumocytes are also important because they secrete surfactant which prevents the lungs from collapsing. Table 2 outlines some common characteristics and functions. Neurons of the cerebral cortex are of varying shapes and sizes, but the most obvious arepyramidal cells. In the PNS, myelin is produced by Schwann cells, which wrap around the axon. within limits that maintain life. Nerve tissue consists of 2 principal types of cells: neurons and supporting cells. How is this different in the spinal cord? The sample on the slide below (Figure 7) was taken from the motor cortex, an area of the frontal lobe of the cerebral cortex that is involved in the conscious planning and execution of voluntary muscle movement. Ana 211 (Histology of Nervous tissue).pptx sunday godwin obaje Read Now Download Free PDF Related Papers Cancer Registry Report 2000 2002 Robina Greaves Download Free PDF View PDF Identification of OTX2 as a Medulloblastoma Oncogene Whose Product can be Targeted by All-Trans Retinoic Acid Timothy Parrett Download Free PDF View PDF 1:00 - 2:55 Cartilage and Bone ppt | pdf | lecture recording. The length of the axon between each gap, which is wrapped in myelin, is referred to as an axon segment. One of the two types of glial cells found in the PNS is the satellite cell. The other processes of the neuron are dendrites, which receive information from other neurons at specialized areas of contact called synapses. The other major glial cell type you should know about are microglia which are small cells derived from blood monocytes. Epithelial cells form two important histological structures within the brain; the blood-brain barrier and the choroid plexus. Neurons (Nerve cell bodies) 5 6 5. Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster. between a tract and a nerve? - PowerPoint PPT presentation Number of Views: 793 Avg rating:3.0/5.0 Slides: 13 Provided by: RachelA156 Category: After preparation, the tissue is stained. Diffuse lymphoid tissues and lymphatic nodules are non-encapsulated accumulations of lymphoid tissue found in locations such as the alimentary, respiratory and genitourinary tracts. Nervous Tissue DR. DEVI 1 16-4-19 2. Anatomy & Physiology I Chapter 4. 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. Mesenchyme gives rise to all types of connective tissue. Myelin is a fatty substance that makes the axon appear white. What is the difference between a ganglion and a nucleus? A unity of tissues with a more complex set of functions, defined by the combination of structure and function of the comprising tissues. The tissue is sectioned thinly enough so that light can pass through it. This technique is used for determining the location of specific DNA or RNA sequences in cells or chromosomes, making it useful for various research and diagnostic purposes. All of these components work together to provide movement to the body. Did you know that there are special cardiomyocytes in your heart that spontaneously generate impulses to initiate heartbeats? Why are perikarya of dorsal horn neurons smaller than those in the ventral horn? It relays sensory input to other neurons in the spinal cord. Author: Adjacent to the neuron, note myelinated axons of various sizes and also that there are no spaces between cell processes. It also includes important proteins that are integral to that membrane. Neuroglia. However, if you take a much closer look, youll see that the histology of bones, is a whole other story. Histology of Nervous TissueNervous system ppt #2. This gives the neuron a polaritymeaning that information flows in this one direction. 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. Together these organs provide the ability of reproduction and sexual intercourse. 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 are organized into lobules, with each lobule containing a parenchyma of seminiferous tubules and a connective tissue stroma. These bulbs are what make the connection with the target cell at the synapse. The ECM contains different protein fibers (collagen, reticular, elastic) embedded in ground substance. Astrocytes in the CNS provide metabolic support for neurons and play an important role in maintaining the blood-brain barrier (see slide 13270 astrocytes View Virtual Slide). 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. It consists of a few cells and an abundance of extracellular matrix. Histology of nervous tissue1 Kifayat Khan 855 views 26 slides Nervous tissue2k1 Hatesh Mahtani 4.8k views 109 slides General histology || Nervous tissue Ali Nasser 457 views 8 slides Nervous tissue i kohlschuetter 3.3k views 25 slides Nervous tissue 1 aiyub medicine 4.3k views 90 slides Introduction to Neuropathology Cassie Porebski Reading time: 28 minutes. The integumentary system consists of the skin and skin appendages. This traps and removes any inhaled dust, bacteria or foregn substances. Schwann cells are different than oligodendrocytes, in that a Schwann cell wraps around a portion of only one axon segment and no others. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. The neuronal bodies within the grey matter are organized into layers (laminae). Grey matter is composed mainly of unmyelinated cell bodies and dendrites, and appears grey in color. All cells of the human body are eukaryotic, meaning that they are organized into two parts: nucleus and cytoplasm. Recall thatSchwann cells are the glial cells responsible for myelination in the peripheral nervous system. The tissues of the nervous system can also be divided into grey matter and white matter. They return this fluid to the heart, passing it through lymphoid organs. Myelin is lipid-rich, and on gross inspection appears white. Blotting technique is a method of localizing and quantifying proteins, DNA and RNA. Four main groups of tissues Epithelial Connective Muscle Nervous tissue. Nervous tissue histology 1. Because of the privileged blood supply inherent in the BBB, the extracellular space in nervous tissue does not easily exchange components with the blood. The CNS contains the brain and spinal cord. Multiple muscle cells are bound by connective tissue into fascicles, and multiple fascicles join to form a muscle belly. Each one reaches out and surrounds an axon to insulate it in myelin. The lighter-colored layers on both sides of the axon are myelin. This actually causes problems with drug delivery to the CNS. Secondly, the cell bodies of unipolar neurons are always found in ganglia. These exclusively contain neurons with a pseudounipolar neuronal arrangement. All rights reserved. It also helps us understand the relationship between structure and function. The most common technique used is the hematoxylin and eosin (H&E) stain. Like a few other parts of the body, the brain has a privileged blood supply. Slide 66a View Virtual Slide shows a section of thoracic spinal cord. Histology Copyright by Malgosia Wilk-Blaszczak. The small gap in the myelin sheath that occurs between adjacent Schwann cells is called a node of Ranvier. And there are many different types of neurons. Because information flows through the neuron from dendrites or cell bodies toward the axon, these names are based on the neurons polarity (Figure 2). The spleen on the other hand, filters blood. Neurons are the basic functional units of nervous tissue. Human unipolar cells have an axon that emerges from the cell body, but it splits so that the axon can extend along a very long distance. The projections connect at the dendrites and are so extensive that they give the microglial cell a fuzzy appearance. Correct answer 1. Epithelial tissue can cover external surfaces (skin), line the inside of hollow organs (intestines) or form glands. Luv ya! The cytoplasm contains specialized subunits called organelles which work like little organs. Test yourself on cardiac muscle tissue with the following quiz. Neurons are specialized cells that contain a body (soma) and one or more processes (dendrites, axons). Resources in the University of Michigan Histology Dropbox, Slide 065-1N spinal chord Masson cross View Virtual Slide, Slide 065-2 spinal cord lumbar H&E cross View Virtual Slide, Slide 065-1 spinal cord lumbar H&E cross View Virtual Slide, Slide 066a thoracic spinal cord thoracic spinal cord luxol blue cross View Virtual Slide. Other methods include histochemistry, immunocytochemistry, hybridization techniques, tissue culture and many others. Histology of the Nervous System Description: Histology of the Nervous System X-Section of Brain Tissue 4 1 2 3 1. Kind of like border police, it controls everything that comes in or out of the cell. Smooth muscle tissue appears non-striated because of the less orderly arrangement of their filaments. Spleen and lymph node histology shows an encapsulated meshwork of fibres, in which immune system cells sit. 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. They can be classified by many different criteria. All Rights Reserved. All content published on Kenhub is reviewed by medical and anatomy experts. Click on the white box with the question mark on it 4. 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 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. Aside from finding efficacious substances, the means of delivery is also crucial. Histology (Tissues). Much like the male, the female reproductive system is also designed for reproduction and sexual pleasure. 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. Wheater's Nervous tissues and Central nervous system, Ross and Pawlina (6th ed), Chapter 12 Nerve Tissue, Except where otherwise noted, this work is licensed under a, Michigan Histology and Virtual Microscopy Learning Resources, Creative Commons Attribution-Noncommercial-Share Alike 3.0 License. At a microscopic level, a nephron consists of a renal corpuscle and a series of tubules. Oligodendrocytes have processes that reach out to multiple axon segments, whereas the entire Schwann cell surrounds just one axon segment. Neurons in the dorsal horn are essentially interneurons that project to other regions of the CNS (e.g. Neurons. One or more cell processes may also be seen emerging from the neuronal perikaryon. An important part of the function of neurons is in their structure or shape. The cardiovascular system consists of the heart and blood vessels (arteries, arterioles, capillaries, venules, veins). Neurons are important, but without glial support they would not be able to perform their function. It relays sensory input to cerebellar cortex. The four main types of stains used in histology are empirical, histochemical, enzyme histochemical and immunohistochemical. The product is the magnifying power of the objective (4x, 10x, 20x, 40x or 100x) multiplied by the power of the ocular lenses (10x). Organelles can be membranous (mitochondria, Golgi apparatus, endoplasmic reticulum) or non-membranous (ribosomes, nucleolus, centrioles). The ventral spinal cord. 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. Histology of Nervous Tissue PROF. DR. FAUZIAH OTHMAN DEPT OF HUMAN ANATOMY 2 Feature of nerves tissue Type of cell neuron neuroglia General feature of neuron Type of neuroglia astrocyte, oligodendrocyte, ependymal cell, microglia Synapses Myelin formation function General structure of peripheral nerves Ganglia dorsal root ganglia autonomic ganglia While this barrier protects the CNS from exposure to toxic or pathogenic substances, it also keeps out the cells that could protect the brain and spinal cord from disease and damage. These sections are then mounted on a glass slide, using a mounting medium as an adhesive. It will also benefit the publication of several new topics (Hematology, Pathogen ID, and Gross Anatomy). Cardiomyocytes contain actin and myosin filaments just like other muscle cells, but they have some special structural and functional properties. Register now Skeletal muscle consists of long cylindrical-shaped muscle cells with multiple, peripherally located nuclei and a cytoplasm filled with myofibrils. What is the distinction between the CNS and the PNS? The endocrine system is divided into major endocrine glands (e.g. Review diagrams illustrating the morphology of neurons in your textbooks. Pia mater 2. This Power point presentation will allow students to practice the skill of identifying tissue types from 25 histology slides. It is the axon that propagates the nerve impulse, which is communicated to one or more cells. Identify all four general tissue types Answer: epithelial, connective, muscular & nervous Which of the four basic types is described below: Contains free edge Lines hollow organs Anchored by basement membrane Answer:Epithelial tissue Which of the four basic types is described below: Lack blood vessels, Readily divide Cells are tightly packed While their origin is not conclusively determined, their function is related to what macrophages do in the rest of the body. It is permeable to oxygen, carbon dioxide and other gases, allowing for the occurrence of gas exchange. Both will appear grey to the naked eye and under the microscope, due to their lack of myelin. These hormones regulate a variety of processes, such as metabolism, growth and blood pressure. You may see small calcific bodies in part of the hippocampus, which occur as a normal part of the aging process. With the exception of the unipolar sensory ganglion cells, and the two specific bipolar cells mentioned above, all other neurons are multipolar. Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). DNA is condensed and coiled up into chromosomes. Basic nervous tissue staining mechanisms and classification of nervous tissue elements will be discussed. 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. Lateral to this structure is the tail of the caudate. Bundles of myelinated axons in the brain are called tracts, while bundles of axons in the PNS are called nerves. 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. Download Presentation Histology of Nervous Tissue An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. During development, the glial cell is loosely or incompletely wrapped around the axon (Figure 6). 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. Name thefunction of the cell marked by the black arrow. Did you know that chronic alcoholics have a lot more smooth endoplasmic reticulum concentrations in their hepatocytes? Chapter 12Nervous Tissue. It is this myelin, a lipid-rich sheath covering axons, that causes white matter to be lighter in color than grey matter. Slide 13270 astrocytes, Gold-staining View Virtual Slide Go to a lighter stained area of the slide, which is in focus, and look for typical star-shaped cells, which represent astrocytes. Lining ventricles of the brain, creating CSF. Typically one or more sulci (infoldings) will extend inward from one edge of the section. All of these features give muscles the ability to contract and perform various functions, such as movement of the extremities (skeletal muscle), peristalsis of the gastrointestinal tract (smooth muscle) and beating of the heart (cardiac muscle). Supporting cells dont get as much credit as neurons in popular culture; but did you know that glial cells make up at least 80% of nervous tissue? Electron microscopy (EM) is a more modern form of microscopy that provides a much higher magnification and high resolution images. First, their dendrites are receiving sensory information, sometimes directly from the stimulus itself. Description: Chapter 11 Histology of Nervous Tissue J.F. Whereas the manner in which either cell is associated with the axon segment, or segments, that it insulates is different, the means of myelinating an axon segment is mostly the same in the two situations. The Schwann cells (in the peripheral nerves) and the satellite cells (in the ganglia) are glial cells (supporting cells) of the PNS. If the myelin sheath were drawn to scale, the neuron would have to be immensepossibly covering an entire wall of the room in which you are sitting. 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. Unipolar cells are exclusively sensory neurons and have two unique characteristics. Want to create or adapt books like this? Next, the tissue is embedded with paraffin wax, which firms the tissue enough permit thin slices. Nervous tissue consists of two cells: nerve cells or neurons and glial cells, which helps transmit nerve impulses and also provides nutrients to neurons. It provides somatic motor output to skeletal muscles. Contents Neuron Nerve cell processes Synapses And impulse transmission The neuroglia Myelin sheath 2 3. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. The relationship of these two types of glial cells to ganglia and nerves in the PNS is seen in Figure 5. Muscle tissue maintains synthesizing and contractile functions. The material presented details the chemistry, diagnostic application, and staining protocols for special stains used to . Onecommonly used technique is Western blot, in which proteins are separated from one another based on molecular weight using gel electrophoresis. Histology Study of Tissues Epithelial Tissue Connective Tissue Nervous and Muscular Tissue Intercellular Junctions, Glands and Membranes Tissue Growth, Development . 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). . Read more. But most everything else cannot, including white blood cells, which are one of the bodys main lines of defense. They are considered part of the mononuclear phagocytic system and will proliferate and become actively phagocytic in regions of injury and/or inflammation. These include epithelial cells, fibroblasts, neutrophils, erythrocytes, keratinocytes, chondrocytes just to name a few. Ependymal cells, which are uniquely located lining the ventricles of the brain the central canal of the spinal cord, are one notable exception. 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). Available at theiTunes Storeand for Android users at theGoogle Play Store. That single axon can branch repeatedly to communicate with many target cells. The BBB also makes it harder for pharmaceuticals to be developed that can affect the nervous system. NERVOUS TISSUE Nervous tissue consists of two groups of cell types: Nerve cells (Neurons) Neuroglia. Histology. 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. They can be classified as sensory or autonomic. 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. The study of. Nutrient molecules, such as glucose or amino acids, can pass through the BBB, but other molecules cannot. Any size contribution is welcomed and will help us to provide these popular review tools to students at the University of Michigan and to many more worldwide. Below the dermis, a layer of subcutaneous tissue (hypodermis) is found. Many types of glial cells require special histological stains and cant be unambiguously identified in regular H&E-stained histological slides. Continue your learning with these resources. 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. EM works by emitting parallel beams of electrons onto the tissue sample. The digestive system consists of the alimentary canal and its associated organs (tongue, teeth, salivary glands, pancreas, liver and gallbladder). Based on their functional properties, these are described as either voluntary (skeletal) or involuntary (cardiac and smooth muscle). Organs work together in systems. ("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. 3. Human anatomy is pretty straightforward. It is categorised as skeletal, cardiac or smooth. Light microscopes (or optical microscopes), use a combination of visible light and lenses to create a magnified image. Because of the difficulty of discerning each glial cell type by routine light microscopy, you will not be required to identify glial cells in HE-stained sections by light microscopy, but you should be aware of their functions. Two large nerve tracts typically leave the top of the cell body but immediately branch many times to form a large web of nerve fibers. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. Astrocytes - Technically, the junctions between endothelial cells constitute the actual "barrier." One is the axon and one the dendrite, forming a straight line. The predominant cells visible on the slide are called pyramidal cells (named for their triangular shape). Uploaded on Jun 06, 2013 Elina + Follow cuboidal epithelium water loss Also found in CNS tissue is the oligodendrocyte, sometimes called just oligo, which is the glial cell type that insulates axons in the CNS. The axon projects from the dendrite endings, past the cell body in a ganglion, and into the central nervous system. Kenhub. Different regions of the nervous system have distinct histological characteristics that make them easily recognizable, under the microscope. Depending on the type of cells present (fibroblasts, osteocytes, erythrocytes) and the ECM arrangement, connective tissue can be classified as connective tissue proper or specialized connective tissue. True unipolar cells are only found in invertebrate animals, so the unipolar cells in humans are more appropriately called pseudo-unipolar cells. Pulmonary capillaries come into close contact with the alveoli, forming the blood-air barrier. The multipolar neurons in this area are known as "mossy cells" slide NP004N View Image and they primarily receive input from mossy fibers of the granule cells of the dentate gyrus and then relay those signals back to other cells in the dentate. Some cutting edge research suggests that certain neurons in the CNS do not conform to the standard model of one, and only one axon. For oligodendrocytes, the rest of the cell is separate from the myelin sheath as a cell process extends back toward the cell body. Work for the lab This website is a great way to view the tissues. The neuronal type is found throughout the entire human nervous system except in dorsal root/sensory ganglia. This system delivers oxygenated blood from the heart to the tissues, and returns deoxygenated blood from the tissues back to the heart and lungs. They also have cilia on their apical surface to help move the CSF through the ventricular space. The ECM of nervous tissue is rich in ground substance, with little to no protein fibers.
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