nervous tissue histology ppt

Nervous tissue is composed of two types of cells, neurons and glial cells. Cerebral cortex 3. 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. Due the nature of histological sampling, it is impossible to see the entirety of a three-foot-long neuron on a single slide. Recall thatSchwann cells are the glial cells responsible for myelination in the peripheral nervous system. This neuron provides preganglionic visceral motor output to sympathetic ganglia - Even though the cord is oriented "sideways," you should still be able to identify this cell as being in the intermediolateral cell column in the lateral extension of the ventral horn where pregagnglionic sympathetic visceral motor neurons are found. It provides preganglionic visceral motor output to sympathetic ganglia. With the exception of the unipolar sensory ganglion cells, and the two specific bipolar cells mentioned above, all other neurons are multipolar. Examine the gray matter on each side of the sulcus using first low and then high power. Satellite cells are found in sensory and autonomic ganglia, where they surround the cell bodies of neurons. Under light microscopy, skeletal and cardiac muscles appear striated due to the parallel arrangement of their contractile filaments into repeating units called sarcomeres. New York, NY: McGraw-Hill Education. For example, the simple columnar epithelium of the stomach fundus contains special parietal cells which secrete HCl to break down meat proteins. 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. Based on morphology, epithelial cells can be either squamous (flat), cuboid (cube) or columnar (rectangular). Nervous tissue histology 1. This Power point presentation will allow students to practice the skill of identifying tissue types from 25 histology slides. Histology: An overview: want to learn more about it? The cells are laid down on top of dense irregular connective tissue, the basement membrane (BM). It is composed of densely packed epithelial cells with only a little extracellular matrix (ECM). . Human anatomy is pretty straightforward. Muscle tissue maintains synthesizing and contractile functions. Four main groups of tissues Epithelial Connective Muscle Nervous tissue. It consists of neurons and supporting cells called neuroglia. Next, the tissue is embedded with paraffin wax, which firms the tissue enough permit thin slices. Grey matter is composed mainly of unmyelinated cell bodies and dendrites, and appears grey in color. Histology. 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. Fetal tissues are classified into two types: mesenchyme and mucoid (mucous) connective tissue. Epithelium is classified by both its cellular morphology and the number of cell layers. During development, the glial cell is loosely or incompletely wrapped around the axon (Figure 6). Kenhub. 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. Many of these astrocytes send out processes that contact and wrap around nearby capillaries, which are also clearly recognizable as tube-shaped segments. This actually causes problems with drug delivery to the CNS. Luv ya! In the PNS, myelin is produced by Schwann cells, which wrap around the axon. 1. Neurons are the basic functional units of nervous tissue. The organization and morphology of the cells shown is found ONLY in the ventral spinal cord. Myelin, however, is more than just the membrane of the glial cell. The excretory system includes the kidneys, ureters, urinary bladder and urethra. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. Multiple muscle cells are bound by connective tissue into fascicles, and multiple fascicles join to form a muscle belly. As such, nerves do not contain neural cell bodies. The tissue is sectioned thinly enough so that light can pass through it. Get an overview of the different types of epithelial tissue: Connective tissue connects, separates and supports the body organs. These cells have a single, long, nerve tract entering the bottom of the cell body. 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. Philadelphia, PA: Lippincott Williams & Wilkins. Using slide 77, determine that the cerebellar cortex is organized into an outer molecular layer slide 077 View Image containing basket and stellate cells (not distinguishable by routine light microscopy) as well as axons of granule cells found in the deeper, highly cellular granule layer slide 077 View Image. A third type of connective tissue is embryonic (fetal) tissue, this is a type of primitive tissue present in the embryo and umbilical cord. Each one reaches out and surrounds an axon to insulate it in myelin. 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. Central Nervous System Connective Tissue Ear Endocrine System Epithelial Tissue Eye Female Reproductive System . Pia mater 2. Review the organization of gray and white matter in cerebral cortex vs. spinal cord. 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 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. The dermis is a layer of connective tissue that contains collagen fibers, blood vessels, lymphatics and nerve endings. The ovary is actually an organ homologous to the male testis, it gives rise to the gametes (ova) and steroid hormones (estrogen, progesterone). The integumentary system consists of the skin and skin appendages. All content published on Kenhub is reviewed by medical and anatomy experts. Pancreatic serous acini secrete digestive enzymes which break down fat, carbohydrates and proteins. They are separated into four categories: muscular, nervous, epithelial and connective. 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. Glucosethe primary energy sourceis allowed, as are amino acids. A few other processes provide the same insulation for other axon segments in the area. Histologically, although there are a few exceptions, endocrine cells generally have an epithelial origin. Many types of glial cells require special histological stains and cant be unambiguously identified in regular H&E-stained histological slides. 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. At low magnification, differentiate inner gray from outer white matter and identify dorsal and ventral horns of the gray matter. Mesenchymal cells are undifferentiated cells, which means they are capable of differentiating into any type of connective tissue cells (fibroblasts, osteoblasts, adipocytes etc.). The CNS consists of nervous tissue that is protected within bony structures the brain within the cranium and the spinal cord within the vertebral column. This system delivers oxygenated blood from the heart to the tissues, and returns deoxygenated blood from the tissues back to the heart and lungs. The latter constitutes the diffuse neuroendocrine system (DNES). The testes produce male gametes (spermatozoa) via the process of spermatogenesis. Read more. Germinal (spermatogenic) epithelium, with spermatogenic cells and nurse (sertoli) cells, forms the convoluted tubules, while small circular interstitial (Leydig) cells are found in the connective tissue between the tubules. Using only histological evidence, could you determine from where in the nervous system a sample of tissue was taken? Look at the margins of the ventricle at higher magnification and note that it is entirely lined by ependymal cells. Wheaters functional histology: A text and colour atlas. Structure of a Neuron. Astrocytes - Technically, the junctions between endothelial cells constitute the actual "barrier." The ventral spinal cord. Figure 1 shows the relationship of these parts to one another. Because of this, ependymal cells can be considered a component of the BBB, or a place where the BBB breaks down. The length of the axon between each gap, which is wrapped in myelin, is referred to as an axon segment. Tissues. It acts as insulation, much like the plastic or rubber that is used to insulate electrical wires. 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. within limits that maintain life. Some neurons are named on the basis of those sorts of classifications (Figure 3). A key difference between myelin and the insulation on a wire is that there are gaps in the myelin covering of an axon. Spleen and lymph node histology shows an encapsulated meshwork of fibres, in which immune system cells sit. The skin is both a medium for interaction with the environment and a barrier, protecting us from outside microbes and chemicals, changes in temperature and dehydration. The blood-brain barrier is a physiological barrier that keeps many substances that circulate in the rest of the body from getting into the central nervous system, restricting what can cross from circulating blood into the CNS. 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 The most used tool today for examining cells, tissues and organs is optic (light) microscopy. Histology. It also includes important proteins that are integral to that membrane. These include epithelial cells, fibroblasts, neutrophils, erythrocytes, keratinocytes, chondrocytes just to name a few. The renal corpuscle contains the glomerulus, a tuft of fenestrated capillaries which creates an ultrafiltrate of blood. Together this gives us the various types of epithelial tissues, such as simple squamous epithelium, stratified cuboidal epithelium, pseudostratified columnar epithelium and many more. The cardiovascular system consists of the heart and blood vessels (arteries, arterioles, capillaries, venules, veins). They also have cilia on their apical surface to help move the CSF through the ventricular space. The relationship of these two types of glial cells to ganglia and nerves in the PNS is seen in Figure 5. Junquieras Basic Histology (13th ed.). Anatomy & Physiology I Chapter 4. Pulmonary capillaries come into close contact with the alveoli, forming the blood-air barrier. 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. The edges of this loose enclosure extend toward each other, and one end tucks under the other. The cells of the genital ducts and glands produce secretions to support this process. Cells are the tiny living units that form the tissues, organs and structures within the body. Also found in CNS tissue is the oligodendrocyte, sometimes called just oligo, which is the glial cell type that insulates axons in the CNS. Those processes extend to interact with neurons, blood vessels, or the connective tissue covering the CNS that is called the pia mater (Figure 4). Alveoli are the primary site of gas exchange. I love Anatomy. Together these organs provide the ability of reproduction and sexual intercourse. Kind of like border police, it controls everything that comes in or out of the cell. True unipolar cells are only found in invertebrate animals, so the unipolar cells in humans are more appropriately called pseudo-unipolar cells. Nervous tissue contains two basic categories of cells: neurons and support cells (glia). Reviewer: Kim Bengochea, Regis University, Denver. The other processes of the neuron are dendrites, which receive information from other neurons at specialized areas of contact called synapses. 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. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. Below the dermis, a layer of subcutaneous tissue (hypodermis) is found. Despite their differences, they all have one thing in common; specialized elongated muscle cells, called muscle fibers. Continue your learning with these resources. Different regions of the nervous system have distinct histological characteristics that make them easily recognizable, under the microscope. Most of the respiratory tract is lined by respiratory mucosa; a pseudostratified columnar ciliated epithelium with mucus producing goblet cells. Learn more about the histology of the upper and lower digestive tract. Neurons of the cerebral cortex are of varying shapes and sizes, but the most obvious arepyramidal cells. At one end of the axon are dendrites, and at the other end, the axon forms synaptic connections with a target. White mater 4. Click on the white box with the question mark on it 4. Axon diameters can be as small as 1 to 20 micrometers. They can be classified by many different criteria. Edinburgh: Churchill Livingstone. The lighter-colored layers on both sides of the axon are myelin. The CNS contains the brain and spinal cord. Interstitial cells produce testosterone, a hormone that regulates spermatogenesis. For oligodendrocytes, the rest of the cell is separate from the myelin sheath as a cell process extends back toward the cell body. Smooth muscle tissue appears non-striated because of the less orderly arrangement of their filaments. An important part of the function of neurons is in their structure or shape. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. The glomerulus contains some interesting cells, such as mesangial cells which have supportive and phagocytic properties; juxtaglomerular cells that secrete renin which acts, in a broad sense, to help regulate our blood pressure; podocytes that control the permeability of the filtration membrane; and many more. It consists of internal genitalia (vagina, uterus, uterine tubes, ovaries) and external genitalia or vulva (mons pubis, labia majora and minora, clitoris, vestibule, vestibular bulb and glands). It is this myelin, a lipid-rich sheath covering axons, that causes white matter to be lighter in color than grey matter. The first step in tissue preparation for optic microscopy is fixation. Epithelial cells form two important histological structures within the brain; the blood-brain barrier and the choroid plexus. As you learned in the first section, the main part of a neuron is the cell body, which is also known as the soma (soma = body). Nails are plates of proliferating keratinized cells that, similar to hair, contain hard keratin. The lipids are essentially the phospholipids of the glial cell membrane. DNA is condensed and coiled up into chromosomes. Description: Chapter 11 Histology of Nervous Tissue J.F. All of this is surrounded by three connective tissue membranes (meninges): dura, arachnoid and the pia mater. Onecommonly used technique is Western blot, in which proteins are separated from one another based on molecular weight using gel electrophoresis. Skin glands include sweat glands (apocrine and eccrine) and sebaceous holocrine glands, both are important in regulating body temperature. 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. Scattered in the cytoplasm are the characteristic clusters of ribosomes and rough ER termed Nissl bodies or Nissl substanceslide 066aView Image. as white matter? It is made up of gray matter and white matter. To visualize this dendritic tree, an osmium stain can be used. The cytoplasm contains specialized subunits called organelles which work like little organs. 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. Click on launch activity 2. The other major glial cell type you should know about are microglia which are small cells derived from blood monocytes. 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. Young, B., Woodford, P., ODowd, G., & Wheater, P. R. (2014). There are 6 classically recognized layers of the cortex: Pyramidal cells in layers III and V tend to be larger because their axons contribute to efferent projections that extend to other regions of the CNS pyramidal neurons in layer V of motor cortices send projections all the way down to motor neurons in the spinal cord! Both neurons and glia have fine processes projecting from the cell body, which generally cannot be resolved in the light microscope without special staining techniques. The product is the magnifying power of the objective (4x, 10x, 20x, 40x or 100x) multiplied by the power of the ocular lenses (10x). This accounts for the name, based on their appearance under the microscope. Tissues join together in different arrangements to form our body organs. Cells are categorized into various types, all of which perform different functions. And there are many different types of neurons. Contrast the differences in the histological appearance of a pyramidal cell versus a Purkinje cell. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. Neuroglia. Click on the tissue and observe. At a microscopic level, a nephron consists of a renal corpuscle and a series of tubules. Any of those processes can function as an axon depending on the conditions at any given time. Cells that are well preserved show features characteristic of most neurons: large cell body, large pale nucleus, Nissl substance, and cell processes (most of which are dendrites). 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. Nervous tissue contains two categories of cellsneurons and neuroglia. The musculoskeletal system consists of hard tissues (bones, joints, cartilage) and soft tissues (muscles, tendons, ligaments). 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. 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. Click on explore at the bottom of the page 3. One is the axon and one the dendrite, forming a straight line. EM works by emitting parallel beams of electrons onto the tissue sample. Many neurons in the spinal cord may appear shrunken and surrounded by an empty space due to poor fixation. 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. behaviors, memories, and movements. It provides somatic motor output to skeletal muscles. I would honestly say that Kenhub cut my study time in half. The digestive system consists of the alimentary canal and its associated organs (tongue, teeth, salivary glands, pancreas, liver and gallbladder). 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. They are stabilized by ligaments, flexible fibrous bands made of dense regular connective tissue. These hormones regulate a variety of processes, such as metabolism, growth and blood pressure. Use the virtual slide of the hippocampal region to study the ependymal cell lining of the choroid plexus. Unlike the highly organized cerebellar cortex, the cerebral cortex appears to be less well-organized when viewed with the light 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. Tissues. One of the two types of glial cells found in the PNS is the satellite cell. Lymph nodes are distributed along lymphatic vessels, filtering lymph as it passes through. In situ hybridisation is a method of localizing and quantifying DNA or RNA sequences. Neurons are the primary type of cell that most anyone associates with the nervous system. Let histology be a piece of cake once you learn how to examine a histology slide! It is permeable to oxygen, carbon dioxide and other gases, allowing for the occurrence of gas exchange. 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 - A free PowerPoint PPT presentation (displayed as an HTML5 slide show) on PowerShow.com - id: 4617df-OTVjO There is a lot more to know about the female reproductive system. But what makes neurons special is that they have many extensions of their cell membranes, which are generally referred to as processes. They return this fluid to the heart, passing it through lymphoid organs. Nervous tissue. Name thefunction of the cell marked by the black arrow. Generally, they are supporting cells for the neurons in the central nervous system. Slide 66a View Virtual Slide shows a section of thoracic spinal cord. Basic nervous tissue staining mechanisms and classification of nervous tissue elements will be discussed. 2023 It monitors and regulates the functions of the body. Adjacent to the neuron, note myelinated axons of various sizes and also that there are no spaces between cell processes. Ongoing research into these cells, although not entirely conclusive, suggests that they may originate as white blood cells, called macrophages, that become part of the CNS during early development. 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). (PWA), including the SecondLookHistology apps. Why are perikarya of dorsal horn neurons smaller than those in the ventral horn? Oligodendrocytes (another type of glial cell) are responsible for the myelination of CNS axons. Unipolar neurons have only one process emerging from the cell body which causes them to appear T-shaped. 3. The three-dimensional shape of these cells makes the immense numbers of connections within the nervous system possible. Correct answer 1. How is this different in the spinal cord? Neurons are specialized cells that contain a body (soma) and one or more processes ( dendrites, axons ). One or more cell processes may also be seen emerging from the neuronal perikaryon. The nucleus and cytoplasm of the Schwann cell are on the edge of the myelin sheath. normal functioning and disorders of the nervous. It is specialized tissue found in the central nervous system and the peripheral nervous system. These layers of myelin are many times thicker than the diameters of the axons. Neuroglia. 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"). The gray matter contains relatively more neuronal and glial perikarya, as well as non-myelinated (e.g. ("6" in the orientation figure) a molecular layer containing dendrites of the granule cells. Muscle attaches to bone via tendons; bundles of dense regular connective tissue made out of many collagen type I fibers. It is related to both the circulatory system and the immune system. Glial cells, such as astrocytes, oligodendrocytes, Schwann cells and others, provide support, nourishment, myelination and protection to neurons. between a tract and a nerve? These cells contain contractile filaments (myofibrils) called actin (thin) and myosin (thick). When macrophages encounter diseased or damaged cells in the rest of the body, they ingest and digest those cells or the pathogens that cause disease. Diffuse lymphoid tissues and lymphatic nodules are non-encapsulated accumulations of lymphoid tissue found in locations such as the alimentary, respiratory and genitourinary tracts. Neurons can also be classified on the basis of where they are found, who found them, what they do, or even what chemicals they use to communicate with each other. All Rights Reserved. Glial cells, or glia, are known to play a supporting role for nervous tissue. Correct answer 4. Be sure you identify the white matter in bothluxol blue-stainedslide 076View ImageandTB&E-stained#076bView Imagesections, as it will appear differently in these two stains. Curated learning paths created by our anatomy experts, 1000s of high quality anatomy illustrations and articles. 1. Information flows through a neuron from the dendrites, across the cell body, and down the axon. Nicola McLaren MSc the peripheral nerves and peripheral ganglia. The primary purpose of this article is to evaluate the histology of peripheral nervous tissue. The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). 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. The endocrine system is divided into major endocrine glands (e.g. Myelin is a fatty substance that makes the axon appear white. The lymphatic system consists of a network of vessels and lymphoid organs. The male reproductive system consist of the internal genitalia (testes, genital ducts and accessory genital glands) and external genitalia (penis and scrotum). This is done by the use of a complementary nucleotide probe, which contains a radioactive or fluorescent label. Histology 5.ppt CT, Bone Histology 5 supplement.ppt : Histology 6.ppt Muscle: Histology Lab 4.doc Muscle and Start of Nervous Tissue: Histology 7.ppt M, Nervous: Histology Lab 5.doc Nervous (continued), Digestion Start: Histology 8.ppt Nervous : Histology 9.ppt : Histology 10.ppt Nervous: Histology11.ppt CNS, Digestion : Histology 12.ppt . These sections are then mounted on a glass slide, using a mounting medium as an adhesive. Nervous Tissue DR. DEVI 1 16-4-19 2. Nervous or the nerve tissue is the main tissue of our nervous system. Neurons are the cells considered to be the basis of nervous tissue. 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. Neurons are important, but without glial support they would not be able to perform their function. Peripheral nerves are bundles of myelinated nerve fibers (axons) wrapped in connective tissue (endo-, peri- and epi- neurium).

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