In the PNS, myelin is produced by Schwann cells, which wrap around the axon. Correct answer 2. Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). Bundles of myelinated axons in the brain are called tracts, while bundles of axons in the PNS are called nerves. They have one axon and two or more dendrites (usually many more). ("6" in the orientation figure) a molecular layer containing dendrites of the granule cells. The four main types of stains used in histology are empirical, histochemical, enzyme histochemical and immunohistochemical. They also have cilia on their apical surface to help move the CSF through the ventricular space. Nails are plates of proliferating keratinized cells that, similar to hair, contain hard keratin. Anaxonic neurons are very small, and if you look through a microscope at the standard resolution used in histology (approximately 400X to 1000X total magnification), you will not be able to distinguish any process specifically as an axon or a dendrite. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. The ventral spinal cord. The first way to classify them is by the number of processes attached to the cell body. Histology of the Nervous System - PowerPoint PPT Presentation - PowerShow Name the part of the central nervous system that isdisplayed in this tissue section. These bulbs are what make the connection with the target cell at the synapse. Typically one or more sulci (infoldings) will extend inward from one edge of the section. The cell body contains the nucleus and most of the major organelles. Histology Special Stains: Nervous Tissue - LabCE Test yourself on cardiac muscle tissue with the following quiz. 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. 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. These exclusively contain neurons with a pseudounipolar neuronal arrangement. 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. Lastly, the specimen is stained with hematoxylin and eosin dyes. Since tissues are normally colourless, applying a dye to the tissue section allows the cells and their components to be seen under a microscope. At one end of the axon are dendrites, and at the other end, the axon forms synaptic connections with a target. Read more. Confusingly, structures within white and grey matter are referred to by different terms, depending on whether they are located in the CNS or the PNS. 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. A cell is the smallest functional unit of an organism. 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. Read more. Microscope Slides of Cells and Tissues | Histology Guide Schwann cells are different than oligodendrocytes, in that a Schwann cell wraps around a portion of only one axon segment and no others. Using only histological evidence, could you determine from where in the nervous system a sample of tissue was taken? Calcific bodies are present in the choroid plexus, another common site of accumulation as the years pass. Skin appendages are derivatives of the epidermis. 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. All rights reserved. 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. Because of the privileged blood supply inherent in the BBB, the extracellular space in nervous tissue does not easily exchange components with the blood. Title: PowerPoint Presentation Author: Jennifer Ann Jost Last modified by: Jeff Keyte Created Date: 10/29/2003 10:25:53 PM Document presentation . Click on a question to reveal the answer. Both will appear grey to the naked eye and under the microscope, due to their lack of myelin. These vibrate to produce sound as air passes through them. Movement on one side of the body is often controlled by nerve impulses originating on the opposite side of the brain. T and B lymphocytes are born and raised in the thymus and bone marrow, respectively. 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. All content published on Kenhub is reviewed by medical and anatomy experts. Skeletal muscle consists of long cylindrical-shaped muscle cells with multiple, peripherally located nuclei and a cytoplasm filled with myofibrils. The spleen on the other hand, filters blood. The dendritic tree and axon of each Purkinje cell can only be seen in thicker sections stained with special silver stains. Thoroughly learn the parts of a cell using our diagrams and cell quizzes! Examine the cross section of the lumbar spinal cord in slide 065-2. New York, NY: McGraw-Hill Education. Bone tissue is a specialized type of connective tissue that contains cells (osteoblasts, osteocytes, osteoclasts), fibers (collagen type I) and mineralized extracellular matrix. The BBB also makes it harder for pharmaceuticals to be developed that can affect the nervous system. They can be classified as sensory or autonomic. Histology - Histology. Chapter 1 The Cell Chapter 2 Epithelium Chapter 3 Connective Tissue Chapter 4 Muscle Chapter 5 Cartilage and Bone Chapter 6 Nervous Tissue Chapter 7 Peripheral Blood Chapter 8 Hematopoiesis Organ Systems It also includes important proteins that are integral to that membrane. 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. The endocrine system is divided into major endocrine glands (e.g. 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 nucleus is considered to be the brain of the cell. Microglia are the cells in the CNS that can do this in normal, healthy tissue, and they are therefore also referred to as CNS-resident macrophages. Nervous tissue (Histology) - SlideShare 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. Continue your learning with these resources. It relays sensory input to cerebellar cortex. 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. Four of them are found in the CNS and two are found in the PNS. The musculoskeletal system consists of hard tissues (bones, joints, cartilage) and soft tissues (muscles, tendons, ligaments). This Power point presentation will allow students to practice the skill of identifying tissue types from 25 histology slides. Central Nervous System Connective Tissue Ear Endocrine System Epithelial Tissue Eye Female Reproductive System . 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. Tissues are routinely visualised using microscopy. Nueron ppt naseemmeeran 139 views . They are separated into four categories: muscular, nervous, epithelial and connective. Where the axon emerges from the cell body, there is a special region referred to as the axon hillock. Like the spleen and lymph nodes, the immune cells in this tissue can mount an immune response against foreign invading material. The accessory genital glands include the prostate, seminal vesicles and bulbourethral glands. When responding to a foreign threat, immune system cells can activate non-specific inflammation or progress to a specific immune response. And there are many different types of neurons. The function of myelin will be discussed below. Get instant access to this gallery, plus: Introduction to the musculoskeletal system, Nerves, vessels and lymphatics of the abdomen, Nerves, vessels and lymphatics of the pelvis, Infratemporal region and pterygopalatine fossa, Meninges, ventricular system and subarachnoid space, keratinized stratified squamous epithelium, Cellular membrane, cytoplasm, organelles, nucleus. 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. Contents Neuron Nerve cell processes Synapses And impulse transmission The neuroglia Myelin sheath 2 3. They have rectangular bodies and many dendrite like projections stemming from their shorter sides. Under light microscopy, skeletal and cardiac muscles appear striated due to the parallel arrangement of their contractile filaments into repeating units called sarcomeres. Description: Chapter 11 Histology of Nervous Tissue J.F. It monitors and regulates the functions of the body. They are stabilized by ligaments, flexible fibrous bands made of dense regular connective tissue. Ependymal cells, which are uniquely located lining the ventricles of the brain the central canal of the spinal cord, are one notable exception. Secondly, the cell bodies of unipolar neurons are always found in ganglia. Neuronal processes form connections (synapses) with each other and with other cell types, in order to exchange electrical signals.