nervous tissue histology ppt

Ependymal cells, which are uniquely located lining the ventricles of the brain the central canal of the spinal cord, are one notable exception. It consists of a few cells and an abundance of extracellular matrix. In general, the brain is composed of an exterior layer of grey matter covering internal areas of white matter, with another internal layer of grey matter in the deepest part of the brain (called the basal nuclei). Did you know that the only thing preventing all the water in your body from leaking out through your skin are the tight junctions between the keratinocytes? Alveoli are the primary site of gas exchange. These vibrate to produce sound as air passes through them. They are considered to be supporting cells, and many functions are directed at helping neurons complete their function for communication. 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. Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). However, the endothelial cells maintain these junctions in response to signals (via foot processes) from ASTROCYTES. 2023 The ovary is actually an organ homologous to the male testis, it gives rise to the gametes (ova) and steroid hormones (estrogen, progesterone). 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. Much like the male, the female reproductive system is also designed for reproduction and sexual pleasure. Histology - study of tissues Tissue - a collection of similar cells that group together to perform a specialized function. Most of the nuclei visible in the granular layer belong to very small neurons, granule cells, which participate in the extensive intercommunication involved in the cerebellums role in balance and coordination. Many axons are wrapped by an insulating substance called myelin, which is actually made from glial cells. Sertoli cells prevent the immune system from attacking and destroying the spermatozoa. After preparation, the tissue is stained. The medial surface of the section is the posterior portion of the thalamus and a small portion of the cerebral peduncle. Bones articulate with other bones by way of joints, which can be synovial, fibrous or cartilaginous. Review diagrams illustrating the morphology of neurons in your textbooks. The endocrine system is a set of tissues that secrete hormones directly into the bloodstream. Kim Bengochea, Regis University, Denver. It is categorised as skeletal, cardiac or smooth. Each organ of the digestive system has properties that make it specialized for its role in the digestion, absorption and excretion of food. 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 ventral spinal cord. Click on launch activity 2. Note that sacral levels of the cord (levels S2-4) also contain visceral motor neurons in the lateral horn, but these are parasympathetic. Contents Neuron Nerve cell processes Synapses And impulse transmission The neuroglia Myelin sheath 2 3. Like a few other parts of the body, the brain has a privileged blood supply. One oligodendrocyte will provide the myelin for multiple axon segments, either for the same axon or for separate axons. Study with Quizlet and memorize flashcards containing terms like Afferent, efferent, visceral and more. 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 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 . Additional sub-classifications are possible, based on the cell specializations. The three-dimensional shape of these cells makes the immense numbers of connections within the nervous system possible. Everything absorbed through the alimentary tract passes through the special discontinued capillaries of the liver before going anywhere else. Mesenchymal cells are undifferentiated cells, which means they are capable of differentiating into any type of connective tissue cells (fibroblasts, osteoblasts, adipocytes etc.). 4.4A: Characteristics of Nervous Tissue - Medicine LibreTexts Because of this, only specific types of molecules can enter the CNS. Light microscopes (or optical microscopes), use a combination of visible light and lenses to create a magnified image. 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 endocrine system is divided into major endocrine glands (e.g. Click on the white box with the question mark on it 4. Mesenchyme gives rise to all types of connective tissue. Both respond immunologically to foreign material in the fluid passing through. 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. These bulbs are what make the connection with the target cell at the synapse. Title: PowerPoint Presentation Author: Jennifer Ann Jost Last modified by: Jeff Keyte Created Date: 10/29/2003 10:25:53 PM Document presentation . When responding to a foreign threat, immune system cells can activate non-specific inflammation or progress to a specific immune response. Lymphatic vessels drain lymph (interstitial fluid) from all the extracellular spaces in the body. Name thefunction of the cell marked by the black arrow. Spleen and lymph node histology shows an encapsulated meshwork of fibres, in which immune system cells sit. The neuron shown is a multipolar neurons. The ECM contains different protein fibers (collagen, reticular, elastic) embedded in ground substance. The axon projects from the dendrite endings, past the cell body in a ganglion, and into the central nervous system. The projections connect at the dendrites and are so extensive that they give the microglial cell a fuzzy appearance. Nervous tissue contains two basic categories of cells: neurons and support cells (glia). A single axon (often called a nerve fiber) leaves the perikaryon and transmits neural signals to other neurons or to the effectororgan (e.g., skeletal muscles) via synapses. Central Nervous System Connective Tissue Ear Endocrine System Epithelial Tissue Eye Female Reproductive System . Together these organs provide the ability of reproduction and sexual intercourse. 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. This accounts for the name, based on their appearance under the microscope. Some well-known lymphatic nodules include; the tonsils, Peyers patches and vermiform appendix. The small gap in the myelin sheath that occurs between adjacent Schwann cells is called a node of Ranvier. Last reviewed: November 28, 2022 The glial cell is wrapped around the axon several times with little to no cytoplasm between the glial cell layers. The other major glial cell type you should know about are microglia which are small cells derived from blood monocytes. The respiratory system consists of the lungs and a series of passageways (nasal cavities, paranasal sinuses, larynx, trachea and bronchi) that connect alveoli to the external environment. Thoroughly learn the parts of a cell using our diagrams and cell quizzes! The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. Learning anatomy is a massive undertaking, and we're here to help you pass with flying colours. 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. A unity of tissues with a more complex set of functions, defined by the combination of structure and function of the comprising tissues. Pia mater 2. Cardiomyocytes contain actin and myosin filaments just like other muscle cells, but they have some special structural and functional properties. Epithelium is classified by both its cellular morphology and the number of cell layers. Type II pneumocytes are also important because they secrete surfactant which prevents the lungs from collapsing. Slides include types of epithelial, connective, nervous, and muscle tissue and is ideal for an anatomy and physiology course. Bipolar cells have two processes, which extend from each end of the cell body, opposite to each other. Eroschenko, V. P. (2017). A few other processes provide the same insulation for other axon segments in the area. It is this myelin, a lipid-rich sheath covering axons, that causes white matter to be lighter in color than grey matter. 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. Some neurons are named on the basis of those sorts of classifications (Figure 3). Oligodendrocytes (another type of glial cell) are responsible for the myelination of CNS axons. Generally, they are supporting cells for the neurons in the central nervous system. 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. EM works by emitting parallel beams of electrons onto the tissue sample. Click on the tissue and observe. 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. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. Copyright Nervous tissue (Histology) - SlideShare Peripheral Nervous System | histology - University Of Michigan Nonetheless, it is loosely stratified into layers containing scattered nuclei of both neurons and glial cells. In this article, we will introduce you to the microscopic world of histology. PPT 2: Nervous Tissue and Histology Flashcards | Quizlet It is specialized tissue found in the central nervous system and the peripheral nervous system. Due the nature of histological sampling, it is impossible to see the entirety of a three-foot-long neuron on a single slide. - PowerPoint PPT presentation Number of Views: 2727 Avg rating:3.0/5.0 Slides: 14 Provided by: apbrwww5A Category: Tags: histology | nervous | tissue less 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"). Pyramidal cells and olfactory cells are two other examples of neurons named for these classifications which will be discussed later. 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. Skeletal muscle consists of long cylindrical-shaped muscle cells with multiple, peripherally located nuclei and a cytoplasm filled with myofibrils. The product is the magnifying power of the objective (4x, 10x, 20x, 40x or 100x) multiplied by the power of the ocular lenses (10x). and grab your free ultimate anatomy study guide! Table 2 outlines some common characteristics and functions. Wednesday, August 24. Nicola McLaren MSc The epithelial lining of the uterine tube and uterus play important roles in the transportation and implantation of a fertilized ovum (zygote). These cells have a single, long, nerve tract entering the bottom of the cell body. To visualize this dendritic tree, an osmium stain can be used. Reading time: 28 minutes. Gordana Sendi MD Astrocytes - Technically, the junctions between endothelial cells constitute the actual "barrier." The ependymal cell is a glial cell that filters blood to make cerebrospinal fluid (CSF), the fluid that circulates through the CNS. Ana 211 (Histology of Nervous tissue).pptx - Academia.edu A group of neuronal cell bodies is called a nucleus in the brain or spinal cord, and a ganglion in the PNS. Junquieras Basic Histology (13th ed.). For oligodendrocytes, the rest of the cell is separate from the myelin sheath as a cell process extends back toward the cell body. The cells are laid down on top of dense irregular connective tissue, the basement membrane (BM). 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. 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. True unipolar cells are only found in invertebrate animals, so the unipolar cells in humans are more appropriately called pseudo-unipolar cells. behaviors, memories, and movements. With one exception, neurons such as this (though not necessarily this large) are found in ALL areas of the nervous system. Nervous or the nerve tissue is the main tissue of our nervous system. Ross, H. M, Pawlina, W. (2011). The spinal cord contains a butterfly-shaped area of grey matter surrounded by an outer layer of white matter. Histology Lecture Slides - Bloomsburg University Of Pennsylvania 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. One of the two types of glial cells found in the PNS is the satellite cell. Let histology be a piece of cake once you learn how to examine a histology slide! 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. 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! Very little can pass through by diffusion. Young, B., Woodford, P., ODowd, G., & Wheater, P. R. (2014). Based on the number of processes, neurons are classified into multipolar, bipolar and unipolar. Myelin is lipid-rich, and on gross inspection appears white. 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. 138, 7.18). Calcific bodies are present in the choroid plexus, another common site of accumulation as the years pass. Axon diameters can be as small as 1 to 20 micrometers. During development, the glial cell is loosely or incompletely wrapped around the axon (Figure 6). The length of the axon between each gap, which is wrapped in myelin, is referred to as an axon segment. Pancreatic serous acini secrete digestive enzymes which break down fat, carbohydrates and proteins. Some ways in which they support neurons in the central nervous system are by maintaining the concentration of chemicals in the extracellular space, removing excess signaling molecules, reacting to tissue damage, and contributing to the blood-brain barrier (BBB). The nucleus is considered to be the brain of the cell. Click on human from the drop down list 5. Any of those processes can function as an axon depending on the conditions at any given time. celiac, aorticorenal, and superior/inferior mesenteric ganglia). Below the dermis, a layer of subcutaneous tissue (hypodermis) is found. All of this is surrounded by three connective tissue membranes (meninges): dura, arachnoid and the pia mater. 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. Many neurons in the spinal cord may appear shrunken and surrounded by an empty space due to poor fixation. You may see small calcific bodies in part of the hippocampus, which occur as a normal part of the aging process. Which are classified as grey matter? 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. Friday, August 26 Some sources describe a fourth type of neuron, called an anaxonic neuron. 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. 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. Tissue preparation, tissue staining, microscopy, hybridisation. It relays sensory input to cerebellar cortex. The neuron is the structural and functional/electrically excitable unit of the nervous system Nervous system The nervous system is a small and complex system that consists of an intricate network of neural cells (or neurons) and even more glial cells (for support and insulation). Peripheral nerves are analogous with neural tracts of the CNS. All cells of the human body are eukaryotic, meaning that they are organized into two parts: nucleus and cytoplasm. . I love Anatomy. The cerebellum consists of an outer cortex of grey matter covering an inner area of white matter, which itself surrounds a deeper layer of grey matter (called the cerebellar nuclei). 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. They also have cilia on their apical surface to help move the CSF through the ventricular space. Controls and integrates all body activities. The tools for studying histology are becoming more diverse everyday. The tissue is sectioned thinly enough so that light can pass through it. Nails are plates of proliferating keratinized cells that, similar to hair, contain hard keratin. Cells come together with extracellular matrix (a jelly-like fluid) to form the four types of tissues found in the human body: epithelial, connective, muscle and nervous. Neurons (Nerve cell bodies) 5 6 5. The neuronal type is found throughout the entire human nervous system except in dorsal root/sensory ganglia. Examine the boundary between molecular and granule cell layers. If you were to look at some bones on a skeleton, youd see a greyish rigid mass with some bumps and depressions. 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). Remember, this entire pathway is traveled by cells whose axons may be three feet long! Using only histological evidence, could you determine from where in the nervous system a sample of tissue was taken? The outer cerebellar cortex, shown in Figure 8, is tightly folded and has three distinct layers: Purkinje cells are typically arranged in a single row between the exterior molecular and interior granular layers. It relays sensory input to cerebral cortex. The nervous system can be organized in several different ways. They return this fluid to the heart, passing it through lymphoid organs. Neurons. Each gap is called a node of Ranvier and is important to the way that electrical signals travel down the axon. In terms of clinical significance, the pyramidal cells of the hippocampus are particularly vulnerable to damage in severe circulatory failure and by anoxia of persistent severe seizures. 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. It is made up of gray matter and white matter. Thus, in the 'white matter' of the brain and spinal cord, myelinated axons are the predominant neuronal cell component and most of the the nuclei that you see in white matter are primarily of glial cells. Those processes extend to interact with neurons, blood vessels, or the connective tissue covering the CNS that is called the pia mater (Figure 4). Skin glands include sweat glands (apocrine and eccrine) and sebaceous holocrine glands, both are important in regulating body temperature. 5 Nervous system The introductory part of the chapter is adapted from BC OpenStax Anatomy and Physiology book under the CC BY license. Where the axon emerges from the cell body, there is a special region referred to as the axon hillock. 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. Thompson, Ph.D. Histology of Nervous Tissue Despite the complexity of organization, there are only two functional cell . What anatomical feature explains this phenomenon? A unity of cells with a similar structure that as a whole express a definite and unique function. Since tissues are normally colourless, applying a dye to the tissue section allows the cells and their components to be seen under a microscope. Histology of the Nervous System Description: Histology of the Nervous System X-Section of Brain Tissue 4 1 2 3 1. The nervous system is responsible for the control of the body and the communication among its parts. Why are perikarya of dorsal horn neurons smaller than those in the ventral horn? What is the difference between a ganglion and a nucleus? These include epithelial cells, fibroblasts, neutrophils, erythrocytes, keratinocytes, chondrocytes just to name a few. Nervous Tissue - PowerPoint PPT Presentation - PowerShow A cell is the smallest functional unit of an organism. It relays sensory input to other neurons in the spinal cord. Test yourself on cardiac muscle tissue with the following quiz. 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. They are organized into lobules, with each lobule containing a parenchyma of seminiferous tubules and a connective tissue stroma. Blotting technique is a method of localizing and quantifying proteins, DNA and RNA. 2. Histology (6th ed.). The dendritic tree and axon of each Purkinje cell can only be seen in thicker sections stained with special silver stains. The first step in tissue preparation for optic microscopy is fixation. It provides somatic motor output to skeletal muscles. Click on explore at the bottom of the page 3. Access to the supplemental resources for this session is password-protected and restricted to University of Michigan students. Nervous tissue histology 1. 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.