nervous tissue histology ppt nervous tissue histology ppt

Tissues. The testes produce male gametes (spermatozoa) via the process of spermatogenesis. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. Slide NP004N hippocampal region, coronal section, luxol blue View Virtual SlideSlide 13270astrocytes,Gold-stainingView Virtual Slide. The projections connect at the dendrites and are so extensive that they give the microglial cell a fuzzy appearance. All of this is surrounded by three connective tissue membranes (meninges): dura, arachnoid and the pia mater. 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 Pyramidal cells and olfactory cells are two other examples of neurons named for these classifications which will be discussed later. Myelin is lipid-rich, and on gross inspection appears white. The lateral extension of the ventral horn slide 065-2 contains relatively large, multipolar visceral motor neurons of the intermediolateral cell column that extends from levels T1 through L2 of the spinal cord. Scattered in the cytoplasm are the characteristic clusters of ribosomes and rough ER termed Nissl bodies or Nissl substanceslide 066aView Image. It provides somatic motor output to skeletal muscles. Young, B., Woodford, P., ODowd, G., & Wheater, P. R. (2014). Some neurons are named on the basis of those sorts of classifications (Figure 3). between a tract and a nerve? All Rights Reserved. The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS). At one end of the axon are dendrites, and at the other end, the axon forms synaptic connections with a target. Some cutting edge research suggests that certain neurons in the CNS do not conform to the standard model of one, and only one axon. 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. The musculoskeletal system consists of hard tissues (bones, joints, cartilage) and soft tissues (muscles, tendons, ligaments). It consists of widely separated mesenchymal cells and ground substance with an abundance of hyaluronic acid. Pia mater 2. 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. It will also benefit the publication of several new topics (Hematology, Pathogen ID, and Gross Anatomy). Typically one or more sulci (infoldings) will extend inward from one edge of the section. Skin glands include sweat glands (apocrine and eccrine) and sebaceous holocrine glands, both are important in regulating body temperature. Learning anatomy is a massive undertaking, and we're here to help you pass with flying colours. 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. Other staining techniques such as Masson trichrome, alcian blue, reticulin stain and others are sometimes used to demonstrate specific tissue components not seen on a H&E stain. 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? Did you know that there are special cardiomyocytes in your heart that spontaneously generate impulses to initiate heartbeats? In the PNS, myelin is produced by Schwann cells, which wrap around the axon. As cells are generally colourless, they need to be stained so that they can be easily viewed under the microscope. Tissues. They are organized into lobules, with each lobule containing a parenchyma of seminiferous tubules and a connective tissue stroma. 5 Nervous system The introductory part of the chapter is adapted from BC OpenStax Anatomy and Physiology book under the CC BY license. Read more. Neurons are characterized by a large cell body or perikaryon containing a large, pale (active, euchromatic) nucleus with a prominentnucleolus. Neurons of the cerebral cortex are of varying shapes and sizes, but the most obvious arepyramidal cells. Figure 1 shows the relationship of these parts to one another. Work for the lab This website is a great way to view the tissues. 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. The membrane wrapped around the fascicle is called an endoneurium and is made of the loose reticular connective tissue. At a histological level, both the heart and blood vessels consist of three layers: The myocardium is formed by striated cardiac muscle cells (cardiomyocytes). The edges of this loose enclosure extend toward each other, and one end tucks under the other. Kenhub. Grey matter is composed mainly of unmyelinated cell bodies and dendrites, and appears grey in color. In contrast, electron microscopes work by emitting parallel beams of electrons onto the sample being observed, resulting in higher resolutions. It is composed of densely packed epithelial cells with only a little extracellular matrix (ECM). In these slides you will not be able to discern the amazing dendritic tree that extends from the Purkinje cell bodies into the molecular layer, nor will you be able to see their axons, which extend down through the granular layer into deeper parts of the cerebellum. And research may find much more about them in the future. Controls and integrates all body activities. A cell is the smallest functional unit of an organism. Unipolar neurons have only one process emerging from the cell body which causes them to appear T-shaped. The epithelial lining of the uterine tube and uterus play important roles in the transportation and implantation of a fertilized ovum (zygote). The Schwann cells (in the peripheral nerves) and the satellite cells (in the ganglia) are glial cells (supporting cells) of the PNS. The gray matter contains relatively more neuronal and glial perikarya, as well as non-myelinated (e.g. 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! Due the nature of histological sampling, it is impossible to see the entirety of a three-foot-long neuron on a single slide. Figure 1, Figure 4, and Figure 5 show the myelin sheath surrounding an axon segment, but are not to scale. Upon maturation, they are released into the blood, lymph and into secondary lymphoid organs, where they work alongside immune system support cells to carry out a detailed surveillance of potential threats. Organs work together in systems. Epithelial cells form two important histological structures within the brain; the blood-brain barrier and the choroid plexus. It is named after the anatomist who discovered it (Jan Evangilista Purkinje, 17871869). The other processes of the neuron are dendrites, which receive information from other neurons at specialized areas of contact called synapses. The digestive system consists of the alimentary canal and its associated organs (tongue, teeth, salivary glands, pancreas, liver and gallbladder). 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. Gray matter is mostly made of neuronal bodies, dendrites and glial cells whereas white matter is made primarily out of myelinated axons. At a microscopic level, a nephron consists of a renal corpuscle and a series of tubules. Available at theiTunes Storeand for Android users at theGoogle Play Store. The only freely mobile joints are synovial joints, in which adjacent joint surfaces are covered with hyaline cartilage, a soft type of cartilage rich in glycoproteins, proteoglycans and type II collagen. By examining a thin slice of bone tissue under a microscope, colorized with special staining techniques, you see that these seemingly simple bones are actually a complex microworld containing an array of structures with various different functions. The tissues of the nervous system can also be divided into grey matter and white matter. (PWA), including the SecondLookHistology apps. These bulbs are what make the connection with the target cell at the synapse. 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. Correct answer 4. It is categorised as skeletal, cardiac or smooth. Other methods include histochemistry, immunocytochemistry, hybridization techniques, tissue culture and many others. Neurons are the basic functional units of nervous tissue. Review the organization of the spinal cord using your atlas. 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. Histology of the Nervous System Description: Histology of the Nervous System X-Section of Brain Tissue 4 1 2 3 1. This method is based on the ability of single stranded DNA or RNA to merge with a complementary strand and build a hybrid which is then detected due to the label. Use the virtual slide of the hippocampal region to study the ependymal cell lining of the choroid plexus. 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 tissue is sectioned thinly enough so that light can pass through it. The basic functional unit of the kidney is the nephron. Type II pneumocytes are also important because they secrete surfactant which prevents the lungs from collapsing. Neurons. Organelles can be membranous (mitochondria, Golgi apparatus, endoplasmic reticulum) or non-membranous (ribosomes, nucleolus, centrioles). Examine the boundary between molecular and granule cell layers. Luv ya! The ECM contains different protein fibers (collagen, reticular, elastic) embedded in ground substance. After preparation, the tissue is stained. Some sources describe a fourth type of neuron, called an anaxonic neuron. Primarily, the PNS is made up of the axons of neurons whose cell bodies are located within the CNS (within the brain for cranial nerves and the spinal cord for peripheral nerves yet another way to divide the nervous system based on location). Review the organization of gray and white matter in cerebral cortex vs. spinal cord. In situ hybridisation is a method of localizing and quantifying DNA or RNA sequences. What is the difference between a ganglion and a nucleus? 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. Where the axon emerges from the cell body, there is a special region referred to as the axon hillock. Peripheral ganglia are clusters of nerve cell bodies surrounded by a dense connective tissue capsule. Junquieras Basic Histology (13th ed.). 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. Using the standard model of neurons, one of these processes is the axon, and the rest are dendrites. Correct answer 1. The medial surface of the section is the posterior portion of the thalamus and a small portion of the cerebral peduncle. It consists of the mouth, pharynx, esophagus, stomach, small intestine, large intestine and anus. Like a few other parts of the body, the brain has a privileged blood supply. There is a lot more to know about the female reproductive system. The length of the axon between each gap, which is wrapped in myelin, is referred to as an axon segment. Satellite cells are found in sensory and autonomic ganglia, where they surround the cell bodies of neurons. 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. Nervous or the nerve tissue is the main tissue of our nervous system. . It is this myelin, a lipid-rich sheath covering axons, that causes white matter to be lighter in color than grey matter. Philadelphia, Pa: Wolters Kluwer. The PNS encompasses all nervous tissue outside of bony structures, and includes all peripheral and cranial nerves, plexuses, and ganglia. This actually causes problems with drug delivery to the CNS. Nutrient molecules, such as glucose or amino acids, can pass through the BBB, but other molecules cannot. Slide of tissue is followed by slide of tissue with correct answer. Many neurons in the spinal cord may appear shrunken and surrounded by an empty space due to poor fixation. 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). Histologically, although there are a few exceptions, endocrine cells generally have an epithelial origin. If you were to look at some bones on a skeleton, youd see a greyish rigid mass with some bumps and depressions. 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 They can be classified as sensory or autonomic. Histology Copyright by Malgosia Wilk-Blaszczak. Examine the gray matter on each side of the sulcus using first low and then high power. The organization and morphology of the cells shown is found ONLY in the ventral spinal cord. Your donation will enable us to update all existingSecondLook resources and to transform them into completely free Progressive Web Applications (PWA), including theSecondLookHistology apps. The ventral spinal cord. Study with Quizlet and memorize flashcards containing terms like Afferent, efferent, visceral and more. Learn more about the histology of the upper and lower digestive tract. It is specialized tissue found in the central nervous system and the peripheral nervous system. Alveoli are the primary site of gas exchange. Chapter 12Nervous Tissue. Water and some other small particles, like gases and ions, can enter. system is called neurology. Light microscopes (or optical microscopes), use a combination of visible light and lenses to create a magnified image. The most common technique used is the hematoxylin and eosin (H&E) stain. These layers of myelin are many times thicker than the diameters of the axons. Correct answer 2. However, the endothelial cells maintain these junctions in response to signals (via foot processes) from ASTROCYTES. 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. 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. Muscle tissue maintains synthesizing and contractile functions. 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. Spermatozoa pass from the testis into the epithelial lined epididymis and ductus (vas) deferens via efferent ductules, then into the ejaculatory duct, which merges with the urethra. True unipolar cells are only found in invertebrate animals, so the unipolar cells in humans are more appropriately called pseudo-unipolar cells. All of these components work together to provide movement to the body. Here, the tissue of interest is immersed in a fixative solution. the peripheral nerves and peripheral 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. The male reproductive system consist of the internal genitalia (testes, genital ducts and accessory genital glands) and external genitalia (penis and scrotum). The predominant cells visible on the slide are called pyramidal cells (named for their triangular shape). 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. Information flows through a neuron from the dendrites, across the cell body, and down the axon. They can be classified by many different criteria. Spleen and lymph node histology shows an encapsulated meshwork of fibres, in which immune system cells sit. The neuron shown is a multipolar neurons. Secondly, the cell bodies of unipolar neurons are always found in ganglia. Glial cells, or glia, are known to play a supporting role for nervous tissue. The axon projects from the dendrite endings, past the cell body in a ganglion, and into the central nervous system. It also includes important proteins that are integral to that membrane. The function of myelin will be discussed below. All rights reserved. Electron microscopy (EM) is a more modern form of microscopy that provides a much higher magnification and high resolution images. Glial cells, such as astrocytes, oligodendrocytes, Schwann cells and others, provide support, nourishment, myelination and protection to neurons. The nucleus and cytoplasm of the Schwann cell are on the edge of the myelin sheath. 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 Nervous tissue. 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. 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. Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). Nervous tissue is made of cells (neurons and glial cells) and extracellular matrix. 2023 The first way to classify them is by the number of processes attached to the cell body. When responding to a foreign threat, immune system cells can activate non-specific inflammation or progress to a specific immune response. Multiple muscle cells are bound by connective tissue into fascicles, and multiple fascicles join to form a muscle belly. as white matter? 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. Tissue preparation, tissue staining, microscopy, hybridisation. 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. How is this different in the spinal cord? behaviors, memories, and movements. This is the reason why people with extensive burns are in life-threatening danger. Vocal cords are housed in the larynx, formed by two folds of mucosa, each containing a supporting ligament (vocalis ligament) and a skeletal muscle (vocalis muscle). Astrocytes - Technically, the junctions between endothelial cells constitute the actual "barrier." Structure of a Neuron. Cerebral cortex 3. The spleen on the other hand, filters blood. Two nodes of Ranvier are circled in Figure 9 below. Want to create or adapt books like this? It is the axon that propagates the nerve impulse, which is communicated to one or more cells. A unity of cells with a similar structure that as a whole express a definite and unique function. The spinal cord contains a butterfly-shaped area of grey matter surrounded by an outer layer of white matter. Muscle attaches to bone via tendons; bundles of dense regular connective tissue made out of many collagen type I fibers. This accounts for the name, based on their appearance under the microscope. 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. 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. 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. 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. Contents Neuron Nerve cell processes Synapses And impulse transmission The neuroglia Myelin sheath 2 3. They also have cilia on their apical surface to help move the CSF through the ventricular space. 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. It consists of a few cells and an abundance of extracellular matrix. 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. Histology of Nervous TissueNervous system ppt #2. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. 1. 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 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 acts as insulation, much like the plastic or rubber that is used to insulate electrical wires. T and B lymphocytes are born and raised in the thymus and bone marrow, respectively. Myelin is a lipid-rich sheath that surrounds the axon and by doing so creates a myelin sheath that facilitates the transmission of electrical signals along the axon. The BBB also makes it harder for pharmaceuticals to be developed that can affect the nervous system. 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). Next, the tissue is embedded with paraffin wax, which firms the tissue enough permit thin slices. All cells contain cytoplasm, are surrounded by a membrane, and contain a variety of structures and organelles. 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. Ppt #2. 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. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. The four main types of stains used in histology are empirical, histochemical, enzyme histochemical and immunohistochemical. The perikarya of large somatic motor neurons slide 065-2 View Image located in the ventral horn of the cord innervate the skeletal muscles of the limbs and trunk, which are embryologically derived from somites (hence, somatic muscles). 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. 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. Access to the supplemental resources for this session is password-protected and restricted to University of Michigan students. Both will appear grey to the naked eye and under the microscope, due to their lack of myelin. Pharmaceutical companies are challenged to design drugs that can cross the BBB as well as have an effect on the nervous system. During development, the glial cell is loosely or incompletely wrapped around the axon (Figure 6). Sertoli cells prevent the immune system from attacking and destroying the spermatozoa. The endocrine system is a set of tissues that secrete hormones directly into the bloodstream. Histology. ("3" in the orientation figure) a molecular layer containing dendrites of the pyramidal cells. Click on explore at the bottom of the page 3. Based on morphology, epithelial cells can be either squamous (flat), cuboid (cube) or columnar (rectangular). Those processes extend to interact with neurons, blood vessels, or the connective tissue covering the CNS that is called the pia mater (Figure 4). NERVOUS TISSUE Nervous tissue consists of two groups of cell types: Nerve cells (Neurons) Neuroglia. Pulmonary capillaries come into close contact with the alveoli, forming the blood-air barrier. Wheaters functional histology: A text and colour atlas. It provides preganglionic visceral motor output to sympathetic ganglia. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. These cells have a single, long, nerve tract entering the bottom of the cell body. Slide 66a View Virtual Slide shows a section of thoracic spinal cord. 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. Name thefunction of the cell marked by the black arrow. Each organ of the digestive system has properties that make it specialized for its role in the digestion, absorption and excretion of food. 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. Note that sacral levels of the cord (levels S2-4) also contain visceral motor neurons in the lateral horn, but these are parasympathetic. Unlike the highly organized cerebellar cortex, the cerebral cortex appears to be less well-organized when viewed with the light microscope. Contrast the differences in the histological appearance of a pyramidal cell versus a Purkinje cell. Smooth muscle tissue appears non-striated because of the less orderly arrangement of their filaments. Four main groups of tissues Epithelial Connective Muscle Nervous tissue. 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.