Which are classified as grey matter? View HISTOLOGY OF NERVOUS TISSUE A.ppt from BIO 001 at Holy Angel University. 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. Much like the male, the female reproductive system is also designed for reproduction and sexual pleasure. Neuronal processes form connections (synapses) with each other and with other cell types, in order to exchange electrical signals. These layers of myelin are many times thicker than the diameters of the axons. At low magnification, differentiate inner gray from outer white matter and identify dorsal and ventral horns of the gray matter. Slide 076cerebrumcerebrum luxol blue crossView Virtual Slide, Slide 076bcerebrumTB&EView Virtual Slide. Kim Bengochea, Regis University, Denver. 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"). What is the difference between a ganglion and a nucleus? The primary purpose of this article is to evaluate the histology of peripheral nervous tissue. They are organized into lobules, with each lobule containing a parenchyma of seminiferous tubules and a connective tissue stroma. Alveoli are the primary site of gas exchange. Oligodendrocytes (another type of glial cell) are responsible for the myelination of CNS axons. The endocrine system is a set of tissues that secrete hormones directly into the bloodstream. 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. Nonetheless, it is loosely stratified into layers containing scattered nuclei of both neurons and glial cells. They are large, easily distinguishable, and have an extensive dendritic tree that is not visible in typical histology. After preparation, the tissue is stained. Two nodes of Ranvier are circled in Figure 9 below. These cells contain contractile filaments (myofibrils) called actin (thin) and myosin (thick). It consists of widely separated mesenchymal cells and ground substance with an abundance of hyaluronic acid. Also found in CNS tissue is the oligodendrocyte, sometimes called just oligo, which is the glial cell type that insulates axons in the CNS. There are more tissues on the website than you are responsible for. Epithelial cells form two important histological structures within the brain; the blood-brain barrier and the choroid plexus. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. Spleen and lymph node histology shows an encapsulated meshwork of fibres, in which immune system cells sit. Nueron ppt naseemmeeran 139 views . Some neurons are named on the basis of those sorts of classifications (Figure 3). Cerebral cortex 3. Ependymal cells, which are uniquely located lining the ventricles of the brain the central canal of the spinal cord, are one notable exception. Unlike the highly organized cerebellar cortex, the cerebral cortex appears to be less well-organized when viewed with the light microscope. Histology. Skin appendages are derivatives of the epidermis. It monitors and regulates the functions of the body. Central Nervous System Connective Tissue Ear Endocrine System Epithelial Tissue Eye Female Reproductive System . One of the two types of glial cells found in the PNS is the satellite cell. Correct answer 4. At a microscopic level, a nephron consists of a renal corpuscle and a series of tubules. 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 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. Pia mater 2. They can be classified as sensory or autonomic. The nucleus and cytoplasm of the Schwann cell are on the edge of the myelin sheath. For Schwann cells, the outermost layer of the cell membrane contains cytoplasm and the nucleus of the cell as a bulge on one side of the myelin sheath. Tissues. Ross, H. M, Pawlina, W. (2011). 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. 3. The four main types of stains used in histology are empirical, histochemical, enzyme histochemical and immunohistochemical. The neuronal type is found throughout the entire human nervous system except in dorsal root/sensory ganglia. Because of this, ependymal cells can be considered a component of the BBB, or a place where the BBB breaks down. Under light microscopy, skeletal and cardiac muscles appear striated due to the parallel arrangement of their contractile filaments into repeating units called sarcomeres. 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. Controls and integrates all body activities. The axon projects from the dendrite endings, past the cell body in a ganglion, and into the central nervous system. All of these features give muscles the ability to contract and perform various functions, such as movement of the extremities (skeletal muscle), peristalsis of the gastrointestinal tract (smooth muscle) and beating of the heart (cardiac muscle). Bipolar cells have two processes, which extend from each end of the cell body, opposite to each other. . Also note these columnar cells lining the ventricles of the brain. These include epithelial cells, fibroblasts, neutrophils, erythrocytes, keratinocytes, chondrocytes just to name a few. Pulmonary capillaries come into close contact with the alveoli, forming the blood-air barrier. 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. The Schwann cells (in the peripheral nerves) and the satellite cells (in the ganglia) are glial cells (supporting cells) of the PNS. They are found mainly in the olfactory epithelium (where smell stimuli are sensed), and as part of the retina. Chapter 12Nervous Tissue. The BBB also makes it harder for pharmaceuticals to be developed that can affect the nervous system. 4. The inner edge wraps around the axon, creating several layers, and the other edge closes around the outside so that the axon is completely enclosed.Myelin sheaths can extend for one or two millimeters, depending on the diameter of the axon. 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). Glial cells, or glia, are known to play a supporting role for nervous tissue. Human anatomy is pretty straightforward. Mucoid connective tissue is a fetal tissue present in the umbilical cord. Histology (6th ed.). This is a tapering of the cell body toward the axon fiber. Based on their functional properties, these are described as either voluntary (skeletal) or involuntary (cardiac and smooth muscle). Typically one or more sulci (infoldings) will extend inward from one edge of the section. Neurons in the dorsal horn are essentially interneurons that project to other regions of the CNS (e.g. These cells have a single, long, nerve tract entering the bottom of the cell body. 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. Where the axon emerges from the cell body, there is a special region referred to as the axon hillock. Nevertheless, even if they cannot be easily seen, and one specific process is definitively the axon, these neurons have multiple processes and are therefore multipolar. Available at theiTunes Storeand for Android users at theGoogle Play Store. In situ hybridisation is a method of localizing and quantifying DNA or RNA sequences. 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. A third type of connective tissue is embryonic (fetal) tissue, this is a type of primitive tissue present in the embryo and umbilical cord. The sample on the slide below (Figure 7) was taken from the motor cortex, an area of the frontal lobe of the cerebral cortex that is involved in the conscious planning and execution of voluntary muscle movement. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. 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 nervous system is responsible for the control of the body and the communication among its parts. Based on the number of processes, neurons are classified into multipolar, bipolar and unipolar. It is categorised as skeletal, cardiac or smooth. These exclusively contain neurons with a pseudounipolar neuronal arrangement. In this article, we will introduce you to the microscopic world of histology. Histology Copyright by Malgosia Wilk-Blaszczak. They are electrically active and release chemical signals to target cells. Movement on one side of the body is often controlled by nerve impulses originating on the opposite side of the brain. - PowerPoint PPT presentation Number of Views: 793 Avg rating:3.0/5.0 Slides: 13 Provided by: RachelA156 Category: Glial cells, or neuroglia or simply glia, are the other type of cell found in nervous tissue. This gives the neuron a polaritymeaning that information flows in this one direction. Gordana Sendi MD Like the spleen and lymph nodes, the immune cells in this tissue can mount an immune response against foreign invading material. 1:00 - 2:55 Cartilage and Bone ppt | pdf | lecture recording. Unipolar cells are exclusively sensory neurons and have two unique characteristics. Kenhub. All Rights Reserved. Smooth muscle tissue appears non-striated because of the less orderly arrangement of their filaments. The product is the magnifying power of the objective (4x, 10x, 20x, 40x or 100x) multiplied by the power of the ocular lenses (10x). Tissues. A key difference between myelin and the insulation on a wire is that there are gaps in the myelin covering of an axon. Did you know that chronic alcoholics have a lot more smooth endoplasmic reticulum concentrations in their hepatocytes? The ECM contains different protein fibers (collagen, reticular, elastic) embedded in ground substance. 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. Both respond immunologically to foreign material in the fluid passing through. Below the dermis, a layer of subcutaneous tissue (hypodermis) is found. This is done by the use of a complementary nucleotide probe, which contains a radioactive or fluorescent label. Because the axon hillock represents the beginning of the axon, it is also referred to as the initial segment. Neurons of the cerebral cortex are of varying shapes and sizes, but the most obvious arepyramidal cells. Nervous tissue contains two basic categories of cells: neurons and support cells (glia). The ECM of nervous tissue is rich in ground substance, with little to no protein fibers. NERVOUS TISSUE Nervous tissue consists of two groups of cell types: Nerve cells (Neurons) Neuroglia. Click on explore at the bottom of the page 3. The gray matter contains relatively more neuronal and glial perikarya, as well as non-myelinated (e.g. Peripheral nerves are bundles of myelinated nerve fibers (axons) wrapped in connective tissue (endo-, peri- and epi- neurium). At a histological level, both the heart and blood vessels consist of three layers: The myocardium is formed by striated cardiac muscle cells (cardiomyocytes). It relays sensory input to cerebral cortex. Histology of Nervous TissueNervous system ppt #2. 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. 2. Note that sacral levels of the cord (levels S2-4) also contain visceral motor neurons in the lateral horn, but these are parasympathetic. 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 cells of the human body are eukaryotic, meaning that they are organized into two parts: nucleus and cytoplasm. Last reviewed: November 28, 2022 The Neuron Special property of irritability & conductivity Nerve cells are capable of receiving the . Correct answer 1. It is named after the anatomist who discovered it (Jan Evangilista Purkinje, 17871869). The dermis is a layer of connective tissue that contains collagen fibers, blood vessels, lymphatics and nerve endings. Learn more about the histology of the upper and lower digestive tract. The lipids are essentially the phospholipids of the glial cell membrane. Information flows through a neuron from the dendrites, across the cell body, and down the axon. 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. To visualize this dendritic tree, an osmium stain can be used. In general, where in the brain can grey matter be found? 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). The cardiovascular system consists of the heart and blood vessels (arteries, arterioles, capillaries, venules, veins). 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. They include hair follicles, skin glands and nails. This preserves it into the same state that it had when it was in the body, and thus, keeps it from degrading. The nasal cavity contains specialized olfactory epithelium, providing the sense of smell. Schwann cells are different than oligodendrocytes, in that a Schwann cell wraps around a portion of only one axon segment and no others. Read more. Nervous tissue consists of two cells: nerve cells or neurons and glial cells, which helps transmit nerve impulses and also provides nutrients to neurons. Since tissues are normally colourless, applying a dye to the tissue section allows the cells and their components to be seen under a microscope. They are responsible for the computation and communication that the nervous system provides. Gray matter is mostly made of neuronal bodies, dendrites and glial cells whereas white matter is made primarily out of myelinated axons. 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. Histology: An overview: want to learn more about it? Next, the tissue is embedded with paraffin wax, which firms the tissue enough permit thin slices. As such, nerves do not contain neural cell bodies. Later in this sequence, you will learn how the hippocampus and dentate gyrus function in what is known as the "limbic system" to integrate inputs from many parts of the nervous system into complicated behaviors such as learning, memory, and social interaction. Tissues join together in different arrangements to form our body organs. The branch of medical science that deals with the. 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. Hair follicles are invaginations of the epidermis that contain rapidly proliferating and keratinizing cells responsible for the production and growth of hair. I love Anatomy. Lymphatic vessels drain lymph (interstitial fluid) from all the extracellular spaces in the body. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. Body tissues are collections of cells, grouped in the body according to structure and function. It contains connective tissue, mostly composed of adipocytes. All of this is surrounded by three connective tissue membranes (meninges): dura, arachnoid and the pia mater. The epidermis (epithelium) and dermis (connective tissue) compose the skin. This traps and removes any inhaled dust, bacteria or foregn substances. Thompson, Ph.D. Histology of Nervous Tissue Despite the complexity of organization, there are only two functional cell . ("1" in the orientation figure) a polymorphic layer containing many nerve fibers and small cell bodies of interneurons, ("2" in the orientation figure) a middle pyramidal cell layer containing hippocampal pyramidal cells. A unity of cells with a similar structure that as a whole express a definite and unique function. Four of them are found in the CNS and two are found in the PNS. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. Histology Study of Tissues Epithelial Tissue Connective Tissue Nervous and Muscular Tissue Intercellular Junctions, Glands and Membranes Tissue Growth, Development . Neurons are specialized cells that contain a body (soma) and one or more processes ( dendrites, axons ). Aside from finding efficacious substances, the means of delivery is also crucial. The spleen on the other hand, filters blood. Skin glands include sweat glands (apocrine and eccrine) and sebaceous holocrine glands, both are important in regulating body temperature. 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 . One oligodendrocyte will provide the myelin for multiple axon segments, either for the same axon or for separate axons. Correct answer 1. 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. A cell is the smallest functional unit of an organism. Here you will see the Purkinje cell bodies slide 077 View Image. Young, B., Woodford, P., ODowd, G., & Wheater, P. R. (2014). Bundles of myelinated axons in the brain are called tracts, while bundles of axons in the PNS are called nerves. It has a similar role as the nervous system, working in tandem with it to maintain homeostasis of the body. The cells are laid down on top of dense irregular connective tissue, the basement membrane (BM). Basic nervous tissue staining mechanisms and classification of nervous tissue elements will be discussed. The edges of this loose enclosure extend toward each other, and one end tucks under the other. 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. Mescher, A. L. (2013). All content published on Kenhub is reviewed by medical and anatomy experts.
nervous tissue histology ppt