This Power point presentation will allow students to practice the skill of identifying tissue types from 25 histology slides. Neurons are characterized by a large cell body or perikaryon containing a large, pale (active, euchromatic) nucleus with a prominentnucleolus. Neurons (Nerve cell bodies) 5 6 5. 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. The arrow indicates a morphological type of neuron. This is why doctors must take extra caution when prescribing medication to these people. 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? This coronal section includes the hippocampus (hippocampus = sea horse), dentate gyrus, and adjacent temporal lobe gyrus (entorhinal cortex). 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). 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. Epithelium is classified by both its cellular morphology and the number of cell layers. Slide NP004N hippocampal region coronal section luxol blue View Virtual Slide [orientation]. Smooth muscle tissue appears non-striated because of the less orderly arrangement of their filaments. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. The Neuron Special property of irritability & conductivity Nerve cells are capable of receiving the . 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. Below the dermis, a layer of subcutaneous tissue (hypodermis) is found. Continue your learning with these resources. With the exception of the unipolar sensory ganglion cells, and the two specific bipolar cells mentioned above, all other neurons are multipolar. Why are perikarya of dorsal horn neurons smaller than those in the ventral horn? But what makes neurons special is that they have many extensions of their cell membranes, which are generally referred to as processes. The neuronal type is found throughout the entire human nervous system except in dorsal root/sensory ganglia. Fetal tissues are classified into two types: mesenchyme and mucoid (mucous) connective tissue. Nervous tissue is composed of two types of cells, neurons and glial cells. DNA is condensed and coiled up into chromosomes. To visualize this dendritic tree, an osmium stain can be used. 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. 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. All content published on Kenhub is reviewed by medical and anatomy experts. Neurons are the primary type of cell that most anyone associates with the nervous system. Study with Quizlet and memorize flashcards containing terms like Afferent, efferent, visceral and more. The gray matter contains relatively more neuronal and glial perikarya, as well as non-myelinated (e.g. There are six types of glial cells. 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. Click on the tissue and observe. The basic functional unit of the kidney is the nephron. Oligodendrocytes have processes that reach out to multiple axon segments, whereas the entire Schwann cell surrounds just one axon segment. Gordana Sendi MD What is the distinction between the CNS and the PNS? 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. Name this exception. Neurons are usually described as having one, and only one, axona fiber that appears as a long cord emerging from the cell body and projects to target cells. The main effector cells of the lymphatic system are the immune system cells. These sections are then mounted on a glass slide, using a mounting medium as an adhesive. 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). They are responsible for the computation and communication that the nervous system provides. For an even more detailed view, an electron microscopy can be used. Use the virtual slide of the hippocampal region to study the ependymal cell lining of the choroid plexus. Here you will see the Purkinje cell bodies slide 077 View Image. It consists of neurons and supporting cells called neuroglia. . Skin glands include sweat glands (apocrine and eccrine) and sebaceous holocrine glands, both are important in regulating body temperature. Like the spleen and lymph nodes, the immune cells in this tissue can mount an immune response against foreign invading material. Thoroughly learn the parts of a cell using our diagrams and cell quizzes! As the name implies, the cell body is shaped somewhat like a pyramid, with a large, branching dendrite extending from the apex of the pyramid toward the cortical surface, and with an axon extending downward from the base of the pyramid. 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. One or more cell processes may also be seen emerging from the neuronal perikaryon. Human anatomy is pretty straightforward. 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. 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. Wednesday, August 24. It houses information about each and every structure and process of the cell and organism, in the form of DNA (deoxyribonucleic acid). They also have cilia on their apical surface to help move the CSF through the ventricular space. The study of. 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. Nervous tissue is made of cells (neurons and glial cells) and extracellular matrix. Nueron ppt naseemmeeran 139 views . Structure of a Neuron. 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. In this article, we will introduce you to the microscopic world of histology. How is this different in the spinal cord? The information we provide is grounded on academic literature and peer-reviewed research. 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. The lighter-colored layers on both sides of the axon are myelin. Histological inspection reveals that each nerve fibre is actually composed of a large number of axons whose cell bodies reside in central or peripheral ganglia, the spinal cord or the brain. 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. The central axons are so thin that they appear as purple dots in the middle of the lighter-colored circles of myelin. Because of this, only specific types of molecules can enter the CNS. The PNS is all neural tissue outside of the CNS, i.e. Your donation will enable us to update all existingSecondLook resources and to transform them into completely free Progressive Web Applications (PWA), including theSecondLookHistology apps. Very little can pass through by diffusion. In general, where in the brain can grey matter be found? Epithelial cells form two important histological structures within the brain; the blood-brain barrier and the choroid plexus. Controls and integrates all body activities. These exclusively contain neurons with a pseudounipolar neuronal arrangement. It consists of a few cells and an abundance of extracellular matrix. Correct answer 2. Grey matter is composed mainly of unmyelinated cell bodies and dendrites, and appears grey in color. Description: Chapter 11 Histology of Nervous Tissue J.F. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. The lipids are essentially the phospholipids of the glial cell membrane. Philadelphia, PA: Lippincott Williams & Wilkins. The ECM contains different protein fibers (collagen, reticular, elastic) embedded in ground substance. In the PNS, myelin is produced by Schwann cells, which wrap around the axon. The dendritic tree and axon of each Purkinje cell can only be seen in thicker sections stained with special silver stains. Kind of like border police, it controls everything that comes in or out of the cell. 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. It is categorised as skeletal, cardiac or smooth. Figure 1 shows the relationship of these parts to one another. 5 Nervous system The introductory part of the chapter is adapted from BC OpenStax Anatomy and Physiology book under the CC BY license. It is related to both the circulatory system and the immune system. It provides somatic motor output to skeletal muscles. 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. Together these organs provide the ability of reproduction and sexual intercourse. Figure 1, Figure 4, and Figure 5 show the myelin sheath surrounding an axon segment, but are not to scale. Diffuse lymphoid tissues and lymphatic nodules are non-encapsulated accumulations of lymphoid tissue found in locations such as the alimentary, respiratory and genitourinary tracts. Cells are the tiny living units that form the tissues, organs and structures within the body. Scattered in the cytoplasm are the characteristic clusters of ribosomes and rough ER termed Nissl bodies or Nissl substanceslide 066aView Image. For example, the simple columnar epithelium of the stomach fundus contains special parietal cells which secrete HCl to break down meat proteins. It is composed of densely packed epithelial cells with only a little extracellular matrix (ECM). Learn more about the histology of the upper and lower digestive tract. Review the organization of the spinal cord using your atlas. With one exception, neurons such as this (though not necessarily this large) are found in ALL areas of the nervous system. Multipolar neurons are all of the neurons that are not unipolar or bipolar. 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. Sertoli cells prevent the immune system from attacking and destroying the spermatozoa. This preserves it into the same state that it had when it was in the body, and thus, keeps it from degrading. 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. One oligodendrocyte will provide the myelin for multiple axon segments, either for the same axon or for separate axons. Nervous tissue is made of cells (neurons and glial cells) and extracellular matrix. In a transverse section of a nerve (Figure 10), single myelinated axons look like little circles organized in bundles called fascicles. Click on launch activity 2. Myelin is lipid-rich, and on gross inspection appears white. 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. Slide of tissue is followed by slide of tissue with correct answer. Muscle attaches to bone via tendons; bundles of dense regular connective tissue made out of many collagen type I fibers. 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. These vibrate to produce sound as air passes through them. Cerebral cortex 3. Remember, a nerve is a bundle of axons, running in parallel, in the PNS. Pancreatic serous acini secrete digestive enzymes which break down fat, carbohydrates and proteins. 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 . 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. 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. Each gap is called a node of Ranvier and is important to the way that electrical signals travel down the axon. Muscle tissue maintains synthesizing and contractile functions. Unipolar cells are exclusively sensory neurons and have two unique characteristics.
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