nervous tissue histology ppt

This ground substance, also referred to as Wharthons jelly, provides insulation and protection to the blood vessels of the umbilical cord. It relays sensory input to cerebral 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). 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. 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). Much like the male, the female reproductive system is also designed for reproduction and sexual pleasure. It is specialized tissue found in the central nervous system and the peripheral nervous system. At a microscopic level, a nephron consists of a renal corpuscle and a series of tubules. . Everything absorbed through the alimentary tract passes through the special discontinued capillaries of the liver before going anywhere else. They are considered part of the mononuclear phagocytic system and will proliferate and become actively phagocytic in regions of injury and/or inflammation. In contrast, electron microscopes work by emitting parallel beams of electrons onto the sample being observed, resulting in higher resolutions. Tissuesare classified into four basic types: epithelium, connective tissue (includes cartilage, bone and blood), muscle, and nervous tissue. It contains connective tissue, mostly composed of adipocytes. Both will appear grey to the naked eye and under the microscope, due to their lack of myelin. If you are a University of Michigan student enrolled in a histology course at the University of Michigan, please click on the following link and use your Kerberos-password for access to download lecture handouts and the other resources. 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). Type II pneumocytes are also important because they secrete surfactant which prevents the lungs from collapsing. Astrocytes have many processes extending from their main cell body (not axons or dendrites like neurons, just cell extensions). It relays sensory input to other neurons in the spinal cord. 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. Then, get ready to test your knowledge! Work for the lab This website is a great way to view the tissues. All cells are enveloped by a semipermeable two-layered membrane, which serves as a dynamic medium for the cells interaction with the external environment. This Power point presentation will allow students to practice the skill of identifying tissue types from 25 histology slides. But most everything else cannot, including white blood cells, which are one of the bodys main lines of defense. Hair follicles are invaginations of the epidermis that contain rapidly proliferating and keratinizing cells responsible for the production and growth of hair. 138, 7.18). 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. White mater 4. 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. Because of this, ependymal cells can be considered a component of the BBB, or a place where the BBB breaks down. Histology Study of Tissues Epithelial Tissue Connective Tissue Nervous and Muscular Tissue Intercellular Junctions, Glands and Membranes Tissue Growth, Development . Dendrites of Purkinje cells extend deep into the molecular layer, while the axons of Purkinje cells cross the granular layer and join other nerve fibers in the interior white matter of the cerebellum. Review diagrams illustrating the morphology of neurons in your textbooks. It monitors and regulates the functions of the body. The ECM of nervous tissue is rich in ground substance, with little to no protein fibers. Astrocytes - Technically, the junctions between endothelial cells constitute the actual "barrier." Therefore, the purkinje cell somewhat resembles a shrub or coral in shape. When responding to a foreign threat, immune system cells can activate non-specific inflammation or progress to a specific immune response. Cells are the tiny living units that form the tissues, organs and structures within the body. Specialized connective tissue includes the blood, reticular, cartilage, bone and adipose tissue. You should also identify the dorsal and ventral horns in slide 65-1N stained with Masson trichrome. Examine the gray matter on each side of the sulcus using first low and then high power. The axon projects from the dendrite endings, past the cell body in a ganglion, and into the central nervous system. Click on the white box with the question mark on it 4. 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 central axons are so thin that they appear as purple dots in the middle of the lighter-colored circles of myelin. Table 2 outlines some common characteristics and functions. They return this fluid to the heart, passing it through lymphoid organs. You may be able to see subtle differences in the distribution of cell types in rather loosely demarcated layers. 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! It provides somatic motor output to skeletal muscles. Figure 1 shows the relationship of these parts to one another. The most common technique used is the hematoxylin and eosin (H&E) stain. Author: Nueron ppt naseemmeeran 139 views . Unlike the highly organized cerebellar cortex, the cerebral cortex appears to be less well-organized when viewed with the light microscope. 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. Review the organization of the spinal cord using your atlas. Resources in the University of Michigan Histology Dropbox, Slide 065-1N spinal chord Masson cross View Virtual Slide, Slide 065-2 spinal cord lumbar H&E cross View Virtual Slide, Slide 065-1 spinal cord lumbar H&E cross View Virtual Slide, Slide 066a thoracic spinal cord thoracic spinal cord luxol blue cross View Virtual Slide. The epidermis (epithelium) and dermis (connective tissue) compose the skin. Cerebral cortex 3. Thus are essential for maintaining homeostasis of the body. Epithelial cells form two important histological structures within the brain; the blood-brain barrier and the choroid plexus. Together these organs provide the ability of reproduction and sexual intercourse. 10:10 - 12:05 Muscle Tissue ppt | pdf WEEK 2 Monday, August 22. Neurons. Mucoid connective tissue is a fetal tissue present in the umbilical cord. Body tissues are collections of cells, grouped in the body according to structure and function. But what makes neurons special is that they have many extensions of their cell membranes, which are generally referred to as processes. NERVOUS TISSUE Nervous tissue consists of two groups of cell types: Nerve cells (Neurons) Neuroglia. These sections are then mounted on a glass slide, using a mounting medium as an adhesive. 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. All Rights Reserved. Mesenchymal cells are undifferentiated cells, which means they are capable of differentiating into any type of connective tissue cells (fibroblasts, osteoblasts, adipocytes etc.). With one exception, neurons such as this (though not necessarily this large) are found in ALL areas of the nervous system. 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. Muscle tissue maintains synthesizing and contractile functions. 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. normal functioning and disorders of the nervous. The tissues of the nervous system can also be divided into grey matter and white matter. Slide of tissue is followed by slide of tissue with correct answer. Slide 66a View Virtual Slide shows a section of thoracic spinal cord. Neuroglia (glial cells) (supporting cells) 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. Depending on the number of layers, epithelial tissue is classified into simple (single layered) or stratified (multi-layered). 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. 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. Germinal (spermatogenic) epithelium, with spermatogenic cells and nurse (sertoli) cells, forms the convoluted tubules, while small circular interstitial (Leydig) cells are found in the connective tissue between the tubules. 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. In this electron micrograph, note some of the features you saw in ventral horn motor neurons with the light microscope, such as the large, pale nucleus, prominent nucleolus, Nissl bodies, dendrites and axon. Unipolar cells are exclusively sensory neurons and have two unique characteristics. T and B lymphocytes are born and raised in the thymus and bone marrow, respectively. Smooth muscle tissue appears non-striated because of the less orderly arrangement of their filaments. Kind of like border police, it controls everything that comes in or out of the cell. It also helps us understand the relationship between structure and function. The epidermis is a keratinized stratified squamous epithelium mostly made out of keratinocytes. At a histological level, both the heart and blood vessels consist of three layers: The myocardium is formed by striated cardiac muscle cells (cardiomyocytes). 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. All cells contain cytoplasm, are surrounded by a membrane, and contain a variety of structures and organelles. Because the axon hillock represents the beginning of the axon, it is also referred to as the initial segment. You may see small calcific bodies in part of the hippocampus, which occur as a normal part of the aging process. 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). It consists of the mouth, pharynx, esophagus, stomach, small intestine, large intestine and anus. Did you know that there are special cardiomyocytes in your heart that spontaneously generate impulses to initiate heartbeats? 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. Please support theSecondLook initiative with a donation to ourMichigan MedicineSecondLook Donation Champaign(link is external). Peripheral nerves are analogous with neural tracts of the CNS. The nucleus is considered to be the brain of the cell. Peripheral ganglia are clusters of nerve cell bodies surrounded by a dense connective tissue capsule. Philadelphia, PA: Lippincott Williams & Wilkins. Unipolar neurons have only one process emerging from the cell body which causes them to appear T-shaped. 4. Remember, a nerve is a bundle of axons, running in parallel, in the PNS. 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. They can be classified by many different criteria. The cell body contains the nucleus and most of the major organelles. Name thefunction of the cell marked by the black arrow. 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. 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. 1:00 - 1:50 Nervous Tissue ppt | pdf | lecture recording (for both hours) 2:05 - 2:55 Connective Tissue ppt | pdf. Access to the supplemental resources for this session is password-protected and restricted to University of Michigan students. Different regions of the nervous system have distinct histological characteristics that make them easily recognizable, under the microscope. Did you know that chronic alcoholics have a lot more smooth endoplasmic reticulum concentrations in their hepatocytes? Using only histological evidence, could you determine from where in the nervous system a sample of tissue was taken? Health Information Technology & Services. Pulmonary capillaries come into close contact with the alveoli, forming the blood-air barrier.

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nervous tissue histology ppt

nervous tissue histology ppt