Cardiomyocytes contain actin and myosin filaments just like other muscle cells, but they have some special structural and functional properties. Table 2 outlines some common characteristics and functions. 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. 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. 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 tools for studying histology are becoming more diverse everyday. All of these components work together to provide movement to the body. Contrast the differences in the histological appearance of a pyramidal cell versus a Purkinje cell. One is the axon and one the dendrite, forming a straight line. Neurons are specialized cells that contain a body (soma) and one or more processes (dendrites, axons). How about the fact that some cardiomyocytes have the ability to secrete hormones that regulate blood pressure? As you learned in the first section, the main part of a neuron is the cell body, which is also known as the soma (soma = body). Neurons of the cerebral cortex are of varying shapes and sizes, but the most obvious arepyramidal cells. 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. Click on a question to reveal the answer. 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 Ross, H. M, Pawlina, W. (2011). One or more cell processes may also be seen emerging from the neuronal perikaryon. Get an overview of the different types of epithelial tissue: Connective tissue connects, separates and supports the body organs. Remember, this entire pathway is traveled by cells whose axons may be three feet long! Confusingly, structures within white and grey matter are referred to by different terms, depending on whether they are located in the CNS or the PNS. Based on their functional properties, these are described as either voluntary (skeletal) or involuntary (cardiac and smooth muscle). 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. 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. 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. 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. Hair follicles are invaginations of the epidermis that contain rapidly proliferating and keratinizing cells responsible for the production and growth of hair. ("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. 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. Name the part of the central nervous system that isdisplayed in this tissue section. 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. The spinal cord contains a butterfly-shaped area of grey matter surrounded by an outer layer of white matter. 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. It will also benefit the publication of several new topics (Hematology, Pathogen ID, and Gross Anatomy). Scattered in the cytoplasm are the characteristic clusters of ribosomes and rough ER termed Nissl bodies or Nissl substanceslide 066aView Image. The ovary is actually an organ homologous to the male testis, it gives rise to the gametes (ova) and steroid hormones (estrogen, progesterone). 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. Nonetheless, it is loosely stratified into layers containing scattered nuclei of both neurons and glial cells. These glial cells appear similar to epithelial cells, making a single layer of cells with little intracellular space and tight connections between adjacent cells. 4. Histology - study of tissues Tissue - a collection of similar cells that group together to perform a specialized function. It is made up of gray matter and white matter. 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). They are responsible for the computation and communication that the nervous system provides. 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. Nervous or the nerve tissue is the main tissue of our nervous system. 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. Neurons in the dorsal horn are essentially interneurons that project to other regions of the CNS (e.g. Body tissues are collections of cells, grouped in the body according to structure and function. Contents Neuron Nerve cell processes Synapses And impulse transmission The neuroglia Myelin sheath 2 3. For example, nerves can be classified based on their function. The relationship of these two types of glial cells to ganglia and nerves in the PNS is seen in Figure 5. How. This technique is used for determining the location of specific DNA or RNA sequences in cells or chromosomes, making it useful for various research and diagnostic purposes. Your donation will enable us to update all existingSecondLook resources and to transform them into completely free Progressive Web Applications (PWA), including theSecondLookHistology apps. Muscle tissue maintains synthesizing and contractile functions. It has a similar role as the nervous system, working in tandem with it to maintain homeostasis of the body. Nutrient molecules, such as glucose or amino acids, can pass through the BBB, but other molecules cannot. This system delivers oxygenated blood from the heart to the tissues, and returns deoxygenated blood from the tissues back to the heart and lungs. There are two types of EM: transmission electron microscopy, which requires very thin sections of tissue, and scanning electron microscopy, which uses larger pieces of tissue and produces 3-dimensional images. Mesenchyme gives rise to all types of connective tissue. A group of organs united by similar functions. 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. Nervous tissue is made of cells (neurons and glial cells) and extracellular matrix. Myelin is a fatty substance that makes the axon appear white. Within the axon hillock, the cytoplasm changes to a solution of limited components called axoplasm. Kind of like border police, it controls everything that comes in or out of the cell. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. Histologically, although there are a few exceptions, endocrine cells generally have an epithelial origin. The main effector cells of the lymphatic system are the immune system cells. They are considered to be supporting cells, and many functions are directed at helping neurons complete their function for communication. It relays sensory input to other neurons in the spinal cord. But what makes neurons special is that they have many extensions of their cell membranes, which are generally referred to as processes. While their origin is not conclusively determined, their function is related to what macrophages do in the rest of the body. 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. It is this myelin, a lipid-rich sheath covering axons, that causes white matter to be lighter in color than grey matter. The renal corpuscle contains the glomerulus, a tuft of fenestrated capillaries which creates an ultrafiltrate of blood. ("6" in the orientation figure) a molecular layer containing dendrites of the granule cells. Neuroglia (glial cells) (supporting cells) But most everything else cannot, including white blood cells, which are one of the bodys main lines of defense. Those processes extend to interact with neurons, blood vessels, or the connective tissue covering the CNS that is called the pia mater (Figure 4). Gray matter is mostly made of neuronal bodies, dendrites and glial cells whereas white matter is made primarily out of myelinated axons. The male reproductive system consist of the internal genitalia (testes, genital ducts and accessory genital glands) and external genitalia (penis and scrotum). Which of the following cell types contributes to maintenance of the blood-brain barrier? Available at theiTunes Storeand for Android users at theGoogle Play Store. Adjacent to the neuron, note myelinated axons of various sizes and also that there are no spaces between cell processes. This is done by the use of a complementary nucleotide probe, which contains a radioactive or fluorescent label. Microglia are, as the name implies, smaller than most of the other glial cells. Describe the organization and understand some of the basic functions of regions of the: Observe the 3-layered organization of the, Outer plexiform (molecular) layer: sparse neurons and glia, Outer granular layer: small pyramidal and stellate neurons, Outer pyramidal layer: moderate sized pyramidal neurons (should be able to see these in either, Inner granular layer: densely packed stellate neurons (usually the numerous processes arent visible, but there are lots of nuclei reflecting the cell density), Ganglionic orinner pyramidal layer: large pyramidal neurons (should be able to see these in either, Multiform cell layer: mixture of small pyramidal and stellate neurons. Be able to identify tissues in the nervous system (nerves, cell bodies and ganglia, and white vs. gray matter in the spinal cord, cerebellum, and cerebrum). All Rights Reserved. The ECM of nervous tissue is rich in ground substance, with little to no protein fibers. 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. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. Neurons are important, but without glial support they would not be able to perform their function. The neuronal type is found throughout the entire human nervous system except in dorsal root/sensory ganglia. This is a tapering of the cell body toward the axon fiber. The first step in tissue preparation for optic microscopy is fixation. It contains connective tissue, mostly composed of adipocytes. The endocrine system is divided into major endocrine glands (e.g. 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. The epithelial lining of the uterine tube and uterus play important roles in the transportation and implantation of a fertilized ovum (zygote). Oligodendrocytes (another type of glial cell) are responsible for the myelination of CNS axons. Review diagrams illustrating the morphology of neurons in your textbooks. The proteins are then exposed to labeled artificial antibodies that bind to the protein of interest and catalyse a chemiluminescent reaction, in which light is emitted as a result of a chemical reaction allowing visualization of the protein. Thoroughly learn the parts of a cell using our diagrams and cell quizzes!

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