Peripheral nerves are bundles of myelinated nerve fibers (axons) wrapped in connective tissue (endo-, peri- and epi- neurium). Axon diameters can be as small as 1 to 20 micrometers. 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. Neurons are the cells considered to be the basis of nervous tissue. Most substances that cross the wall of a blood vessel into the CNS must do so through an active transport process. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. Histology of Nervous Tissue Feature of nerves tissue Type of cell: neuron & neuroglia General feature of neuron Type of Expert Help Slide 66a View Virtual Slide shows a section of thoracic spinal cord. Learn more about the histology of the upper and lower digestive tract. 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 Because of this, only specific types of molecules can enter the CNS. The membrane wrapped around the fascicle is called an endoneurium and is made of the loose reticular connective tissue. 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). Specialized connective tissue includes the blood, reticular, cartilage, bone and adipose tissue. Bipolar cells have two processes, which extend from each end of the cell body, opposite to each other. Tissues. 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. 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. Correct answer 2. Get an overview of the different types of epithelial tissue: Connective tissue connects, separates and supports the body organs. Since tissues are relatively colorless, the magnifying properties of the optic microscope are not sufficient for proper visualization of a specimen; therefore staining techniques described above are coupled with optic microscopy. This is why doctors must take extra caution when prescribing medication to these people. A key difference between myelin and the insulation on a wire is that there are gaps in the myelin covering of an axon. The first step in tissue preparation for optic microscopy is fixation. 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. 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. Above the temporal (ventral or inferior) horn of the lateral ventricle the lateral geniculate nucleus is present. It is named after the anatomist who discovered it (Jan Evangilista Purkinje, 17871869). 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. The Schwann cells (in the peripheral nerves) and the satellite cells (in the ganglia) are glial cells (supporting cells) of the PNS. But most everything else cannot, including white blood cells, which are one of the bodys main lines of defense. The nervous system is responsible for the control of the body and the communication among its parts. EM works by emitting parallel beams of electrons onto the tissue sample. The male reproductive system consist of the internal genitalia (testes, genital ducts and accessory genital glands) and external genitalia (penis and scrotum). Water and some other small particles, like gases and ions, can enter. Pyramidal cells and olfactory cells are two other examples of neurons named for these classifications which will be discussed later. Bones articulate with other bones by way of joints, which can be synovial, fibrous or cartilaginous. Neurons. 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). For oligodendrocytes, the rest of the cell is separate from the myelin sheath as a cell process extends back toward the cell body. Muscle cells have a specialized type of smooth endoplasmic reticulum called sarcoplasmic reticulum, which stores calcium ions. 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. The length of the axon between each gap, which is wrapped in myelin, is referred to as an axon segment. Neurons are characterized by a large cell body or perikaryon containing a large, pale (active, euchromatic) nucleus with a prominentnucleolus. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. Myelin is lipid-rich, and on gross inspection appears white. ("3" in the orientation figure) a molecular layer containing dendrites of the pyramidal cells. For an even more detailed view, an electron microscopy can be used. 4. All of these components work together to provide movement to the body. Histology. They are highly specialized to transmit nerve impulses. Cells that are well preserved show features characteristic of most neurons: large cell body, large pale nucleus, Nissl substance, and cell processes (most of which are dendrites). 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. The main effector cells of the lymphatic system are the immune system cells. Slide of tissue is followed by slide of tissue with correct answer. Lymph nodes are distributed along lymphatic vessels, filtering lymph as it passes through. The function of myelin will be discussed below. As a muscle contracts, its tendon transmits the force to the bone, pulling on it and causing movement in the associated synovial joint. The nervous system is responsible for all our. It houses information about each and every structure and process of the cell and organism, in the form of DNA (deoxyribonucleic acid). Some well-known lymphatic nodules include; the tonsils, Peyers patches and vermiform appendix. New York, NY: McGraw-Hill Education. Uploaded on Jun 06, 2013 Elina + Follow cuboidal epithelium water loss Light microscopes (or optical microscopes), use a combination of visible light and lenses to create a magnified image. 5 Nervous system The introductory part of the chapter is adapted from BC OpenStax Anatomy and Physiology book under the CC BY license. 1. Pulmonary capillaries come into close contact with the alveoli, forming the blood-air barrier. It is permeable to oxygen, carbon dioxide and other gases, allowing for the occurrence of gas exchange. 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. - PowerPoint PPT presentation Number of Views: 2727 Avg rating:3.0/5.0 Slides: 14 Provided by: apbrwww5A Category: Tags: histology | nervous | tissue less At one end of the axon are dendrites, and at the other end, the axon forms synaptic connections with a target. Table 2 outlines some common characteristics and functions. All cells are enveloped by a semipermeable two-layered membrane, which serves as a dynamic medium for the cells interaction with the external environment. Learn more about how Pressbooks supports open publishing practices. They return this fluid to the heart, passing it through lymphoid organs. Neurons of the cerebral cortex are of varying shapes and sizes, but the most obvious arepyramidal cells. Click on the white box with the question mark on it 4. Histology Study of Tissues Epithelial Tissue Connective Tissue Nervous and Muscular Tissue Intercellular Junctions, Glands and Membranes Tissue Growth, Development . As such, nerves do not contain neural cell bodies. At low magnification, differentiate inner gray from outer white matter and identify dorsal and ventral horns of the gray matter. Remember, a nerve is a bundle of axons, running in parallel, in the PNS. This gives the neuron a polaritymeaning that information flows in this one direction. Thus are essential for maintaining homeostasis of the body. Histology (Tissues). 1:00 - 2:55 Cartilage and Bone ppt | pdf | lecture recording. It provides somatic motor output to skeletal muscles. Because of this, ependymal cells can be considered a component of the BBB, or a place where the BBB breaks down. This system delivers oxygenated blood from the heart to the tissues, and returns deoxygenated blood from the tissues back to the heart and lungs. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. 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. Like the spleen and lymph nodes, the immune cells in this tissue can mount an immune response against foreign invading material.

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