Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. 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. 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 Mescher, A. L. (2013). 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. Recall thatSchwann cells are the glial cells responsible for myelination in the peripheral nervous system. It provides preganglionic visceral motor output to sympathetic ganglia. adipose tissue, gastrointestinal tract, cardiovascular system). Skin glands include sweat glands (apocrine and eccrine) and sebaceous holocrine glands, both are important in regulating body temperature. Continue your learning with these resources. Read more. Connective tissue proper is further subdivided into loose connective tissue, mostly found in internal organs as supporting tissue stroma, and dense connective tissue, which can be regular (tendons, ligaments) or irregular (dermis of the skin, organ capsules). 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). Myelin is a fatty substance that makes the axon appear white. Learning anatomy is a massive undertaking, and we're here to help you pass with flying colours. That single axon can branch repeatedly to communicate with many target cells. The epithelial lining of the uterine tube and uterus play important roles in the transportation and implantation of a fertilized ovum (zygote). You should also identify the dorsal and ventral horns in slide 65-1N stained with Masson trichrome. Slide 13270 astrocytes, Gold-staining View Virtual Slide Go to a lighter stained area of the slide, which is in focus, and look for typical star-shaped cells, which represent astrocytes. Correct answer 1. The Neuron Special property of irritability & conductivity Nerve cells are capable of receiving the . The first way to classify them is by the number of processes attached to the cell body. One is the axon and one the dendrite, forming a straight line. The cells of the genital ducts and glands produce secretions to support this process. The nucleus and cytoplasm of the Schwann cell are on the edge of the myelin sheath. This system delivers oxygenated blood from the heart to the tissues, and returns deoxygenated blood from the tissues back to the heart and lungs. Nervous tissue. It monitors and regulates the functions of the body. Thompson, Ph.D. Histology of Nervous Tissue Despite the complexity of organization, there are only two functional cell . All cells contain cytoplasm, are surrounded by a membrane, and contain a variety of structures and organelles. For an even more detailed view, an electron microscopy can be used. Skeletal muscle consists of long cylindrical-shaped muscle cells with multiple, peripherally located nuclei and a cytoplasm filled with myofibrils. Review the organization of the spinal cord using your atlas. These cells have a single, long, nerve tract entering the bottom of the cell body. Last reviewed: November 28, 2022 Histology of the Nervous System Description: Histology of the Nervous System X-Section of Brain Tissue 4 1 2 3 1. White mater 4. Fetal tissues are classified into two types: mesenchyme and mucoid (mucous) connective tissue. Slide 66a View Virtual Slide shows a section of thoracic spinal cord. Some well-known lymphatic nodules include; the tonsils, Peyers patches and vermiform appendix. ("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. Because of this, ependymal cells can be considered a component of the BBB, or a place where the BBB breaks down. Aspects of peripheral nerve embryology and clinically . Light microscopes (or optical microscopes), use a combination of visible light and lenses to create a magnified image. 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. Some of the proteins help to hold the layers of the glial cell membrane closely together.The appearance of the myelin sheath can be thought of as similar to the pastry wrapped around a hot dog. Based on morphology, epithelial cells can be either squamous (flat), cuboid (cube) or columnar (rectangular). 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. Pyramidal cells and olfactory cells are two other examples of neurons named for these classifications which will be discussed later. Grey matter is composed mainly of unmyelinated cell bodies and dendrites, and appears grey in color. These sections are then mounted on a glass slide, using a mounting medium as an adhesive. Bipolar cells have two processes, which extend from each end of the cell body, opposite to each other. It acts as insulation, much like the plastic or rubber that is used to insulate electrical wires. The epidermis is a keratinized stratified squamous epithelium mostly made out of keratinocytes. It consists of neurons and supporting cells called neuroglia. Movement on one side of the body is often controlled by nerve impulses originating on the opposite side of the brain. This is the reason why people with extensive burns are in life-threatening danger. DiFiores atlas of histology with functional correlations. This actually causes problems with drug delivery to the CNS. The integumentary system consists of the skin and skin appendages. Specialized connective tissue includes the blood, reticular, cartilage, bone and adipose tissue. Basic nervous tissue staining mechanisms and classification of nervous tissue elements will be discussed. The nervous system can be organized in several different ways. Histology Complete and Basic Tissues. Some neurons are named on the basis of those sorts of classifications (Figure 3). Note that sacral levels of the cord (levels S2-4) also contain visceral motor neurons in the lateral horn, but these are parasympathetic. Despite their differences, they all have one thing in common; specialized elongated muscle cells, called muscle fibers. Interstitial cells produce testosterone, a hormone that regulates spermatogenesis. They are electrically active and release chemical signals to target cells. 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. The excretory system includes the kidneys, ureters, urinary bladder and urethra. A group of organs united by similar functions. Click on a question to reveal the answer. Tissues join together in different arrangements to form our body organs. The tools for studying histology are becoming more diverse everyday. 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. 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. Human anatomy is pretty straightforward. They have rectangular bodies and many dendrite like projections stemming from their shorter sides. 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. Each one reaches out and surrounds an axon to insulate it in myelin. The predominant cells visible on the slide are called pyramidal cells (named for their triangular shape). White matter consists of myelinated axons. Astrocytes in the CNS provide metabolic support for neurons and play an important role in maintaining the blood-brain barrier (see slide 13270 astrocytes View Virtual Slide). 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. Use the virtual slide of the hippocampal region to study the ependymal cell lining of the choroid plexus. Author: 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). It relays sensory input to other neurons in the spinal cord. If you were to look at some bones on a skeleton, youd see a greyish rigid mass with some bumps and depressions. To visualize this dendritic tree, an osmium stain can be used. Specialised cells (melanocytes, Merkels cells, Langerhans cells) and free nerve endings are found within the epidermis, providing pigmentation, protection and sensation. Copyright The ECM of nervous tissue is rich in ground substance, with little to no protein fibers. 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). Ependymal cells, which are uniquely located lining the ventricles of the brain the central canal of the spinal cord, are one notable exception. It is permeable to oxygen, carbon dioxide and other gases, allowing for the occurrence of gas exchange. . Any size contribution is welcomed and will help us to provide these popular review tools to students at the University of Michigan and to many more worldwide. 5 Nervous system The introductory part of the chapter is adapted from BC OpenStax Anatomy and Physiology book under the CC BY license. They are large, easily distinguishable, and have an extensive dendritic tree that is not visible in typical histology. The tissue is sectioned thinly enough so that light can pass through it. This nerve was additionally stained with osmium and the membranes of myelin are visible as dark rings. Lymph nodes are distributed along lymphatic vessels, filtering lymph as it passes through. 138, 7.18). These glial cells appear similar to epithelial cells, making a single layer of cells with little intracellular space and tight connections between adjacent cells. Neurons are the cells considered to be the basis of nervous tissue. The study of. Remember that the perikaryon is the metabolic support center for each neuron, so, therefore, motor neurons require much larger perikarya. They are stabilized by ligaments, flexible fibrous bands made of dense regular connective tissue. Muscle tissue maintains synthesizing and contractile functions. the peripheral nerves and peripheral ganglia. The nucleus is considered to be the brain of the cell. Mesenchyme gives rise to all types of connective tissue. Supporting cells dont get as much credit as neurons in popular culture; but did you know that glial cells make up at least 80% of nervous tissue? Since tissues are normally colourless, applying a dye to the tissue section allows the cells and their components to be seen under a microscope. Epithelial tissue can cover external surfaces (skin), line the inside of hollow organs (intestines) or form glands. The central axons are so thin that they appear as purple dots in the middle of the lighter-colored circles of myelin. All of these components work together to provide movement to the body. Additional sub-classifications are possible, based on the cell specializations. - PowerPoint PPT presentation Number of Views: 793 Avg rating:3.0/5.0 Slides: 13 Provided by: RachelA156 Category: The gray matter contains relatively more neuronal and glial perikarya, as well as non-myelinated (e.g. The arrow indicates a morphological type of neuron. The digestive system consists of the alimentary canal and its associated organs (tongue, teeth, salivary glands, pancreas, liver and gallbladder). 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 related to both the circulatory system and the immune system. All cells of the human body are eukaryotic, meaning that they are organized into two parts: nucleus and cytoplasm. But most everything else cannot, including white blood cells, which are one of the bodys main lines of defense. 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 The nervous system is responsible for the control of the body and the communication among its parts. The CNS contains the brain and spinal cord. Nerve tissue consists of 2 principal types of cells: neurons and supporting cells. 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! Click on human from the drop down list 5. Slide 076cerebrumcerebrum luxol blue crossView Virtual Slide, Slide 076bcerebrumTB&EView Virtual Slide. Four main groups of tissues Epithelial Connective Muscle Nervous tissue. as white matter? Mucoid connective tissue is a fetal tissue present in the umbilical cord. Many of these astrocytes send out processes that contact and wrap around nearby capillaries, which are also clearly recognizable as tube-shaped segments. Alveoli are the primary site of gas exchange. Organs work together in systems. Four of them are found in the CNS and two are found in the PNS. Luv ya! Pia mater 2. In the hippocampus orientation Image, observe: In the dentate gyrus orientation Image, observe: The "hilus" is the region where the head of hippocampus abuts the dentate gyrus. All cells are enveloped by a semipermeable two-layered membrane, which serves as a dynamic medium for the cells interaction with the external environment. 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. The tissues of the nervous system can also be divided into grey matter and white matter. Other methods include histochemistry, immunocytochemistry, hybridization techniques, tissue culture and many others. The ovary is actually an organ homologous to the male testis, it gives rise to the gametes (ova) and steroid hormones (estrogen, progesterone). These bulbs are what make the connection with the target cell at the synapse. What is the difference between a ganglion and a nucleus? How. Tissues are routinely visualised using microscopy. 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. 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).