Use the virtual slide of the hippocampal region to study the ependymal cell lining of the choroid plexus. As a muscle contracts, its tendon transmits the force to the bone, pulling on it and causing movement in the associated synovial joint. Because of this, only specific types of molecules can enter the CNS. You should also identify the dorsal and ventral horns in slide 65-1N stained with Masson trichrome. Next, the tissue is embedded with paraffin wax, which firms the tissue enough permit thin slices. Examine the cross section of the lumbar spinal cord in slide 065-2. Continue your learning with these resources. Name the part of the central nervous system that isdisplayed in this tissue section. 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. It relays sensory input to cerebral cortex. Nervous tissue histology 1. I love Histology! Muscle tissue maintains synthesizing and contractile functions. Junquieras Basic Histology (13th ed.). For now, focus just on the morphology of these regions and observe the presence of three distinct layers rather than the six layers found in the cerebral cortex (evolutionarily speaking, the three-layered organization is considered to be "older," so this type of cortex is also known as "archicortex" whereas the "newer" six-layered cerebral cortex is "neocortex"). This is done by the use of a complementary nucleotide probe, which contains a radioactive or fluorescent label. Myelin is lipid-rich, and on gross inspection appears white. It is made up of gray matter and white matter. Glial cells, or neuroglia or simply glia, are the other type of cell found in nervous tissue. Spleen and lymph node histology shows an encapsulated meshwork of fibres, in which immune system cells sit. Mesenchymal cells are undifferentiated cells, which means they are capable of differentiating into any type of connective tissue cells (fibroblasts, osteoblasts, adipocytes etc.). 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. 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? 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. Anatomy & Physiology I Chapter 4. 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. Contrast the differences in the histological appearance of a pyramidal cell versus a Purkinje cell. Click on human from the drop down list 5. However, if you take a much closer look, youll see that the histology of bones, is a whole other story. - PowerPoint PPT presentation Number of Views: 793 Avg rating:3.0/5.0 Slides: 13 Provided by: RachelA156 Category: The membrane wrapped around the fascicle is called an endoneurium and is made of the loose reticular connective tissue. ("4" in the orientation figure) a polymorphic layer containing nerve fibers (known as "mossy fibers") and cell bodies of interneurons, ("5" in the orientation figure) a middle granule cell layer containing the round, neuronal cell bodies of dentate granule cells. Many axons are wrapped by an insulating substance called myelin, which is actually made from glial cells. This actually causes problems with drug delivery to the CNS. The other major glial cell type you should know about are microglia which are small cells derived from blood monocytes. Deep to the gray matter of the cerebral cortex is the white matter that conveys myelinated fibers between different parts of the cortex and other regions of the CNS. 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). The renal corpuscle contains the glomerulus, a tuft of fenestrated capillaries which creates an ultrafiltrate of blood. The alimentary canal is a tube extending from the mouth to the anus that serves as a channel for food and water to be digested, their nutrients absorbed and indigestible portions excreted. Body tissues are collections of cells, grouped in the body according to structure and function. On a longitudinal section, cardiomyocytes appear branched, joined together by specialized junctions called intercalated discs which allow them to quickly exchange electrical impulses and work as a syncytium. The ECM of nervous tissue is rich in ground substance, with little to no protein fibers. Tissues join together in different arrangements to form our body organs. This is because the liver, among many other things, is the major detoxifying machine of the body. between a tract and a nerve? Thus are essential for maintaining homeostasis of the body. 4. Hair follicles are invaginations of the epidermis that contain rapidly proliferating and keratinizing cells responsible for the production and growth of hair. The name suggests that it has no axon (an- = without), but this is not accurate. All cells contain cytoplasm, are surrounded by a membrane, and contain a variety of structures and organelles. Specialized connective tissue includes the blood, reticular, cartilage, bone and adipose tissue. The glial cell is wrapped around the axon several times with little to no cytoplasm between the glial cell layers. I would honestly say that Kenhub cut my study time in half. 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. The kidneys clear waste products and control plasma pH, electrolytes and extracellular fluid volume. True unipolar cells are only found in invertebrate animals, so the unipolar cells in humans are more appropriately called pseudo-unipolar cells. 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. Within the medulla, most axons will cross over to the opposite hemisphere of the brain from which they originated a process called decussation and then continue within the white matter of the spinal cord, before synapsing with interneurons and lower motor neurons, in the grey matter of the spinal cord. It is categorised as skeletal, cardiac or smooth. It consists of neurons and supporting cells called neuroglia. The cell body contains the nucleus and most of the major organelles. They can be classified by many different criteria. The three-dimensional shape of these cells makes the immense numbers of connections within the nervous system possible. Tissues are routinely visualised using microscopy. Based on the number of processes, neurons are classified into multipolar, bipolar and unipolar. Ross, H. M, Pawlina, W. (2011). The neuron shown is a multipolar neurons. The delicate meshwork of dendritic processes and nerve fibers (axons) lying between cells in the gray matter is called the neuropil. thyroid, ovaries, suprarenal) and individual hormone-secreting cells found in many organs of the body (e.g. Cells are categorized into various types, all of which perform different functions. Histology - Histology. 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. 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. All of this is surrounded by three connective tissue membranes (meninges): dura, arachnoid and the pia mater. The ECM of nervous tissue is rich in ground substance, with little to no protein fibers. 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. 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. Peripheral nerves are analogous with neural tracts of the CNS. It is related to both the circulatory system and the immune system. 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. But what makes neurons special is that they have many extensions of their cell membranes, which are generally referred to as processes. Nutrient molecules, such as glucose or amino acids, can pass through the BBB, but other molecules cannot. 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. Many of these astrocytes send out processes that contact and wrap around nearby capillaries, which are also clearly recognizable as tube-shaped segments. Glucosethe primary energy sourceis allowed, as are amino acids. Register now The nucleus is considered to be the brain of the cell. Let histology be a piece of cake once you learn how to examine a histology slide! A key difference between myelin and the insulation on a wire is that there are gaps in the myelin covering of an axon. Because of the privileged blood supply inherent in the BBB, the extracellular space in nervous tissue does not easily exchange components with the blood. Nervous tissue is composed of two types of cells, neurons and glial cells. Access to the supplemental resources for this session is password-protected and restricted to University of Michigan students. 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. They are highly specialized to transmit nerve impulses. Do you know why some structures stain blue (basophilic) and others pink (eosinophilic)? However, the endothelial cells maintain these junctions in response to signals (via foot processes) from ASTROCYTES. The study of. At a microscopic level, a nephron consists of a renal corpuscle and a series of tubules. Contents Neuron Nerve cell processes Synapses And impulse transmission The neuroglia Myelin sheath 2 3. In contrast, electron microscopes work by emitting parallel beams of electrons onto the sample being observed, resulting in higher resolutions. The male reproductive system consist of the internal genitalia (testes, genital ducts and accessory genital glands) and external genitalia (penis and scrotum). Neurons are the primary type of cell that most anyone associates with the nervous system. The neuronal bodies within the grey matter are organized into layers (laminae). Click on the white box with the question mark on it 4. They are responsible for the computation and . If the myelin sheath were drawn to scale, the neuron would have to be immensepossibly covering an entire wall of the room in which you are sitting.