what are the purkinje fibers?
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- 1 Purkinje fibers refer to specialized muscle fibers in the heart that are located beneath the innermost layer of the heart, known as the endocardium.
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Purkinje fiber | Purkinje fibre | Purkinje fibres. One of a group of fibers in the heart, consisting of specialized cardiomyocytes, that allow the heart's conduction system to create synchronized contractions of its ventricles and thus maintain a consistent rhythm. en​.wiktionary​.org​/wiki​/Purkinje fiber.
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Human Physiology/Print Version Conduction System of the Heart. Author: Ramin Assadi, MD; Chief Editor: Richard A Lange, MD, MBA more... Overview. The conducting system of the heart consists of cardiac muscle cells and conducting fibers (not nervous tissue) that are specialized for initiating impulses and conducting them rapidly through the heart (see the image below). They initiate the normal cardiac cycle and coordinate the contractions of cardiac chambers.
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Group C nerve fiber Group C nerve fibers are one of three classes of nerve fiber in the central nervous system and peripheral nervous system. The C group fibers are unmyelinated and have a small diameter and low conduction velocity. They include Postganglionic fibers in the autonomic nervous system (ANS), and nerve fibers at the dorsal roots (IV fiber). These fibers carry sensory information. Damage or injury to nerve fibers causes neuropathic pain.
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- There are two types of peripheral nerve fibers, afferent and efferent. 1  Afferent fibers are those that carry neural impulses toward the central nervous system. 2  Efferent fibers carry impulses from the central nervous system to effectors such as muscles and glands.
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Neurons and Support Cells In addition to Purkinje cells and granule cells, the cerebellar cortex also contains stellate cells, basket cells, and Golgi cells.) [See your favorite neuro text (e.g., Kandel et al., 4th ed., pp. 835 ff) for elegant details of neural circuitry in the cerebellar cortex.
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- Purkinje fibers are specialized muscle fibers found in the heart. They originate at the atrioventricular bundle and extend into the ventricles. Their function is to relay impulses from the bundle to the ventricles, causing a contraction.
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definitions - Perineuriumreport a problem In the peripheral nervous system, nerve fibers are each wrapped in a protective sheath known as the endoneurium. These are bundled together into groups known as fascicles, each surrounded by a protective sheath known as the perineurium.Several fascicles may be in turn bundled together with a blood supply and fatty tissue within yet another sheath, the epineurium.This grouping structure is analogous to the muscular organization system of epimysium, perimysium and endomysium.everal fascicles may be in turn bundled together with a blood supply and fatty tissue within yet another sheath, the epineurium. This grouping structure is analogous to the muscular organization system of epimysium, perimysium and endomysium.
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perineurium per·i·neu·ri·um. n. pl. per·i·neu·ri·a (-no͝or′ē-ə, -nyo͝or′-). The sheath of connective tissue enclosing a bundle of nerve fibers. [New Latin: peri- + Greek.
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- It should be noted that one of the most common and easily recognized conduction pathways found in mammalian hearts is the moderator band, which contains Purkinje fibers from the right bundle branch (see: http://www.vhlab.umn.edu/atlas/right-ventricle/moderator-band/index.shtml).
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Nerve Bundles of fibres or axons, in the peripheral nervous system are called nerves, and bundles of afferent fibers are known as sensory nerves. An efferent nerve fiber conducts signals from a motor neuron in the central nervous system to muscles. Bundles of these fibres are known as efferent nerves.
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adrenergic fibers adrenergic fibers. 1. nerve fiber's that transmit nervous impulses to other nerve cells (or smooth muscle or gland cells) by the medium of the adrenalinelike transmitter substance norepinephrine (noradrenaline).
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Nervous System Nerves. Nerves are bundles of axons in the peripheral nervous system (PNS) that act as information highways to carry signals between the brain and spinal cord and the rest of the body. Each axon is wrapped in a connective tissue sheath called the endoneurium.
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- Four different terms are often used to describe bundles of axons such as those found in the white matter: funiculus, fasciculus, tract, and pathway. Funiculus is a morphological term to describe a large group of nerve fibers which are located in a given area (e.g., posterior funiculus).
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- Abstract. Purkinje fibers or Purkinje cardiomyocytes are part of the whole complex of the cardiac conduction system, which is today classified as specific heart muscle tissue responsible for the generation of the heart impulses.
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Cardiac physiology It is noteworthy that only the cells within the bundle of His, left and right bundle branches, and Purkinje fibers satisfy all three criteria. No structure within the atria meets all three criteria, including the Bachmann's bundle, sinoatrial node, and atrioventricular node (which are all uninsulated tissues).
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- (Note the distinction between the Purkinje cells, which constitute the sole output of the cerebellar cortex, and the cerebellar nuclei, which constitute the sole output of the entire cerebellum.) Almost all of the spikes generated by the Purkinje cell are caused by its parallel-fiber inputs.
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- Not all cardiac cells are autorhythmic. The cells of the SA node, the AV bundle, the AV node, and the Perkinje fibers are because they are self-excitable, able to generate an action potential without external stimulation by nerve cells. Michelle · 5 years ago.
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Group C nerve fiber Group C nerve fiber. Group C nerve fibers are one of three classes of nerve fiber in the central nervous system and peripheral nervous system. The C group fibers are unmyelinated and have a small diameter and low conduction velocity. They include Postganglionic fibers in the autonomic nervous system (ANS), and nerve fibers at the dorsal roots (IV fiber).
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Reticular fiber Reticular fibers, reticular fibres or reticulin is a type of fiber in connective tissue composed of type III collagen secreted by reticular cells.Reticular fibers crosslink to form a fine meshwork (reticulin).he term reticulin was coined in 1892 by M. Siegfried. Today, the term reticulin or reticular fiber is restricted to referring to fibers composed of type III collagen. However, during the pre-molecular era, there was confusion in the use of the term 'reticulin', which was used to describe two structures:
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Histology@ Yale Purkinje fibers are specialized for the transmission of excitation. They are larger than ordinary muscle fibers. The bulk of the sarcoplasm is occupied by glycogen that is not preserved in most histological preparations; consequently, Purkinje fibers have a clear empty appearance in most preparations.
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Purkinje cell Both basket and stellate cells (found in the cerebellar molecular layer) provide inhibitory (GABAergic) input to the Purkinje cell, with basket cells synapsing on the Purkinje cell axon initial segment and stellate cells onto the dendrites.
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Cardiac conduction system Cardiac conduction system. Overview. The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle of His, bundle branches, and Purkinje fibers. The SA node (anatomical pacemaker) starts the sequence by causing the atrial muscles to contract. From there, the signal travels to the AV node, through the bundle of His, down the bundle branches, and through the Purkinje fibers, causing the ventricles to contract. This signal creates an electrical current that can be seen on a graph called an Electrocardiogram (EKG or ECG).
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- The node in an ostrich heart is composed of fibers, which in appearance are intermediate between muscle fibers and true Purkinje fibers. Peripherally within the node and passing away from it are several true P-fibers.
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