Type II sensory fiber are the second of the two main groups of stretch receptors. They are non-adapting, meaning that they keep responding even when the muscle has stopped changing its length. Stretch receptor are mechanoreceptors responsive to distenstion. ...
Their firing rate is directly related to the muscle's instantaneous length, or position. This information would indicate the position of one's leg once it has stopped moving.
Type I fibers connect to nuclear chain fibers, but not to nuclear bag fibers. These connections are also called "flower spray endings". Brief Outline: There are 3-9 nuclear chain fibres per muscle spindle that are half the size of the nuclear bag fibres. ... Brief Outline: 1-3 nuclear bag fibres lie in the centre of each intrafusal muscle fibre of a muscle spindle. ...
Category: Sensory system A thin section of lung tissue stained with hematoxylin and eosin. ... Nervous tissue is the fourth major class of vertebrate tissue. ... Drawing by Santiago RamÃ³n y Cajal of neurons in the pigeon cerebellum. ... Grey matter (or gray matter) is a major component of the central nervous system, consisting of nerve cell bodies, glial cells (astroglia and oligodendrocytes), capillaries, and short nerve cell extensions/processes (axons and dendrites). ... The soma is the bulbous end of a neuron, containing the nucleus. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... The arrow labeled axon is pointing directly at the axon hillock. ... Axoplasm is the cytoplasm of the axon of a neuron. ... The axolemma is the membrane of a neurons axon. ... Intermediate filaments are one component of the cytoskeleton - important structural components of living cells. ... Dendrites (from Greek dendron, âtreeâ) are the branched projections of a neuron that act to conduct the electrical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. ... Image of a Nissl-stained histological section through the rodent hippocampus showing various classes of neurons. ... Close up of the dendrite of a striatal medium spiny neuron. ... As a part of the retina, the bipolar cell exists between photoreceptors (rod cells and cone cells) and ganglion cells. ... Pseudounipolar cells (Pseudo- false, uni- one) are sensory neurons in the peripheral nervous system. ... The multipolar neuron possesses a single (usually long) axon and many dendrites, allowing for the integration of a great deal of information from other neurons. ... A pyramidal cell (or pyramidal neuron, or projection neuron) is a multipolar neuron located in the hippocampus and cerebral cortex. ... Drawing of pigeon Purkinje cells (A) by Santiago Ramon y Cajal Purkinje cells are a class of GABAergic neuron located in the cerebellar cortex. ... In neuroscience, granule cells are tiny cells found within the granular layer of the cerebellum. ... The mechanism of the reflex arc In the nervous system, afferent neurons--otherwise known as sensory or receptor neurons--carry nerve impulses from receptors or sense organs toward the central nervous system. ... The mechanism of the reflex arc Sensory neurons (or neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal electrical impulses. ... The mechanism of the reflex arc Sensory neurons (or neurones) are nerve cells within the nervous system responsible for converting external stimuli from the organisms environment into internal [[electrical poop is responsible for it aright underlie motor reflex loops and several forms of involuntary behavior, including pain avoidance. ... The general somatic afferent fibers (or somatic sensory fibers), afferent fibers, arise from cells in the spinal ganglia and are found in all the spinal nerves, except occasionally the first cervical, and conduct impulses of pain, touch and temperature from the surface of the body through the posterior roots to... The general visceral afferent fibers (or sympathetic afferent fibers), conduct sensory impulses from the viscera through the rami communicantes and posterior roots to the spinal cord. ... Special somatic afferent (SSA) refers to efferent nerves which supply muscles derived from ectoderm. ... Special visceral afferent (SVA) refers to afferent nerves supporting the gastrointestinal tract. ... Type Ia Sensory Fiber also called Primary Afferent Type 1A Fiber or Group II sensory fibers is a component of a muscle fibers muscle spindle which keeps track of the how fast a muscle stretch changes (the velocity of the stretch). ... Organ of Golgi (neurotendinous spindle) from the human tendo calcaneus. ... A delta fibers (AÎ´) are the fibers which convey fast pain information. ... C-fibers are unmyeliniated and as a result, have a slower conduction velocity, lower than 2 m/s. ... In the nervous system, efferent nerves otherwise known as motor or effector neuron carry nerve impulses away from the central nervous systemto effectors - either muscles or glands. ... Motor nerves enable the brain to stimulate muscle contraction. ... â In vertebrates, the term motor neuron (or âmotoneuronâ) classically applies to neurons located in the central nervous system (CNS) which project their axons outside the CNS and directly or indirectly control muscles. ... The general somatic efferent fibers (or somatic motor fibers), efferent fibers, arise from cells in the anterior column of the spinal cord and pass out through the anterior roots to the voluntary muscles. ... The general visceral efferent fibers (GVE or sympathetic efferent fibers), probably arise from cells in the lateral column or the base of the anterior column and emerge through the anterior roots and white rami communicantes. ... Special visceral efferent (SVE) refers to efferent nerves which supply muscles which derived from the branchial arches. ... Upper motor neurons are any neurons that carry motor information down to the final common pathway, that is, any neurons that are not directly responsible for stimulating the target muscle. ... Lower motor neurons (LMNs) are the motoneurons connecting the brainstem and spinal cord to muscle fibers, bringing the nerve impulses from the upper motor neurons out to the muscles. ... Alpha motor neurons (Î±-MNs) are large lower motor neurons of the brainstem and spinal cord. ... Î³-motoneurons (gamma-motoneurons or motor neurons) are a component of the fusimotor system, the system by which the CNS controls muscle spindle sensitivity. ... Illustration of the major elements in a prototypical synapse. ... Neuropil is the feltwork of unmyelinated neuronal processes (axonal and dendritic) within the gray matter of the central nervous system Traditionally, when pathologists looked at brain tissue they concentrated on neurons (the active functioning cells of the brain), glial cells and axons (especially in white matter, which is mostly composed... In a neuron, synaptic vesicles, also called neurotransmitter vesicles, store the various neurotransmitters that are released during calcium-regulated exocytosis at the presynaptic terminal into the synaptic cleft of a synapse. ... A neuromuscular junction is the junction of the axon terminal of a motoneuron with the motor end plate, the highly-excitable region of muscle fiber plasma membrane responsible for initiation of action potentials across the muscles surface. ... An electrical synapse is a mechanical and electrically conductive link between two abutting neurons that is formed at a narrow gap between the pre- and postsynaptic cells known as a gap junction. ... An interneuron (also called relay neuron,association neuron or bipolar neuron) is a term used to describe a neuron which has two different common meanings. ... Renshaw cells are located in the spinal cord horn. ... In a sensory system, a sensory receptor is a structure that recognizes a stimulus in the internal or external environment of an organism. ... NERVE ENDINGS SUCK PENIS!!! ... Meissners corpuscles (discovered by the anatomist Georg Meissner (1829-1903) are a type of mechanoreceptor and more specifically, a tactile corpuscle(corpusculum tactus). ... Merkel nerve endings are mechanoreceptors found in the skin and mucosa of vertebrates that provide touch information to the brain. ... A muscle spindle is a specialized muscle structure innervated by both sensory and motor neuron axons. ... A Pacinian corpuscle is a structure that functions as a mechanoreceptor. ... Ruffini Endings are one of the four main cutaneous mechanoreceptors. ... An olfactory receptor neuron, also called an olfactory sensory neuron, is the primary transduction cell for olfaction in the olfactory system. ... Photoreceptor cells are contained in the retina and are responsible for transducing, or converting, light into signals that can be ultimately transmitted to the brain via the optic nerve. ... Hair cells are the sensory cells of both the auditory system and the vestibular system in all vertebrates. ... Taste buds are small structures on the upper surface of the tongue, soft palate, and epiglottis that provide information about the taste of food being eaten. ... This article or section does not cite its references or sources. ... Astrocytes, also known as astroglia, are characteristic star-shaped glial cells in the brain. ... It has been suggested that this article or section be merged with Ependyma. ... Microglia are a type of glial cell that act as the immune cells of the Central nervous system (CNS). ... Radial glial cells are a pivotal cell type in the developing CNS involved in key developmental processes, ranging from patterning and neuronal migration to their newly described role as precursors during neurogenesis. ... In neuroscience, myelin is an electrically insulating phospholipid layer that surrounds the axons of many neurons. ... White matter is one of the two main solid components of the central nervous system. ... Named after the German physiologist Theodor Schwann, Schwann cells are a variety of neuroglia that mainly provide myelin insulation to axons in the peripheral nervous system of jawed vertebrates. ... Oligodendrocytes (from Greek literally meaning few tree cells), or oligodendroglia (Greek, few tree glue), are a variety of neuroglia. ... This article is about anatomy; for the musical group see Nodes of Ranvier (band) Nodes of Ranvier are regularly spaced gaps in the myelin sheath around an axon or nerve fiber. ... The portion of nerve fiber between two Nodes of Ranvier is called an internodal segment (or internode). ... Oblique clefts may be seen in the medullary sheath, subdividing it into irregular portions, which are termed Schmidt-Lanterman incisures (or clefts of schmidt-lanterman, segments of Lantermann, medullary segments. ... Neurolemma (spelled also neurolema, neurilemma and neurilema, and used interchangeably with epineurium) is the insulating myelin layer that surrounds an individual peripheral nerve fiber. ... Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue. ... Neurolemma (spelled also neurolema, neurilemma and neurilema, and used interchangeably with epineurium) is the insulating myelin layer that surrounds an individual peripheral nerve fiber. ... In a nerve fiber, the tubular sheath of the funiculi, perineurium, is a fine, smooth, transparent membrane, which may be easily separated, in the form of a tube, from the fibers it encloses; in structure it is made up of connective tissue, which has a distinctly lamellar arrangement. ... The nerve fibers are held together and supported within the funiculus by delicate connective tissue, called the endoneurium. ... A small bundle of fibers, enclosed in a tubular sheath, is called a funiculus; if the nerve is of small size, it may consist only of a single funiculus; but if large, the funiculi are collected together into larger bundles or nerve fascicles, which are bound together in a common... The meninges (singular meninx) are the system of membranes that envelop the central nervous system. ...
Primary and secondary sensoryfibers spiral around and terminate on the central portions of intrafusal fibers, providing the sensory component of the structure via stretch-sensitive ion-channels of the axons.
When a muscle is stretched, primary sensoryfibers (Group Ia afferent neurons) of the muscle spindle respond to both the velocity and the degree of stretch, and send this information to the spinal cord.
This information is transmitted monosynaptically to an alpha efferent motor fiber, which activates extrafusal fibers of the muscle to contract, thereby reducing stretch, and polysynaptically through an interneuron to another alpha motoneuron, which inhibits contraction in opposing muscles.
Both types of receptors have an inner segment, consisting of the cell body and efferent process, and an outer segment, connected to the inner segment by a cilium and consisting mainly of layers of folded membrane (Fig.
We have seen that generator or receptor potentials in all types of receptors except those in the eye are hypopolarizing.
Suppose that these mainly defenseless fish-like creatures developed a type of cell (a receptor) that contained a photopigment and was capable of secreting a substance (let’s call it a hormone) that could cause the animal to begin swimming.
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