how are smooth muscles stimulated
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Smooth muscle tissue A smooth muscle is excited by external stimuli, which causes contraction. Each step is further detailed below. Inducing stimuli and factors. Smooth muscle may contract spontaneously (via ionic channel dynamics) or as in the gut special pacemakers cells interstitial cells of Cajal produce rhythmic contractions.
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- Electrical activitation of smooth muscle is passed from cell to cell by gap junctions. Smooth muscle of the gut can generate intrinsic rhythmic contraction, independent from direct neural control.Input from the autonomic nervous system increases or decreases the level of this spontaneous activity.mooth muscle ((unlike skeletal muscle) consists of individual cells (leiomyocytes), each cell with its own nucleus. The function of smooth muscle also differs substantially from that of striated muscle.
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Acetylcholine and catecholamines Majority released from gut: Responsible for smooth muscle contraction, it's release is stimulated by food intake. It inhibits release of gastric acid and softens stool. Also involed in vasoconstriction/vasodilation of vessels and uterine contractions. ff. Receptors of epinephrine.
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sphincter muscle small, smooth muscle attached to the bulb of the hair which causes erection of the hair and compression of the attending sebaceous gland when it contracts. arterial muscle. part of the tunica media; smooth muscle fibers arranged in a circular pattern around the lumen.
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- 1 Smooth muscle or involuntary muscle is found within the walls of organs and structures such as the esophagus, stomach, intestines, bronchi, uterus, urethra, bladder, blood vessels, and the arrector pili in the skin (in which it controls erection of body hair).
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Kansas City University of Medicine & BiosciencesDepartment of PhysiologyAbout the Department Helpful Links BlackboardExcitation-Contraction Coupling in Smooth Muscle Unlike skeletal muscle, smooth muscle is dependent on two sources of calcium in order to initiate contraction. These two sources are: 1  calcium sequestered in the S.R. of the smooth muscle cell.
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Vascular smooth muscle Vascular smooth muscle contracts or relaxes to change both the volume of blood vessels and the local blood pressure, a mechanism that is responsible for the redistribution of the blood within the body to areas where it is needed (i.e. areas with temporarily enhanced oxygen consumption).
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- Contraction of the smooth muscles of the media is called vasoconstriction and results in a decrease in the size of the lumen and a decrease in blood flow. Relaxation of the smooth muscles is vasodilation which has the opposite effects.
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Black panther Melanism is the result of a dominant allele and remains relatively rare in jaguars. A black panther is the melanistic color variant of any Panthera species. Black panthers in Asia and Africa are leopards (Panthera pardus) and black panthers in the Americas are black jaguars (Panthera onca).elanism in the jaguar (Panthera onca) is conferred by a dominant allele, and in the leopard (Panthera pardus) by a recessive allele.
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Frequently Asked Questions There are two main effects: reflexive and mechanical. Massage stimulates a chain of events which tells the body to relax. For example, nerves in the skin and muscles send impulses to the brain, and the brain in turn tells the muscles to release. These reflexive effects are known as the relaxation response, or rest and digest: the heart and breath rate slows, stress hormone production slows, blood pressure goes down.
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Kansas City University of Medicine & BiosciencesDepartment of PhysiologyAbout the Department Helpful Links BlackboardExcitation of Smooth Muscle Cells Unlike skeletal muscle, there is no specialized connection between the nerve fiber and the smooth muscle cell. The nerve fibers essentially passes close to the smooth muscle cells and releases the neurotransmitter (which is not restricted to acetylcholine-see below) from swellings in the fiber, called varicosities.n target cells, activates the production of cGMP. NO is the major inhibitory neurotransmitter causing relaxation of smooth muscle in the GI tract, and it is a significant contributor to the relaxation of vascular smooth muscle (Ach causes release of NO in the vasculature).
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- The Stretch Reflex : (See Figure 13.15). The stretch reflex in its simplest form involves only 2 neurons, and is therefore sometimes called a 2-neuron reflex. The two neurons are a sensory and a motor neuron. The sensory neuron is stimulated by stretch (extension) of a muscle.Stretch of a muscle normally happens when its antagonist contracts, or artificially when its tendon is stretched, as in the knee jerk reflex.Muscles contain receptors called muscle spindles. (See Figure 13.13) These receptors respond to the muscles's stretch.he two neurons are a sensory and a motor neuron. The sensory neuron is stimulated by stretch (extension) of a muscle. Stretch of a muscle normally happens when its antagonist contracts, or artificially when its tendon is stretched, as in the knee jerk reflex.
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How does smooth muscle contraction differ from skeletal muscle contraction? This calcium then binds to troponin, causing tropomyosin to move and allowing cross-bridges to form between the myosin and actin filaments. The actin is then pulled (slides) across the myosin. Unlike skeletal muscle, there is no neuromuscular junction or troponin in smooth muscle.Instead, contraction is started by the release of neurotransmitter vesicles (membrane bound containers) into the space between the cells. In smooth muscle calcium acts directly on the myosin head-causing cross-bridges to form.nstead, contraction is started by the release of neurotransmitter vesicles (membrane bound containers) into the space between the cells. In smooth muscle calcium acts directly on the myosin head-causing cross-bridges to form.
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- Increased stretching of smooth muscle fibers in afferent arteriole walls due increased blood pressure. - stimulates to contract smooth muscle fibers, thereby narrowing the lumen of the afferent arteriolar.eload the page to try again! Press Cmd-0 to reset your zoom. Press Ctrl-0 to reset your zoom. It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
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What are four types of movement controlled by smooth muscles? Answered by The Community. Making the world better, one answer at a time. Smooth muscles push materials through passageways, remove materials from body parts, make body openings larger and smaller, and contract and restrict tubes in your body.
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- This calcium then binds to troponin, causing tropomyosin to move and allowing cross-bridges to form between the myosin and actin filaments. The actin is then pulled (slides) across the myosin. Unlike skeletal muscle, there is no neuromuscular junction or troponin in smooth muscle.Instead, contraction is started by the release of neurotransmitter vesicles (membrane bound containers) into the space between the cells. In smooth muscle calcium acts directly on the myosin head-causing cross-bridges to form. Thick filaments are scattered throughout the sarcoplasm of a smooth muscle cell. The myosin proteins are organized differently than in skeletal or cardiac muscle cells, and smooth muscle cells have more cross-bridges per thick filament.
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Kansas City University of Medicine & BiosciencesDepartment of PhysiologyAbout the Department Helpful Links BlackboardExcitation of Smooth Muscle Cells The process in smooth muscle cells: Smooth muscle, like skeletal muscle, needs some signal to begin contraction. However, there are many signals that lead to contraction in smooth muscle, not just one (acetylcholine released from the motoneuron) as in skeletal muscle.
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Potassium-induced contraction in smooth muscle. High K-induced contractions in the smooth muscle of rabbit aorta and guinea pig taenia coli may be described as follows: High K depolarizes the smooth muscle cell membrane and opens voltage dependent Ca channels, resulting in an influx of extracellular Ca and an activation of contractile machinery.
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- Function of smooth muscles depends on the tissues where they are present.... In blood vessels, when the smooth muscles contract, they constrict the lumen of the blood vessels …( arteries ) thus increasing the blood pressure, and when they relax, the lumen increases in diameter and thus brings down the blood pressure..
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- Introduction Muscle tissues share four basic properties:  Excitability: the ability to respond to stimulation Skeletal muscles normally respond to stimulation by the nervous system.Cardiac and smooth muscles respond to the nervous system and circulating hormones.uscle Contraction Contracting muscle fibers exert a pull, or tension, and shorten in length.Caused by interactions between thick and thin filaments in each sarcomereTriggered by presence of calcium ionsContraction itself requires the presence of ATP.
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RIXIMKA DUMARKA What are smooth muscles?   Smooth muscle is a type of non-striated muscle, found within the tunica media layer of large and small arteries and veins, the bladder, uterus, male and female reproduct … ive tracts, gastrointestinal tract, respiratory tract, the ciliary muscle, and iris of the eye.2 people found this useful. Smooth muscle is a type of non-striated muscle, found within the tunica media layer of large and small arteries and veins, the bladder, uterus, male and female reproduct … ive tracts, gastrointestinal tract, respiratory tract, the ciliary muscle, and iris of the eye. 2 people found this useful.
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- Answer: Contraction of both skeletal and smooth muscles involves ATP-powered interaction between myosin and actin. Cytoplasmic Ca 2+ regulates this interaction. In skeletal muscle, this is done through a steric mechanism.In smooth muscle, this is done through a biochemical pathway.nswer: Contraction of both skeletal and smooth muscles involves ATP-powered interaction between myosin and actin. Cytoplasmic Ca 2+ regulates this interaction. In skeletal muscle, this is done through a steric mechanism.
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Slow-wave potential Slow waves cause no smooth muscle contraction.When the amplitude of slow waves in smooth muscle cells reaches a certain threshold—the slow-wave threshold —a particular membrane ion channel, L-type Ca 2+ channels, are activated, resulting in calcium influx and initiation of motility.low waves cause no smooth muscle contraction.When the amplitude of slow waves in smooth muscle cells reaches a certain threshold—the slow-wave threshold —a particular membrane ion channel, L-type Ca 2+ channels, are activated, resulting in calcium influx and initiation of motility.
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Kansas City University of Medicine & BiosciencesDepartment of PhysiologyAbout the Department Helpful Links BlackboardExcitation of Smooth Muscle Cells Review of the process in skeletal muscle: Skeletal muscle has a well-defined system for producing excitation of the skeletal muscle cells. An alpha-motoneuron innervates the muscle cell, forming a neuromuscular junction.
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How does smooth muscle contraction differ from skeletal muscle contraction? Contraction in skeletal muscle begins with a nerve impulse-acetlycholine is released at the neuromuscular junction and binds to receptors in the muscle. This causes the rele … ase of calcium ions from the sarcoplasmic reticulum.he actin is then pulled (slides) across the myosin. Unlike skeletal muscle, there is no neuromuscular junction or troponin in smooth muscle. Instead, contraction is started by the release of neurotransmitter vesicles (membrane bound containers) into the space between the cells.
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SMOOTH MUSCLE CONTRACTION AND RELAXATION Layers of smooth muscle cells line the walls of various organs and tubes in the body, and the contractile function of smooth muscle is not under voluntary control. Contractile activity in smooth muscle is initiated by a Ca2+-calmodulin interaction to stimulate phosphorylation of the light chain of myosin.