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Acetylcholine (ah-Seh-til-KO-leen) is the organic molecule that triggers muscle contractions in humans. Acetylcholine acts on both the central nervous system (CNS) and on the peripheral nervous system (PNS). It is also the principal neurotransmitter in autonomic ganglia.
Wiki User
∙ 9y ago
Wiki User
∙ 11y agoDepends on the muscle. If you are talking about skeletal muscles like your biceps and calves then it is acetylcholine that synapses on the neuromuscular junction. When enough acetylcholine binds to enough receptors this triggers a voltage change via sodium channels, which results in calcium influx. That is what actually causes the muscle to turn "on" and causes contraction.
Wiki User
∙ 7y agoVoluntary muscle contraction is controlled by the central nervous system. The brain sends signals, in the form of action potentials, through the nervous system to the motor neuron that innervates several muscle fibers.
Acetylcholine (ACh) is commonly secreted at neuromuscular junctions, the gaps between motor neurons and muscle cells, where it stimulates muscles to contract (by opening gated positive ion channels).
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Steps in impulse transmission?
Brain send the message via nerve impulses involving neurons which use the neuro-transmitter AcetylcholineEach nerve impulse begins in the dendrites of a neuron's. the impulse move rapidly toward the neuron's cell body and then down the axon until it reaches the axon tip.a nerve impulse travels along the neuron in the form of electrical and chemical signals.Acetylcholine- a neurotransmitter released at the neuromuscular junction triggers a muscleaction potential, which leads to muscle contraction
What does myosin attach to?
During muscle contraction, myosin cross bridges attach to active sites of ACTIN FILAMENTS.
What shortens during muscle contraction?
Uponmuscle contraction, the A-bands do not change their length (1.85 micrometer in mammalian skeletal muscle) whereas the I-bands and the H-zone shorten.The protein tropomyosin covers the myosin binding sites of the actin molecules in the muscle cell. To allow the muscle cell to contract, tropomyosin must be moved to uncover the binding sites on the actin. Calcium ions bind with troponin-C molecules (which are dispersed throughout the tropomyosin protein) and alter the structure of the tropomyosin, forcing it to reveal the cross bridge binding site on the actin. The concentration of calcium within muscle cells is controlled by thesarcoplasmic reticulum, a unique form of endoplasmic reticulum. Muscle contraction ends when calcium ions are pumped back to the sarcomere. Once Calcium goes back into the sarcoplasmic reticulum, muscle relaxation starts.During stimulation of the muscle cell, themotor neuronreleases the neurotransmitter acetylcholine which travels across the neuromuscular junction (the synapse between the terminal bouton of the neuron and the muscle cell). Acetylcholine binds to a post-synaptic nicotinic acetylcholine receptor. A change in the receptor conformation allows an influx of sodium ions and initiation of a post-synaptic action potential. The action potential then travels along T (transverse) tubules until it reaches the sarcoplasmic reticulum; the action potential from the motor neuron changes the permeability of the sarcoplasmic reticulum, allowing the flow of calcium ions into the sarcomere. The outflow of calcium allows the myosin heads access to the actin cross bridge binding sites, permitting muscle contraction.Source(s):wikipedia "sarcomere"the sarcomere is the functional unit of the muscle cellutube "sarcomere" would give you a visual Do actin and myosin shorten during muscle contraction?
Where is ATPase enzyme needed for muscle contraction located?
It is in the mitochodria and speeds up the formation of ATP by breaking down ATP into ADP + energy. Muscle cells have many more mitochrondia than other cells.
Do you agree that expansion and contraction only cause problems?
No, we use expansion and contraction to tell temperature(thermometer).
Role of ionic calcium in muscle contraction?
triggers neurotransmitter secretion, removes contraction inhibitor, and binds with troponin.
What is the neurotransmitter that initiates muscle contraction?
Voluntary muscle contraction is controlled by the central nervous system. The brain sends signals, in the form of action potentials, through the nervous system to the motor neuron that innervates several muscle fibers.Acetylcholine (ACh) is commonly secreted at neuromuscular junctions, the gaps between motor neurons and muscle cells, where it stimulates muscles to contract (by opening gated positive ion channels).
The calcium that triggers muscle contraction is stored in?
he endoplasmic reticulum -mastering bio
Neurotransmitter used to cause muscle contraction?
A neurotransmitter that causes muscle movement is called Acetylcholine. Acetycholine acts as on both the central nervous system and the peripheral nervous system.
The impulse that triggers a contraction travels deep into a muscle fiber by means of what?
transverse tubules
Is calcium a neurotransmitter responsible for muscle contraction?
Potassium deficiency more likely, but yes.
What usually triggers muscle fibers to contract or relax?
The contraction is triggered by the release of calcium within the muscle which is triggered by an electrical signal from a nerve.
Describe the path a nerve impulse travels throughout your body from stimulus to response?
Brain send the message via nerve impulses involving neurons which use the neuro-transmitter AcetylcholineAcetylcholine- a neurotransmitter released at the neuromuscular junction triggers a muscle action potential, which leads to muscle contraction
What ion triggers the release of a neurotransmitter at the presynaptic membrane?
Calcium triggers synaptic vesicles to discharge the neurotransmitter into the synaptic cleft.
Which neurotransmitter is responsible for the excitatory phase of muscle contraction a. dopamine b. serotonin c. GABA d. none of the above?
Acetyl Choline
Is calcium a neurotransmitter?
No, calcium itself is not a neurotransmitter BUT it is highly important in the process of the action potential. The action potential triggers the influx of calcium at the end of the terminal bouton, causing the influx of Ca2+ into the cell and this triggers for the release of the neurotransmitter. :)
Whats the name of the chemical in the muscular system that causes contraction?
There's more than one chemical that causes contraction. The neurotransmitter (usually acetylcholine) is released from the nerve and excites the muscle. There is a change in calcium, sodium and potassium ion concentrations. ATP is used. All of these work together to produce a muscle contraction.
