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What causes an action potential when it binds the motor end plate?
Wiki User
∙ 9y ago
Chemically gated sodium channels open up when neurotransmitters bind to receptors in the motor end plate. This causes an action potential along a muscle membrane or nerve cell.
Wiki User
∙ 9y ago
Wiki User
∙ 11y agoInflux of Na+ ions.
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What part of the muscle cell membrane contain acetylcholine receptors?
When the Ach binds to receptor sites on the muscle cell membrane it causes channels to open and allows Na+ to move into the cell which then causes an action potential.
What is the neurotransmitter of the motor neuron?
Alpha-Motor neurons release the neurotransmitter acetylcholine at a synapse called the neuromuscular junction. When the acetylcholine binds to acetylcholine receptors on the muscle fiber, an action potential is propagated along the muscle fiber in both directions.
Contraction mechanism in a skeletal muscle cell?
ACH is released at the end-plate potential. ACH diffuses into the sarcolemma, attaches to the receptors in the motor end plate and causes a change in the ions permeability that creates graded depolarization of the end-plate potential. Basically, it attaches to the receptors in the motor-end plate and creates the beginning process of triggering muscle contractions.
Motor end plate is?
Motor end plate of a cell is the dendritic portion that have cholinergic receptors to receive neurotransmitters in order to propagate an action potential.
What cell membrane do action potentials travel along?
The membrane or resting potential is the difference in voltage within and outside the cell when that cell is at rest. In a typical neuron it is usually around -65mV, meaning the neuron is negatively charged relative to the extracellular space. This potential is due to various ions and the permeability of the neuronal membrane. When a neuron gets a signal from another neuron, this causes the concentration of various ions to change (some flow in, others out of, the cell). In some cases, the signal causes positive ions to flow into the cell, making the membrane potential less negative. Once it reaches a threshold, usually around -55mV, the cell "fires" or makes an action potential, which is when the membrane potential temporarily shoots up to around +40mV. This signal propagates down the length of the neuron and then passes that message on to other cells.
What causes depolarisation of sarcolemma of muscle fibre?
An incoming action potential to an alpha motor neuron causes acetylcholine (Ach)release at the end plate, Ach binds to Ach receptors on the sarcolemma causing a sodium influx which causes depolarization.
What happens to the muscle membrane when acetylcholine binds to receptors at the motor plate?
When acetylcholine binds to receptors at the motor plate, this binding opens ligand-gated ion channels on the motor end plate, ions diffuse through the open ligand gated ion channels, and the flow of ions causes the motor end plate to reach threshold and an action potential is generated at the motor end plate.
What part of the muscle cell membrane contain acetylcholine receptors?
When the Ach binds to receptor sites on the muscle cell membrane it causes channels to open and allows Na+ to move into the cell which then causes an action potential.
What is the neurotransmitter of the motor neuron?
Alpha-Motor neurons release the neurotransmitter acetylcholine at a synapse called the neuromuscular junction. When the acetylcholine binds to acetylcholine receptors on the muscle fiber, an action potential is propagated along the muscle fiber in both directions.
What is the neurotransmitter of alpha-motor neuron?
Alpha-Motor neurons release the neurotransmitter acetylcholine at a synapse called the neuromuscular junction. When the acetylcholine binds to acetylcholine receptors on the muscle fiber, an action potential is propagated along the muscle fiber in both directions.
Response of a motor unit to a single action potential of it motor neuron is called?
muscle twitch
The response of a motor unit to a single action potential of its motor neuron is called?
muscle twitch
Chemical released to stimulate muscle contraction?
A signal is generated in the motor cortex of the brain, and travels down the spinal cord to the affected motor neurons. As the action potential travels down the axon of the final motor neuron, it causes calcium influx and exocytosis of acetylcholine-containing vesicles, releasing acetylcholine into the neuromuscular junction. From there, acetylcholine binds with receptors on the muscle fiber end plates, where it depolarizes the muscle fiber, causing contraction of the muscle.
How does the nervous stimulus pass to the motor end plate?
An activated neuron will send an action potential from upper motor neurons to lower motor neurons to effector organs. It is able to propagate the action potential to the motor end plate by release of neurotransmitters, chiefly acetylcholine. On the terminal bouton the action potential opens voltage gated calcium channels. There is an influx of calcium in the pre-synaptic cell and it pushes the vesicles that contain acetylcholine. These vesicles will pass through the synaptic cleft and bind to cholinergic receptors on the post synaptic neuron. Each vesicle has a miniature end plate potential of 0.5mV. In a normal action potential, it will depolarize the post synaptic motor neuron from -85mV to approximately 0-15mV. So that's approximately 180 vesicles.* The influx of neurotransmitters (primarily acetylcholine) will depolarize the motor end plate and propagate the action potential. *Threshold of an action potential is approximately -55mV so technically the minimum required to continue an action potential is around 60 vesicles.
What causes muscle contraction?
Muscle contraction in initiated by an action potential sent from the brain or spinal cord to the axon terminal of a motor neuron. Calcium then goes into the axon terminal which causes the release of the neurotransmitter acetylcholine which binds to receptors on the plasmalemma. Calcium then diffuses into the sarcoplasm and binds to troponin. The troponin is then shifted to expose binding sites on the actin filament allowing for the linkage of actin and myosin. The the actin filaments are then pulled inward during shortening the sarcomere and resulting in muscular contraction :) I learnt this stuff in year 9
Which fibers carry action potential to cause skeletal muscles to contract?
Alpha motor neurons
An action potential in the axon terminal of a motor neuron opens what type of ion channels?
Exocytosis
