neuromuscular junction anki

• What is the Neuromuscular Junction?

  The point of contact between the motor neuron and the skeletal muscle fiber.
• What is the function of the Neuromuscular Junction?

  To allow the transmission of nerve impulses to the muscle fiber, leading to muscle contraction.
• What are the components of the Neuromuscular Junction?

  Axon terminal, Synaptic vesicles, Synaptic cleft, and Post-synaptic membrane.
• What is the Axon Terminal?

  The end of the motor neuron that forms the neuromuscular junction.
• What are Synaptic Vesicles?

  Small sacs within the axon terminal that store neurotransmitters.
• What is the Synaptic Cleft?


  The small gap between the axon terminal and the muscle fiber.
• What is the Post-synaptic Membrane?


  The specialized region of the muscle fiber membrane that contains neurotransmitter receptors.
• What are Subneural Folds?

  Folds in the post-synaptic membrane that increase the surface area for neurotransmitter receptor binding.
• What are Post-synaptic (ACh) Receptors?

  Receptors on the post-synaptic membrane that bind to the neurotransmitter acetylcholine (ACh).
• What is the sequence of events at the Neuromuscular Junction?

  1. Nerve impulse reaches the axon terminal. 2. Synaptic vesicles release neurotransmitter into the synaptic cleft. 3. Neurotransmitter binds to receptors on the post-synaptic membrane. 4. This generates an action potential in the muscle fiber.
• What is the definition of Neuromuscular Junction?

  The point of contact between the motor neuron and the skeletal muscle fiber.
• What are the components of Neuromuscular Junction?

  Axon terminal, Synaptic Vesicles, Synaptic Cleft, Post Synaptic Membrane, Subneural Folds, Post Synaptic (ACh) Receptor.
• What is the sequence of events at Neuromuscular Junction?

  1. Nerve impulse arrives at the axon terminal. 2. Calcium ions enter the axon terminal. 3. Synaptic vesicles release acetylcholine (ACh) into the synaptic cleft. 4. ACh binds to receptors on the post-synaptic membrane. 5. This triggers an action potential in the muscle fiber. 6. The muscle fiber contracts.
• What is the definition of the neuromuscular junction?

  The point of contact between the motor neuron and the skeletal muscle fiber.
• What is the definition of Neuromuscular Junction?

  It is the junction between the terminal branch of a nerve fiber and a skeletal muscle fiber.
• What is the function of the neuromuscular junction?

  To transmit signals from the nervous system to the muscular system, leading to muscle contraction.
• What is the function of the neuromuscular junction?

  Converting electrical impulses generated by motor neurons into chemical and then again into electrical activity in the muscle fibers.
• What are the components of the neuromuscular junction?

  Axon terminal, synaptic cleft, and post synaptic membrane.
• What is the function of the axon terminal?

  To release neurotransmitters into the synaptic cleft.
• What is the role of the presynaptic membrane?


  It is the membrane of the neuron's axon terminal that faces the synaptic cleft and releases neurotransmitters.
• What is the function of synaptic vesicles?

  To store and release neurotransmitters into the synaptic cleft.
• What is the synaptic cleft or space?

  The small gap between the presynaptic membrane and the postsynaptic membrane where neurotransmitters are released.
• What is the role of the postsynaptic membrane or motor end plate?

  It contains receptors that bind to neurotransmitters and initiate a response in the muscle fiber.
• What is the function of postsynaptic receptors?

  To bind to neurotransmitters released from the presynaptic neuron and initiate a response in the postsynaptic cell.
• What is the role of the acetylcholinesterase enzyme?


  To break down acetylcholine in the synaptic cleft, terminating its action.
• What are calcium channels responsible for at the neuromuscular junction?

  They allow the influx of calcium ions, triggering the release of neurotransmitters from the synaptic vesicles.
• What is the terminal branch of a motor nerve fiber called?

  Axon terminal.
• How is the axon terminal enlarged?

  It is enlarged into a knob-like structure.
• What is the function of mitochondria in the axon terminal?

  Supplying ATP for the synthesis of acetylcholine.
• What does the axon terminal contain that supplies acetylcholine?

  Synaptic vesicles containing acetylcholine (ACh).
• What is the membrane of the nerve ending called?

  Pre synaptic membrane.
• What does the pre synaptic membrane contain?

  Voltage gated calcium channels.
• Where are the synaptic vesicles made?

  By the Golgi apparatus in the nerve soma (cell-body).
• How are the synaptic vesicles transported to the axon terminal?

  By axoplasmic transport.
• How many vesicles are present at the axon terminal?

  Around 300,000.
• How many molecules of ACh are filled in each vesicle?

  Around 10,000 molecules.
• What synthesizes ACh for filling the synaptic vesicles?

  Choline acetyl transferase.
• What is the space between the pre and post synaptic membrane called?

  Synaptic Cleft.
• How wide is the space between the axon terminal and the muscle cell membrane?

  About 20 - 30 nm.
• What does the synaptic cleft contain?

  The enzyme cholinesterase.