5.2.3 Synapses

• A synapse is a junction between two nerve cells, where signals pass from the pre-synaptic neuron to the post-synaptic neuron
• What triggers a response in the post-synaptic neuron?

  Neurotransmitter binding
• Match the synapse type with its feature:

  Electrical Synapse ↔️ Connected by gap junctions

  Chemical Synapse ↔️ Separated by a synaptic cleft
• The synaptic cleft is a small gap between neurons in a synapse


  True
• There are two main types of synapses: electrical and chemical
• Which type of synapse is faster: electrical or chemical?

  Electrical
• Order the components of a synapse:

  1️⃣ Pre-synaptic neuron's axon terminal

  2️⃣ Synaptic cleft

  3️⃣ Post-synaptic neuron's dendrite
• The synaptic cleft is a small gap
• Electrical synapses are connected by gap junctions
• Chemical synapses transmit signals in a unidirectional direction
• Which type of synapse is typically unidirectional?

  Chemical
• Synaptic vesicles in the pre-synaptic neuron contain neurotransmitters


  True
• Match the component of a chemical synapse with its function:

  Synaptic Cleft ↔️ Small gap between neurons

  Post-Synaptic Neuron ↔️ Receives the signal
• The synaptic cleft is a small gap between the pre-synaptic and post-synaptic neurons
• What triggers a response in the post-synaptic neuron?

  Neurotransmitter binding
• When an action potential reaches the axon terminal, it triggers the release of neurotransmitters from synaptic vesicles
• Neurotransmitter binding can either excite or inhibit the post-synaptic neuron.

  True
• What is the primary mechanism of signal transmission in a chemical synapse?

  Neurotransmitter diffusion
• Steps of signal transmission in a chemical synapse

  1️⃣ Action potential reaches axon terminal

  2️⃣ Neurotransmitter release

  3️⃣ Neurotransmitter diffusion

  4️⃣ Neurotransmitter binding

  5️⃣ Postsynaptic response
• What is the structural difference between electrical and chemical synapses?

  Gap junctions vs synaptic cleft
• The synaptic cleft is a small gap between the pre-synaptic and post-synaptic neurons
• Steps of neurotransmission at a chemical synapse

  1️⃣ Action potential reaches axon terminal

  2️⃣ Neurotransmitters released into synaptic cleft

  3️⃣ Neurotransmitters diffuse across cleft

  4️⃣ Neurotransmitters bind to receptors on post-synaptic neuron

  5️⃣ Post-synaptic neuron is excited or inhibited
• What effect does an excitatory neurotransmitter have on the post-synaptic neuron?

  More likely to fire
• Two primary mechanisms of synaptic plasticity are long-term potentiation and long-term depression
• Electrical synapses use neurotransmitters to transmit signals.

  False
• Electrical synapses can transmit signals in both directions


  True
• What is the role of neurotransmitters in a synapse?

  Signal transmission
• Neurotransmitters bind to receptors on the post-synaptic neuron


  True
• Why are electrical synapses faster than chemical synapses?

  Direct ion flow
• Match the synapse type with its modulation capability:

  Electrical Synapse ↔️ Less modifiable

  Chemical Synapse ↔️ Highly modifiable
• Neurotransmitters cross the synaptic cleft to transmit signals


  True
• Order the components of a chemical synapse in terms of signal flow:

  1️⃣ Pre-synaptic neuron's axon terminal

  2️⃣ Synaptic cleft

  3️⃣ Post-synaptic neuron's dendrite
• The synaptic cleft is a small gap between the pre-synaptic and post-synaptic neurons
• What does the axon terminal of the pre-synaptic neuron contain?

  Synaptic vesicles
• The post-synaptic neuron receives signals through receptors on its dendrite.

  True
• Steps of neurotransmission at a chemical synapse

  1️⃣ Neurotransmitter release

  2️⃣ Neurotransmitter diffusion

  3️⃣ Neurotransmitter binding

  4️⃣ Postsynaptic response
• What happens to neurotransmitters after their release into the synaptic cleft?

  They diffuse
• Match the type of synapse with its key feature:

  Electrical synapse ↔️ Connected by gap junctions

  Chemical synapse ↔️ Separated by a synaptic cleft
• Electrical synapses are faster and more reliable, while chemical synapses offer more control through neurotransmitter modulation
• Chemical synapses are highly modifiable compared to electrical synapses.


  True