Synapses & Reflexes - Synapses (GCSE Biology)
Synapses
Synapses
In order for an impulse to be conducted from one neurone to another, it must travel across the synapse which is the junction between 2 neurones. Axons are well designed to allow this, and use chemical messengers called neurotransmitters:
- Impulse arrives at the first axon. The impulse reaches the end of the first axon, and arrives at the synapse.
- Neurotransmitters are released from the first axon. The end of the first axon has vesicles containing chemicals called neurotransmitters. The arrival of the electrical impulse triggers the release of the neurotransmitters from these vesicles into the synaptic cleft (the gap between the first and second axons).
- Neurotransmitters bind to the second axon. The neurotransmitter diffuses across the synaptic cleft and binds with receptors on the second axon. The receptors are complementary to the neurotransmitter, so only specific chemicals can bind to it.
- Impulse created in the second axon. Binding of neurotransmitters to the receptors leads to the stimulation of the second neurone. A new electrical impulse is started in the second axon. The receptors are only on one side of the synaptic cleft which ensures the impulse can only travel in one direction.
Different drugs for example, heroin can act on synapses and can interfere with the receptors and neurotransmitters
A synapse is a junction between two nerve cells or between a nerve cell and an effector cell, such as a muscle or gland. It allows for the transmission of signals between these cells.
A synapse consists of a presynaptic cell, a synaptic cleft, and a postsynaptic cell. The presynaptic cell releases neurotransmitters into the synaptic cleft, which then bind to receptors on the postsynaptic cell, triggering a response.
A neurotransmitter is a chemical messenger that is released by the presynaptic cell and binds to receptors on the postsynaptic cell, transmitting a signal across the synapse.
Synaptic transmission is the process by which a signal is transmitted across a synapse. It involves the release of neurotransmitters by the presynaptic cell, their diffusion across the synaptic cleft, and their binding to receptors on the postsynaptic cell.
The different types of neurotransmitters include acetylcholine, dopamine, serotonin, norepinephrine, and gamma-aminobutyric acid (GABA).
Synapses are critical for the proper functioning of the nervous system, allowing for the transmission of signals between nerve cells and between nerve cells and effector cells such as muscles and glands. They play a key role in many functions of the body, including movement, sensation, and thought.
A reflex is an automatic response to a stimulus, which occurs without conscious thought or control. It is a rapid and predictable response that helps to protect the body from harm.
Synapses are involved in reflexes by allowing for the transmission of signals from the sensory neuron to the motor neuron, which triggers the reflex response. The synapse between these neurons allows for the rapid and automatic response of the reflex.
An example of a reflex is the knee-jerk reflex, in which a tap to the knee causes the leg to jerk automatically.
Synaptic plasticity is the ability of synapses to change and adapt in response to experience and learning. It allows for the strengthening or weakening of synapses, which can have important implications for memory and learning.
Understanding synapses is critical for understanding the functioning of the nervous system and its role in controlling and coordinating the various functions of the body. It has important implications for medicine, neuroscience, and psychology, among other fields.
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