Topic 43 Terminal section of nerve cells. Synapses - principle of organization, types.
Covers the terminal section of nerve cells and how synapses pass signals between neurons or to effector cells. It walks through the pre-synaptic, cleft and post-synaptic components, then the calcium-triggered release of neurotransmitters. Synapses are classified in several ways: electrical or chemical transmission, contacting structures such as axosomatic, axodendritic and axoaxonic, morphology, functionality, and atypical forms. A closing section lists neurotransmitters, including acetylcholine at the neuromuscular junction and the CNS categories with their excitatory or inhibitory effects.
Topic 43 of 59 in the MU Pleven syllabus for Cytology (Medicine, Year 1). The free AceMed note covers it in 1 section, about 283 words (2 min of reading), with 13 flashcards.
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Topic 43 Terminal section of nerve cells. Synapses - principle of organization, types.
Topic 43 Terminal section of nerve cells. Synapses - principle of organization, types.
Nerve endings
Each terminal button is connected to other neurons across a small gap called a synapse
The physical and neurochemical characteristics of each synapse determine the strength and polarity of the new input signal
Synaptic communication
Synapses are the sites where nerve impulses are transmitted from one neuron to another, or from neurons to other effector cells
The structure of the synapse ensures that transmission is uni-directional
Synapses convert an electrical signal (nerve impulse) from the pre-synaptic cell into a chemical signal that affects the post-synaptic cell
Most act by releasing neurotransmitters (small molecules that bind to specific receptors to open/close channels or initiate second messenger cascades)
