Chapter 12 - Part III - Principles of Anatomy and Physiology

A ____________ is a region where communication occurs between two neurons or between a neuron and an effector cell (muscle cell or glandular cell)

The nerve cell that is in the position of sending the signal from its axon hillock before the synapse is called the ______________ neuron. 

The nerve cell that is in the position of receiving the signal after the synapse is called the ______________ neuron. 

Where the axon meets the dendrites at the synapse is called _________.

Where the axon meets the cell body at the synapse is called _________.

There are two types of synapses based on the signal being sent: electrical synapse and chemical synapse. 

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At an electrical synapse, action potentials conduct directly between the plasma membranes of adjacent neurons through structures called gap junctions. Each gap junction contains a hundred or so tubular connexons, which act like tunnels to connect the cytosol of the two cells directly. Gap junctions are common in visceral smooth muscle, cardiac muscle, and the developing embryo. They also occur in the brain.

Because action potentials conduct directly through gap junctions, electrical synapses are slower than chemical synapses.

Electrical synapses are slower at synchronization. In other words, they take longer to find the correct path of communication, or coordination. 

Although the plasma membranes of presynaptic and postsynaptic neurons in a chemical synapse are close, they do not touch. They are separated by the ______________, a space of 20–50 nm* that is filled with interstitial fluid.

Nerve impulses cannot conduct across the synaptic cleft, so an alternative, indirect form of communication occurs. In response to a nerve impulse, the presynaptic neuron releases a ___________________ that diffuses through the fluid in the synaptic cleft and binds to receptors in the plasma membrane of the postsynaptic neuron.

The postsynaptic neuron receives the chemical signal and in turn produces a _________________potential, a type of graded potential.

The presynaptic neuron converts an electrical signal (nerve impulse) into a chemical signal (released neurotransmitter). The postsynaptic neuron receives the chemical signal and in turn generates an electrical signal (postsynaptic potential).