pre- and postsynaptic processes are contiguous so stimulus can pass directly from one cell to next (no chemical mediation required)
Types of chemical synapses
asymmetrical
symmetrical
Asymmetrical chemical synapse
thicker postsynaptic membrane density of protein material
Symmetrical chemical synapse
pre- and postsynaptic membrane densities are same thickness
Synaptic Cleft
stimulus requires chemical carrier to bridge gap between pre- and postsynaptic structures
Synaptic vesicles
located in presynaptic terminals. variety of shapes and sizes associated with specific transmitters
Mitochondria
provide energy for release of NT into synaptic cleft
Dendrites
increase SA of neurone, collect afferent info
Dendritic Spine
projections of dendrites that receive incoming impulses, extremely plastic
Axon hillock
separates cell body and axon
Axon collaterals
side branches of axons that help bring info to several parts of NS simultaneously
Synaptic terminals
found at terminal ends of axons and transmit nerve impulses from neuron to neuron, primary means of intercommunication in NS
Centrifugal bifurcation
branching pattern of dendrites: first-order segment (few spines), second order segment, third order segment. spines become more numerous and then decrease again as become more peripheral