Topic 5 - Synaptic Signaling

Central Nervous System (CNS)

includes the brain and spinal cord

Peripheral Nervous System (PNS)

the sensory and motor neurons that connect the CNS to the rest of the body

sensory neurons (afferent)

neurons that carry incoming info from the sensory receptors to the brain and spinal cord

motor neurons (efferent)

neurons that carry outgoing information from the brain and spinal cord to the muscles and glands

Interneurons (association neurons)

found in neural pathways in the CNS, connect sensory and motor neurons

glial cells

cells in the nervous system that support, nourish, and protect neurons

schwaan cells

glial cells in the PNS that form myelin sheaths around axons

Dendrites

Branchlike parts of a neuron that are specialized to receive information.

axon hillock

the cone-shaped area on the cell body from which the axon originates

Axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

Nodes of Ranvier

Gaps in the myelin sheath to which voltage-gated sodium channels are confined.

myelin sheath

A layer of fatty tissue segmentally encasing the fibers of many neurons; enables vastly greater transmission speed of neural impulses as the impulse hops from one node to the next.

synaptic bouton

end of the axon from which neurotransmitters are released

terminal branches

Branched endings of an axon that transmit messages to other neurons

Nernst equation

a mathematical relationship used to calculate an ionic equilibrium potential

Goldman equation

a mathematical formula that takes into consideration the relative permeability of the membrane to different ions.

voltage-gated ion channels

A specialized ion channel that opens or closes in response to changes in membrane potential

passive spread of depolarization

process in which cations (mostly K+) move away from the site of membrane depolarization to regions of membrane where the potential is more negative

transmission of action potential

Nerve impulse occurs, impulse reach voltage gated

ca+ channels causing influx of Ca+, this allows synaptic vessels to fuse with the presynaptic membrane, these are then released into the synaptic cleft, and will bind with the post synaptic receptors

myelination of axons

the process of insulating axons in myelin, which speeds their conductivity and allows information to move more rapidly through the brain and body