Transcript Neurons

Neurons and
Neurotransmitters
by Diana Last modified by: Ashley Heather Brock last
Modified by Angela Sagner
The Nervous System
• A physical organ system like any other
• The main kind of cell we are studying
today:
– Neurons
which are the basic units of the nervous system.
Neurons
Receive, integrate, and transmit information
 Operate through electrical impulses
 Communicate with other neurons through
chemical signals
The Withdrawal Reflex
T
Neuron Anatomy and Neural
Communication
Neural Anatomy
 Dendrite
 the bushy, branching extensions of a
neuron that receive messages and
conduct impulses toward the cell body
 Axon
 the extension of a neuron, ending in
branching terminal fibers, through which
messages are sent to other neurons or to
muscles or glands
Neural Anatomy and
communication
 Synapse
 junction between the axon tip of the sending
neuron and the dendrite or cell body of the
receiving neuron
 Cell Body-main body connected to dentrites
and axon
Specific Parts: The Neuron
Structure
Specific Parts: The Neuron
Function
1.
3.
2.
Neurons = 3 functions: Reception, Conduction, Transmission
ACTION POTENTIAL VIDEO
Relay Race
Action Potential starts at the dendrite, travels through the
cell body, down the Axon to the Axon Terminals.
• How does it get to the next cell’s dendrites?
Neurons don’t touch
The Synapse has a millionth inch gap.
In the synapse there are vesicles w/ neurotransmitters that
are chemical messengers that transmit info to the next
dendrite.
How does it get to the next cell’s
dendrites?
Neurotransmitters
 chemical messengers that traverse the
synaptic gaps between neurons
 when released by the sending neuron,
neurotransmitters travel across the
synapse and bind to receptor sites on
the receiving neuron, thereby
influencing whether it will generate a
neural impulse
Myelin Sheath
– Fatty material
– Insulates the axon
– Allows for rapid movement of
electrical impulses along the axon
– The Nodes of Ranvier are gaps in the
myelin sheath where action potentials are
transmitted.