The Biological Perspective
The Nervous System, Neurons, Nerves and Their Relation to One Another
The nervous system is a complex network of cells that carry information to and
from all parts of the body
Structure Of The Neuron: The Nervous System’s Building Block
The brain is made up of two types of cells, neurons and glial cells.
Neurons have dendrites, which receive input, a soma or cell body, and axons,
which carry the neural message to the other cells.
Glial cells separate, support, and insulate the neurons from each other and make
up 90% of the brain.
Myelin insulates and protects axons of neurons that travel in the body
These axons bundle together in “cables” called nerves. Myelin also speeds up
the neural message
Generating the Message within the Neuron— the Neutral Impulse
A neuron contains charged particles called ions. When at rest, the neuron is
negatively charged on the inside and positively charged on the outside (the
resting potential). When stimulated, this reverses the charge by allowing positive
sodium ions to enter the cell. The action potential is the sequence of electrical
charges moving down the cell.
, Neurons fire in an all-or-nothing manner. It is the speed and number of neurons
firing that tells researchers the strength of the stimulus.
Neurotransmitters and Neural Communication
Sending the Message to Other Cells: The Synapse
Synaptic vesicles in the end of the axon terminal release neurotransmitter
chemicals in to the synapse, or gap, between one cell and the next.
The neurotransmitter molecules fit into receptor sites on the next cell, stimulating
or inhibiting that cell’s firing.
There are excitatory and inhibitory synapses
Neurotransmitters: Messengers of the Network
The first known neurotransmitter was acetylcholine. It stimulates muscles and
helps in memory formation. Curare is a poison that blocks its effects.
Endorphins are neural regulators that control our pain response.
Cleaning Up the Synapse: Reuptake and Enzymes
Most neurotransmitters are taken back into the synaptic vesicles in a process
called reuptake.
Acetylcholine is cleared out of the synapse by enzymes that break up molecules.
The Central Nervous System— Interactions between the Brain and Spinal Chord
The Brain
The brain makes sense of the information received from the senses, makes
decisions, and sends commands out to the rest of the body.
The Nervous System, Neurons, Nerves and Their Relation to One Another
The nervous system is a complex network of cells that carry information to and
from all parts of the body
Structure Of The Neuron: The Nervous System’s Building Block
The brain is made up of two types of cells, neurons and glial cells.
Neurons have dendrites, which receive input, a soma or cell body, and axons,
which carry the neural message to the other cells.
Glial cells separate, support, and insulate the neurons from each other and make
up 90% of the brain.
Myelin insulates and protects axons of neurons that travel in the body
These axons bundle together in “cables” called nerves. Myelin also speeds up
the neural message
Generating the Message within the Neuron— the Neutral Impulse
A neuron contains charged particles called ions. When at rest, the neuron is
negatively charged on the inside and positively charged on the outside (the
resting potential). When stimulated, this reverses the charge by allowing positive
sodium ions to enter the cell. The action potential is the sequence of electrical
charges moving down the cell.
, Neurons fire in an all-or-nothing manner. It is the speed and number of neurons
firing that tells researchers the strength of the stimulus.
Neurotransmitters and Neural Communication
Sending the Message to Other Cells: The Synapse
Synaptic vesicles in the end of the axon terminal release neurotransmitter
chemicals in to the synapse, or gap, between one cell and the next.
The neurotransmitter molecules fit into receptor sites on the next cell, stimulating
or inhibiting that cell’s firing.
There are excitatory and inhibitory synapses
Neurotransmitters: Messengers of the Network
The first known neurotransmitter was acetylcholine. It stimulates muscles and
helps in memory formation. Curare is a poison that blocks its effects.
Endorphins are neural regulators that control our pain response.
Cleaning Up the Synapse: Reuptake and Enzymes
Most neurotransmitters are taken back into the synaptic vesicles in a process
called reuptake.
Acetylcholine is cleared out of the synapse by enzymes that break up molecules.
The Central Nervous System— Interactions between the Brain and Spinal Chord
The Brain
The brain makes sense of the information received from the senses, makes
decisions, and sends commands out to the rest of the body.
