neuron a nerve cell receives signals from other neurons or sensory organs processes these signals and sends signals to other neurons muscles or bodily organs the basic unit of the nervous system ID: 784631
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Slide1
Starting small: The Neuron
neuron
: a nerve cell; receives signals from other neurons or sensory organs, processes these signals, and sends signals to other neurons, muscles, or bodily organs
the basic unit of the nervous system
Slide2The Neuron
3 types of neurons:
1.
sensory neurons
: respond to input from sensory organs (skin, eyes, etc.)
2.
motor neurons
: send signals to muscles to control movement
3.
interneurons
: connect the sensory neurons and motor neurons
most of the neurons in the brain =
interneurons
average human brain
100 billion
neurons
Slide3Structure of the Neuron
Slide4Structure of the Neuron
cell body (soma)
: the central part of the neuron, contains the nucleus
regulates cell functioning
dendrites
: the branching part of the neuron that receives messages from other neurons and relays them to the cell body
Slide5Structure of the Neuron
axon
:
the long, cable-like extension that delivers messages to other neurons
myelin sheath
: layer of fatty tissue that insulates the axon and helps speed up message transmission
multiple sclerosis: deterioration of myelin leads to slowed communication with muscles and impaired sensation in limbs
knobs
:
structure at the end of one of the axon’s branches that releases chemicals into the space between neurons, when the neuron is fired
Slide6From Neuron to Neuron
≈100 billion neurons in a human brain, connected to an average of 10,000 others; some up to 100,000
synapse
: the place where an axon of one neuron meets with the dendrite/cell body of another neuron
Slide7From Neuron to Neuron
Slide8From Neuron to Neuron
neurotransmitters
: a chemical that sends signals from one neuron to another over the
synapse
Slide9From Neuron to Neuron
Neurotransmitters are stored in
vesicles
in the
knobs,
and bind to
receptors
on the cell membrane of the next neuron.
Each receptor can only bind with one kind of neurotransmitter
.
Slide10(Some) Neurotransmitters
Neurotransmitter
Function
Examples of malfunctions
Acetylcholine (ACh)
Enables muscle action, learning & memory
Alzheimer’s disease
less ACh production
Dopamine
Influences movement, learning, attention, & emotion
Excess
schizophrenia
Undersupply Parkinson’s disease
Serotonin
Affects mood, hunger, sleep, and arousal
Undersupply
depression
Norepinephrine
Helps control alertness & arousal
Undersupply
depressed mood
Glutamate
Excitatory neurotransmitter involved in memory
Excess
overstimulation of brain, seizures
Slide11Central Nervous System (CNS)
Brain
Spinal Cord
Peripheral Nervous System (PNS)
Sensory Neurons
Motor Neurons
Somatic Nervous System
voluntary movements via skeletal muscles
Autonomic Nervous System
organs, smooth muscles
Sympathetic
- “Fight-or-Flight” responses
Parasympathetic
- maintenance
The Nervous System
The Nervous System
Slide12The Nervous System
Made up
of the
1. central
nervous system
and
the
peripheral
nervous
system
Slide13The Nervous System
The Central Nervous
-
brain and spinal
cord
Peripheral
Nervous System
: links central nervous system to organs
comprised of the
somatic
nervous system
and the
autonomic nervous
system (sympathetic and
parasympatheic
nerves)
Slide14CNS
Sensory division
Motor division
Autonomic
nervous
system
Sympathetic
division
Parasympathetic
division
PNS
Somatic
nervous
system