The Nervous SystemUnit II: Biology and Behavior
-What is it?-How does it affect our behavior?
Vocab
Biology-Study or science of life in all its forms, esp. the origin, growth, reproduction, structure, and behavior.
Peripheral-the external boundary of any surface or area.
Involuntary-not voluntary; independent of one's will; not by one’s own choice.
Vocab
Neuron-a specialized, impulse-conducting cell that is the basic unit of the nervous system. (A nerve cell)
Hormone-various internally secreted compounds formed in the endocrine glands that affect the functions of the body.
Heredity-the transmission of genetic characteristics from parents to offspring.
The Nervous System
Will Explain Why We FEEL…
PainStrong Nervous
The Nervous System is …
A big communication system between the brain and the body.
Helps us to gain information that is going on inside and
around our bodyrespond accordingly
The Nervous System is …
Made up of nerves – bundles of long thin cells called neurons.
Nerves send messages between the brain and the body.
The Nervous System is …
Neurons – fundamental unit of the nervous system nerve cell (5 parts)have the ability to communicate with
one another
Neuron Structure
5 Major parts to a neuron
1. Dendrites
2. Cell Body
3. Axon- 1. can be thousandths of an inch or up to three feet!
4. Myelin Sheath- aids transmission1. Degeneration can result in Multiple Sclerosis
5. Axon Terminals1. Synaptic Gap- fluid filled and 5 millionth of an inch
wide. Takes 10 millionth of a second to cross.
Synaptic Gap
Fluid filled and 5 millionth of an inch wide10 millionth of a second to cross
The Nervous System is …
Two Parts1. Central Nervous
System (CNS)brain and spinal
cord – encased in bone
The Nervous System is…
2. Peripheral Nervous System (PNS)Nerves cells/
Neurons Connects the CNS
to the body Carries information
to and from the brain & spine.
“Outer Edge”
2 Parts of the Peripheral Nervous System
Somatic nervous systemControls voluntary muscles and transmits
sensory information to the CNS
Autonomic nervous systemControls involuntary body functions
Heartbeat, Blood pressure, Breathing, Digestion…Has two parts
SympatheticParasympathetic
A “blueprint” of the Nervous System
How the Autonomic System affects our behaviors…Sympathetic Nervous System “Fight or Flight” ResponsePrepares our body to confront the situation or RUN!Remember that sympathetic, stress, and sympathy begin with “S”.
How the Autonomic System affects our behaviors…
Parasympathetic Nervous System Restores the body’s energy reserves after
an event has occurred.Remember that parasympathetic and
peaceful both begin with “P”.SLUDD (salivation, lacrimation, urination,
digestion and defecation).
How it affects our behaviors…Sympathetic VS. Parasympathetic
How the Nervous Systems affects our behaviors …
Neurotransmitters – chemicals released by neurons which help them pass messages to the next neuron.
Three important neurotransmitters (over 100 are known) have a big influence on our feelings and behavior.SerotoninDopamineEndorphins
SerotoninFunction deals with mood control and sleepProduced in the brain and intestines
Melatonin-Different hormone that helps those with insomniaAbnormal levels of serotonin have been linked to depression and obsessive-compulsive disorder (OCD).
DopamineDeals with motor
movement and alertness.
Produced in brain Deficiency of dopamine is
associated with Parkinson’s disease.
Excess is associated with schizophrenia.
Antipsychotic drugs block dopamine receptors.
Cocaine, nicotine, & amphetamines increase dopamine activity.
EndorphinsRegulates pain
control/pain perception during stress or trauma.
Can give a euphoric feeling
We can become addicted to endorphin causing feelings. Similar to opiate
addiction (morphine, heroin, & codeine).
Acupuncture
Another important neurotransmitter
Acetylcholine-”uh-seet-ul-KO-leen” Muscle control
Low amounts linked to Alzheimer's
Nerve gas & black widow venom cause too much acetylcholine to be released resulting in convulsions and suffocation.
Nicotine mimics acetylcholine.
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