Post on 30-Dec-2015
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Systems of Coordination Animals have two systems of coordination, Animals have two systems of coordination,
the the nervous systemnervous system and the and the endocrine endocrine system.system.
The nervous system coordinates rapid The nervous system coordinates rapid responses to external stimuli. responses to external stimuli.
The endocrine system controls slower, The endocrine system controls slower, longer lasting responses to internal stimuli.longer lasting responses to internal stimuli.
Activity of both systems is integrated.Activity of both systems is integrated.
Chemical messengers
3 types of chemical messengers:3 types of chemical messengers: Neurotransmitters (NTs)Neurotransmitters (NTs)
Come from NeuronsCome from Neurons EndorphinsEndorphins
Various SourcesVarious Sources HormonesHormones
Come from glands (the Endocrine System)Come from glands (the Endocrine System)
Review: Synapse
What is a synapse?What is a synapse? A synapse is the “gap” between the A synapse is the “gap” between the
axon of one nerve and the dendrite of axon of one nerve and the dendrite of the next one. the next one.
NT’s travel through the SynapseNT’s travel through the Synapse
Review: Neurotransmitters
Chemical messengers released from Chemical messengers released from neurons into the synapseneurons into the synapse
There are dozens of different There are dozens of different neurotransmittersneurotransmitters (NT) in the neurons of (NT) in the neurons of the body.the body.
NTs can be either NTs can be either excitatoryexcitatory or or inhibitoryinhibitory
What happens to NTs after they give their signal? They may return to their starting vesicles in They may return to their starting vesicles in
the axon button – “reuptake”the axon button – “reuptake” They may be absorbed and broken down by They may be absorbed and broken down by
the bodythe body
Mnemonics for remembering our 4 NTs and 4 hormones NTs: SAND = Serotonin, Acetylcholine, NTs: SAND = Serotonin, Acetylcholine,
Norepinephrine, DopamineNorepinephrine, Dopamine Hormones: COME = Cortisol, Oxytocin, Hormones: COME = Cortisol, Oxytocin,
Melatonin, EpinephrineMelatonin, Epinephrine
1. Serotonin Important in mood, sleep, aggression, Important in mood, sleep, aggression,
impulsive behavior, movement, appetite, impulsive behavior, movement, appetite, perception, attention and learning. perception, attention and learning.
In the spinal cord, serotonin is inhibitory in In the spinal cord, serotonin is inhibitory in pain pathways.pain pathways.
Serotonin level is related to carbohydrate Serotonin level is related to carbohydrate intake.intake.
Undersupply linked to depression; Prozac Undersupply linked to depression; Prozac raises serotonin levelsraises serotonin levels
2. Acetylcholine (ACh)
Controls motion; plays a role in attention & Controls motion; plays a role in attention & memory. memory.
Usually excitatory. Usually excitatory. Anything that interferes with acetylcholine Anything that interferes with acetylcholine
will produce paralysis. will produce paralysis. Alzheimer’s Disease results from Alzheimer’s Disease results from
degeneration of the cells that produce degeneration of the cells that produce acetylcholine.acetylcholine.
3. Norepinephrine (noradrenaline)
Important in wakefulness, learning, and Important in wakefulness, learning, and mood. mood.
Can be excitatory or inhibitory. Can be excitatory or inhibitory. Released during stress reactions (fight Released during stress reactions (fight
or flight; sympathetic nervous system) or flight; sympathetic nervous system) Imbalance associated with depression.Imbalance associated with depression.
4. Dopamine
Important in movement, attention, Important in movement, attention, learning and the regulation of emotional learning and the regulation of emotional response. response.
Necessary for the experience of Necessary for the experience of reward/pleasure. reward/pleasure.
Usually inhibitoryUsually inhibitory Excess associated with schizophrenia; Excess associated with schizophrenia;
decrease associated with Parkinson’s decrease associated with Parkinson’s Disease.Disease.
Endorphins
Another chemical messengerAnother chemical messenger Naturally occurring substances that Naturally occurring substances that
act like morphine in the body. act like morphine in the body. Reduce pain and increase pleasure.Reduce pain and increase pleasure. Some endorphins act as NTs, some Some endorphins act as NTs, some
act on NTsact on NTs
The Endocrine System (hormones)
Endocrine SystemEndocrine System the body’s “slow” the body’s “slow”
chemical chemical communication communication systemsystem
a set of glands a set of glands that secrete that secrete hormones into the hormones into the bloodstreambloodstream
Hormones
Hormones act through the bloodstream, Hormones act through the bloodstream, instead of being released by neuronsinstead of being released by neurons
Hormones are slower but longer lasting Hormones are slower but longer lasting than NTsthan NTs
Key HormonesHormoneHormone GlandsGlands FunctionFunction
CortisolCortisol AdrenalsAdrenals Stress; MemoryStress; Memory
OxytocinOxytocin PituitaryPituitary AttachmentAttachment
MelatoninMelatonin PinealPineal Regulates sleepRegulates sleep
Epinephrine Epinephrine (Adrenaline)(Adrenaline)
AdrenalsAdrenals Fight or flight; Fight or flight; emotion; stressemotion; stress
A spider’s venom causes paralysis. The venom probably affects:
A.A. SerotoninSerotonin
B.B. EndorphinsEndorphins
C.C. NorepinephrineNorepinephrine
D.D. AcetylcholineAcetylcholine