Module 3
Neural and Hormonal
Systems
Body’s communication system:
Neural Communication
Neuron: the building block of the nervous system
How do the neurons communicate?
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How do the neurons
communicate? Neurotransmitters
• Chemical messengers that go across the
synaptic gaps between neurons.
• They bind to the receptor sites on the
receiving neuron
• They influence whether the receiving
neuron will respond with a “neural
impulse”.
Neural Communication
Serotonin Pathways
Dopamine pathways
Neural Communication
• Acetylcholine: Learning, memory, muscle
contraction (Alzheimer’s)
• Endorphins: (“morphine within”) pain control and
to pleasure
• Dopamine: Movement, learning, attention,
emotion (Schizophrenia, Parkinson’s)
• Serotonin: Mood, hunger, sleep, arousal
(depression)
• Norepinephrine: alertness and arousal
• GABA: Inhibitory (seizures, tremors, insomnia)
• Glutamate: Excitatory, memory (seizures,
migranes, “MSG”)
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How do the drugs work?
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The Nervous System
Neurons of different
systems
• CNS
• Interneurons
• CNS’s internal
communications
• Peripheral system
• Sensory neurons
• From tissues to CNS
• Motor neurons
• From the CNS to the tissues
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The Central Nervous System
• There exist an intense information network
within the brain
•
•
•
•
40 billion neurons
Each with 10,000 contacts
400 trillion synapses
Organized into neural networks
• Spinal cord maintains the communications
between the peripheral system and the
brain
• Reflexes
The Peripheral Nervous
System
ƒ Somatic Nervous System
ƒ the division of the peripheral nervous system
that controls the body’s skeletal muscles
ƒ Autonomic Nervous System
ƒ the part of the peripheral nervous system that
controls the glands (salgi bezi) and the muscles of
the internal organs (such as the heart)
Peripheral System: the
Sympathetic System
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Peripheral System: the
Parasympathetic System
The Endocrine System
• Endocrine System
• the body’s “slow”
chemical
communication
system
• a set of glands that
secrete hormones into
the bloodstream
• Act on brain to
influence our
growth/emotions/moti
vations/mood.
The Endocrine System:
Hormones
ƒ Hormones: chemical messengers
ƒ manufactured by the endocrine glands
ƒ Produced in one tissue and affect another
ƒ Pituitary Gland
ƒ Controlled by the hypothalamus
ƒ regulates growth and controls other endocrine glands
ƒ Adrenal Glands
ƒ just above the kidneys
ƒ secrete epinephrine (adrenaline) and norepinephrine
(noradrenaline), which help to arouse the body in times
of stress
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Feedback system between the
nervous and endocrine systems
CNS
Behavior
changed
DANGER
Pituitary
Message to
adrenal glands
Other
glands
Hormones
Epinephrine is
released
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