Download Unit III: Biological Bases of Behavior

Unit III:
Biological Bases
of Behavior
Module 10
The Nervous & Endocrine
Systems
The Nervous System
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The Nervous System
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Fig. 10.1
p. 87
Peripheral Nervous System
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Somatic Nervous System: The division of the peripheral
nervous system that controls the body’s skeletal muscles.
Autonomic Nervous System: Part of the PNS that controls
the glands and other muscles, such as the heart.
Autonomic Nervous System
(ANS)
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Sympathetic Nervous System: Division of the
ANS that arouses the body, mobilizing its
energy in stressful situations (fight-or-flight).
Parasympathetic Nervous System: Division of
the ANS that calms the body, conserving its
energy (rest and digest).
In everyday situations, these two systems work together to
keep you in a steady internal state.
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Figure 10.2, p. 88
Central Nervous System
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The brain’s neurons cluster into neural networks.
Neurons networked with each other can have short, fast
connections. Learning occurs as feedback strengthens
connections.
A grain-of-sand-sized speck of your brain contains some 100,000
neurons and 1 billion “talking” synapses!
Central Nervous System
Fig. 10.4, p. 89
The Endocrine System
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The Endocrine System
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The endocrine system is the body’s “slow” chemical
communication system.
Communication is
carried out by hormones
synthesized by a set of
glands.
Figure 10.5, p. 90
Hormones
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Hormones are chemicals synthesized by the
endocrine glands that are secreted in the
bloodstream. Hormones affect the brain and many
other tissues of the body.
For example, epinephrine
(adrenaline) increases heart rate,
blood pressure, blood sugar, and
feelings of excitement during
emergency situations.
Pituitary Gland
The “master gland” (and is the
most influential endocrine gland).
It releases hormones that
influence growth and its
secretions also influence the
release of hormones by other
endocrine glands.
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