Download Nervous System

3/5/2017
Command and Control Center
Nervous systems consist of neurons and
supporting cells
 The human brain contains about 100 billion
neurons, organized into circuits more complex
than the most powerful supercomputers
 Powerful imaging techniques allow researchers to
monitor multiple areas of the brain while the
subject performs various tasks
 A recent advance uses expression of
combinations of colored proteins in brain cells, a
technique called “brainbow”
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Figure 49.2
Glia
Eyespot
Nerve net
(a) Hydra (cnidarian)
Brain
Brain
Nerve
cords
Radial
nerve
Nerve
ring
Ventral
nerve cord
Transverse
nerve
(b) Sea star (echinoderm)
Segmental
ganglia
(c) Planarian (flatworm)
(d) Leech (annelid)
 astrocytes
Brain
Ganglia
Brain
Ventral
nerve
cord
Anterior
nerve ring
Spinal
cord
(dorsal
nerve
cord)
Brain
Ganglia
Segmental
ganglia
 Glial cells, or glia
Sensory
ganglia
Longitudinal
nerve cords
(e) Insect (arthropod)
(f) Chiton (mollusc)
(g) Squid (mollusc)
(h) Salamander
(vertebrate)
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Figure 49.3
Organization of the Vertebrate Nervous System
Capillary
CNS
Neuron
PNS
VENTRICLE
Cilia
Ependymal
cells
© 2014 Pearson Education, Inc.
Astrocytes
Oligodendrocytes
Microglia
Schwann cells
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3/5/2017
Figure 49.5
 The brain and spinal cord contain
Gray matter
 Gray matter
White
matter
 White matter
Ventricles
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Figure 49.6
Figure 49.7
Central
nervous
system
(CNS)
Brain
Spinal
cord
Cell body of
sensory neuron in
dorsal root ganglion
Cranial nerves
Ganglia
outside CNS
Peripheral
nervous
system
(PNS)
Gray
matter
White
matter
Quadriceps
muscle
Spinal cord
(cross section)
Spinal nerves
Hamstring
muscle
Key
Sensory neuron
Motor neuron
Interneuron
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Figure 49.8
CENTRAL NERVOUS
SYSTEM
(information processing)
The Peripheral Nervous System
PERIPHERAL NERVOUS
SYSTEM
Efferent neurons
Afferent neurons
Sensory
receptors
Autonomic
nervous system
Motor
system
Control of
skeletal muscle
Internal
and external
stimuli
Sympathetic Parasympathetic
division
division
Enteric
division
Control of smooth muscles,
cardiac muscles, glands
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
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3/5/2017
 motor system
 sympathetic division
 autonomic nervous system
 parasympathetic division
© 2014 Pearson Education, Inc.
© 2014 Pearson Education, Inc.
Figure 49.9
Parasympathetic division
Sympathetic division
Dilates pupil of eye
Constricts pupil of eye
Inhibits salivary
gland secretion
Stimulates salivary
gland secretion
Constricts
bronchi in lungs
Cervical
Sympathetic
ganglia
Relaxes bronchi in lungs
Slows heart
Accelerates heart
Stimulates activity of
stomach and intestines
Inhibits activity of
stomach and intestines
Thoracic
Stimulates activity
of pancreas
Inhibits activity
of pancreas
Stimulates gallbladder
Stimulates glucose
release from liver;
inhibits gallbladder
Lumbar
Stimulates
adrenal medulla
Promotes emptying
of bladder
Promotes erection
of genitalia
Inhibits emptying
of bladder
Sacral
Synapse
Promotes ejaculation and
vaginal contractions
© 2014 Pearson Education, Inc.
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