The Nervous System
Chapter 49
http://topnews.in/health/files/human-brain011.jpg
OVERVIEW: COMMAND AND CONTROL
CENTER
•
The human brain contains
about 100 billion neurons,
organized into circuits more
complex than the most
powerful supercomputers
•
A recent advance in brain
exploration involves a method
for expressing combinations of
colored proteins in brain cells, a
technique called “brainbow”
•
This may allow researchers to
develop detailed maps of
information transfer between
regions of the brain
FIGURE 49.1
49.1 VERTEBRATE NERVOUS SYSTEM
AUTONOMIC NERVOUS SYSTEM
Parasympathetic Sympathetic
Heart rate slows,
pupils constrict,
blood vessels
dilate
Heart rate
increases, pupils
dilate, blood
vessels constrict
Returns body to
rest
Regulates
arousal and
energy
generation
(“fight-or-flight”
response)
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information, and
produce responses. d. Different regions of the vertebrate brain have different functions.
LO 3.45 The student is able to describe how nervous systems transmit information.
CONCEPT 49.2: THE VERTEBRATE BRAIN
IS REGIONALLY SPECIALIZED
FIGURE 49.9C
Left cerebral
hemisphere
Right cerebral
hemisphere
Cerebral cortex
Corpus callosum
Cerebrum
Basal nuclei
Cerebellum
Adult brain viewed from the rear
SLEEP AND AROUSAL
• The brainstem and cerebrum control arousal
and sleep
• The core of the brainstem has a diffuse
network of neurons called the reticular
formation
• This regulates the amount and type of
information that reaches the cerebral cortex
and affects alertness
• The hormone melatonin is released by the
pineal gland and plays a role in bird and
mammal sleep cycles
EMOTIONS IN THE LIMBIC SYSTEM
• Generation and
experience of
emotions involve
many brain structures
including the
amygdala,
hippocampus, and
parts of the thalamus
• The limbic system also
functions in
motivation, olfaction,
behavior, and
memory
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information,
and produce responses.
d. Different regions of the vertebrate brain have different functions.
EMOTIONS IN THE LIMBIC SYSTEM
• Generation and experience of emotion also
require interaction between the limbic
system and sensory areas of the cerebrum
• The structure most important to the storage
of emotion in the memory is the amygdala,
a mass of nuclei near the base of the
cerebrum
BRAINSTEM
• Medulla oblongata
• Contains centers that control
visceral (autonomic,
homeostatic) functions
• Breathing, heart and blood vessel
activity, swallowing, vomiting, and
digestion
• Pons
• Have nuclei in the medulla that
regulate breathing centers
• Midbrain
• Centers for receipt and
integration of sensory
information
• Coordinates large-scale body
movements such as walking
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information,
and produce responses.
d. Different regions of the vertebrate brain have different functions.
CEREBELLUM
• Primary function is
coordination of movement
and balance
• Receives information about
position from joints and length
of muscles, as well as auditory
and visual systems
• Plays role in learning and
remembering motor
responses (hand-eye
coordination)
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information, and
produce responses. d. Different regions of the vertebrate brain have different functions.
LO 3.44 The student is able to describe how nervous systems detect external and internal signals.
LO 3.45 The student is able to describe how nervous systems transmit information.
LO 3.46 The student is able to describe how the vertebrate brain integrates information to produce a response.
THALAMUS AND HYPOTHALAMUS
• Thalamus
• Main input center for sensory
information going to cerebrum
• Receives input from cerebrum
to regulate emotion and
arousal
• Hypothalamus
• Source of posterior pituitary
hormones and releasing
hormones that act on anterior
pituitary
• Regulates body temp, thirst,
hunger, other basic survival
mechanisms
• Plays role in sexual response
and mating behaviors, fightor-flight response, and
pleasure
Essential knowledge 3.E.2: Animals have nervous systems that detect
external and internal signals, transmit and integrate information, and
produce responses. d. Different regions of the vertebrate brain have
different functions.
LO 3.45 The student is able to describe how nervous systems transmit
information.
LO 3.46 The student is able to describe how the vertebrate brain
integrates information to produce a response.
CONCEPT 49.3: THE CEREBRAL CORTEX
CONTROLS VOLUNTARY MOVEMENT AND
COGNITIVE FUNCTIONS
• The cerebrum, the
largest structure in the
human brain
• Controls skeletal muscle
contraction
• Essential for awareness,
language, cognition,
memory, consciousness,
and perception
• Four regions, or lobes
(frontal, temporal,
occipital, and parietal),
are landmarks for
particular functions
LANGUAGE AND SPEECH
• Studies of brain activity
have mapped areas
responsible for language
and speech
• Broca’s area in the frontal
lobe is active when
speech is generated
• Wernicke’s area in the
temporal lobe is active
when speech is heard
• These areas belong to a
larger network of regions
involved in language
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information,
and produce responses.
d. Different regions of the vertebrate brain have different functions.
LO 3.46 The student is able to describe how the vertebrate brain integrates information to produce a response.
LATERALIZATION OF CORTICAL
FUNCTION
• The left hemisphere -language, math, logic,
and processing of serial
sequences
• The right hemisphere -pattern recognition,
nonverbal thinking, and
emotional processing
• The two hemispheres
work together by
communicating
through the fibers of
the corpus callosum
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information,
and produce responses.
d. Different regions of the vertebrate brain have different functions.
LO 3.46 The student is able to describe how the vertebrate brain integrates information to produce a response.
LATERALIZATION OF CORTICAL
FUNCTION
• Clusters of neurons
(basal nuclei) are
centers for planning
and learning
movement sequences
• Damage here during
fetal development can
result in cerebral palsy,
a disorder resulting
from a disruption in the
transmission of motor
commands to the
muscles.
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate
information, and produce responses.
LO 3.46 The student is able to describe how the vertebrate brain integrates information to produce a response.
INFORMATION PROCESSING
• The cerebral cortex receives input from
sensory organs and somatosensory
receptors
• Somatosensory receptors provide
information about touch, pain, pressure,
temperature, and the position of muscles
and limbs
• The thalamus directs different types of input
to distinct locations
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate
information, and produce responses.
LO 3.44 The student is able to describe how nervous systems detect external and internal signals.
INFORMATION PROCESSING
• Adjacent areas process features in the
sensory input and integrate information from
different sensory areas
• Integrated sensory information passes to the
prefrontal cortex, which helps plan actions
and movements
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information,
and produce responses.
LO 3.44 The student is able to describe how nervous systems detect external and internal signals.
SOMATOSENSORY CORTEX AND
MOTOR CORTEX
• Neurons are arranged
according to the part
of the body that
generates input or
receives commands
• Motor- surface area
related to neuronal
control needed
• Somatosensory- surface
area related to number
of sensory neuron axons
to that part
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information,
and produce responses.
d. Different regions of the vertebrate brain have different functions.
LO 3.46 The student is able to describe how the vertebrate brain integrates information to produce a response.
FRONTAL LOBE FUNCTION
• Frontal lobe damage
may impair decision
making and
emotional responses
but leave intellect
and memory intact
• The frontal lobes
have a substantial
effect on “executive
functions”
Essential knowledge 3.E.2: Animals have nervous systems that detect external and internal signals, transmit and integrate information,
and produce responses.
d. Different regions of the vertebrate brain have different functions.
LO 3.46 The student is able to describe how the vertebrate brain integrates information to produce a response.