InSight
T h e b r a in
Figure 7.1 0
a.
Cerebrum controls all sensory and motor functions, thought processes, and memories
Frontal lobe - sends motor output:
Primary
motor
area
(precentral gyrus)
• Premotor
area
• Broca’s
area
(speech center)
• Frontal
eye
field
area
• Prefrontal lobe (personality, intellect, learning,
reasoning, judgment, mood, recall, intuition, abstraction)
Lateral cerebral sulcus
Parietal
lobe - receives and associates
somatosensory information:
Primary
sensory
area
(postcentral gyrus) ■
Primary
gustatory
area
(taste) -
• Somatosensory association
area
• Common integrative
area
(receives and interprets a variety of
sensory information: visual, auditory,
somatosensory, taste, smell)
Parieto-occipital sulcus
Central
sulcus
Occipital lobe - receives
visual information
Temporal lobe - receives auditory information:
• Auditory association area (green)
• Wernicke’s area interprets speech (partially
located in parietal lobe)
b. Diencephalon, cerebellum, and brainstem
Brainstem is continuous with the spinal cord and
controls involuntary functions, movements of the
head and neck, and is the origin of the cranial nerves:
• Midbrain (contains sensory and motor tracts, controls
movement of head, eyes, and trunk in response to visual
and auditory stimuli, origin of cranial nerves III and IV)
• Pons (contains sensory and motor tracts, origins of
cranial nerves V and VIII, helps regulate breathing)
• Medulla oblongata (contains sensory and motor
tracts, functions in consciousness and arousal,
regulates vital functions (heart rate, breathing, blood
vessel diameter), origins of cranial nerves VIII - XII)
Diencephalon:
Thalamus
(relays sensory information
to sensory cortex, motor information
from cerebellum and basal ganglia to
frontal cortex, role in conciousness)
• Hypothalamus (controls ANS and
pituitary gland, emotional states, eating,
drinking, sexual activity, circadian
rhythms, sleep/wake cycles)
• Pineal gland (secretes melatonin)------
Cerebellum is attached to the brainstem by -
two bundles of axons called cerebellar
peduncles, one from each hemisphere. The
cerebellum smoothes and coordinates
voluntary movements of skeletal muscles,
regulates posture and balance, and may have
a role in cognition and language processing.
Cerebrum
ANTERIOR
POSTERIOR
The Brain Is Composed of Many
Different Parts
The brain itself consists of four parts: brainstem, di-
encephalon, cerebellum, and cerebrum (Figure 7.10).
The cerebrum (Figure 7.10a) is located superior to
the other parts of the brain and is divided into two
hemispheres, which communicate through a tract of
axons called the corpus callosum (Figure
7.10b).
The brainstem (Figure 7.10a) is continuous with the
spinal cord and controls involuntary movements of the
head and neck, and is the origin of the cranial nerves.
In addition, the brainstem regulates many important
physiological activities that keep you alive, including
breathing and blood pressure. The diencephalon (Fig-
ure 7.10a) contains a relay station that coordinates
sensory pathways to the brain from the periphery and
motor pathways among various regions within the brain
and an area which controls many vital functions, includ-
202 CHAPTER 7
The Nervous System
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