Transcript Guided Notes for the Central Nervous System

Guided Notes for the Central
Nervous System
1. During embryonic development, the
CNS frist appears as a simple tube,
the neural tube, which extends down
the dorsal median plane of the
embryo’s body.
2. By the fourth week, brain formation
begins.
3. The brain is often discussed in terms
of its four major regions—cerebral
hemispheres, diencephalon, brain
stem, and cerebellum.
4. The paired cerebral hemispheres
enclose and obscure most of the brain
stem. The entire surface of the
cerebral hemispheres exhibits
elevated ridges of tissue called gyri,
which are separated by shallow
grooves called sulci. Less numerous
are the deeper grooves called
fissures, which separate large regions
of the brain.
5. The cerebral hemispheres are
separated by a single, deep fissure
called the longitudinal fissure.
Lobes of the Cerebrum
Name
Parietal
Location
Function
Areas
Posterior to the Interprets
central sulcus
impulses from
body sensory
receptors
Somatic
sensory area
Occipital
Rear of brain
above the
cerebellum
Interprets
impulses from
the eyes
Visual area
Temporal
Bordering the
lateral sulcus
Interprets
impulses from
the ears
Auditory area
Frontal
Anterior to the
central sulcus
Allows us to
consciously
move skeletal
muscles
Primary motor
area
7. Although most of the gray matter is
in the cerebral cortex, there are
several “islands” of gray matter,
called basal nuclei, buried deep within
the white matter of the cerebral
hemispheres. The basal nuclei help
regulate voluntary motor activities by
modifying instructions sent to skeletal
muscles by the primary motor cortex.
8. The 3 major structures of the
diencephalon are the thalamus,
hypothalamus, and the epithalamus.
The thalamus is a relay station for
sensory impulses passing upward to
the sensory cortex.
8. The hypothalamus is an important
autonomic nervous system center
because it plays a role in the
regulation of body temperature,
water balance, and metabolism.
Additionally, the hypothalamus
regulates the pituitary gland and
produces 2 hormones of its own.
9. The pituitary gland hangs from the
anterior floor of the hypothalamus by
a slender stalk.
10. The brain stem has 3 structures:
the midbrain, pons, and medulla
oblongata.
11. The pons is the rounded structure
that protrudes just below the
midbrain. It has important nuclei
involved in the control of breathing.
12. The medulla oblongata contains
centers that control heart rate, blood
pressure, breathing, swallowing, and
vomiting.
13. Like the cerebrum, the cerebellum
has 2 hemispheres and a convoluted
surface. The cerebellum provides the
precise timing for skeletal muscle
activity and controls our balance and
equilibrium.
4 ways that the brain and spinal
cord are protected by the body
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Enclosing them within bone
Membranes
A watery cushion
The blood/brain barrier