Why
is it important to learn how brains are constructed?
For
a brain to perform all the functions that it must do, it must:
1. Detect and locate the great variety of stimulus types, sources,
and happenings in the environment; 2. Make sense of all these
sensory events; 3. Respond to all these features by expressing
an elaborate behavioral repertoire; and 4. Make judgments, learn,
and think about all these things.
This
diagram indicates that the circuits of the brain have
evolved to extract (from the great complex flux of energies
that course through space) a representation of the physical
world that is realistic. Thus the brain creates a reasonable
conception of reality to which the brain can behave
in adaptive and creative ways.
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Over
the last 50 years, a great number of neuronal cell groups, circuits
and connections have been identified and named in the several
different regions of the brain. In addition, the functions of
these different nuclei and circuits have been identified. Moreover,
the neuroanatomical and neurochemical mechanisms by which these
circuits operated to produce and enable them to function effectively
have begun to be clarified. But much remains to be done, and
in the next two decades, it is estimated that modern technology
will provide ever greater insight as to how the circuits of
the brain perform the functions that they do.
However,
a major part of learning about the architecture of the brain
and its parts involves becoming familiar with the names of the
different structures.
External Structures visible by mere inspection of the
brain include the cerebrum: brain lobes + hemispheres; cerebellum,
gyri and sulci, Olfactory bulbs & tract, cranial nerves, peduncles,
midbrain, medulla, and spinal cord)
Internal regions of the brain as viewed in cross section
include the following structures or nuclei and fiber tracts:
NOMENCLATURE: abbreviations used
for brain structures and nuclei
Telencephalon
(Forebrain):
Cerebral
cortex
Basal ganglia
Olfactory
cortex
Septum
Anterior commissure
Fornix
Subfornical organ
Corpus Callosum
Basal forebrain
Olfactory tubercle
Olfactory cortex
Hippocampus
Caudate
nucleus
Putamen
Globus pallidus (internal & external)
Ventral striatum
Claustrum
Amygdalar complex
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Diencephalon:
Thalamus
Hypothalamus
Pituitary
Epithalamus
Pineal body
Red nucleus
Subthalamus
Substantia nigra
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Mesencephalon
(Midbrain):
Tectum
Superior colliculus
Inferior Colliculus
Periaquaductal nuclei
Posterior commissure
Superior olive
Inferior olive
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Metencephalon
(Hindbrain):
Pons
Cerebellum (basal cerebellar nuclei, cerebellar cortex;
convoluted into lobes, lobules and folia)
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Myelencephalon
(Brainstem, medulla):
Basic Brain nuclei and fiber tracts
Neurons; their structure and connectivities. Major sensory,
motor, and other functional connections.