Amen Clinics Inc. - Parts of the Brain
Brain Systems: Physiology, Functions and Associated Problems
Defining Parts of the Brain in Directional Terms
Anterior - toward the front
Posterior - toward the back
Medial - toward the middle
Lateral - toward the outside
Rostral - toward the mouth (beak)
Caudal - toward the feet
Dorsal - toward the back surface
Ventral -- toward the belly or undersurface
Cell layers
There are six cells layers of the cerebral cortex. Here is a brief summary of what each layer seems to do.
Layers 1, 2, 3 - cortical projections from primary cortex originate here
Layer 4 - sensory, receives projections from other areas
of cortex and brain, higher in sensory cortex, ascending projections terminate
here
Layers 5, 6 - zone of output, send axons to other brain areas, high in motor cortex
Posterior Cerebral Cortex
Sensory - receives, processes, and stores information.
Anterior Cerebral Cortex
The Motor Unit (formulates intentions, and organizes them
into programs of actions, and executes the actions/programs) Both the anterior
and
posterior
cortex has primary, secondary, and tertiary zones.
Primary Sensory Zone - sensory input enters the primary
sensory zones.
Secondary Sensory Zone - elaborates sensory
information.
Tertiary Sensory Zone - integration sensory
information.
Primary Motor Zone - execution is initiated.
Secondary Motor Zone - information from tertiary motor zone is elaborated
upon
and processed.
Tertiary Motor Zone - information received from the sensory
cortex.
Dominant Hemisphere Characteristics (usually the left side of the brain)
- More grey matter
- Extends farther posteriorly
- Longer Sylvian Fissure
- Larger insular cortex
- More dense
- Doubling of cingulate gyrus
- Larger inferior parietal lobe
- Increased lateral posterior thalamic nucleus
- Wider occipital lobe
- Larger total area of inferior frontal operculum
- Speech center
- Perception of words
- Process language related sounds
- Sequential analysis
- Increased blood flow during speech perception
- Process details, individual units
- Letters and words
- Language related sounds
- Complex voluntary movements
- Verbal memory
- Speech
- Reading
- Writing
- Arithmetic
Non-dominant Hemisphere Characteristics (usually the right side of the brain)
- Larger and heavier
- Extends farther anteriorly
- Longer internal skull size
- Doubling of Heschel's gyrus
- Wider frontal area
- Larger medial geniculate thalamic nucleus
- Larger convexity of frontal operculum
- Facial recognition
- Perception of melodies
- Pitch/prosody
- Social cues
- Reading facial expression
- Increased blood flow during tonal memory
- Read Braille better with left hand
- Process spatial information (parietal)
- Recognition of objects by touch
- Slightly more blood flow to right side
- Integrate information (gestalt or big picture)
- Complex geometric patterns
- Faces
- Music
- Nonlanguage environmental sounds
- Movements in spatial patterns
- Nonverbal memory
- Geometry
- Sense of direction
- Mental rotation of shapes
Parts of the Brain and Functions - Detail
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