Download Brain Higher Functions Diencephalon Cerebellum Cerebral

Brain Higher Functions
• Diencephalon
• Cerebellum
• Cerebral Hemispheres
Cerebral
hemispheres
Cerebellum
“2-oval skull”
(includes regions of higher functions)
Diencephalon
(integrates conscious and unconscious activity)
• Between cerebral hemispheres
• Mostly thalamus and hypothalamus
Thalamus
Diencephalon
(relays sensory information and emotional state)
• Five groups of nuclei
– Anterior group—limbic system
– Medial group—hypothalamus
emotion center to cerebrum
frontal lobe
– Ventral group—touch and
proprioceptive information
relayed to cerebral cortex
– Posterior group—optic and
auditory information to cerebral
cortex
– Lateral group—emotional state
feedback from limbic system;
integrates with sensory
information
Limbic system
Diencephalon
Limbic system
Diencephalon
Hypothalamus
Diencephalon
• Superior to pituitary gland (gland is in sella
turcica)
• Connected to pituitary by infundibulum
stalk
Diencephalon
Hypothalamus function
• Feeding reflexes—licking, swallowing, etc.
• Subconscious skeletal muscle movements—facial expressions,
sexual movements
• Autonomic center—control medulla oblongata nuclei for
cardiovascular, respiration
• Secretes oxytocin that stimulates smooth muscle of uterus,
mammary glands and prostate
• Regulates body temperature
• Controls pituitary gland by hormonal secretion—pituitary in turn
regulates many hormonal endocrine functions
• Produces emotions/sensations/drives: e.g. thirst, hunger (not
really “sensations” from periphery)
• Coordinates autonomic response to conscious input—thought
of fear produces accelerated heart rate, etc.
Pineal gland
• Regulates Cycles
• Secretes melatonin
which helps regulate
circadian and
reproductive cycles
Diencephalon
Cerebellum
(posture and movement)
• Oval at back of cranial cavity
• Convoluted surface of neural
cortex (like cerebrum)
• Huge branching Purkinje cells—
each cell gets input from 200,000
synapses
• Internal branching looks like
tree—called “arbor vitae (tree of
life)
• Damage leads to “ataxia”—
disturbance of muscular
coordination
Cerebrum
(processing central for somatic/conscious information)
• Two cerebral hemispheres
separated by longitudinal
fissure (sagittal plane)
• Central sulcus divide
(coronal plane) separates
frontal lobe from parietal
lobe
• Horizontal lateral sulcus (in
transverse plane)
separates frontal lobe from
temporal lobe
• Parietal-occipital sulculs
separates parietal lobe
from occipital lobe
Cerebrum
Cerebrum overall organization
• Left side receives somatic
sensory and controls somatic
motor of right side of body
(and vice versa)
• Two hemispheres have
different specialized areas (not
symmetrical)
• Correspondence of functions
with regions is difficult—lots of
overlap and ability to “fill in” if
areas are damaged
• Corpus callosum is bundle of
axons that link two sides
Cerebrum
Cerebrum
Cerebral function in brief
• Basal nuclei/ganglia (sometimes considered part of midbrain)
– Deep in hemispheres
– Subconscious control of skeletal muscle
– Rhythmic movements—overall walking coordination
• Frontal Lobe (primary motor cortex)-voluntary control of
skeletal muscle
• Parietal lobe (primary sensory cortex)—conscious perception
from skin—touch, pressure, pain
• Occipital lobe (visual cortex)—conscious perception of visual
field
• Temporal lobe (auditory cortex and olfactory cortex)—
conscious perception of sound and smell
• All Lobes—integration and processing of sensory input to
initiate conscious motor output
Cerebrum