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The Brain
Parts of the Brain
• Cerebrum
• Diencephalon
– Thalamus
– hypothalamus
• Cerebellum
• Brainstem
– Midbrain
– Pons
– Medulla oblongata
• Limbic system
• Ventricles
The human brain
Cerebrum
• Largest part of the brain
• Most highly developed part of the human
brain
• Outer portion: cerebral cortex
– Cell bodies and unmyelinated axons
• Inner portion: central white matter
– Myelinated axons
– How parts of cerebrum communicate with each
other and other parts of brain.
Gray v. White Matter
Cerebrum
2 Hemispheres (R and L)
Gyri and Sulci
Controls L. side of body
Controls R. side of body
Cerebrum
• Corpus Collosum
– Connects two
hemispheres together
Lobes of Brain
Frontal Lobe
Frontal Lobe Function
• Function:
– Higher Level Cognitive Function /Executive
Function
• Judgment and reasoning
– Control of voluntary muscle movement (MOTOR
FUNCTION)
• Including speech and swallowing
Frontal Lobe- Important Areas
• Primary Motor Cortex
– Anterior to Central Sulcus
– Controls voluntary movements of skeletal mm.
– More area dedicated to muscles of mouth and fingers
(use more)
• Premotor Cortex
– Programming of motor movements (except for speech)
• Prefrontal Cortex
– Complex cognitive process (reason and judgement)
• Broca’s Area
– Coordination of motor movement for production of
speech sounds. Creates motor plan which is then sent to
primary motor cortex
The lobes of a cerebral hemisphere
Parietal Lobe
• Posterior to central sulcus
• Function:
– Associated with Sensation
• Touch, kinesthesia, perception of warmth and cold and vibration
• Important Parts:
– Primary sensory area
• Receives sensory information from the joints and tendons in body ,
organized similar to motor area
– Somatosensory Association Area:
• Detailed discrimination and analysis of 1 Sensory area
• ***angular gyrus: recognition of sensory symbols
Temporal Lobe
• Function:
– Auditory processing and olfaction (smelling)
– Involved in semantics / word meaning
• Important areas:
– Primary auditory area
– Wernicke’s Association Area: dominant hem.
• Understand and produce meaningful speech
Occipital Lobe
• Function: Vision
• Important parts:
– Primary Visual Area: receives input from the optic
tract.
– Secondary visual area: integrates visual
information, give meaning to what is seen,visual
memories.
Body areas of primary motor and somatosensory
areas of the cortex
Basal nuclei
a.Masses of gray matter deep in the
cerebrum
b.Integrate motor commands
c.Huntington disease and Parkinson’s
disease – uncontrollable movements
believed to be from neurotransmitter
imbalances in the basal nuclei
Diencephalon
Thalamus – “the router”
• Function:
– Relays sensory, spatial sense and motor signals to
cerebral cortex
• Receives auditory, somatosensory and visual sensory
signals, sorts data and relays it to proper area in brain
– Regulation of consciousness
• Controls sleep and awake states of consciousness
• Sides of third ventricle
Hypothalamus
• Function:
– Maintaining homeostasis
• Integrating center involved in maintaining homeostasis
• Regulates hunger, sleep, thirst, temperature and water
balance
– Autonomic control
– Link between nervous system and endocrine
system
– Involved in emotional responses
The Limbic System
Limbic System: “Emotional Brain”
• Deals with
– Emotions- fear, anger, happiness, pleasure
– Memories/ learning
– Arousal (stimulation)
• Several parts above brainstem and within cerebrum
• Important parts:
– Amygdala: responsible for memory of emotion (especially
fear)
– Hippocampus: responsible for processing of long term
memory and emotional responses
• Short term to long term memory and learning
Cerebellum
Cerebellum
• Function:
– Responsible for balance and coordination of
muscles in the body
– Important in
•
•
•
•
preforming voluntary tasks (walking, writing)
Maintaining balance and posture
Muscle memory
Learning new muscle skills
• Remember: separated from brain by 4th
ventricle
Brainstem
Brain Stem• 3main functions:
– Conduction of
information/relay center:
• All information relayed b/n
body and cerebrum/cerebellum
– Cranials nerves emerge from
here:
– Integrative function: Control
HR, RR, pain sensitivity,
awareness, alertness,
consciousness, sleep
• Damage = catastophic
Brain Stem
• Midbrain:
– Response to sight, eye movements, pupil dilation,
hearing
• Pons
– Communication/coordination center between the two
hemispheres
– Important in arousal and sleep
• Medulla Oblongata
– Controls autonomic functions
• RR, HR, Blood vessel function, swallowing, sneezing