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Medulla
- Includes lots of sensory and motor tracts traveling between brain and spinal cord
- Also regulates breathing, heart rate, blood pressure, vomiting, muscle coordination
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Pons
- Continuation of tracts between brain and spinal cord
- Connections with cerebellum (lots of fascicles that connect two hemispheres of cerebellum)
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Locked-In Syndrome
- Typically caused by damage to ventral pons
- Patient is fully conscious but can't move
- Sometimes voluntary eye blinks and some facial movements are possible
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Midbrain
- Auditory and visual attention, movement regulation, pain processing
- Continuation of tracts between telencephalon and spinal cord
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Substantia Nigra
- "Black substance" that prevents unwanted movements
- Degenerates in Parkinson's disease
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Reticular Foramen
- Web of cell bodies throughout brainstem
- Lots of connections with cerebral cortex (via thalamus) and spinal cord
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Functions of Reticular Formation
- Motor control: rhythmic coordination of breathing and swallowing; balance; posture; combines auditory, visual, vestibular information to regulate muscle coordination
- Cardiovascular control
- Pain modulation
- Sleep and consciousness
- Habituation
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Coma
- Often results from damage to reticular formation
- Tests for brainstem function: breathing pattern, posture, eye movement reflexes, and pupillary reflexes
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Cerebellum
- 2 hemispheres, vermis in the middle
- Folia and sulci make up cerebellar cortex
- Contains 50% of the neurons in the brain
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Cerebellar Peduncles
Connect cerebellum to pons
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Function of Cerebellum
- Motor coordination
- Motor learning
- Timekeeper
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Diencephalon
Main components are thalamus and hypothalamus
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Thalamus
- Gateway to the cerebral cortex
- Processes almost all sensory information passing to cortex
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Functions of Thalamus
Memory, emotion, awareness of emotions,
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Hypothalamus
Important for basic functions: thirst, hunger, reproduction, aggression, and circadian rhythms
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Hypothalamus Monitors Signals in Blood
- Circle of Willis surround hypothalamus
- Hormones, body temperature, glucose levels monitored by hypothalamus
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Paraventricular Nucleus of Hypothalamus
- Lots of neurons project to pituitary gland which controls the release of hormones
- Releases oxytocin and vasopressin into the bloodstream
- Regulates some functions of the brainstem
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Suprachiasmatic Nucleus of the Hypothalamus
- SCN has approximately 24 hours of gene expression that regulates sleep, alertness, body temperature, hormone secretion and digestion
- Eyes have pathway to SCN so that light can adjust cycle
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Mammillary Nucleus (bodies)
- Involved in memory processing (especially smell-associated memories)
- Caused by vitamin B deficiency (chronic alcoholism)
- Results in anterograde memory loss
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Superior Temporal Lobe
Auditory
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Medial Temporal Lobe
Memory
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Inferior Temporal Lobe
Visual
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Frontal Lobe
- Motor cortex: cell bodies of corticospinal tract
- Premotor cortex: motor planning
- Prefrontal cortex: decision making, planning, social judgment, motivation
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Phineas Gage
Iron rod went through his left frontal lobe = fitful and irreverent
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Parietal Lobe
- Somatosensory Cortex: touch, pain, and temperature
- Sensory integration and visual localization
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Insular Cortex
Gustatory cortex (taste), emotion, degree of pain, and effects autonomic nervous system
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Cingulate Cortex
- Part of limbic system
- Emotional processing, learning and memory
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Aphasia
Language deficit due to lesions (damage) to Broca or Wernicke area
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Broca's Aphasia
Slow speech, can't find correct words
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Wernicke's Aphasia
Can't understand written or spoken words
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Basal Ganglia
Helps regulate movement
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Amygdala
- Lots of connection to/from hypothalamus
- Lots of olfactory input
- Involved in fear perception, emotional memory formation, social behavior and sexual desire
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Hippocampus
- Just under medial temporal lobe (and lots of connections)
- Involved in memory formation and spatial learning
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H.M.
- Medial temporal lobe cortex and hippocampus removed bilaterally to reduce seizures
- Anterograde memory loss, and some retrograde memory loss
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Alzheimer's Disease
Preferentially destroys hippocampus
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