NormalAbnnormalAging/diencephalon Flashcards
Normal Aging
• Fallout: whole brain weight decreases by about 18% • Shrinkage: large-sized neocortical neurons become smaller • Decreased processing and efficiency of information processing • Plaques in hippocamp. And para-hippocamp. Will decrease working and short term memory, losses in spatial processing • Decreased in concentration (dopamine, norepinephrine, serotonin), Losses of dopamine in substantia niagra=decreases in balance • Cerebral blood flow decreased 23% • Sleep wake cycles disturbed • Decreased vision, smell, taste • Decreased somatosensory functions (proprioception/temp/vibratory sense) Decreased nerve conduction velocity and muscle mass, decreased gait speed, smaller steps
Dementia
• Complex intellectual, behavioral, personality deterioration in an otherwise healthy adult that is severe enough to compromise occupational or social performance, fourth leading cause of death
Alzeihmers
Alzheimer’s Disease:
Most prominent cause of dementia
Age is a risk factor, but not a process of accelerated aging
Progressive degenerative disease of brain with features not associated with normal aging
60% of hippocampal formation neurons lost (memory)
nucleus basilis of meynart (where ACH is made) has problems–> so less ACH!! (mediotemporal lobe)
RISK FACTORS
AGE family, lack of education, environmental factors
Most Common Features
Insidious onset
Impairment of two or more areas f cognition and behavior
Mean survival of 9 years
Sorpatic: 90-95% of cases, typically of late onset, without genetic causes
Familial: 5-10% of cases, early onset, result of genetic mutation
Greater loss: blood flow, & brain weight (medial temporal lobe), memory/emotional most predominate
components of the diencephalon
Epithalamus: single midline structure, pineal gland that secreted melatonin
Hypothalamus: small, mediates complex functions, endocrine system, body temp regulation, sleep, emotional/behavioral functions.
Subthalamus: wedge-shaped transition between thalamus and midbrain-contains subthalamic nucleus of the basal ganglia.
Thalamus: grand central station, large, bilaterally symmetrical, egg shaped like structure, relay and association nuclei
Epithalamus
Nuclei of diencephalon
Epithalamus: single midline structure, pineal gland that secreted melatonin
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Hypothalamus: small, mediates complex functions, endocrine system, body temp regulation, sleep, emotional/behavioral functions. (ACA blood supply, and penetrating brances of PCA)
Subthalamus: wedge-shaped transition between thalamus and midbrain-contains subthalamic nucleus of the basal ganglia.
Thalamus: grand central station, large, bilaterally symmetrical, egg shaped like structure, relay and association nuclei
Thalamic syndrome: PCA, symptoms: contralateral hemianesthai, ataxia, excruciating neurogenic pain
Hypothalamus
Nuclei of diencephalon
Hypothalamus: small, mediates complex functions, endocrine system, body temp regulation, sleep, emotional/behavioral functions. (ACA blood supply, and penetrating brances of PCA)
Subthalamus: wedge-shaped transition between thalamus and midbrain-contains subthalamic nucleus of the basal ganglia.
Thalamus: grand central station, large, bilaterally symmetrical, egg shaped like structure, relay and association nuclei
Thalamic syndrome: PCA, symptoms: contralateral hemianesthai, ataxia, excruciating neurogenic pain
Epithalamus: single midline structure, pineal gland that secreted melatonin
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Subthalamus
Nuclei of diencephalon
Subthalamus: wedge-shaped transition between thalamus and midbrain-contains subthalamic nucleus of the basal ganglia. (hemibalism)
Hypothalamus: small, mediates complex functions, endocrine system, body temp regulation, sleep, emotional/behavioral functions. (ACA blood supply, and penetrating brances of PCA)
Thalamus: grand central station, large, bilaterally symmetrical, egg shaped like structure, relay and association nuclei
Thalamic syndrome: PCA, symptoms: contralateral hemianesthai, ataxia, excruciating neurogenic pain
Epithalamus: single midline structure, pineal gland that secreted melatonin
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Epithalamus
Nuclei of diencephalon
Epithalamus: single midline structure, pineal gland that secreted melatonin
====
Hypothalamus: small, mediates complex functions, endocrine system, body temp regulation, sleep, emotional/behavioral functions. (ACA blood supply, and penetrating brances of PCA)
Subthalamus: wedge-shaped transition between thalamus and midbrain-contains subthalamic nucleus of the basal ganglia.
Thalamus: grand central station, large, bilaterally symmetrical, egg shaped like structure, relay and association nuclei
Thalamic syndrome: PCA, symptoms: contralateral hemianesthai, ataxia, excruciating neurogenic pain
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Thalamus
Nuclei of diencephalon
Thalamus: grand central station, large, bilaterally symmetrical, egg shaped like structure, relay and association nuclei
Thalamic syndrome: PCA, symptoms: contralateral hemianesthai, ataxia, excruciating neurogenic pain
====
Epithalamus: single midline structure, pineal gland that secreted melatonin
====
Hypothalamus: small, mediates complex functions, endocrine system, body temp regulation, sleep, emotional/behavioral functions. (ACA blood supply, and penetrating brances of PCA)
Subthalamus: wedge-shaped transition between thalamus and midbrain-contains subthalamic nucleus of the basal ganglia.
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Brown-Sequard Syndrome
avocado browns only halfway (or cut it in half an see the brown thing)
Brown-Sequard Syndrome: very rare, involves lesion involving only one-half of spinal cord
IPSILATERAL spastic paralysis below level of lesion
IPSILATERAL Flaccid paralysis at level of lesion
DCML: below level of lesion will have IPSILATERAL loss of discriminative touch and proprioception
STT: below lesion will have CONTRALATERAL loss of pain, temp, pressure,
At level of lesion will have BILATERAL losses
CST: below level of lesion will have IPSILATERAL spastic paralysis loss, at the level of lesion will have IPSILATERAL flaccid paralysis
Syringomyelia
Syringomyelia (think a syringe putting fluid into the STT so it’s painless)
chronic progressive degenerative disorder of the spinal cord, characterized by development of irregular fluid-filled most commonly in lower cervical or upper thoracic regions
Slow progression in beginning
Loss of pain and temperature fibers crossing the ventral white commissure
BILATERAL loss of pain and thermal sensation
May further enlarge and move into syringobulbia
Diencephalic Nuclei
Diencephalon Nuclei: receive inputs from tracts and project/receive fibers from cortex related to specific sensory, motor, or limbic systems
- VA/VL—relay motor inputs from basal ganglia and cerebellum
- VPM—relay of somatosensory inputs from face and head
- VPL—relay of somatosensory inputs from the body
- MGB (medial geniculate body)— relay of auditory inputs from inferior colliculus
- LGB (lateral geniculate body)—relay of visual input from optic tract
