Diencephalon Flashcards
Diencephalon
-subthalamus
-epithalamus
-Thalamus
-Hypothalamus
Subthalamus/Subthalamic Nuclei
-superior to substantia nigra
-inferior to thalamus
-Lateral to hypothalamus
-functionally a part of basal ganglia
-initiates and suppresses movement
-excitatory input to basal ganglia
Epithalamus
-pineal gland/body biggest in epithalamus
-innervated by SNS
-control carcadian rhythm and glandular secretions
Thalamus
-collection of nuclei that actt as a filter and processor of info to cortex from cerebellum, basal gangilia, all sensory (except olfactory)
-regulate neural activity
-recieves blood from PCA (thalamoperforator, thalamoteniculate and posterior chorodial A.)
Thalamic Projections
-all projection roject to cortex EXCEPT thalamic reticular nucleus (TRN)
TRN: projects to thalamic nuclei, RF; GABA=inhibitory
Relay Nuclei
-infor from basal ganglia, cerebellum, or sensory sys. to cerebral cortex
-motor, sensation, hearing, vision
Leision
-can disrupt contra sensation (proprioception)
-thalamic pain syndrome
-Lateropulsion/Pusher Syndrome: pushing toward weak side where it is believed to have equilibrium
Association Nuclei
-process memory and emotional info
-connect areas of cortex
-sensory integration
Nonspecific Nuclei
-consiousness, arousal and attention
Cerebellar and Thalamus Pathways
-cerebellum projects through superior cerebellar peduncle to thalamus
-spinocerebellar
-Closed Cerebro-cerebellar-cerebral loop: from lateral cerebellar cortex afferents through middle CP, efferents leave thru superior CP
Hypothalamus
Homeostasis: Vitals, digestion, sleep
Endocrine: growth, metabolism, reproduction
Autonomic control: SNS
Limbic system: emotions
-mammilarry bodies are post. hypothalamus
Hypothalamic Homeostasis Control
-carcadian rhy: light receptors
-appetite
-thirst: osmorrerceptors
-body temp
-sexual development
Hypothalamic Endocrine Contol
-Hypothal to infundibulum to pituitary stalk to pituitary gland
Hypothalamic Limbic Control/Amygdala
-emotional influences on ANS and homeostasis
-Hippocampus > fornix > mammillary bodies > mammilothalamic tract > thalamus > limbic cortex in cingulate gyrus
Clinical Implications
-pituitary tumor 10-17% of all intracranial neoplasms
-can put pressure on optic chiasm causing Bitemportal Hemianopia
Posterior Pituitary
-continuous with brain
-release neurohormones
ADH, Oxcytocin
Anterior Pituitary
outgrowth of epthelial tissue
-activated by neurohormones that then release/inhibit specific hormones
GH, TSH, ACTH, LH
Growth Hormone
-stimulates skeletal and visceral growth
-increases after stress
Thyroid Stimulating Hormone
-stimulates the thyroid to release T3 and T4
-growth, development, metabolism
Adenocorticotrophic Hormone
-ACTH
-release of gluticosteroids from adrenal cortex
-inhibits immune reaction, inflammation, protein breakdown
Luteinizing Hormone/Folicle Stimulating Hormone
-lactating and maturation of gonads
Antidiuretic Hormone
-maintains pH and fluid levels
-increase absorbtion in kidneys
Oxcytocin
-uterine contractions and milk expulsion
Bitemporal Hemianopia
-pituitary tumor puttiing pressure on optic chiasm takes out temoral fibers but keeps nasal
-Loss of vision on both sides of visual field
L eye: no left half vision
R eye: no right half vision
Pineal Body
-rest btwn superior coliculi
-part of epithalamus
-secretes melatonin for body’s carcadian rhythm
-modulate onset of puberty
Lateral Geniculate Nucleus
-posterior aspect of thalamus
-relay station for visual info from retina
Medial Geniculate Nucleus
-ventrolateral aspect of thalamus
-major auditory nucleus of thalamus
-directing auditory attention from inf. colliculi
Amygdala
-anterior hippocampus
-center of emotions, behavior and motivation
-process fearful info to detect harm and activate appropriate response
Fornix
-white matter tract connecting to hipocampus
-transmit info from hippocampus to mammilary bodies
Cingulate Gyrus
-limbic system; process emotions and regulate ANS
Septum pellucidum
-partition bettween lateral ventricles
Mammilary Bodies
-Recollective memory
-limbic sys
