Diencephalon Flashcards
What are the two major subdivisions of the diencephalon?
Pars dorsalis
Pars ventralis
What separates the pars dorsalis and pars ventralis?
Hypothalamic sulcus
What makes up the pars dorsalis?
Thalamus
Metathalamus
Epithalamus
What makes up the metathalamus?
Medial and lateral geniculate bodies
What makes up the epithalamus?
Pineal gland
habenular nuclei and commissure
Posterior commissure
Stria medullaris thalami
What makes up the pars ventralis?
Subthalamus
Hypothalamus
What divides the thalamus into a medial and lateral group?
Internal medullary lamina
What covers the lateral surface of the thalamus?
External medullary lamina
What are the three basic groups in the thalamus?
Anterior group
Medial/dorsomedial group
Lateral group
What are the subdivisions the ventrolateral group of the thalamus?
Ventral anterior
Ventral lateral
Ventral posterior medial and lateral
Medial geniculate body
Lateral geniculate body
What are divisions of the dorsolateral group of the hypothalamus?
Lateral dorsal
Lateral posterior
Pulvinar
What structures project to the ventral anterior and ventral lateral nuclei of the thalamus?
Basal ganglia
Cerebellum
Where do the ventral anterior and ventral lateral nuclei of thalamus project?
Motor areas
What structures project to the ventral posterolateral and ventral posteromedial nuclei?
Medial lemniscus
Spinothalamic tract
Where do the ventral posterolateral and ventral posteromedial nuclei project?
Somatosensory cortex
What structure projects to the medial geniculate body?
Brachium of inferior colliculus
Where does the medial geniculate body project to?
Auditory cortex
What projects to the lateral geniculate body?
Optic tract
Where does the lateral geniculate body project to?
Visual cortex
What structure projects to the anterior thalamus?
Mammillothalamic tract
Where does the anterior thalamus project to?
Cingulate gyrus
What part of the thalamus is related to the head?
VPM
What part of the thalamus is related to the body?
VPL
What is the function of the dorsomedial group of the thalamus?
Provides mood of feeling tone to the emotional aspect of behavior
Integrating center for somatic and visceral impulses
What is the function of the ventral anterior nucleus of the thalamus?
Convey information to motor area of frontal lobe
What is the function of the ventral lateral nucleus?
Prime mover of motor pathway
What is the function of ventral posterior nucleus?
Largest somatosensory relay nucleus
What is the function of the medial geniculate body?
Auditory pathway
Perception of painful stimuli
What is the function of the intralaminar nuclei?
Control of electrocortical activity of cerebral cortex
Influences levels of sensations and consciousness
What is the function of the midline nucleus of the thalamus?
Regulation of visceral activities
What is the function of the reticular thalamic nucleus?
Likely concerned with regulation of intrathalamic activity
What is the function of the lateral geniculate body?
Concerned with visual pathway
What occurs with a lesion to the thalamus?
Sensory loss
Possible choreo-athetosis with ataxia
What are the nuclei of the medial zone of the hypothalamus?
Part of preoptic nucleus
Anterior nucleus
Part of suprachiasmatic nucleus
Paraventricular nucleus
Dorsomedial nucleus
Ventromedial nucleus
Arcuate nucleus
Posterior nucleus
What are the nuclei of the lateral zone of the hypothalamus?
Part of preoptic nucleus
Part of suprachiasmatic nucleus
Supraoptic nucleus
Lateral nucleus
Tuberomammillary nucleus
From where does the hypothalamus receive afferents?
Medial and spinal lemniscus
Tractus solitarius
Reticular formation
Visual fibers
Medial forebrain bundle
Auditory fibers
Corticohypothalamic fibers
Hippocampohypothalamic fibers
Amygdalohypothalamic fibers
Thalamohypothalamic fibers
To where does the hypothalamus send efferents?
Descending fibers in RF to brainstem and spinal cord
Mammillothalamic tract
Mammillotegmental tract
What two nuclei of the hypothalamus send fibers to the posterior pituitary?
Supraoptic and paraventricular nuclei via hypothalmohypophyseal tract
What hormones are synthesized in the supraoptic and paraventricular nuclei that act in the posterior pituitary?
Vasopressin
Oxytocin
What hypothalamic nuclei produce hormones that are sent to the anterior pituitary?
Tuberal and infundibular nuclei via tubero-infundibular tract and hypothalamohypophyseal portal system
What is the function of the anterior hypothalamic nucleus?
Control PsNS system
Heat dissipation
What are the functions of the preoptic nucleus of hypothalamus?
Sex regulation
Control PsNS system
What is the function of the paraventricular nucleus of the hypothalamus?
Synthesizes oxytocin
What is the function of the supraoptic nucleus of the hypothalamus?
Synthesizes vasopressing/ADH
What is the function of posterior hypothalamus?
Heat conservation
Control SyNS activity
What is the function of the lateral hypothalamic nuclei?
Hunger and thirst center
Emotion and behavior
What is the function of the ventromedial hypothalamic nucleus?
Satiety center
Emotion and behavior
What is the function of the suprachiasmatic hypothalamic nucleus?
Controls circadian rhythms
What is the function of the arcuate nucleus?
Releasing and inhibiting hormones
