lecture 12: Diencephalon thalamic structure Flashcards
the subthalamus/ subthalamic nuclei is located ___- to the substantia nigra in the midbrain , inferior to the ___ and lateral to the _____
superior
thalamus
hypothalamus
what is the biggest structure of the epithalamus
pineal gland/body
what is the pineal gland innervated by
sympathetic fibers
what assists in controlling circadian rhythms and impacts glandular secretions
epithalamus
what is a Large collection of nuclei in 2 egg-shaped structures immediately superior to top of brainstem/midbrain (gray matter)
thalamus
the thalamus has ______ ____ white matter that dividies thalamus into _____, ____ ,_____ groups
intramedullary lamina
anterior , lateral and medial
the lateral wall of the thalamus is formed by a thin sheet of cells called what
thalamic reticular nucleus
what separates L from R thalamus with medial thalamic wall formed by
thin sheet of cells called midline nucleus
3rd ventricle
R and L thalamus are adjoined in most human brains by what
massa intermedia/interthalamic adhesions
deep branches of the ___ ___ ___ supply the thalamus
posterior cerebral arteries
what are the 3 deep bracnhes of the posterior cerebral arteries that supply the thalamus
- Thalamoperforator artery
- Thalamogeniculate artery
- Posterior choroidal artery
what is the function of the thalamus
acts as filter and processor of information to cortex from basal ganglia , cerebellum and all sensory systems except for olfactory
what functions as Relays processed input to discrete areas of cerebral cortex, thereby regulating cortical neuronal activity
thalamus
all thalamus nuclei project to the cerebral cortex except for what
thalamic reticular nucleus
All thalamic nuclei project to the cerebral cortex except for thalamic reticular nucleus (TRN), what are the 2 fibers name
- Thalamocortical fibers
- Corticothalamic fibers
what projects to thalamic nuclei, reticular formation in brainstem, and other parts of TRN
the thalamic reticular nucleus
Most thalamic efferents and afferents
(to/from cerebral cortex) pass thru the ___ with collaterals synapsing with TRN cells
TRN
many TRN neurons contain what
GABA ( inhibitory)
what are the 3 main functional groups of the thalamus nuclei
relay nuclei , association nuclei , and nonspecific nuclei
which functional nuclei of the thalamus transmit info from basal ganglia, cerebellum, or sensory systems to cerebral cortex
relay nuclei
which functional nuclei of the thalamus processes memory and emtional info , integrate different sensory inputs and connects to specific areas of cerebral cortex with same areas projecting back to these nuclei
association nuclei
what does the nonspecific nuclei of the thalamus regulate
consciousness , arousal , and attention
what are the 2 major somatosensory pathwaysa
Posterior/dorsal column medial lemniscal
pathway
Spinothalamic tract
the cerebellum projects thru the which peduncle to the thalmus , relaying signals to (upper/lower) motor neurons in primary and premotor cortices
superior cerebellar peduncle
upper
the spinocerebellar output goes from the ___ which is from the ____ zone thru the ____ ____ ____ to the thalmus
vermis
intermediate
superior cerebellar peduncle
closed cerebro cerebellar cerebral loop goes from the ___ cerebellar cortex and afferents enter thru the ___ cerebellar peduncle and ____ leave via ____ cerebellar peduncle
to thalamus
laterla
middle
efferents
superior
the thalamus and hypothalamus imput for what
sleep regulation
how is the thalamus related to descending tracts for motor function?
bc things go thru the thalamus and control fine motor aspect
for thalamic lesions , relay sensory neurons can disrupt ____ sensation
contralateral
what is most commonly affected by thalamic lesions
proprioceptions
thalamic pain syndrome is ___ but severe
rare
lateropulsion , pusher sundrome or contraversive pushing is common with what type of lesions
thalamic
what is lateropulsion , pusher sundrome or contraversive pushing
strong pushing with less affected side towards weaker side
lateropulsion , pusher syndrome or contraversive pushing is usually accompanied by ___ push also
posterior
what is located inferior and anterior to the thalamus
hypothalmus
the hypothalamus is separted by from the thalamus by what sulcus ? and what ventricle is it from
hypothalamic sulcus
3rd
what forms the walls and floor of the inferior part of the the 3rd ventricle
hypothalamus
what forms the posterior aspect of the hypothalamus
mammillary bodies
is the hypothalamus necessary for survival
yes
what are the 4 functions of the hypothalamus
maintenance of Homeostatic functions
Endocrine control
Autonomic control
Limbic systmem
H.E.A.L
the hypothalamus functions for the limbic system and what does that control
expression of emotions
the hypothalamus functions as a autonomic control and what does that control
facilitation of sympathetic nervous system
the hypothalamus functions as a endocrine control and what does that control
growth , metabolism , and reproductive organs
hypothal helps control ___ , ____ and other behaviors necessary for survival
appetitive , homeostatic
the hypothalamus can control the ____ rhythm thru light sensitive receptors
circadian
arousal/sleep can be facilitated or inhibited thru what rhythm
circadian rhythm
what results from the stim of osmoreceptors of hypothalamus
thirst
the hypothalamus detects body ___ and stimulates mechanism to dissipate or conserve heat
temp
where is the pituitary gland contained
in sella turcica/ pituitary fossa of sphenoid bone
hypothalamus > ____ > pituitay stalk >____
infundibulum
pituitary gland
where does the anterior pituitary comes from
outgrowth of epithelial tissue
what comes from outgrowth of inferior brain in region of hypothalamus and is continuous with brain
posterior pituitary
secretions from posterior pituitary are ____
neurohormones
___ pituitary has ___ cells that secrete hormones into blood stream
anterior
glandular
what are the 6 hormones secreted by anterior pituitary
growth hormone
thyroid stimulating hormone
Adenocorticotropic hormone (ACTH)
Luteinizing hormone (LH),
follicle stimulating hormone (FSH),
prolactin
what controls the releasae or inhibitoion of growth hormone
hypothal
hypothal elicits release of thyroid stimulating hormone to cause ___ gland to release ___ and ___
thyroid
T3 and T4
thyroid stimulating hormone (TSH) is necessary for ___ , ____ , ___ ___ and body temp
growth
development
metabolic rate
what stimulates the release of Adenocorticotropic hormone (ACTH)
hypothal
Adenocorticotropic hormone (ACTH) Facilitates release of ______ from adrenal cortex which inhibit immune reaction, ____ inflammation, increase protein/fat breakdown, ____ glucose production and reduce glucose and amino acid use in skeletal muscles
glucocorticoids
decrease
increase
luteinizing hormone (LH), follicle stimulating hormone (FSH), and
prolactin impact ____/___ and ____ production in lactating females
ovaries /testes
milk
Action potentials in hypothalamus thru axons of ____ ____ release neurohormones from ___ pituitary gland
pituitary stalk
posterior
what hormone maintains pH level and extracellular fluid volume by increasing reabsorption of water in kidney and reducing excretion of urine? and does it come from anterior or posterior pituitary
Antidiuretic hormone (ADH)
posterior
what facilitates uterine contractions during labor/delivery and milk expulsion in lactating females from the posterior pituitary
Oxytocin
Hypothal has descending projections to ___ and ____
systems
sympathetic
parasympathetic
descending Projections from the hypothal extend from hypothal nuclei thru ___ forebrain bundle, to DL brainstem, periaqueductal gray matter to where for the preganglionic sympathetic and parasympathetic
medial
Preganglionic parasympathetic nuclei in brainstem and intermediate zone to sacral SC
*Preganglionic sympathetic neurons in intermediolateral cell column of TL SC
Hypothal receives inputs from ____ and regions of ___ cortex (orbital frontal, insular, ant cingulate, temporal cortices) fro control of autonomic system
amygdala
limbic
limbic pathways from the hypothal may explain ___- influences on autnoic and homestatic pathways
emotional
what is the pathway for the limbic systme from hypothalamic
Hippocampus > fornix > hypothal mammillary bodies
Mammillary bodies> mammillothalamic tract > thalamus > limbic cortex of cingulate gyrus
what makes up 10-17% of all intracranial neoplasms
pituitary adenomas
what type of tumor is a pituitary adenomas
slow growing , benign tumor
where can the pituitary adenomas arise from
any anterior pituitary cell types that secrete hormones
Even microadenomas of __ mm or less can cause sig endocrine issues
1
Larger pituitary adenomas put pressure on surrounding structures such as ___ ___
optic chiasm
Larger pituitary adenomas put pressure on surrounding structures such as optic chiasm causing what
bitemporal hemianopia
