B4 - cerebellum and internal brain structure stuff not in case flashcards
what does the superior surface of the cerebellum lie beneath?
dural tentorium cerebelli
how are the folds on the cerebellum orientated?
transversely
what divides the anterior lobe (small) from the posterior lobe (large)?
primary fissure
the neocerebellum receives afferents from where and projects where?
- pons
- to VL nucleus of thalamus
where does the STN lie?
in the diencephalon
where is the substantia nigra?
mesencephalon
what forms the lateral wall of the lateral ventricle?
caudate nucleus
the caudate nucleus can be identified as the collection of grey matter on what?
the wall of the lateral ventricles
the caudate nucleus is separated from the putamen by descending white matter fibres known as what?
internal capsule
what forms the lateral aspect of the lentiform nucleus?
putamen
where do the putamen and caudate receive input from and project to?
- putamen — receives almost exclusive input from motor and somatosensory cortices and projects back to motor areas (thus related to motor loop)
- caudate — input from cortical association areas and projects to prefrontal areas
what kind of input does the ventral striatum (including nucleus accumbens) receive?
limbic input and thus related to emotions
The arterial supply to the basal ganglia comes mainly from the_______ artery,a continuation of the _______ artery.
- MCA
- ICA
what provides ,post of the circulation to the striatum and lenticular nucleus?
lenticulostriate artery
what branches of the internal carotid artery supply the more anterior aspect of the basal ganglia? (ie. head of caudate nucleus and the nucleus accumbens)
anterior cerebral artery and the anterior choroidal artery
what artery supplies the head of caudate nucleus, anterior portion of lentiform nucelus (GP + putamen) and anterior limb of the internal capsule?
medial striate artery (of Heubner)
what are more posterior structures of the basal ganglia and thus receive vasculature from branches of the posterior cerebral and posterior communicating arteries?
STN and substantia nigra
venous drainage of basal ganglia?
via striate branches of the internal cerebral vein whcih drain into the great cerebral vein
the curved, tapering tail of the caudate follows the curvature of the ______ into the _______ lobe
lateral ventricle into the temporal lobe
what lies lateral to the internal capsule?
putamen and GP
lesions of the basal ganglia produce effects on what side of the body?
contralateral
what is the diencephalon made up of?
thalamus, epithalamus, subthalamus and hypothalamus
the thalamus contributes to the lateral wall of what and extends anteriorly into what?
- lateral wall of 3rd ventricle
- anteriorly to the interventricular foramen
the thalamus lies medial to what?
the posterior limb of the internal capsule
what connects the thalamus to the other side?
massa intermedia
what in the diencephalon contributes to the lateral wall of the 3rd ventricle?
hypothalamus and thalamus
what attaches the hypothalamus to the pituitary gland?
pituitary stalk
what are the functions of the hypothalamus?
endocrine control, temperature control, homeostasis, water balance
what are the mammillary bodies?
2 rounded elevations that overlie the mammillary nuclei of the hypothalamus
what is the most posterior structure of the diencephalon, located rostral to the superior colliculus?
epithalamus
what are the main components of the epithalamus?
habenular nucleus and pineal gland
what does the pineal gland produce?
melatonin
where is subthalamus?
inferior to the thalamus, dorsolateral to the hypothalamus and superior to the tegmentum of the midbrain
what does the subthalamus contain and therefore do?
contains subthalamic nucleus which has connections with the globus pallidus + substantia nigra — therefore involved in the control of movement
diencephalon function?
Primary relay and processing center for sensory information and autonomic control:
- via connectionslimbic system - seat of memory and emotion
- via connections with basal ganglia - motor coordination
- via connections with primary sensory areas, such as auditory or visual
what is the limbic system involved in?
memory, behaviour, emotion and olfaction
what are the several important components in the limbic system?
- amygdala
- hippocampus
- thalamus
- hypothalamus
- basal ganglia
- cingulate gyrus
limbic system :
afferent info is received from ________ and fibres leaving the limbic system project to the _______
- afferent info is received from the association cortex and fibres leaving the limbic system project to the hypothalamus
describe the limbic lobe
= forms a border around the corpus callosum and rostral brain stem
- consists of the parahippocampal gyrus, cingulate gyrus and subcallosal gyrus
what does the hippocampal formation consist of?
- hippocampus
- dentate gyrus
- parahippocampal gyrus
what does the hippocampal formation play a major part in?
memory, learning and spatial navigation
where does the hippocampal formation receive input from?
entorhinal area of the parahippocampal gyrus
where does the hippocampus lie along the floor of?
the inferior horn of the lateral ventricle
what does the dentate gyrus extend between?
hippocampus and parahippocampal gyrus
the hippocampus is c-shaped and is on the inferomedial aspect of the what?
temporal lobe
what is the amygdaloid body involved in?
the formation and storage of memories; associated with the acquisition and expression of fear conditioning and is also involved in olfaction
what does the amygdaloid body receive input from?
the association cortices, cingulate gyrus and olfactory bulb and from brainstem visceral pathways
where is the amygdaloid body?
- at the anterior end of the tail of the caudate nucleus
- lies in the temporal lobe near the uncus, overlying the anterior part of the inferior horn of the lateral ventricle
what does the fornix connect and what can it be divided into?
- connects the posterior part of the hippocampus with the mammillary bodies of the hypothalamus
- can be divided into the crus, body, commissure and the anterior columns
what does the stria terminalis connect?
connects the amygdaloid body with the anterior hypothalamus and the septal nuclei
what does the mammillothalamic tract connect?
connects the mammillary bodies of the hypothalamus with the anterior nuclei of the thalamus
what is the papez circuit?
= a neural pathway leading from the hippocampus by way of the forniz to the mammillary body and thence returning to the hippocampus by way of, sequentially, the anterior thalamic nuclei, cingulate gyrus, and parahippocampal gyrus
fill in the gaps of the Papez circuit
what are primary olfactory neuroens like?
bipolar
primary olfactory neurons are bipolar whose receptors are dispersed where?
the olfactory mucosa on the superior nasal concha and upper part of the nasal septum
what do the central processes of the primary olfactory neurons form?
the axons of the olfactory nerves
where do olfactory nerves enter the skull?
through the cribiform plate
olfactory nerves terminate in the _____ by synapsing on ______
- olfactory bulb
- mitral cells
what do the axons of mitral cells enter?
the olfactory tract
what happens at the posterior end of the olfactory tract?
the fibres divide into 2 bundles; the medial and lateral stria
what happens to the fibres that enter the medial stria?
pass in the anterior commissure to the contralateral olfactory bulb and septal area
what happens to the fibres in the lateral stria?
- most fibres enter here
- continue on to the primary olfactory cortex in the uncus and amygdaloid body
where is the uncus?
on medial surface of temporal lobe in anterior part of parahippocampal gyrus
where are the habenular nuclei?
just anterior to the pineal gland
