Flashcards in The Brain I Deck (57):
The rostral portion of the neural tube is divided into which parts
Prosencephalon, mesencephalon, rhomboencephalon
The prosencephalon becomes the
Telencephalon and the diencephalon
The fourth ventricle is from the
The telencephalon gives rise to
The cerebral cortex and the corpus striatum
The diencephalon gives rise to
The thalamus and the hypothalamus
Which structure acquires a C shape
The telencephalon and it surrounds the diencephalon
Detail the shape of the lateral ventricles
Go to slide
What are the 4 divisions of the telencephalon
Paleopallium( is ventral but becomes very thin), corpus striatum/basal eminence( this large circle moves from lateral to medial) , neopallium (along the edge) , archipallium (moves from dorsal to ventral)
What happens during expansion of the telenceohalon
The hippocampus (oldest) moves into the temporal lobe and leaves behind a fornix. The chordoid plexus which was at the level of the telencephalon vesicles and is placed in a cavity beneath the fornix called the chordoid fissure. The lamina terminalis is the anterior region of the fornix and it gives rise to the corpus collosum. The caudate nucleus also forms a Cshape
What is the site of fusion
The area where there is a gap between the telencephalon vesicles and the diencephalon which eventually fuses together.
What splits the corpus striatum? Into What?
A bundle of ascending and descending fibers called the internal capsule. Into the medial division (caudate nucleus) and the lateral division (the putamen and the globus pallidus nucleus)
where are the anterior limb and the posterior limb of the internal capsule?
anterior limb is between caudate nucleus and the putamen and the globus pallidus. posterior limb is between thalamus and the putamen and globus pallidus
what is the INSULA. How can you see it?
it is the part of the telencephalic vesicle that doesn't expand, it is covered by the frontal/temporal/parietal opercula. It can be seen by displacing the lateral/sylvian sulcus. It is an area where you find 2 layers of gray matter*
what does not have a C shape?
the putamen because it is very close to the insular and so it does not get stretched
what are the 3 major sulci and when are they present in the fetus?
the central sulci, lateral sulci, calcarine sulci, present at 28 Wks
name the lobes
frontal lobe, temporal lobe, parietal lobe, occipital lobe, insula, the limbic lobe
the central sulcus of rolondus divides what?
the frontal lobe from the parietal lobe
the limbic lobe is made of what 2 structures
the cingulate gyrus and the parahippocampus gyrus
name the gyri of the frontal lobe
the pre-central gyrus (anterior to the central sulcus), superior-middle-inferior frontal gyri
what are the gyri of the parietal lobe?
post central gyrus, superior-inferior parietal lobules, the inferior is divided into the supramarginal gyrus and the angular gyrus
name the gyri in the temporal lobe
superior-middle-inferior temporal gyri
name the gyri of the insula
short gyri (anterior) and the long gyri (posterior)
name the gyri of the occipital lobe
above the calcarine sulcus we have the cuneus, and below we have the lingual gyrous
list the gyri on the ventral surface of the frontal lobe
straight gyrus and the orbital gyrus
list the gyri on the ventral surface of the temporal lobe
medial occipitotemporal gyrus, lateral occipitotemporal gyrus
list the gyri on the ventral surface of the limbic lobe
parahippocampal gyrus, uncus
the gyri of the temporal and limbic lobes are separated by?
the collateral sulcus and the rhinal sulcus
Where is the hippocampus. The fornix connects the hippocampus with? Where is the fornix
It is stretched on the floor of the temporal horn of the lateral ventrical. With the forebrain. It is below the corpus callosum.
How is the hippocampus/archicortex situated. Where is the tail of the caudate nucleus?
It is coiled up. The tail of the caudate nucleus is in the roof of the floor of the lateral ventrical
The hippocampus belongs to the hippocampal formation. What else is in this formation?
The dentate gyros and the hippocampus proper which together can be called the cornu ammonis. And the subiculum And the parahippocampal formation (the entorhinal area)
Where is the amygdala. It is near to which complex?
In the deep nuclei of the brain, infront of the hippocampus. And very near to the olfactory complex.
The limbic system consists of?
The limbic lobe, hippocampal formation, amygdala, and part of the diencephalon.
When the body is stressed it triggers the release of ? from the ?
Cortisol from the zona fasciculata of the adrenal gland
What is the stria terminalis
It is a trail of fibers of white matter left by the amygdala, note that when we dig deeper to it we find the basal forebrain.
Function of the stria terminalis is?
Reaction of anxiety in response to threat monitoring relay site within the hypothalmic pituitary adrenal axis.. It regulates activity in response to acute stress
Locate the primary and secondary sensory and motor area of the brain
Go to slide 51
White matter is divided into 3 sections, name them and their functions
Commisural fibers: which connect the 2 sides of the brain
Associative fibers: which connect different parts of the cortex within the same hemisphere
Projecting fibers: project out of the brain
The projecting fibers is divided into 3 sections what are they
The internal capsule, the external capsule and the extreme capsule.
Name 3 commisural fibers
Corpus callosum, the commisure of the fornix, the anterior commisure
Name the different parts of the corpus callosum
It is white matter connecting 2 hemispheres. It is found when you enter the interhemispheric groove, below the great cerebral falx.
- 5 forceps minor : connect frontal lobes.
- 6 forceps major: connect occipital lobes.
- 4 radiated fibers: they are in the center and aka Tapetum
- 1,2 induseum griseum: is on top of the corpus callosum and is grey.
Name the divisions of the corpus callosum in the medial aspect
Rostrum, genu, trunk, splenium
The gap between the corpus callosum and the fornix is called
The septum pellucidum. It forms the medial wall of the anterior horn of the lateral ventrical
Where is the anterior fissure? What does it do? What can it be divided into? What do these two areas connect?
It is a bundle of white matter fibers located in the anterior of the fornix.
It connects the forebrain of the two hemispheres.
It can be divided into an anterior and posterior commisure.
The anterior commisure connects the olfactory bulbs/tracts/and cortexes.
The posterior commisure connects the gyri of the temporal lobes and amygdala and the fibers of the stria terminalis.
Detail the characteristics of the fornix, as a projecting and commisural fiber
This originates form the hippocampal formation, thus the most posterior part is called the fimbriae. Then further along we have the crura, then we have the body where the two crura join together, then they split and form the columns of the fornix and
Septal nuclei are?
Cholinergic, they project all over the cortex using the mynert nucleus and reach the amygdala
What is the psultarium of the fornix
It the area between the crura of the fornix where they are joined by commisural and projecting fibers. This connects the hippocampal regions of the 2 hemispheres
Where is the internal capsule, external capsule, extreme capsule?
The internal capsule is the white matter that passes through the caudate nucleus and the putamen and the globus pallidus and the thalamus.
External capsule: inbetween the extreme capsule and internal capsule
Extreme capsule: is the white matter closest to the Gray matter of the insula
Where do fibers of the internal capsule run to and from?
they run from the thalamus to the cortes. And from the cortex to the thalamus/brainstem/spinal chord--> these are descending fibers
what is the corona radiata?
it is part of the internal capsule spanning the region from the thalamus to the cortex, it is the open part of he internal capsule
is the putamen and the caudate nucleus separated?
not completely, there are cell bridges connecting them (they are not completely separated by the internal capsule)
what is the basal ganglia?
they are the deep nuclei of the telencephalon. (caudate/putamen/pallidus inner and outer)
what is the corpus striatum?
the putamen, caudate nucleus, pallidus
what is the striatum?
the caudate and the pallidus
what is the lenticular nucleus?
the putamen and the pallidus
where and what is the nucleus accumbes?
it is in the ventral surface of the area where the putamen and the caudate nucleus are still together. The most anterior region of the corpus striatum
the sublenticular nucleus fibers run where?
they run below the lenticular nucleus to reach the auditory cortex