Subcortical nuclei (VI) Flashcards
(37 cards)
Cover the labels and identify each of the structures here. Where is the inderpedincular fossa? https://quizlet.com/gb/274895161/session-5-coronal-section-diagram/
https://quizlet.com/gb/595698327/coronal-section-of-the-brain-diagram/
https://quizlet.com/gb/274895161/session-5-coronal-section-diagram/
whats the central core
all the collection of nuclei deep deep in the white matter of the brain
what parts of the lateral ventricles can you see on a coronal section?
you can see the bodies and maybe atrium(s) of the lateral ventricles and the temporal horns going into the temporal lobes
If we divide the brain into: forebrain and brainstem, what two regions do we have in the forebrain? Show the areas on a saggital section.
Which foramen can we see here, at what is it for?
- telencephalon (cerebrum(al hemisphreres))
- diencephalon: thalamus, hypothalamus, hypothalamic sulcus (/subthalamus), epithalamus (pineal gland)
- foramen monro: connect the paired lateral ventricles with the third ventricle at the midline of the brain. As channels, they allow cerebrospinal fluid (CSF) produced in the lateral ventricles to reach the third ventricle and then the rest of the brain’s ventricular system.
- Location: on a sagittal section, you would find the foramina of Monro in the midline of the brain, at the level where the lateral ventricles connect with the third ventricle, JUST IN FRONT OF THE THALAMUS
What part of the internal capsule runs laterally to the thalamus? show it on an axial section
the posterior limb. This is long.
What important structure forms the wall of the third ventricle?
which tracts go through the Internal capsule? give examples,
and which part do the descending tracts go down?
thalamo-cortical, cortico-thalamic and decending tracts
- posterior limb
which parts of the thalamus are the medial and geniculate bodies at?
right at the bum of it! two little bodies at the bottom.
what actually is the thalamus?
a collection of nuclei, its a relay structure
It is above the midbrain or mesencephalon, allowing for nerve fiber connections to the cerebral cortex in all directions — each thalamus connects to the other via the interthalamic adhesion, but th
optic radiations go from where to where?
Axons go from the lateral geniculate nucleus, as “thalamic radiations”to the V1 in the occipital lobe.
Do the descending pathways go through the thalamus? What about the ascending pathways?
While the descending motor pathways bypass (ignore) the thalamus, the ascending sensory pathways do involve the thalamus as a relay station for sensory information on its way to the cerebral cortex. The thalamus plays a crucial role in filtering and routing sensory signals to the appropriate areas of the brain for further processing and perception
Which layer of the cortex does the corticothalamic projections go up to, and from where do they come back down?
Cortical areas receive thalamo-cortical projections in L4 and send back L6 cortico-thalamic projections !
where do the corticospinal tract upper motor neurons originate? i.e., where are their cell bodies?
The cell bodies of these upper motor neurons are primarily located in the fifth layer of the cerebral cortex, known as the internal pyramidal layer or layer V. This layer is also referred to as the “pyramidal layer” because it contains large pyramidal-shaped neurons, including the Betz cells, which are particularly prominent in motor areas of the cortex.
does the thalamus just relay sensory info?
No! its also a site where sensory inputs can be modulated!
does the thalamus relay ALL sensory info? What about motor info?
- No, it relays all but not olfaction!!!
- the thalamus does relay motor control from the cerebellum and the basal ganglia
LGN and MGN of the thalamus have functions in what?
LGN: visual info
MGN: auditory info
4 functions of thalamus?
- Sensory gating: relay and filtering of all specific sensory information (but smell!)
- Motor gating: relay and filtering of motor control from the cerebellum and the basal ganglia
- Cognition, autonomous and emotion: association nuclei
connecting association and limbic areas - Arousal: regulation of sleep, arousal, awareness
What are the 7 basal ganglia?
those in the telencephalon:
* caudate nucleus
* Putamen
* Nucleus Accumbens
* External Globus Pallidus (Gpe)
* Internal Globus Pallidus (Gpi)
those in diencephalon
Subthalamic nucleus
those in mesencephalon
Substancia Nigra
what is Dyskinesia and what are the two types?
- movement disorders in basal ganglia diseases.
- 1) hypokinetic disorders e.g., parkinsons disease (bradykinesia, rigidity, tremor, postural instability)
- 2) hyperkinetic disorders e.g., huntington’s disease (involuntary jerking - “chorea”)
what is the “striatum”? Why striatum?
*Caudate nucleus - curling around, encircling the lenticulate nucleus (putamen + globus pallidus)
*Putamen
*Nucleus Accumbens (ventral striatum)
“striatum” is derived from the Latin word “striae,” which means “stripes” or “streaks,”
the caudate and putamen are separated from one another by a white matter tract called the internal capsule, but there are many strands of grey matter that cross the internal capsule, giving the structure a striped appearance.
the caudate and putamen are separated by what?
internal capsule, with axons
what’s the paler area deeper inside the putamen?
the globus pallidus - that’s why its called “pallidus” because its paler than the putamen
caudate has what shape?
c-shaped, encircles the lenticulate nucleus!
where is the NAcc?
It’s the NOSE Of the striatum!!!! frontal, a bit downwards
positioned at the frontal interface between the caudate nucleus and the putamen.
