Exam 2- week 7 ppt 4 Cerebrum Basal Nuclei and Internal Capsule Anatomy Flashcards
Where are the basal nuclei located?
in the subcortical white matter and midbrain
the basal nuclei are highly interconnected and massively connected with
cerebral cortex and thalamus
basal nuclei and multiple circuits
there are a lot of parallel processing in multiple circuits
basal nuclei have a role in
~major role in the selection of motor plan, sequencing, and timing of movements
~recent role in cognitive function a focus of research
basal nuclei: paired subcortical nuclei (5)
~Caudate nucleus
~Putamen
~Globus pallidus (internal and external segments)
~Subthalamic nucleus
~Substantia nigra (pars compacta & reticulata)
Caudate nucleus: what is it composed of
a large head and long tapering body and very small tail in the temporal lobe
Caudate nucleus: it forms the lateral wall of
the lateral ventricle
Caudate nucleus: rostally head is contiguous with
nucleus accumbens
Caudate nucleus: rostallu, lateral aspect merges with
putamen
caudate nucleus + putamen =
striatum
Caudate nucleus: head and body is medial to
internal capsule
~specifically the anterior limb of the internal capsule
Caudate nucleus: in the temporal lobe, the tail is contiguous with
amygdala
Amygdala
part of the limbic system
Putamen: location
lateral to internal capsule with anterior limb separating it from the caudate nucleus and the posterior limb is separating it from the thalamus
Putamen: numerous interconnections with
caudate nucleus
~these two nucleus merge rostally (striatum)
Globus pallidus: location
located medial to putamen and lateral to internal capsule
Globus pallidus + putamen =
lentiform nucleus
Globus pallidus: connections btw GP and putamen
there are numerous connections btw GP and putamen but they function as distinct components of the basal nuclei
Globus Pallidus: made of 2 parts
internal (inner) and external (outer) nuclei
Subthalamic nucleus: location
~Ventral to posterior aspect of thalamus
~Medial to internal capsule which separates it from the globus pallidus but there are many connections between these two nuclei
Substantia nigra: location
~ largest nucleus of the midbrain
~extending complete caudo-rostral length of midbrain
~seen as a black stripe through the length of the midbrain ventral to the subthalamus and red nucleus of the midbrain
Substantia nigra: pigments
Neuromelanin pigment in cell bodies of dopaminergic neurons
Substantia nigra: 2 regions
~pars compacta
~pars reticulata
Substantia nigra: pars compacta
~cell-rich regions
~more dorsal
Substanta nigra: pars reticulata
~cell sparse, dense, well-organized neuropil
~more ventral
Striatum =
caudate + putamen
corpus striatum =
striatum + globus pallidus
lenticular nuclei =
putamen + globus pallidus
pallidum=
globus pallidus
ventral striatum =
nucleus acumben
Internal capsule: is a V shaped structure that forms _ parts (name them)
3
~anterior limb
~genu
~posterior limb
Internal capsule: anterior limb
between caudate and lentiform nucleus
Internal capsule: genu
the bend
Internal capsule: posterior limb
between thalamus and lentiform nucleus
the internal capsule contain ascending and descending fibers to the
cerebral cortex
Fibers in the anterior limb of the internal capsule
~thalamocortical fibers
~corticothalamic fibers
Fibers in the genu of the internal capsule
corticobulbar fibers
Fibers in the posterior limb of the internal capsule
~corticospinal fibers
~thalamocortical fibers
~corticothalamic fibers
define neuropil
a dense network of interwoven nerve fibers and their branches and synapses, together with glial filaments.