test 1: lecture 10 Flashcards
three divisions of the brain
cerebrum
cerebellum
brainstem
brainstem is divided into the
medulla oblongata
pons
midbrain
diencephalon
caudal and rostral boundaries of diencephalon
caudal: a line drawn between the caudal commissure and the caudal edge of the mammillary bodies.
•Rostral:a line drawn between therostral commissureand the rostral edge of theoptic chiasm.
___ goes from the optic chiasm to caudal to the mammary bodies
diencephalon
dorsal border of the diencephalon
•Dorsal: is complex because of adjacent structures or fissures: part of fornix** and **transverse cerebral fissure.
fissure dorsal to diencephalon
transverse cerebral fissure
medial and lateral boundary of the diencephalon
medial → 3rd ventricle
lateral → internal capsule (white matter fiber tract thalamus to cerebrum)
white matter = black
the 3rd ventricle is divided by the __
interthalmic adhesion
4 subdivisions of the diencephalon
epithalamus
thalamus
subthalamus
hypothalamus
epithalamus
a. Most dorsal and phylogenetically oldest diencephalic subdivision
b. Consists of: pineal gland, habenular nuclei, and stria medullaris
c. Associated with reproductive behavior rhythms and emotions via limbic system connectivity
d. Will not be discussing this subdivision
Consists of: pineal gland, habenular nuclei, and stria medullaris
epithalamus part of the diencephalon
Associated with reproductive behavior rhythms and emotions via limbic system connectivity
epithalamus part of the diencephalon
thalamus
The largest of the subdivisions and a very important one to CNS function.
b. Consists of a large number of nuclei.
c. Has many functions, including activation of entire cerebral cortex, projects specific point-to-point sensory information to primary sensory areas of cerebral cortex for conscious discrimination, distributes more complex information to association areas of cerebral cortex for cognition, and participates in the regulation of motor activities of the cerebral cortex via axonal connections from the cerebellum and basal
* *ganglia.**
thalamus has many functions, including activation of entire cerebral cortex, projects specific point-to-point sensory information to ___ of cerebral cortex for conscious discrimination.
primary sensory areas (auditory, visual, somatosensory, primary motor cortex)
Thalamus distributes more complex information to ___of cerebral cortex for cognition
association areas
subthalamus
A small subdivision just beneath the thalamus.
b. Consists of nuclei associated with the basal ganglia.
c. Involved with control of complex motor functions.
___ is Involved with control of complex motor functions.
subthalamus part of the diencephalon
hypothalamus
a. Ventral-most subdivision with its ventral border being the ventral surface of the diencephalon.
b. Although small in size, the hypothalamus has extremely important functions.
c. Some of its most important functions are the regulation of: the autonomic nervous system, emotional responses, body
temperature, food intake, water balance, thirst, sleep- wake cycles, and control of endocrine system functions.
____ controls regulation of: the autonomic nervous system, emotional responses, body temperature, food intake, water balance, thirst, sleep- wake cycles, and control of endocrine system functions.
hypothalamus of the diencephalon
how does thalamus regulate movement
will sense what motor neuron passed and what was done and will change impulse to correct
projection nuclei
the thalamus is associated with emotional behavior via
connectivity with the___system.
limbic
The thalamus is Involved with arousal (consciousness) of CNS via the ___
reticular formation
organization of thalamic nuclei
medio-lateralorientation:
midline/medial nuclei,
intralaminar nuclei
lateral nuclei.
midline/medial nuclei of the thalamus
Phylogenetically older portion of thalamus and represents a rostral continuation of the more caudal brainstem reticular formation.
b. Have diffuse connections with the cerebral cortex and are associated with its arousal- consciousness
c. Functionally non-specific- light touch, visual ect. not a specific sensory modality
d. Also possesses connectivity with the hypothalamus
intralaminar nuclei of the thalamus
Positioned centrally and consists of a small number of nuclei.
b. Connects with the hypothalamus, basal ganglia, and diffusely with the cerebral cortex.
c. Functionally non-specific.
d. Extensive basal ganglia connectivity suggesting an important role in motor integration.
e. Significant local connections with other thalamic nuclei, integrating/modulating their activity.
what nuclei in the thalamus are functionally non-specific and associated with consciousness?
midline/medial nuclei
what nuclei of the thalamus is involved in motor integration
intralaminar nuclei
lateral group nuclei of the thalamus have what two parts?
ventral tier and dorsal tier
ventral tier of the lateral group of nuclei in the thalamus
ventral tier group of the lateral group of nuclei in the thalamus
Composed of projection nuclei associated with classical sensory pathways (somatosensory, visual, auditory, vestibular, and gustatory).
b. Sensory receptors are represented in an orderly, point-to- point manner (topographically organized).
c. For example, in somatosensory projection nuclei VPL & VPM), the body istopographically represented (somatotopically organized)
d. Projection station in the cerebello-cerebrum pathway.
e. Projection nuclei send their axons to primary sensory areas (primary receiving areas) of cerebral cortex.
f. Primary sensory areas of cerebral cortex are correspondingly topographically organized as illustrated in the primary somatosensory cortex.
___ has significant local connections with other thalamic nuclei, integrating/modulating their activity.
intralaminar nuclei of the thalamus
___ are composed of projection nuclei associated with classical sensory pathways (somatosensory, visual, auditory, vestibular, and gustatory).
ventral tier group of the lateral group of nuclei of the thalamus
topographically organization
VPL= ventral posterolateral nucleus
VPM= ventral posteromedial nucleus
Ventral tier group of the lateral group of nuclei of the thalamus
Projection nuclei send their axons to ___ areas (primary receiving areas) of cerebral cortex.
primary sensory
Primary sensory areas of cerebral cortex are correspondingly topographically organized as illustrated in the primary somatosensory cortex.
dorsal tier group of the lateral group of nuclei in the thalamus
a. Consists of Association nuclei.
b. Do not receive direct sensory or cerebellar- cerebral pathway projections.
c. Receive afferent projections from other CNS structures, for example, superior colliculus and pretectal nuclei.
d. Do not possess a topographical organization.- more complicated
f. Project their axons to association areas of the cerebral cortex.
g. association areas of the cerebral cortex are involved with complex, sophisticated functions.
___ consists of association nuclei that project their axons to association areas of the cerebral cortex
dorsal tier group of the lateral group of nuclei of the thalamus
ventral tier projection nuclei
a. Involved with perception of different sensory modalities (somatosensory, visual, auditory, vestibular, and gustatory).
b. Involved with detecting the location, intensity, and type (submodality) of sensory stimulus.
c. More complete information on the connectivity and function of the individual thalamic nuclei will be covered in upcoming lectures on sensory pathways and cerebellar- cerebral projections.
ventral poterolateral nucleus
a. Receives afferents from somatosensory tracts having sensory receptors caudal to the head region (e.g., DC-ML(touch,proprioception) and spinothalamic tracts- (pain and temp).
b. Projects its axons to First Somatosensory (SI) area of the cerebral cortex in the parietal lobe
c. VPL is somatotopically organized. (little weird shape body shows where information comes from)
somatotopically organized body are based upon the ___
density of sensory receptors
bigger things have better capacity for sensory discrimination
VPL and VPM →
first somatosensory area of the brain
(SI)
somatosensory cortex of raccoon
have very good sensory in fingers
Individual neurons within VPL (as is true of other projection nuclei) respond to stimuli from ___
only one type of receptor (e.g., pressure, hair touch).
this is called submodality specificity
submodality specificity
Individual neurons within VPL (as is true of other projection nuclei) respond to stimuli from only one type of receptor (e.g., pressure, hair touch).
VPM
ventral posteromedial nucleus
a. Receives afferents from the head via the trigemino-thalamic tract.
b. Is somatotopically organized.
c. VPM projects to face area of SI cortex in the parietal lobe.
___ Receives afferents from the head via the trigemino-thalamic tract.
VPM
VPM projects to face area of SI cortex in the ___ lobe
parietal
VPMpc
Ventral Posteromedial nucleus, pars parvocellularis(VPMpc):
a. Receives gustatory (taste) afferents from the tongue.
b. Projects to the primary taste area of the cerebral cortex adjacent to the face area of SI.
___ Receives gustatory (taste) afferents from the tongue
VPMpm
Ventral Posteromedial nucleus, pars parvocellularis
VPMpc
taste projection nucelus
MGN
- *Medial Geniculate nucleus (MGN):**
a. Receives auditory receptor afferents from the inferior colliculus located in the midbrain.
b. It is topographically organized (tonotopia).
c. Tones/frequencies are represented in a point-to-point manner and in a definite sequence.
d. Projects its axons to the primary auditory cortex (AI) in the temporal lobe.
____receives auditory receptor afferents from the inferior colliculus located in the midbrain.
MGN medial geniculate nucleus (sound)
___ Projects its axons to the primary auditory cortex (AI) in the temporal lobe.
MGN
medial geniculate nucleus
LGNd
dorsal lateral geniculate nucleus
a. Receives visual receptor afferents (rods and cones) via retinal ganglion cell axons traveling in the optic nerves and optic tracts.
b. It is topographically organized (retinotopy).
c. Regions of retina are represented in a point-to-point manner and in a definite sequence.
d. Projects its axons to the primary visual cortex located in the occipital lobe.
____ Receives visual receptor afferents (rods and cones) via retinal ganglion cell axons traveling in the optic nerves and optic tracts.
LGNd
dorsal lateral geniculate nucleus
___ Projects its axons to the primary visual cortex located in the occipital lobe.
LGNd
Dorsal Lateral Geniculate nucleus
ventral lateral nucleus
a. Receives cerebellar nuclei projections.
b. Projects its axons to the primary motor cortex (MI) in the frontal lobe.
c. VL is part of a cerebellar-cerebral pathway permitting the cerebellum to modulate the intended voluntary movements initiated in MI.
___ Projects its axons to the primary motor cortex (MI) in the frontal lobe
ventral lateral nucleus
___ is part of a cerebellar-cerebral pathway permitting the cerebellum to modulate the intended voluntary movements initiated in MI.
ventral lateral nucleus
dorsal tier nuclei of the thalamus (association nuclei) are:
lateral posterior (LP)
pulvinar (PUL)
lateral dorsalis (LD)
posterior nuclear complex (POM)
medialis Dorsalis (MD)
thalamic association nuclei project axons to ___
association areas of the cerebral cortec
___ do not receive direct afferents from the classical sensory pathway
Dorsal Tier nuclei of Thalamus (Association nuclei):
___ Are not topographically organized nor submodality specific
Dorsal Tier nuclei of Thalamus (Association nuclei):
Dorsal Tier nuclei of Thalamus (Association nuclei) are involved with ___
complex cognitive function
____ is the most rostral subdivision of the brainstem.
Diencephalon
The diencephalon has four subdivisions:
epithalamus, thalamus, subthalamus, and
hypothalamus.
Thalamus functions as projection station for ___ pathways and ___projections destined for the cerebral cortex
sensory
cerebellar
Thalamic connectivity and function is complex. Is involved with ___ /integration of sensory information.
modulation
Parts of the thalamus play a dominant role in the maintenance and state of___ and alertness.
consciousness
Thalamus also functions as a gate, controlling information that it projects to the cerebral cortex. It ___some and suppresses other information as part of a selective attention system.
amplifies
Thalamus possesses a ___organization of its nuclei
medio-lateral
___ nuclei are functionally non-specific projecting diffusely to their terminal targets and involved with the state of consciousness and alertness.
Midline/Medial
____are more centrally-located and functionally non-specific projecting their axons to other thalamic nuclei. Involved with integration/modulation of other thalamic nuclei.
Intralaminar nuclei
The___ are organized into two groups: ventral tier nuclei and dorsal tier nuclei. The lateral thalamic nuclei are functionally specific projecting their axons to specific areas of the cerebral cortex.
lateral thalamic nuclei
The ____ are thalamic projection nuclei of the classical sensory pathways, which are destined for the primary sensory (receiving) areas of the cerebral cortex. They are topographically organized and functionally submodality specific.
ventral tier
The ____nuclei are association nuclei which project their axons to association areas located within the frontal, parietal, temporal, and occipital lobes of the cerebral cortex.
dorsal tier
Somatosensory, Visual, Auditory, Vestibular, and Gustatory pathways each have their own specific projection nucleus in the ____group.
ventral tier
The ___ nuclei do not receive direct projections from the classical sensory or cerebellar pathways.
dorsal tier
The ___nuclei (and association areas of the cerebral cortex) are not topographically organized nor governed by a single sensory modality.
dorsal tier
The____ nuclei and ___ areas are involved with complex functions such as cognition, planning and programming of movements, acquired inhibitions, and appropriate emotional responses.
association
association
