Neuro Diencephalon- Shurn

Front 1

What forms the walls and floor of the third verntricle?

Back 1

thalamus, epithalamus, hypothalamus

Front 2

What forms the floor of the lateral ventricle?

Back 2

thalamus

Front 3

What does the reticular nucleus do?

Back 3

modulates the exchange of signals between other thalamic nuclei and the cerebral cortex

Front 4

What do most thalamic nuclei receive?

Back 4

subcortical afferents

Front 5

How are the neurons in the thalamus connected with the cerebral cortex?

Back 5

reciprocally connected

Front 6

What do the ventral group of thalamic nuclei include and what are they involved with?

Back 6

medial and lateral geniculate bodies, which are parts of the auditory and visual systems and somtosensory ventral posterior nucleus

Front 7

Which thalamic nuclei are parts of pathways to motor areas of the cerebral cortex?

Back 7

ventral lateral and ventral anterior

Front 8

What is the importance of the intralaminar nuclei?

Back 8

receives afferents from many sources, projects to the whole neocortex and the striatum, involved in awareness, arousal, and motors controls

Front 9

Which is the largest thalamic nuclei?

Back 9

pulvinar nucleus

Front 10

Which thalamic nuclei are part of the limbic system?

Back 10

anterior and lateral dorsal nuclei of the thalamus

Front 11

What is the importance of the mediodorsal thalamic nucleus?

Back 11

receives afferents from the amygdala, entorhinal area, spinal cord, and corpus striatum; it projects to the prefrontal cortex

Front 12

What is the importance of the lateral posterior nucleus and the pulvinar nucleus?

Back 12

receives input from the visual system and porjects to the cortex of the parietal and frontal lobes and the cingulate gyrus

Front 13

What are the characteristics of the subthalamus?

Back 13

contains various bundles of fibers connected with the thalamus, rostral parts of some midbrain nuclei, and the subthalamic nucleus

Front 14

What is subthalamic nuclei connected with?

Back 14

pallidum

Front 15

What does a destructive lesion to the subthalamic nucleus result in?

Back 15

contralateral hemiballismus (lurch forward)

Front 16

What does the epithalamus consist of?

Back 16

stria medullaris thalami, habenular nuclei, posterior commissure, pineal gland

Front 17

Where do hypothalamic efferent fibers go and what do they control

Back 17

go to brain stem and spinal cord for control of autonomic and other involuntary functions

Front 18

What does the forebrain consist of?

Back 18

diencephalon (interbrain) and paired cerebral hemispheres

Front 19

the diencephalon contains functional centers for the integration of what?

Back 19

all information passing from the brainstem and spinal cord to the cerebral hemispheres; motor and visceral activities

Front 20

What do the two cerebral hemispheres integrate?

Back 20

highest mental function such as awareness of sensations, emotions, learning and memory, intelligence and creativity, language

Front 21

What cranial nerve feeds directly into the diencephalic area?

Back 21

optic nerve (CN II)

Front 22

What are the subdivisions of the diencephalon?

Back 22

thalamus, hypothalamus, subthalamus, epithalamus

Front 23

What does the diencephalon contain?

Back 23

the third ventricle

Front 24

What cranial nerve do the cerebral hemispheres receive?

Back 24

olfactory (CN I)

Front 25

What do the cerebral hemispheres contain?

Back 25

lateral ventricles separated by the septum pellucidum

Front 26

What does the thalamus decide?

Back 26

which information is worthy of cognition

Front 27

What is located in the thalamus in terms of somatosensory?

Back 27

third order cells bodies for sensory

Front 28

How does the cerebral cortex shut down processes?

Back 28

it sends information down via reticular formation. Lateral branches coming off the reticular formation hit interneurons and shut down the process

Front 29

What is the only part of the diencephalon that can be seen in the intact brain?

Back 29

hypothalamus because fo the mamillary bodies and infundibular stalk

Front 30

What forms the wall of the third ventricle?

Back 30

medial surface of the diencephalon

Front 31

What does the superior portion of the diencephalon border?

Back 31

the body of the lateral ventricle and the subarachnoid space of the transverse cerebral fissure

Front 32

What is the diencephalon exposed to inferiorly?

Back 32

subarachnoid space

Front 33

What laterally bounds the diencephalon?

Back 33

internal capsule

Front 34

What is the caudal boundary of the diencephalon?

Back 34

plane through the posterior commissure and the caudal edge of the mammillary bodies

Front 35

How does the pineal gland arise?

Back 35

as an evagination from the roof of the diencephalon

Front 36

What does the pineal gland consist of?

Back 36

pinealocytes (secretory cells), glial cells, and a rich vascular supply

Front 37

What is the pineal gland involved in?

Back 37

regulation of some form of rhythm in the body

Front 38

What can pineal gland tumors result in?

Back 38

closure of cerebral aqueduct leading to hydrocephalus; defects of eye movements and pupilarry reactions b/c of damage to the oculomotor and trochlear nuclei and pathways that end at these nuclei; change in sexual function; changes in mood and depression

Front 39

Nonparenchymal pineal tumors results in what?

Back 39

destruction of pinealocytes and are associated with stopping of anti-gonadotropic substance production

Front 40

Why is the pineal gland of clinical importance?

Back 40

at about 17 years old, it calcifies to some degree and is useful as a landmark in x-rays

Front 41

How is the pineal gland attached to the dorsal surface of the diencephalon?

Back 41

by a stalk, caudally at the base of the stalk is the posterior commissure, rostrall is a swellin gon each side called the habenula

Front 42

How are the two habenular nuclei interconnected?

Back 42

habenular commissure

Front 43

What is the major input buncle that the habenula receive?

Back 43

stria medullaris of the thalamus which gives rise to the habenulointerpeduncular tract

Front 44

What is the habenulointerpeduncular tract involved in?

Back 44

involved in limbic structures and can influence the reticular formation

Front 45

What do parts of the tegmetum continue into the diencephalon as?

Back 45

subthalamus, area is completely surrounded by neural tissue and is located inferior to the thalamus, lateral to the hypothalamus and medial to the internal capsule

Front 46

What does the subthalamus contain?

Back 46

rostral portions of the red nucleus and substantia nigra and is traversed by somatosensory pathways on the way to the thalamus as well as several pathways involving the cerebellum and basal ganglia

Front 47

What is the subthalamus involved in?

Back 47

fine motor control and proprioception

Front 48

describe the subthalamic nucleus.

Back 48

lens shaped, biconvex structure located just medial and superior to portions of the internal capsule

Front 49

What is interconnected with the subthalamic nucleus?

Back 49

basal ganglia

Front 50

What is the zona incerta?

Back 50

a small mass of gray matter intervening between the subthalamic nucleus and the thalamus

Front 51

Which is the only subdivision of the diencephalon on the ventral surface of the brain?

Back 51

hypothalamus, located in the median part of the middle cranial fossa just above the diaphragma sella

Front 52

What are the three main subdivisions of the hypothalamus in the anterior plane?

Back 52

supraoptic (anterior part located dorsal to the optic chiasm); tuberal (located between the mamillary and supraoptic regions; contains infundibulum); mammillary (posterior, named owing to the relation to the mamillary bodies of the cerebral hemisphers which are small ball barring sized located in the rostral part of the interpeduncular fossa)

Front 53

What are the thalami?

Back 53

two egg shaped masses bordering the third ventricle and dorsal to the hypothalamic sulcus

Front 54

What is the interthalamic adhesions (or massa intermedia)?

Back 54

in most brains the right and left thalami are fused, partially, across the third ventricle

Front 55

What is the location of the thalamus?

Back 55

extends anteriorly to the interventricular foramen anterior tubercle; superiorly to the transverse cerebral fissure; and the floor of the lateral ventricle; inferior to the hypothalamic sulcus in the back it overlaps the midbrain

Front 56

What is relayed in the thalamus?

Back 56

all sensory pathway

Front 57

anatomical circuits used by what also have relays in the thalamus?

Back 57

cerebellum; basal ganglia; and limbic structure (these various systems utilize more or less separate portions of the thalamus, which has therefore been subdivided into a series of nuclei)

Front 58

What is the anterior tubercle?

Back 58

a swelling in the thalamus at the interventricular foramen

Front 59

what is the medullary stria?

Back 59

a bundle of fibers on the dorsal medial surface of the thalamus

Front 60

Where is the pulvinar nucleus located?

Back 60

to the posterior of the thalamus

Front 61

What are the eight nuclear masses formed for the large number of nuclei in the thalamus?

Back 61

anterior, medial dorsal, ventral nuclear mass, ventral posterior mass dorsal nuclear mass, pulvinar, centromedian, reticular nucleus

Front 62

What is the internal medullary lamina?

Back 62

a thin sheet of bundles of myelinated fibers that separates the thalamus into three major divisions: anterior, medial, lateral

Front 63

What is the anterior division of the thalamus?

Back 63

located at the anterior tubercle of the thalamus and consists of the anterior nucleus

Front 64

What does the medial subdivision of the thalamus include?

Back 64

larger medial dorsal nucleus and a thing nucleus called the midline nucleus (along the wall of the third ventricle)

Front 65

The interthalamic adhesion is a bridge of what?

Back 65

the midline nuclei

Front 66

What is the lateral subdivision composed of?

Back 66

ventral nuclear mass and dorsal nuclear mass

Front 67

What are the subdivisions of the ventral nuclear mass?

Back 67

ventral anterior, ventral lateral , ventral posterior (ventral posterolateral, ventral posteromedial)

Front 68

What are the subdivisions of the dorsal nuclear mass?

Back 68

lateral dorsal; lateral posterior; pulvinar

Front 69

which thalamic nuclei are involved in motor control circuits that include the cerebellum and basal ganglia?

Back 69

ventral anterior and ventral lateral

Front 70

which thalamic nuclei are involved in sensory?

Back 70

ventral posterior nuclei

Front 71

The undersurface of the pulvinar has which nuclei?

Back 71

metathalamic, lateral geniculate, medial geniculate

Front 72

Which nuclei have interconnections to the tectum and are involved in coordinating head and eye movements to sound?

Back 72

lateral and medial geniculate

Front 73

Where is the centromedian located?

Back 73

within the internal medullary lamina

Front 74

Which nuclei are related to the medullary laminae?

Back 74

lateral and medial geniculate (one of each on each side)

Front 75

Where is the reticular nucleus?

Back 75

lateral to the external medullary lamina; it's a thin nucleus forming the most lateral part of the nucleus

Front 76

What are the intralaminar nuclei?

Back 76

a group of cells enclosed by the internal medullary lamina which splits at other locations within the thalamus

Front 77

What are the largest of the intralaminar nuclei?

Back 77

centromedia and parafascicular nuclei

Front 78

What is the centromedian nucleus?

Back 78

a large, rounded nucleus located medial to the VPL/VPM complex; in which the VPM conforms to the rounded shape of the CM (CM is dense collection of cell bodies that cannot be condensed any further)

Front 79

What is the parafascicular nucleus?

Back 79

located medial to the centromedian nucleus and has the habenulointerpeduncular tract pass through it

Front 80

What is the second curved sheet of myelinated fibers that covers the lateral surface of the thalamus?

Back 80

external medullary lamina

Front 81

What is the thalamic reticular nucleus?

Back 81

thin shell of cell that intervenes between the external medullary lamina and the internal capsule

Front 82

What is the midline nuclei?

Back 82

a rostral continuation of the parts of the periaqueductal gray matter and covers portions of the medial surface of the thalamus

Front 83

Where is the midline nuclei located?

Back 83

ventricular surface of the thalamus at the third ventricle

Front 84

What is the posterior thalamus?

Back 84

area that underlies the rostral part of the cerebral peduncles and the level includes part of the cerebral hemispheres; the corpus callosum; the lateral ventricles; and the caudate and lentiform nuclei

Front 85

All thalamic nuclei are a mixture of projection neurons (except the reticular nuclei) whose axons provide what?

Back 85

output from the thalamus and small inhibitory interneurons that use GABA as the neurotransmitter

Front 86

What percentage fo projection neurons account for in most thalamic nuclei?

Back 86

75%

Front 87

What are the two types of inputs into the thalamus?

Back 87

specific and regulatory

Front 88

What are specific inputs?

Back 88

neurons that convey information to a given thalamic nucleus may pass on the cerebral cortex and also to additional sites.

Front 89

What are two tracts that are examples of specific inputs?

Back 89

medial lemniscus to VPL; optic tract to lateral geniculate nucleus

Front 90

What are regulatory inputs?

Back 90

neurons that contribute to decisions about whether and in what form information leaves the thalamic nucleus

Front 91

Where do most regulator inputs come from?

Back 91

cortical area to which a given thalamic nucleus projects; thalamic reticular nucleus; diffure cholinergic, noradrenergic, and serotonergic endings from the brainstem reticular formation

Front 92

Which input exists in the greatest number in thalamic nuclei?

Back 92

regulatory inputs

Front 93

What is an example of a projection input?

Back 93

The lateral geniculate nucleus is a good example of this. 10% of the synapses on projection neurons come from optic tract fibers and half or more come from the visual cortex (projection inputs)

Front 94

Distinctive patterns of outputs and specific inputs allow thalamic nuclei to be grouped into what 3 categories?

Back 94

relay nuclei, assoication nuclei, intralaminar and midline nuclei

Front 95

What are relay nuclei?

Back 95

receive a well defined bundle of specific input fibers and project to the particular area of the cerbral cortex; role is to deliver information from particular functional system to appropriate cortical areas

Front 96

What are association nuclei?

Back 96

project to areas defined as association areas of the cortex but they have characterized patterns of inputs as well; they receive major contingents of specific inputs from the cerebral cortex itself and some from a variety of subcortical structures; thought to be important in distributino and gating of informaiton between cortical areas

Front 97

What are the roles of intralminar and midline nuclei?

Back 97

involved in the function of basal ganglia and limbic systems; their specific inputs come from a wide array of sites prominently from the basal ganglia and the limbic system; they project not only areas of the cerebral cortex but even more prominently to parts of the basal ganglia and limbic systems

Front 98

What are the two physiological states of projection neurons?

Back 98

tonic mode and burst mode

Front 99

What determines the functional mode of a thalamic projection neuron at any given moment?

Back 99

its regulatory inputs

Front 100

What is the mode of projection neurons during sleep?

Back 100

during sleep projection neurons are in the burst mode dominated by rhythmic waves of depolarization and are effectively unable to transmit information about their specific inputs.

Front 101

What are the two areas of association in the cortex of in the human brain?

Back 101

prefrontal cortex; parietal occipital temporal association cortex (which occupies the area surrounded by the primary somatosensory, visual, and auditory cortices) - each of these areas have a specific nuclei or nuclear complex associated with it

Front 102

What is the interconnection with the prefrontal cortex and is involved in prefrontal functions such as affect and foresight?

Back 102

dorsomedial nucleus

Front 103

What are the results of bilateral damage to the dorsomedial nucleus or conections to the forebrain?

Back 103

lose ability to have projected thought or advanced thoughts

Front 104

Major inputs from the dorsal medial nucleus also come from various elements of what system?

Back 104

limbic system (amygdala)

Front 105

The parietal occipital temporal association cortex involves what?

Back 105

pulvinar/lateral posterior complex of interconnection with the parietal, occipital, and temportal lobes.

Front 106

What is the major inputs to the parietal occipital temporal association cortex?

Back 106

visual system

Front 107

Which thalamic nucleus has no projection to the cerebral cortex?

Back 107

thalamic reticular nucleus

Front 108

What are the reticular nuclei?

Back 108

a sheet of neurons that receive inputs from the cortex and from thalamic projection neurons and send inhibitory (GABA) projections back to he thalamus. It also receives input from fibers near giving off collaterals such as the VPL/ VPM nuclei complex.

Front 109

What is the internal capsule?

Back 109

a compact bundle of fibers in the cleft between the lenticular nucleus (laterally) and the thalamus and the head of the caudate nucleus medial

Front 110

What travels through the internal capsule?

Back 110

almost all neural traffic to and from the cerebral cortex

Front 111

What are the 5 parts of the internal capsule?

Back 111

anterior limb, posterior limb, genu, retrolenticular part, sublenticular part

Front 112

Where is stroke usually in the internal capsule?

Back 112

posterior limb

Front 113

What does the anterior limb of the internal capsule contain?

Back 113

contains the fibers interconnecting that anterior nucleus and the cingulate gyrus and most of those interconnecting the dorsomedial nucleus and prefrontal cortex. Also included in this are the fibers (some) from the frontal lobe to the ipsilateral pontine nuclei (frontopontine fibers)

Front 114

What does the posterior limb of the internal capsule contain?

Back 114

contains fibers interconnecting the VA and VL with the motor and premotor cortex. It also contains corticospinal and corticobulbar fibers and somatosensory fibers projecting from the VPL /VPM to the post central gyrus.

Front 115

What does the genu of the internal capsule contain?

Back 115

a transitional zone between the anterior and posterior limbs and contains some frontopontine fibers and many of the interconnecting VA and VL fiber with the motor and premotor cortex. Corticobulbar fibers to motor nuclei of cranial nerves are also located anterior to the corticospinal fibers in the genu.

Front 116

What does the retrolenticular part of the internal capsule contain?

Back 116

contains most of the fibers interconnecting the thalamus with the posterior portions of the cerebral hemispheres. This includes fibers in both directions to the parietal occipital temporal association complex and the pulvinar / LP complex. There is also a optic radiation which is a large collection of visual system fibers projection from the lateral geniculate nucleus to the calcarine sulcus

Front 117

What does the sublenticular part of the internal capsule contain?

Back 117

continuous with the retrolenticular part and contains the remainders of the optic radiation. This part also contains the auditory radiation whose fibers pass laterally from the medial geniculate nucleus under the lenticular nucleus and lateral sulcus and then turn superiorly to end in the transverse temporal gyri.