Diencephalon

Question 1

The ______________ is the largest portion of the diencephalon. It is a complex group of nuclei interposed between the _________ and lower centers of the ______________.

Answer 1

thalamus

cortex

brain stem

Question 2

The thalamus receives ______________________ information from sensory pathways, processes this information and relays it to the ____________. It is also intimately associated with the motor systems - in particular with the _______________________________.

Answer 2

ascending sensory

cortex

basal ganglia, cerebellum and motor cortex

Question 3

Is the thalamus a part of the reticular activating system?

Answer 3

yes

Question 4

The brain has two thalami which are egg shaped nuclear masses, one on each side of the _____________________. They function with respect to reciprocal connections with the ________________ cortex.

Answer 4

third ventricle

ipsilateral

Question 5

What are the two gross subdivisions of the thalamus?

Answer 5

A. Fiber layers

B. Nuclear subdivisions

Question 6

What are the 6 nuclear subdivisions of the thalamus (part of the gross subdivisions of the thalamus)?

Answer 6

1. anterior group
2. medial group
3. lateral group
4. metathalamic group
5. intralaminar group
6. reticular coat

Question 7

The anterior group nuclear subdivision =

Answer 7

related to the limbic system

Question 8

The media group nuclear subdivision =

Answer 8

related to a number of systems, but the primary access to prefrontal cortex

Question 9

The lateral group nuclear subdivision =

Answer 9

relay nuclei for somatosensory and motor cortical areas

Question 10

The metathalamic group nuclear subdivision =

Answer 10

Lateral and Medial Geniculate nuclei

Question 11

The intralaminar group nuclear subdivision =

Answer 11

Centromedian nucleus that is related to the reticular formation

Question 12

The reticular coat nuclear subdivision =

Answer 12

outer most shell of the thalamus (not a part of the reticular formation)

Question 13

What are the 6 SPECIFIC nuclear groups?

Answer 13

1. Anterior thalamic group
2. Medial group
3. Lateral group
4. Metathalamus
5. Intralaminar
6. Thalamic reticular coat

Question 14

Describe the anterior thalamic group SPECIAL nuclear group:

Answer 14

limbic

Question 15

Describe the media group SPECIAL nuclear group:

Answer 15

• limbic, association cortex, basal ganglia

* Dorsomedial nuc. - major one

Question 16

Describe the lateral group SPECIAL nuclear group:

Answer 16

•Lateral group - divided into dorsal and ventral tier

• • Dorsal tier - pulvinar
• • Ventral tier - VPM, VPL, VL,VA (nuclei relaying sensory and motor information)

Question 17

Describe the metathalamus SPECIAL nuclear group:

Answer 17

Lateral and medial geniculate nuclei

Question 18

Describe the intralaminar SPECIAL nuclear group:

Answer 18

associated with reticular formation, almost everything else; Centromedian nucleus

Question 19

Describe the thalamic reticular coat SPECIAL nuclear group:

Answer 19

not reticular formation, acts in gating efferent thalamic information

Question 20

What are the subcortical afferents to thalamic nuclei? (We have already done a lot of these)

Answer 20

• sensory pathways
• basal ganglia
• cerebellum
• reticular formation

Question 21

Name the 4 functions of the thalamic nuclei:

Answer 21

1. Gated relay for transmission of all sensations (except olfaction) for conscious perception
2. Chief integrating center of all sensory information
3. Plays dominant role in maintenance and regulation of the state of consciousness, alertness and attention = Awareness; area of affect-deals with emotion, pain, agreeableness; highly subjective
4. Integrative center for motor activity - basal ganglia and cerebellum

Question 22

The cortical relay nuclei receive:

Answer 22

highly ordered SENSORY and MOTOR information and then relay it in an accurate manner (maintaining topographic, tonotopic, visuotopic organization) to specific sensory and motor cortices, i.e. VPM, VPL, VA, VL, LGN, MGN

Question 23

Association nuclei receive:

Answer 23

little or no direct afferents from sensory/motor pathways, but have extensive interthalamic connections and receive afferents from other subcortical nuclei (limbic, etc.). These project back to association cortices (mostly frontal, parietal and temporal lobes); includes pulvinar, dorsomedial

Question 24

Nonsepcefic nuclei; intralaminar nuclei (CM) associated with ___________________________________________. Reticular thalamic nucleus functions as an ______________________________________.

Answer 24

behavioral arousal and sensory/motor integration, sleep.

inhibitory feedback regulator of thalamic neuronal activity-gating of sensory information.

Question 25

Thalamic pain syndrome - usually ____________ in origin; thalamogeniculate artery (by loss of connections at the thalamic level or cortical level, pain sensations cannot be interpreted accurately.) The ability to discriminate between an ____________________ vs. a painful one becomes blurred.

Answer 25

vascular irritating stimulus

Question 26

In thalamic pain syndrome, studies on the pathways and sensitization of the central pathways reveal a very broad scope of regions involved in the “increased” perception of pain. This can be as a result of either:

Answer 26

irritative stimuli such as an intervertebral disc or radiculopathy to more centrally mediated changes to circuitry as a result of stroke, TBI, SCI.

Question 27

In thalamic pain syndrome, central sensitization of pain has shown __________________________________________. This heightened response begins at _____________________________________________________.

Answer 27

heightened cortical responses in the thalamus, cingulated gyrus (limbic or emotion), parietal lobe and prefrontal cortex. the synapse in the dorsal horn and can involve more than just the transfer of noxious sensations to ultimately affect non-noxious stimuli such as touch. Clinically this is seen as hyperalgesia or allodynia.

Question 28

In thalamic pathologies, changes in stimulus thresholds:

Answer 28

1. elevated for tactile and position sense | 2. lowered for nociorecptive stimuli

Question 29

In thalamic pathologies, at threshold, sensations are exaggerated, exceptionally unpleasant =

Answer 29

1. pin prick leads to severe burning pain | 2. muscle leads to unpleasant responses

Question 30

In thalamic pathologies, _______________ pain is experienced.

Answer 30

spontaneuos

Question 31

In thalamic pathologies, emotional instability =

Answer 31

inappropriate laughing or crying; altered gating of emotion to cortex

Question 32

In thalamic pathologies, pseudobulbar affect =

Answer 32

stroke patients with brainstem and thalamic lesions

Question 33

The hypothalamus is responsible for:

Answer 33

homeostatic influences necessary for life; i.e., cardiorespiratory, thermoregulation, metabolic, water resorption, digestive activity.

Question 34

Activites, by the hypothalamus, are manifested by ____________________________________________________________________________. This area acts in a reflexive manner receiving _________________________________.

Answer 34

control or influence over the pituitary gland, autonomic nervous system at the level of the brainstem and the spinal cord. afferent visceral information.

Question 35

It is also influenced by higher centers, primarily _________________________________.

Answer 35

limbic system and prefrontal cortex.

Question 36

The limbic system, responsible for _____________________________, influences the hypothalamus and thus the autonomic nervous system effecting cardiovascular, respiratory and emotional reactions to ___________________________________________.

Answer 36

emotion, moods and motivation, ongoing situations; embarrassment, fear, anxiety.

Question 37

List 3 autonomic control areas of the hypothalamus:

Answer 37

1. anterior hypothalamus 2. lateral hypothalamus 3. ventromedial hypothalamus

Question 38

What is the anterior hypothalamus related to?

Answer 38

related to septal region of limbic system

Question 39

What are the autonomic control areas of the hypothalamus looked as?

Answer 39

"upper motor neurons" of the ANS