diencephalon

Question 1

where is thalamus located?

Answer 1

lies in floor of central portion of lateral ventricles and forms superior part of lateral wall of 3rd ventricle

Question 2

what is the thalamus?

Answer 2

a collection of nuceli and asssociated laminae

Question 3

interthalamic adhesion

Answer 3

connect 2 thalami in 70% of population, transverses 3rd ventricle

Question 4

what covers lateral surface of thalamus?

Answer 4

thin sheet of fibers called external medullary lamina

Question 5

how is ependymal lining of 3rd ventricle reflected?

Answer 5

from one side to the other along the stria medullaris thalami to form roof of 3rd ventricle

Question 6

what divides thalamus internally into vertical sheet of white matter?

Answer 6

internal medullay lamina

Question 7

functions of thalamus

Answer 7

receives info about sensation, vision, and hearing. mediates motor info from cerebellum and basal ganglia to motor cortex. involved in autonomic maintenance of consciousness

Question 8

nuclear groups?

Answer 8

anterior, medial, ventrolateral, reticular, intralaminar, midline

Question 9

what does ventrolateral nuclear group include?

Answer 9

lateral and ventral nuclei, pulvinar, and medial and lateral geniculate bodies

Question 10

anterior nucelus structure

Answer 10

forms anterior tubercle which is posterior boundary of interventricular foramen of Monroe

Question 11

anterior nucelus function

Answer 11

receives limbic system info from mammillary bodies via mammillothalamic tract and projects to cingulate gyrus and frontal cortex

Question 12

two main functions of anterior nucleus?

Answer 12

memory and emotions

Question 13

what is Korsakoff’s psychosis (syndrome)?

Answer 13

metabolic disturbance caused by severe chronic alcoholism causing lesions around 3rd ventricle, esp medial and anterior thalamic nuclei, mamm bodies and/or connections b/ween them

Question 14

what does Korsakoff’s psychosis cause?

Answer 14

short term memory loss which patients attempts to compensate for by confabulating

Question 15

confabulating

Answer 15

inserting remote past memories into fluent by blatantly untrue stories

Question 16

medial group of nuceli function?

Answer 16

receive info from basal ganglia, the amygdala, the midbrain and some spinothalamic fibers (emotional response to pain). memory and behavior.

Question 17

ablation to medial group of nuceli causes what?

Answer 17

symptoms that parallel those of prefontal lobotomy

Question 18

where do medial nuceli project to?

Answer 18

prefrontal lobe

Question 19

ventral anterior and ventral lateral receive info from?

Answer 19

basal ganglia and dentate nucelus

Question 20

where do ventral anterior and ventral lateral project to?

Answer 20

motor and premotor cortices

Question 21

what do ventral anterior and ventral lateral function in?

Answer 21

motor integration and maintenance of consciousness

Question 22

what happens when ventral anterior and ventral lateral are stimulated?

Answer 22

an increase in Parkinsonian rigidity and tremor

Question 23

what does ablation to ventral anterior and ventral lateral result in?

Answer 23

amelioration of Parkinsonian symptoms

Question 24

ventral posterior nucelus function?

Answer 24

all sensation except olfaction reaches consciounessness here, integrated and sent to sensory cortex

Question 25

ventral posterior medial nucelus?

Answer 25

all sensory info from head and face reaches consciousness and integrated

Question 26

ventral posterior lateral nucleus?

Answer 26

all sensory info form body reaches consciousness and is integrated

Question 27

what happens if ventral posterior nucelus is lesioned?

Answer 27

anesthesia (loss of sensation) or thalamic syndrome (hypersensitivity)

Question 28

medial geniculate body receives info from?

Answer 28

inferior brachium

Question 29

where does medial geniculate body project to?

Answer 29

auditory cortex via auditory radiation

Question 30

what happens if medial geniculate body is lesioned?

Answer 30

diminished hearing more pronounced contralaterally

Question 31

lateral geniculate body receieves info from and projects to where?

Answer 31

receives from optic tract and projects to visual cortex via option radiation

Question 32

what happens if lateral geniculate body is lesioned?

Answer 32

visual loss (contralateral homonymous hemianopsia)

Question 33

lateral dorsal nucelus?

Answer 33

reciprocal connections with limbic system areas, functions in emotional expression

Question 34

lateral posterior nucelus

Answer 34

reciprocal connections with sensory association cortex of parietal lobe and functions in integration of sensory info

Question 35

pulivar receieves from where and projects to where?

Answer 35

from retina and superior colliculus and projects to parietal, occipital, and temporal lobes.

Question 36

what does pulvinar function in?

Answer 36

visual reflexes and eye movement

Question 37

reticular nucelus?

Answer 37

reciprocal connections with thalamus and cortex and functions in modulaton of thalamic activity

Question 38

intralaminar nuceli

Answer 38

centromedian nucelus that functions as part of limbic system in maintaining consciousness and alertness and in integrating emotional responses to pain

Question 39

midline nuceli function in doing what?

Answer 39

form most of interthalamic adhesion

Question 40

hypothalamus?

Answer 40

part of limbic system, controls autonomic responses. anterior, intermediate, and posterior zone. forms inferior part of lateral wall and flood of 3rd ventricle

Question 41

where are mammillary bodies located?

Answer 41

hypothalamus

Question 42

endocrine function of hypothalamus?

Answer 42

form and release inhibiting factors that promote production and secretion of hormones by cells of anterior pituitary

Question 43

neurosecretion function of hypothalamus?

Answer 43

via hypothalamohypohysial tract of oxytocin by paraventricular nucelus. ADH by supraoptic nucleus

Question 44

lesion to supraoptic nucelus results in what?

Answer 44

diabetes insipidus resulting in polydipsia and polyuria

Question 45

functions of hypothalamus?

Answer 45

Endocrine control Nuerosecretion General autonomic effects Temperature Regulation Blood pressure & osmollarity control Sexual behavior and reproduction Biological clocks Emotion, Aversion, Pleasure, Reward

Question 46

anterior zone temp regulation hypothalamus?

Answer 46

cutaneous vasodilation and sweating

Question 47

posterior zone temp regulation hypothalamus?

Answer 47

cutaneous vasoconstriction and shivering

Question 48

lesion to glucose sensitive satiety centre?

Answer 48

hyperphagia

Question 49

lesion to hunger and thirst centre?

Answer 49

hypoaphagia

Question 50

how does hypothalamus control sexual behavior and reproduction?

Answer 50

by controlling gonadotrophin production by anterior pituitary

Question 51

what nucelus is involved in circadian rhythm?

Answer 51

suprachiasmatic nucelus

Question 52

what is the subthalamus?

Answer 52

transition zone between midbrain and thalamus. contains subthalamic nucleus.

Question 53

what happens if you lesion the subthalamus?

Answer 53

hemiballismus (uncontrollable, violent torsional movements)

Question 54

what is epithalamus composed of?

Answer 54

habenula, stria medullaris thalami, pineal gland, posterior commissure, and habenular commissure

Question 55

what does habenula function in?

Answer 55

olfactory reflexes (limbic)

Question 56

stria medullaris thalami function?

Answer 56

connect septal area to habenula

Question 57

posterior commissure does what in epithalamus?

Answer 57

connects two superior colliculi and functions in visual reflexes

Question 58

pineal gland function?

Answer 58

secrete antigonadotropin which inhibits the gonadotropin of anterior pitutary, and melatonin is involved in circadian

Question 59

pineal growth results in what?

Answer 59

delayed puberty

Question 60

pineal destruction results in what?

Answer 60

precocious puberty.