B7.061 Thalamus and Hypothalamus

Question 1

function of the thalamus

Answer 1

last synaptic relay station in ascending pathways before they reach the cerebral cortex
“gateway to the cerebral cortex”
contains specific and diffuse projection nuclei

Question 2

how are the thalamus and cortex connected

Answer 2

reciprocally

Question 3

embryonic origin of thalamus

Answer 3

diencephalon (along w hypothalamus)

Question 4

function of internal medullary lamina

Answer 4

fiber bundle that divides the thalamus into 3 regions
1. medial
2. lateral
3. anterior
also contains intralaminar nuclei

Question 5

lateral nuclear group

Answer 5

ventral anterior
lateral dorsal
ventral lateral
lateral posterior
ventral posterior lateral 
ventral posterior medial
lateral geniculate
medial geniculate
pulvinar

Question 6

how do thalamic nuclei receive input

Answer 6

from specific subcortical regions

Question 7

input to anterior nucleus

Answer 7

mammillothalamic tract

fornix

Question 8

input to ventral anterior

Answer 8

motor nuclei:
substantia nigra pars reticulata
internal globus pallidus
deep cerebellar nuclei

Question 9

input to ventral lateral

Answer 9

motor nuclei:
internal globus pallidus
deep cerebellar nuclei
substantia nigra pars reticulata

Question 10

input to ventral posterior lateral

Answer 10

somatic sensation of body:
medial lemniscus
spinothalamic

Question 11

input to ventral posterior medial

Answer 11

somatic sensory of face:
trigeminal lemniscus
trigeminothalamic tract
gustatory input

Question 12

input to lateral geniculate

Answer 12

optic tract

Question 13

input to medial geniculate

Answer 13

inferior colliculus

Question 14

input to pulvinar

Answer 14

multisensory:
superior colliculus
tectum (extrageniculate visual pathways)
other sensory inputs

Question 15

input to intralaminar nuclei

Answer 15

internal globus pallidus
brainstem reticular formation
sensory pathways

Question 16

input to medial group

Answer 16

amygdala
olfactory cortex
basal ganglia

Question 17

output of anterior nucleus

Answer 17

cingulate gyrus (Papez circuit)

Question 18

output of ventral anterior

Answer 18

frontal cortex

Question 19

output of ventral lateral

Answer 19

motor and premotor cortex

Question 20

output of ventral posterior lateral

Answer 20

somatosensory cortex

Question 21

output of ventral posterior medial

Answer 21

somatosensory cortex

Question 22

output of lateral dorsal

Answer 22

cingulate gyrus (Papez circuit)

Question 23

output of medial group

Answer 23

prefrontal cortex

Question 24

output of intralaminar nuclei

Answer 24

widespread cortical region

Question 25

output of pulvinar

Answer 25

parieto-occipital cortex

Question 26

output of medial geniculate

Answer 26

auditory cortex

Question 27

output of lateral genicular

Answer 27

visual cortex

Question 28

function of ventral posterior lateral

Answer 28

relays somatosensory spinal inputs to cortex

Question 29

function of ventral posterior medial

Answer 29

relays somatosensory cranial nerve inputs and taste to cortex

Question 30

function of lateral geniculate

Answer 30

relays visual inputs to cortex

Question 31

function of medial geniculate nucleus

Answer 31

relays auditory inputs to cortex

Question 32

function of ventral lateral nucleus

Answer 32

relays basal ganglia and cerebellar inputs to cortex major motor relay nucleus between the cerebellum and primary motor cortex thalamic portion of cerebellar feed forward system for smoothing out movements

Question 33

function of ventral anterior nucleus

Answer 33

relays basal ganglia and cerebellar inputs to cortex more widespread projections than ventral lateral receives input from the BG and projects widely to the frontal eye fields and premotor cortex in the frontal lobe

Question 34

which thalamic nuclei are part of limbic circuits

Answer 34

``` anterior nucleus mediodorsal nucleus (medial group) ```

Question 35

function of mediodorsal nucleus

Answer 35

limbic pathways | major relay to frontal cortex

Question 36

function of anterior nucleus

Answer 36

limbic pathways

Question 37

function of pulvinar

Answer 37

behavioral orientation to relevant visual and other stimuli

Question 38

function of intralaminar nuclei

Answer 38

maintain alert consciousness | motor relay for basal ganglia and cerebellum

Question 39

where is the reticular nucleus

Answer 39

anterior area

Question 40

input to reticular nucleus

Answer 40

cerebral cortex thalamic relay and intralaminar nuclei ARAS

Question 41

output of reticular nucleus

Answer 41

thalamic relay and intralaminar nuclei ARAS no cortical projections!! modulates other nuclei in the thalamus

Question 42

function of reticular nucleus

Answer 42

regulates state of other thalamic nuclei

Question 43

functions of hypothalamus

Answer 43

homeostasis endocrine autonomic limbic

Question 44

rostral to caudal components of the hypothalamus

Answer 44

preoptic area anterior (supraoptic) region middle (tuberal) region posterior (mammillary) region

Question 45

structure of the pituitary gland

Answer 45

anterior and posterior component | both components controlled by the hypothalamus separately

Question 46

neurohypophyseal system

Answer 46

direct control of posterior pituitary by hypothalamus neurons from supraoptic and paraventricular nuclei release oxytocin and vasopressin deep within the posterior pituitary

Question 47

tuberoinfundibular system

Answer 47

indirect control of anterior pituitary by hypothalamus | neurons of arcuate and periventricular nuclei release releasing factors that act on anterior pituitary cells

Question 48

why are there 2 lobes of the pituitary

Answer 48

distinct embryological origins Rathke's pouch > anterior infundibulum > posterior

Question 49

homeostatic functions of the hypothalamus

Answer 49

temperature regulation feeding behavior circadian rhythm thirst/ body fluid

Question 50

how is temperature information conveyed to hypothalamus

Answer 50

1. somatosensory system; temp sensitive afferents | 2. neurons in the anterior nucleus of the thalamus sense temp

Question 51

how is the body response to change in temperature coordinated

Answer 51

anterior nucleus of hypothalamus: response to warm | posterior nucleus of hypothalamus: response to cold

Question 52

change in body temp set point (fever)

Answer 52

hypothalamic neurons activated in the pre-optic area | activation of septum can reduce fever

Question 53

function of ventromedial hypothalamic nucleus

Answer 53

satiety stimulation reduces food intake lesions produce overeating and obesity

Question 54

function of lateral hypothalamic nuclei

Answer 54

feeding center stimulation produces eating lesions produce anorexia

Question 55

leptins

Answer 55

produced in adipose tissue | reduce appetite

Question 56

ghrelin

Answer 56

produced in gastric mucosa | stimulates appetite

Question 57

regulation of circadian rhythm

Answer 57

suprachiasmatic nucleus receives input from retinal ganglion cells containing melanopsin regulates core body temp, ACTH levels, slow wave sleep, and skin temp

Question 58

thirst/ body fluid regulation

Answer 58

ADH (vasopressin) release by supraoptic nucleus | anterior nucleus involved in coordinating drinking behavior

Question 59

autonomic functions of the hypothalamus

Answer 59

descending control of preganglionic parasympathetic and sympathetic neurons comes for the paraventricular nucleus of the hypothalamus

Question 60

functions of the limbic system

Answer 60

homeostasis olfaction memory emotions and drives