prosencephalon (forebrain)- diencephalon Flashcards

1
Q

what is the general function for the diencephalon?

A
  • most significant relay center for sensory input to the cerebrum (all sensation except olfaction)
  • autonomic and endocrine fx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

where is the epithalamus located?

A

superior to the midbrain tectum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what structures are in the epithalamus?

A

pineal gland and posterior commissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is another name for the pineal gland?

A

epiphysis cerebri

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is the pineal gland filled with?

A

highly modified neurons called pineal or epiphyseal cells, fenestrated vascular capillary beds and glial support cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does the pineal gland excrete?

A

fenestrated capillaries- secrete melatonin, serotonin and norepinephrine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

the pineal gland is not sensitive to light directly but through a pathway originating in the?

A

retina and synapsing in the hypothalamus (suprachiasmatic nucleus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how many people are affected by SAD?

A

1 in 20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a small but identifiable commissure just superior to the midbrain tectum?

A

posterior commissure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are located in the posterior commissure?

A

pupillary light reflex fibers and nuclei

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a small structure just anterior and inferior to the posterior commissure?

A

subcommissural organ- may produce aldosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the largest of all nuclei of the CNS?

A

thalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the metathalamus?

A

lateral and medial geniculate bodies included with the thalamus but classified separately

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where is the thalamus located?

A

thalamus means couch- looks like it is sitting; forms the bulk of the side walls of the 3rd ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the thalamus composed of?

A

2 large ovoid masses of gray matter joined together by a bridge of gray substance called the MASSA INTERMEDIA or INTERTHALAMIC ADHESION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

lateral to each thalamic mass is the?

A

posterior limb of the internal capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are 3 general functions of the thalamus?

A
  • all sensory but olfaction is integrated here
  • focus the attention of the cerebral cortex
  • some pain and temp sensations; higher relay is needed for complete integration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the structure of myelinated fibers that runs through the substance of each thalamic mass and helps divide them into subdivisions?

A

internal medullary lamina

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

the thalamus is divided into equal right and left thalamic masses held together by?

A

the massa intermedia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the largest part of the thalamus and only found in highest of primates?

A

pulvinar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

where is the hypothalamus located?

A

forms the floor of the 3rd ventricle ventricle and portions of the lateral walls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

the hypothalamus includes as part of its structure the _____ and _____

A

infundibular stalk and optic chiasm NOT pituitary

23
Q

what are the zones and areas of the hypothalamus?

A

medial and lateral zones and anterior, intermediate and posterior areas

24
Q

what are the basic functions of the hypothalamus?

A
  • hunger, thirst and sex
  • physical aspects of emotional expression
  • central control over visceral functions
25
Q

what is the parasympathetic control of the hypothalamus?

A

increase digestive motility
decrease heart rate
constrict pupils

26
Q

what is the sympathetic control of the hypothalamus?

A

increase heart rate and vasoconstriction
decrease digestive motility
pupil dilation, piloerection and sweat secretions

27
Q

what is the endocrine control of the hypothalamus?

A

directly- neuron axon extensions into POSTERIOR pituitary

indirectly- neurohormones to control release of ANTERIOR pituitary HORMONES

28
Q

the anterior area of the hypothalamus just above the optic chiasma include which nuclei? (5)

A

supraoptic and paraventricular
suprachiasmatic
anterior
pre optic area nucleus

29
Q

supraoptic and paraventricular nuclei send axons down through the infundibular stalk via what?

A

hypothalamohypophyseal or supra-opticohypophyseal tract and terminate in the posterior pituitary

30
Q

what do the supraoptic and paraventricular nuclei release?

A

oxytocin and ADH

31
Q

what is the suprachiasmatic nuclei responsible for?

A

circadian rhythms such as temperature, sleep, light, feeding etc- connected to pineal gland and secretions to bloodstream

32
Q

what is the anterior nucleus of the hypothalamus known for?

A

primarily parasympathetic functions

33
Q

what is the pre optic area of the hypo responsible for?

A

a thermo-regulator; especially as body heats up

34
Q

what are the nuclei of the intermediate area of the hypothalamus? (4)

A

dorsomedial
ventromedial
arcuate
tuber cinereum

35
Q

what is the dorsomedial nucleus responsible for?

A

significant GI tract parasympathetic influence

36
Q

what is the ventromedial nucleus responsible for?

A

satiety center- eating and thirst gratification

37
Q

what do the arcuate nuclei contribute axons to?

A

tuberoinfundibular tract- terminate and secrete neurohormones into perivascular spaces of infundibular stalk; then pass to anterior pituitary where they influence release of pituitary hormones; “releasing factors”

38
Q

what is a term used to describe the undulating bulge between the infundibular stalk and large mammillary bodies?

A

tuber cinereum- several of nuclei including arcades create this “gray swelling” or tuber cinereum

39
Q

what are the nuclei included in the posterior area of the hypothalamus?

A

mammillary bodies

posterior nuclei

40
Q

mammillary bodies are important for?

A

short term memory- korsakovs syndrome- alcohol

41
Q

posterior nuclei of posterior hypothalamus are responsible for?

A

thermoregulation- body cools down, shivering

42
Q

the posterior area of the hypothalamus is known for diverse ______?

A

sympathetic actions

43
Q

which area gives rise to the anterior pituitary and intermediate pituitary?

A

rathke’s pouch (oropharyngeal membrane)

44
Q

the posterior pituitary develops from the _____ embryologically?

A

diencephalon

45
Q

describe the differences between the posterior and anterior pituitary travel?

A

posterior- mere extension of brain and neurons run directly into its substance
anterior- receives its hypothalamic influence via bloodstream

46
Q

where does most blood to the pituitary and infundibular stalk come from?

A

branches off the internal carotid arteries

47
Q

within the infundibular stalk the small arteries break into highly permeable capillaries called

A

fenestrated sinusoids- these pick up “releasing factors” from tuberoinfundibular tract fibers

48
Q

once releasing factors enter the substance of the anterior pituitary they exert control on the release of what?

A

pituitary hormones

49
Q

which veins are porting blood between 2 capillary beds of the anterior pituitary?

A

hypophyseal portal veins

50
Q

where is the subthalamus located?

A

just under the lateral ventral aspect of the thalamus

51
Q

what nuclei are present in the subthalamus?

A

parvocellular region of the red nucleus
superior portion of substantia nigra
subthalamic nuclei

52
Q

what is the function of the subthalamic nuclei?

A

part of the extrapyramidal system and sends and receives fibers to and from the globus pallid us of the telencephalon

53
Q

what do lesions in the sub thalamus present as?

A

dramatic forceful flinging movements of shoulders or hips- ballism or hemiballism