prosencephalon (forebrain)- diencephalon

Question 1

what is the general function for the diencephalon?

Answer 1

• most significant relay center for sensory input to the cerebrum (all sensation except olfaction)
• autonomic and endocrine fx

Question 2

where is the epithalamus located?

Answer 2

superior to the midbrain tectum

Question 3

what structures are in the epithalamus?

Answer 3

pineal gland and posterior commissure

Question 4

what is another name for the pineal gland?

Answer 4

epiphysis cerebri

Question 5

what is the pineal gland filled with?

Answer 5

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

Question 6

what does the pineal gland excrete?

Answer 6

fenestrated capillaries- secrete melatonin, serotonin and norepinephrine

Question 7

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

Answer 7

retina and synapsing in the hypothalamus (suprachiasmatic nucleus)

Question 8

how many people are affected by SAD?

Answer 8

1 in 20

Question 9

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

Answer 9

posterior commissure

Question 10

what are located in the posterior commissure?

Answer 10

pupillary light reflex fibers and nuclei

Question 11

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

Answer 11

subcommissural organ- may produce aldosterone

Question 12

what is the largest of all nuclei of the CNS?

Answer 12

thalamus

Question 13

what is the metathalamus?

Answer 13

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

Question 14

where is the thalamus located?

Answer 14

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

Question 15

what is the thalamus composed of?

Answer 15

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

Question 16

lateral to each thalamic mass is the?

Answer 16

posterior limb of the internal capsule

Question 17

what are 3 general functions of the thalamus?

Answer 17

• 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

Question 18

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

Answer 18

internal medullary lamina

Question 19

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

Answer 19

the massa intermedia

Question 20

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

Answer 20

pulvinar

Question 21

where is the hypothalamus located?

Answer 21

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

Question 22

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

Answer 22

infundibular stalk and optic chiasm NOT pituitary

Question 23

what are the zones and areas of the hypothalamus?

Answer 23

medial and lateral zones and anterior, intermediate and posterior areas

Question 24

what are the basic functions of the hypothalamus?

Answer 24

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

Question 25

what is the parasympathetic control of the hypothalamus?

Answer 25

increase digestive motility decrease heart rate constrict pupils

Question 26

what is the sympathetic control of the hypothalamus?

Answer 26

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

Question 27

what is the endocrine control of the hypothalamus?

Answer 27

directly- neuron axon extensions into POSTERIOR pituitary | indirectly- neurohormones to control release of ANTERIOR pituitary HORMONES

Question 28

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

Answer 28

supraoptic and paraventricular suprachiasmatic anterior pre optic area nucleus

Question 29

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

Answer 29

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

Question 30

what do the supraoptic and paraventricular nuclei release?

Answer 30

oxytocin and ADH

Question 31

what is the suprachiasmatic nuclei responsible for?

Answer 31

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

Question 32

what is the anterior nucleus of the hypothalamus known for?

Answer 32

primarily parasympathetic functions

Question 33

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

Answer 33

a thermo-regulator; especially as body heats up

Question 34

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

Answer 34

dorsomedial ventromedial arcuate tuber cinereum

Question 35

what is the dorsomedial nucleus responsible for?

Answer 35

significant GI tract parasympathetic influence

Question 36

what is the ventromedial nucleus responsible for?

Answer 36

satiety center- eating and thirst gratification

Question 37

what do the arcuate nuclei contribute axons to?

Answer 37

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"

Question 38

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

Answer 38

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

Question 39

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

Answer 39

mammillary bodies | posterior nuclei

Question 40

mammillary bodies are important for?

Answer 40

short term memory- korsakovs syndrome- alcohol

Question 41

posterior nuclei of posterior hypothalamus are responsible for?

Answer 41

thermoregulation- body cools down, shivering

Question 42

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

Answer 42

sympathetic actions

Question 43

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

Answer 43

rathke's pouch (oropharyngeal membrane)

Question 44

the posterior pituitary develops from the _____ embryologically?

Answer 44

diencephalon

Question 45

describe the differences between the posterior and anterior pituitary travel?

Answer 45

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

Question 46

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

Answer 46

branches off the internal carotid arteries

Question 47

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

Answer 47

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

Question 48

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

Answer 48

pituitary hormones

Question 49

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

Answer 49

hypophyseal portal veins

Question 50

where is the subthalamus located?

Answer 50

just under the lateral ventral aspect of the thalamus

Question 51

what nuclei are present in the subthalamus?

Answer 51

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

Question 52

what is the function of the subthalamic nuclei?

Answer 52

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

Question 53

what do lesions in the sub thalamus present as?

Answer 53

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