Neuroanatomy 17: Pituitary And Hypothalamus

Front 1

What is the anterior pituitary derived from?

Back 1

Rathkes pouch from roof of developing pharynx

Front 2

Where does the neurohypophysis come from?

Back 2

evagination from floor of 3rd ventricle

Front 3

What part of the 3rd ventricle does the hypothalamus form?

Back 3

inferior walls and floor

Front 4

The hypothalamic sulcus separates what?

Back 4

hypothalamus and thalamus

Front 5

Where does the tuber cinereum reside?

Back 5

bulge between optic chiasm and the mamillary bodies

Front 6

Where do the mamillary bodies reside in relation to the hypothalamus?

Back 6

posterior to it

Front 7

What does the infundibulum arise from?

Back 7

tuber cinereum and is the pituitary stalk

Front 8

Where does the median eminence arise from? What happens here?

Back 8

1) arises from anterior infundibulum
2) point where hypothalamus releases hormones to portal system

Front 9

What are the boundaries for the pituitary fossa? What is the other name?

Back 9

1) anterior clinoid process and posterior clinoid process and laterally by the cavernous sinus
2) sella turcica

Front 10

What sinus is immediately deep to the sella turcica?

Back 10

sphenoid sinus

Front 11

What covers the top of the pituitary fossa?

Back 11

dura called diaphragma sella

Front 12

What type of vision loss occurs with a pituitary tumor?

Back 12

bitemporal hemianopia

Front 13

What divides the hypothalamus into medial and lateral portions?

Back 13

fibers from the fornix that begin in the supraoptic nucleus and end in the mamillary body

Front 14

There is a diffuse group of fibers in the hypothalamus that interconnect areas of the hypothalamus and areas outside the hypothalamus. What are the fibers called?

Back 14

medial forebrain bundle runs rostral caudally

Front 15

What is the most medial nucleus in the thalamus that borders the 3rd ventricle?

Back 15

periventricular nucleus

Front 16

Where is the preoptic nucleus derived from?

Back 16

telencephelon

Front 17

What runs superior to the medial and lateral preoptic nuclei

Back 17

anterior commisure

Front 18

Which nuclei are most rostral in the hypothalamus?

Back 18

preoptic nucleus

Front 19

The supraoptic region is also called?

Back 19

anterior hypothalamic region

Front 20

Which nuclei are found in the anterior hypothalamic region?

Back 20

anterior hypothalamic nucleus, supraoptic nucleus, paraventricular nucleus, suprachiasmatic nucleus

Front 21

What is the function of the suprachiasmatic nucleus? Which region is the nucleus in?

Back 21

1) master clock regulating circadian rhythm by recieving info from retinal ganglion cells
2) anterior region

Front 22

What is the tuberal region also known as? Which nuclei compose it?

Back 22

1) middle region
2) arcuate nucleus, ventromedial nucleus, dorsomedial nucleus

Front 23

Which nucleus projects mainly to the median eminence? Which region is the nucleus in?

Back 23

1) arcuate nucleus
2) middle region

Front 24

What is the posterior hypothalamic region also called? What nuclei are found in this region

Back 24

1) mammilary region
2) medial mammillary nucleus, intermediate mammillary nucleus, posterior hypothalamic nucleus

Front 25

Which nuclei do descending autonomic fibers primarily originate from?

Back 25

1) primarily paraventricular nucleus, also dorsomedial nucleus

Front 26

Where do descending autonomic fibers synapse?

Back 26

1) preganglionic parasympathetic nuclei in brainstem
2) intermediate zone of sacral spinal cord
3) preganglionic sympathetic neurons in intermediolateral cell column of thoracolumbar spinal cord

Front 27

The subiculum is part of the hippocampal formation and projects to the hypothalamus via?

Back 27

the fornix

Front 28

What connects the anterior thalamic nucleus with the mammillary bodies? Where do the fibers go from the thalamic nucleus

Back 28

1) mammillothalamic tract
2) limbic cortex in cingulate gyrus

Front 29

How is the amygdala connected with the hypothalamus?

Back 29

via 2 tracts:
1) stria terminalis
2) ventral amygdalofugal pathway

Front 30

Some that is depressed may have a depressed immune system what pathway to the hypothalamus may mediate this? What other symptoms may occur via this pathway?

Back 30

1) limbic-hypothalamic pathway has effect on autonomics which may impact immune system function
2) emotional stimuli causing sweaty palms and stomach churning via autonomic stimulation

Front 31

How does the ventral lateral preoptic area contribute to nonREM sleep?

Back 31

It has GABAergic neurons that project to the tuberomamillary nucleus that inhibit histaminergic neurons

Front 32

A lesion to the lateral hypothalamus may cause what?

Back 32

weight loss because this area is important in appetite stimulation

Front 33

What is the function of the medial hypothalamus?

Back 33

appetite suppression, lesions can cause obesity

Front 34

Leptin is released from adipocytes to signal sateity where does this hormone go?

Back 34

binds Ob receptors in hypothalamus regulating food intake

Front 35

If someone has lesion to the lateral hypothalamus what symptom may they present with?

Back 35

dehydration, this controls water intake

Front 36

What function does the anterior hypothalamus have in terms of body temp?

Back 36

detects increased body temp and thus activates heat dissipating pathways

Front 37

bilateral lesions of the posterior hypothalamus are associated with what?

Back 37

poikilothermia in which body temp varies with environment because heat conservation is produced here

Front 38

Describe the flow of blood to and from the pituitary?

Back 38

internal carotid gives rise to the inferior and superior hypophysial arteries. The superior artery ends at the median eminance when it forms the primary capillary plexus. The hypophysial portal veins take the blood to the secondary capillary plexus. Veins leave this plexus and enter cavernous sinus. Both inferior and superior hyposphysial arteries go to posterior pituitary

Front 39

What nuclei project to the median eminence?

Back 39

1) primarily arcuate, then periventricular, medial preoptic, and paraventricular a little

Front 40

are most pituitary tumors benign or malignant?

Back 40

benign glandular tumors typically of anterior pituitary

Front 41

What is the mean age for presenting with pituitary adenoma?

Back 41

40

Front 42

Nonfunctioning pituitary adenomas typically cause what? how?

Back 42

headache from irritation of pain fibers in the cavernous sinus

Front 43

What is the most common pituitary tumor?

Back 43

prolactin secreting tumor followed by ACTH then GH

Front 44

What can be given to treat prolactinomas?

Back 44

bromocriptine and cabergoline

Front 45

What can be given to treat GH secreting tumor?

Back 45

octreotide

Front 46

What are general presenting symptoms of men and women with prolactinoma?

Back 46

1) amenorrhea
2) hypogonadism (men)
3) galactorrhea, infertility, hair loss, decreased libido, weight gain

Front 47

The dexamethasone suppression test is given at night. Why is only a small amount initially given? When a large does is given what happens?

Back 47

1) to try and suppress cortisol levels measured in urine the next morning.
2) suppresses pituitary tumors, but not ectopic ACTH tumors or adrenal tumors

Front 48

Besides dexamethasone what else can be given to determine where the tumor is?

Back 48

CRH can be given. it increases plasma ACTH and cortisol in pituitary tumors but not in ectopic tumors or adrenal tumors

Front 49

In petrosal sinus sampling ACTH is typically 2 to 3 times higher in one vein. When CRH is administered during this procedure ACTH rises. Which vein will have a larger increase in ACTH with CRH?

Back 49

The contralateral side to the tumor because it is being suppressed then all of the sudden it gets a huge stimulus to release a large amount of ACTH

Front 50

In primary hyperthyroidism are TSH levels high or low?

Back 50

low... primary is Graves, thyroiditis, thyroid adenomas

Front 51

myxedema coma occurs in what?

Back 51

hypothyroidism

Front 52

What are common manifestations of LH and FSH secreting tumors?

Back 52

hypogonadism and infertility with high or low estradiol and testosterone

Front 53

To treat SIADH hypertonic saline is given. What is an adverse reaction if given too rapidly?

Back 53

central pontine myelinolysis

Front 54

What is pituitary apoplexy? What are presenting symptoms?

Back 54

1) spontaneous hemorrhage
2) headache, meningeal signs, unilateral or bilateral cavernous sinus syndrome, vision loss, hypotension, depressed consciousness