Download Neuroanatomy 17 [3-6

Chapter 17
Learning Objectives
1.
Within what structure are hypothalamic regulating factors released into the portal system?
 Median eminence
2.
Where does the medial forebrain bundle run?
 Through the lateral hypothalamus
3. What is the embryologic origin of the preoptic area? Where is the rest of the hypothalamus
derived from?
 Telencephalon; POA is the most anterior nucleus
 Most of the hypothalamus is from the diencephalon
4.
Which nuclei produce oxytocin and vasopressin? Which nucleus is the master clock for circadian
rhythms?
 Preoptic area and paraventricular nuclei
 Suprachiasmatic nucleus
[right over the chiasm so it can get some light]
5.
What nuclei do do autonomic fibers originate from (although not all autonomics originate in the
hypothalamus)? What pathway do they follow?
 Primarily the paraventricular nucleus, but also dorsomedial nucleus and lateral & posterior
hypothalamus
[the most superior nuclei]
 Nuclei=> medial forebrain bundle=> dorsolateral brainstem=> periacqueductal grey=>
parasympathetic nuclei in brainstem & IML in spinal cord
6.
By what pathways do emotions influence autonomic pathways and the immune system (2)?
What rare hypothalamic tumor can cause gelastic epilepsy through this pathway?
 Amygdala <=> ventral amygdofugal pathway OR stria terminalis <=> hypothalamus
 Hypothalamic hamartoma
7.


Which hypothalamic lesion causes insomnia? Hypersomnia?
Anterior lesion=> insomnia
[Mr. Burns’ head nodding forward waking him up]
Posterior lesion=> sleepy time
8.
Which hypothalamic lesion causes anorexia? Hyperphagia?
 Medial lesion=> anorexia
[shrinking happens inward/medially]
 Lateral lesion=> Fatty McButterpants
9.
What lesion causes poikilothermia?
 Bilateral posterior hypothalamic lesions
10. What is the most common hormone secreted by pituitary adenomas? What are the clinical
signs of this type?
 Prolactin
 Amenorrhea in women, hypogonadism in men, weight gain, decreased libido, and
galactorrhea
11. How should you localize the lesion in Cushing syndrome when high-dose dexamethasone
suppresses cortisol?
 Pituitary sources of ACTH (Cushing disease) are usually suppressed by high dose, whereas
nonpituitary ectopic sources are usually not
12. What sign is noticeably absent when patients have a TSH-secreting adenoma instead of Grave’s
disease?
 There will be no exopthalmos when the cause is a TSH adenoma
i. It’s caused by the autoimmunity in Grave’s disease
13. What treatment for SIADH can cause central pontine myelinolysis if not properly monitored?
 Hypertonic saline causes central pontine myelinolysis if the hyponatremia is corrected too
rapidly
14. What is the most common cause of panhypopituitarism? Rare, unique cause? Clinical signs?
 adenoma
 pituitary apoplexy (spontaneous hemorrhage)
 sudden headache, meningeal signs, cavernous sinus syndrome, visual loss, unconciousness