Chapter 47. Neuroendocrinology Flashcards
Question 47-1:
Which of the following statements is NOT true regarding temperature regulation?
A. Temperature regulation is mediated by the hypothalamus
B. Hyperthermia may develop because of subarachnoid hemorrhage
C. Hyperthermia may develop from trauma
D. Hyperthermia persists after development despite improvement in other spheres
Answer 47-1: D.
Hyperthermia can develop in patients from a variety of causes, including damage to the hypothalamus from ischemia, trauma, hemorrhage or surgery. temperature control is severely damaged but usually recovers in these individuals over a period of days to weeks. Chronic hyperthermia of hypothalamic origin has been decribed but is uncommon
Question 47-2:
Appetite is clearly under cortical and subcortical control with influences at multiple levels. Which of the following statements is NOT true regarding control of appetite and weight?
A. Weight increase can be provoked by sight, aroma, and taste of food
B.Weight increase can be caused by lesion of the ventromedian thalamus
C. Weight increase can be caused by lesion of the dorsomedial nucleus
D. The brainstem functions in the hypothalamic control over appetite
Answer 47-2: C.
Lesions of the dorsomedial nucleus of the
hypothalamus produce weight decrease, as do
lesions of the lateral hypothalamus. Lesions of
the ventromedian hypothalamus produce
weight gain. Although most individuals keep
their weight in a f”irly narrow range, sensory
experience oHood can alter appetite and be
responsible at least in part for obesity. The
brainstem is integral to hypothalamic control
over appetite, and in this action, there may be
a modulatoly effect of the hypothalamus on
brainstem function. (p884)
Question 47-3:
Which of the following statements regarding eating disorders is true?
A. Patients with anorexia have low levels of norepinephrine
B. Patients with anorexia have low levels of serotonin
C. Patients with bulimia nervosa have enhanced secretion of cholecystokinin
D. Patients with bulimia nervosa have no measurable biochemical changes
Answer 47-3: A.
Patients with anorexia nervosa have low levels
of norepinephrine and have enhanced
secretion of CCK.. Patients with bulimia have
low serotonin levels in the CSF. while it is
not definitively known whether these changes
are effects of the eating disorder or a
reflection of the underlying cause, the changes
clearly need further study. Increasingly,
disorders once thought to be purely
psychiatric have been found to have a
biochemical foundation. (P885)
Question 47-4: Which of the following pituitary hormones are under hypothalamic control? A. Growth hormone B. Prolactin C. Thyrotropin D. Lutenizing hormone E. All of these
Answer 47-4: E.
All of these are pituitary hormones which are under control by the hypothalamus. growth hormone is influenced by GH-releasing hormone and the inhibitting hormone somatostatin. prolactin-releasing factor and an inhibiting factor, dopamine, are released by the hypothalamus. thyrotropi-releasing hormone and an inhibiting factor control thyrotropin release. LH is controlled by gonadotropin-releasing hormone. (p856)
Question 47-5: What effect does increased production of prolactin commonly have on men? A. Galactorrhea B. Acromegaly C. Impotence D. None
Answer 47-5: C
Increased prolactin production in men commonly produces impotence and infertility. Galactorrhea is a common manifestation in women but is only rarely seen in men. acromegaly is due to increased production of Growth hormone rather than prolactin (p858)
Question 47-6: A 10-year-old female child is brought in because of development of secondary sexual characteristics. Which diagnostic studies are appropriate? A. MRI B. CT C. Serum growth hormone levels D. All of these E. None of these
Answer 47-6: E
Development of secondary sexual characteristics in a 10 year old girl is normal, and evaluation on the basis of this information alone is not warranted. precocious puberty is defined as development of these characteristics before the age of 8 in girls and 9 in boys (p859)
Question 47-7:
Prolactin levels are frequently obtained in patients with suspected seizures. Which of the following statements are true regarding the use of prolactin to differentiate seizures from non-epileptic events?
A. Prolactin is devated in patients with generalized tonic-clonic seizures
B. Prolactin is not elevated in patients with simple partial seizures
C. Prolactin elevation in the morning is normal
D. Prolactin elevation is short-lived after a seizure
E. All are true
Answer 47-7: E.
Prolactin levels are increased in patients with
generalized tonic-donic and complex partial
seizures, but are not increased in most patients
with psychogenic seizures. absence seizures,
and simple panial seizures. Also. complex
partial seizures of frontal lobe origin rnay not
have an elevation in prolactin level. A
baseline measurement is needed because the
elevation is relative, and care must be
exercised in interpreting levels, since there
may be a 50-100% increase shortly before
aWakening. Unfortunately, prolactin may be
increased by other conditions, Clouding utility
of this measure. Prolactin measurements
should be considered evidentiary but not
definitive. (p859)
Question 47-8:
Which of the following statement are true regarding pituitary apoplexy?
1.Patients may have the clinical presentation of subarachnoid hemorrhage
2. Cause may be pituitary infarction
3. Cause may be pituitary hemorrhage
4. Diagnosis is usually missed on CT
Select: A = 1, 2, 3. B = 1, 3. C = 2, 4. 0 = 4 only. E = All
Answer 47-8: A.
Pituitary apoplexy is usually seen on CT or
MRI. Patients can present with symptoms
which are indistinguishable from .
subarachnoid hemorrhage, including acUte
onset of headache, encephalopathy, and
meningeal signs. The cause can be infarction
or hemorrhage into the pituitary. (p858-859)
Question 47-9:
Which of the following statements are true regarding evaluation of Cushing’s syndrome?
1. Dexamethasone suppression test is important to diagnosis of Cushing’s syndrome
2. Administration of dexamethasone normally results in increased urinary excretion of 17-ketogenic steroids and urinary-free cortisol
3. Failure to suppress cortisol production with dexamethasone with immeasurable ACTH levels suggests adenoma or carcinoma of the adrenal
4. ACTH levels in Cushing’s disease are markedly suppressed
Select: A = 1,2,3. B = 1,3. C = 2, 4. D = 4 only. E = All
Answer 47-9: B.
Cushing’S syndrome is the clinical
presentation of excessive exposure to
corticosteroids, whether endogenous or
exogenous. Cushing’s disease is the syndrome
produced by excessive production of ACTH
from the pituitary. In Cushing’s disease,
ACTH levels are either normal or moderately
elevated. Administration of dexamethasone
for the suppression test normally results in
decreased production of 17 -ketogenic steroids
and urinary free cortisol. (P860)
Question 47-10:
Which of the following statements are true regarding gonadotropin-secreting tumors?
1. Most gonadotropin -secreting tumors produce LH
2. Some tumors produce both LH and FSH
3. Gonadotropin-secreting tumors result in patients who are hypergonadal
4. Patients with LH-secreting tumors have increased testosterone or estradiol levels
Select:A= 1,2,3. B= 1,3. C=2,4. D= 4 only. E= All
Answer 47-10: C.
288
Patients with gonadotropin-secreting tumors
often secrete FSH alone or both FSH and LH.
Tumors which produce LH alone are rare.
Patients with FSH-secreting tumors typically
have low levels of estradiol or testosterone
whereas the levels with LH-producing tum~rs
are high. However. in both instances, the
patients are hypogonadal. Some tumors
produce inactive subunits. (p861)
