DIRECTIONS: Each of the numbered items or incomplete statements in this section is followed by answers or by completions of the statement. Select the ONE lettered answer or completion that is the BEST in each case.
1. Which of the following conditions is consistent with a decreased rate of ACTH secretion?
(A) Hyperosmolality of the blood
(B) Low serum glucocorticoid
(C) Loss of hypothalamic neurons
(D) Primary adrenal insufficiency
(E) Stress as a result of emotional trauma
(F) Increased PKA activity in corticotrophs
2. Which of the following statements most accurately describes the feedback effects of thyroid hormones?
(A) They increase the sensitivity of thyrotrophs to TRH
(B) They stimulate transcription of the a and ß subunits of TSH in thyrotrophs
(C) They increase the secretion of TSH by thyrotrophs
(D) They stimulate the expression of the GH gene in somatotrophs
(E) They increase IP3 in thyrotrophs
(F) They increase ACTH release
3. A 30-year-old woman completed a routine pregnancy with the uncomplicated delivery of a normal-sized baby girl 6 months ago. The woman is currently experiencing galactorrhea (persistent discharge of milk-like secretions from the breast) and has not yet resumed regular menstrual periods. The baby had been bottle-fed since birth. What is the most likely explanation of the galactorrhea?
(A) Normal postpartum response
(B) Excess PRL secretion
(C) Insufficient TSH secretion
(D) Reduced GH secretion
(E) Increased dopamine synthesis in the hypothalamus
4. A decrease in blood volume would result in an increase in the secretion of
5. A 50-year-old man complains of decreased muscle strength, libido, and exercise intolerance. Examination reveals a 10% reduction in lean body mass and an increase in body fat, primarily localized to the abdominal region. Thyroid hormone levels are normal. Which diagnosis is most consistent with these symptoms?
(A) Glucocorticoid deficiency
(B) Addison's disease
(C) GH deficiency
(D) PRL deficiency
6. For evaluation of possible adrenocortical dysfunction in a middle-aged man, ACTH and cortisol were measured in blood samples taken at 8 AM, 8:30 AM, 8 PM, and 8:30 PM. The values obtained for ACTH were 110, 90, 120, and 200 pg/mL, respectively. The values obtained for cortisol were 10, 15, 25, and 20 pg/dL. These concentrations of ACTH demonstrate
(A) Normal circadian pulsatile release
(B) Primary adrenal insufficiency
(C) Inverted circadian pulsatile release
(D) Secondary adrenal insufficiency
(E) Normal circadian nonpulsatile release
(F) ACTH-secreting tumor
7. Which treatment would provide the greatest therapeutic benefit in patients with acromegaly?
(C) Growth hormone
(F) Thyroid hormone
8. Which of the following is mediated by a rise in cAMP?
(A) Inhibition of GH secretion by somatostatin
(B) Stimulation of GH gene expression by GHRH
(C) Stimulation of TSH secretion by TRH
(D) Inhibition of TSH a and ß subunit gene expression by TRH
(E) Release of AVP
(F) Inhibition of ACTH synthesis in corticotrophs
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This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.