Deck 38: Introduction to the Endocrine System

Question 1

An elderly person becomes confused and takes an overdose of a medication designed to block both cholesterol uptake from the GI tract and cholesterol synthesis by all cells.After 24 hours,the individual is severely hypocholesterolemic (i.e.,has very low levels of circulating cholesterol).This effect is transient: as the effects of the drug wear off,hormone levels rebound.Which of the following is most responsible for stability of hormone levels in this situation?

A)Hepatic turnover
B)Negative feedback loop
C)Peripheral conversion
D)Renal excretion
E)Melatonin

Answer 1

B

Question 2

An elderly person becomes confused and takes an overdose of a medication designed to block both cholesterol uptake from the gastrointestinal (GI)tract and cholesterol synthesis by all cells.After 24 hours,the individual is severely hypocholesterolemic (i.e.,has very low levels of circulating cholesterol).This individual would exhibit a transient lower level of which type of hormone?

A)Catecholamines
B)Protein hormones
C)Steroid hormones
D)Iodothyronines
E)Peptide hormones

Answer 2

C

Question 3

Many pituitary hormones are secreted in a circadian rhythm.A structure important in the regulation of circadian hormonal rhythms is:

A)The paraventricular nucleus.
B)The supraoptic nucleus.
C)The superior fornix.
D)The suprachiasmatic nucleus.
E)The arcuate nucleus.

Answer 3

D

Question 4

Hormones act through binding to their receptors.Which of following hormones binds only to a receptor located on the cell membrane?

A)Thyroid hormone
B)Catecholamine
C)Estrogen
D)Progesterone
E)Vitamin D

Question 5

Endocrine glands are organs dedicated to making hormones.Some organs make hormones but have other important functions.An example of such a hormone-producing organ that is not considered a dedicated endocrine gland is:

A)The adrenal gland.
B)The thyroid gland.
C)The liver.
D)The pituitary gland.
E)The parathyroid gland.

Question 6

Many hormones are synthesized as preprohormones.A mutation in a preprohormone-encoding gene that changed the amino acid sequence of the signal peptide could result in:

A)Inability of the hormone to be secreted.
B)Decreased circulating half-life of the hormone.
C)Secretion of a smaller hormone.
D)Inability of the hormone gene to be transcribed.
E)Reduced affinity of the hormone for its receptor.

Question 7

An important process that can activate a steroid hormone or even change a steroid hormone into a different type of hormone (e.g.,changing an androgen molecule into an estrogen molecule)is called:

A)Renal excretion.
B)Peripheral conversion.
C)Steroid hormone-receptor binding.
D)Hepatic conjugation.
E)Dimerization.

Question 8

Endocrine diseases are often due to loss of hormone (i.e.,a hormone deficiency).Which of the following would cause an endocrine disease that mimicked a protein hormone deficiency without a deficiency in the levels of a circulating protein hormone?

A)Inactive prohormone convertase
B)Defective exocytotic machinery
C)Loss of blood transport proteins
D)Defective receptor
E)Null mutation in corresponding hormone gene

Question 9

Protein hormones are secreted in a regulated manner,through a mechanism referred to as:

A)Stimulus-secretion coupling.
B)Constitutive secretion.
C)Endocytosis recycling.
D)Signal peptidase-induced cleavage.
E)Membrane shedding.

Question 10

The hypothalamus has an important role in the hypothalamic-pituitary-endocrine gland axes.As part of these axes,hypothalamic neuroendocrine neurons secrete:

A)Tropic hormones.
B)Steroid hormones.
C)Releasing hormones.
D)Thyroid hormones.