Question 1

A primary endocrine disorder occurs when

Accepted Answer

A primary endocrine disorder occurs when the target gland itself is dysfunctional and unresponsive to regulation, leading to abnormal hormone levels.

Question 2

Growth hormone has several effects on the body, including

Accepted Answer

Growth hormone has been shown to increase lean body mass by promoting protein synthesis and inhibiting protein breakdown. It also stimulates the growth of bone, cartilage, and other tissues. It does not decrease plasma glucose level or enhance deposition of fat, and while it may have some effects on immune function, it is not known to depress it.

Question 3

Which of the following hormones is regulated by releasing and inhibiting factors from the hypothalamus?

Accepted Answer

Adrenocorticotropic hormone (ACTH) is regulated by releasing and inhibiting factors from the hypothalamus. Oxytocin and vasopressin are produced by the hypothalamus and released directly into the bloodstream, while aldosterone is regulated by the renin-angiotensin-aldosterone system.

Question 4

The release of prolactin is normally inhibited by

Accepted Answer

Prolactin release is normally inhibited by dopamine.

Question 5

Growth hormone stimulates the liver to release

Accepted Answer

Growth hormone stimulates the liver to release somatomedins, which are responsible for promoting growth and development of various tissues and organs in the body.

Question 6

An increase in serum osmolality would be expected to _____ secretion.

Accepted Answer

An increase in serum osmolality triggers the release of vasopressin (also known as antidiuretic hormone or ADH) from the posterior pituitary gland to promote water conservation by reabsorbing water in the kidneys. Therefore, an increase in serum osmolality would be expected to increase vasopressin secretion.

Question 7

Which of the following is a characteristic of lipid-soluble hormones?

Accepted Answer

Lipid-soluble hormones are able to pass through the plasma membrane of target cells and bind with intracellular receptors. This allows them to directly affect gene expression and protein synthesis within the cell.

Question 8

Releasing and inhibiting hormones travel from the hypothalamus to the anterior pituitary gland through portal veins.

Accepted Answer

This is true. The releasing and inhibiting hormones produced by the hypothalamus travel to the anterior pituitary gland through the hypophyseal portal system, which consists of a network of portal veins connecting the two organs.

Question 9

Normally secretion of growth hormone is suppressed by all of the following except

Accepted Answer

The answer of Normally secretion of growth hormone is suppressed...

Question 10

Secretion of most hormones is regulated by negative feedback mechanisms.

Accepted Answer

Most hormones are regulated by negative feedback mechanisms, which means that the hormone acts to reduce or stop its own secretion when levels in the body reach a certain point. This allows for precise control of hormone levels and helps to maintain homeostasis in the body.

Question 11

Oxytocin and ADH are secreted in response to hypothalamic releasing hormones.

Accepted Answer

Oxytocin and ADH (antidiuretic hormone) are secreted by the posterior pituitary gland, and their release is directly controlled by neuronal signals from the hypothalamus, not by hypothalamic releasing hormones.

Question 12

Most endocrine hormones are water soluble and exert their effects on target cells by

Accepted Answer

Most water-soluble hormones, like peptide hormones and catecholamines, bind to receptors on the surface of the target cell, triggering the activation of intracellular messengers (like cyclic AMP, calcium ions, or inositol phospholipids) that transmit the signal to effector proteins and modulate various cellular processes. These second messengers amplify and integrate the hormonal signal and can modify the activity of ion channels, enzymes, transcription factors, and other signaling molecules in the cytoplasm or nucleus. Some hormones may also activate receptor tyrosine kinases, stimulate guanylyl cyclase, or influence membrane potential, but they still rely on the generation of second messengers to convey their message to the cell. Hormones that are lipid soluble, such as steroid hormones, thyroid hormones, and nitric oxide, can cross the plasma membrane and bind to intracellular receptors, directly modulating gene expression and protein synthesis. However, this is not the case for most endocrine hormones.

Question 13

Which of the following hormones is highly bound to carrier proteins in the bloodstream?

Accepted Answer

Thyroid hormones, including thyroxine (T4) and triiodothyronine (T3), are highly bound to carrier proteins in the bloodstream. Specifically, they bind to thyroxine-binding globulin (TBG), transthyretin, and serum albumin. This binding protects the hormones from rapid degradation, allows for their transport through the bloodstream, and regulates their availability to target tissues.

Question 14

A patient receiving thyroid replacement hormone for primary hypothyroidism who has a low TSH should have a(n)

Accepted Answer

A low TSH in a patient receiving thyroid replacement hormone for primary hypothyroidism indicates that the dose of thyroid replacement hormone may be too high and needs to be reduced. This is because the low TSH feedback loop is indicating that there is already enough thyroid hormone in the body, and increasing the dose could lead to hyperthyroidism. A pituitary or thyroid scan is not indicated in this situation unless there are other symptoms or concerns.

Question 15

An example of a lipid-soluble hormone is

Accepted Answer

Lipid-soluble hormones can pass through the cell membrane easily and bind to receptors inside the cell. Thyroid hormone is a lipid-soluble hormone. Catecholamines, peptide hormones, and pituitary hormones are water-soluble hormones that cannot pass through the cell membrane and bind to receptors on the cell surface.

Question 16

TSH passes directly through the cell membrane and binds to intracellular receptors.

Accepted Answer

TSH binds to transmembrane receptors on the surface of the cell, not intracellular receptors.

Question 17

Up-regulation of target cell receptors results in

Accepted Answer

Up-regulation of target cell receptors means that the number of receptors on the surface of the cell increases, making the cell more responsive to the hormone. Therefore, the correct choice is C, which states that increased target cell receptor number results in increased target cell responsiveness to hormone.

Question 18

Most pituitary hormones are carried in the bloodstream bound to protein carrier molecules.

Accepted Answer

Most pituitary hormones are water-soluble and circulate freely in the bloodstream without the need for protein carriers.

Question 19

An example of a secondary endocrine disorder is

Accepted Answer

Secondary endocrine disorders involve the pituitary gland. Pituitary hypersecretion of TSH is a secondary disorder because it originates from the pituitary gland affecting the thyroid gland.

Question 20

Which of the following hormones is not released from the anterior pituitary gland?

Accepted Answer

Oxytocin is not released from the anterior pituitary gland. It is actually synthesized and released from the hypothalamus, but it travels down the pituitary stalk to be released from the posterior pituitary gland.

Quiz 39: Endocrine Physiology and Mechanisms of Hypothalmic-Pituitary Regulation