Question 1

Which of the following is a primary endocrine organ?

Accepted Answer

A

Question 2

Hormones that act on the same target cells yet have opposite effects are said to be:

Accepted Answer

Hormones that act on the same target cells yet have opposite effects are called antagonists. Examples include insulin and glucagon, which both act on liver cells to regulate glucose levels but have opposite effects.

Question 3

What type of hormone is made from cholesterol?

Accepted Answer

Steroid hormones, such as testosterone and estrogen, are made from cholesterol.

Question 4

Hormones that control hormone secretion from other glands are known as:

Accepted Answer

Hormones that control hormonal secretion from other glands are known as tropic hormones. Tropic hormones are secreted by the pituitary gland and stimulate other endocrine glands to release their hormones. Examples of tropic hormones include follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), and adrenocorticotropic hormone (ACTH).

Question 5

What type of hormone can cross the plasma membrane to bind to a receptor in the cytosol or nucleus?

Accepted Answer

Hydrophobic hormones, such as steroid hormones and thyroid hormones, are able to cross the plasma membrane because they are lipid soluble. Once inside the cell, they can bind to receptors in the cytosol or nucleus to initiate gene expression.

Question 6

Target cells make more receptors for a particular hormone when the level of that hormone declines in the blood stream.This process is known as:

Accepted Answer

Upregulation is a process in which the target cells increase the number of receptors for a particular hormone when the hormone level decreases in the blood. This is done to increase the sensitivity of the target cells to the hormone and to maintain the hormonal balance in the body. Downregulation, on the other hand, is a process in which the number of receptors for a particular hormone decreases when the hormone level is high in the blood.

Question 7

Endocrine cells that increase hormone secretion in response to other hormones are controlled by:

Accepted Answer

Endocrine cells that increase hormone secretion in response to other hormones are controlled by hormonal stimuli. This is known as the hormonal feedback loop, where the target gland or organ is stimulated by a hormone released from another endocrine gland.

Question 8

How are the nervous system and endocrine system similar?

Accepted Answer

Both the nervous system and the endocrine system communicate with cells using chemicals. The nervous system uses neurotransmitters to send signals across synapses to target cells, while the endocrine system uses hormones released into the bloodstream to affect distant cells.

Question 9

With which gland does the hypothalamus have a close anatomical and physiological relationship?

Accepted Answer

The hypothalamus and pituitary gland are closely linked anatomically and functionally. The hypothalamus controls the release of hormones from the pituitary gland by releasing factors that stimulate or inhibit pituitary hormone production. In turn, the pituitary gland secretes hormones that regulate numerous physiological processes throughout the body.

Question 10

Upon binding to a receptor to form a hormone-receptor complex,steroid hormones may cause:

Accepted Answer

Steroid hormones typically enter cells and bind to receptors located in the cytoplasm or nucleus, forming a hormone-receptor complex. This complex can then bind to DNA and activate or repress specific genes, ultimately leading to an increase in protein synthesis. Steroid hormones do not activate adenylate cyclase, protein kinases, or form cAMP.

Question 11

What connects the hypothalamus and pituitary gland?

Accepted Answer

The hypothalamus and pituitary gland are connected by a stalk-like structure called the infundibulum. This structure allows for communication and coordination between the two organs, as the hypothalamus controls the release of hormones from the pituitary gland.

Question 12

When blood glucose levels increase,a hormone called insulin is released from endocrine cells in the pancreas.The role of insulin is to return blood glucose levels to normal.Which part of this negative feedback loop is the stimulus?

Accepted Answer

The stimulus in this negative feedback loop is the increasing blood glucose levels which triggers the release of insulin from the pancreas.

Question 13

Increasing levels of blood glucose stimulate the release of insulin.This type of stimulation is known as:

Accepted Answer

Humoral stimulation refers to the control of hormone release in response to changes in extracellular fluids, such as the blood glucose level influencing insulin release.

Question 14

All target cells:

Accepted Answer

Target cells have receptors to which hormones bind. This allows for a specific hormone to interact with and affect only the cells that have the appropriate receptor. Target cells can be found in a variety of tissues and organs throughout the body, not just in the blood. They do not necessarily secrete hormones or produce their own hormones.

Question 15

What type of hormone usually travels in the blood plasma bound to a protein?

Accepted Answer

Hydrophobic hormones, such as thyroid hormones and steroid hormones, are usually bound to carrier proteins in the blood due to their low solubility in water. This allows them to be transported to their target cells efficiently.

Question 16

What do paracrine cells target?

Accepted Answer

Paracrine cells target nearby but different types of cells, as they communicate through the release of signaling molecules that act on neighboring cells. They do not typically act on distant tissues or the same cell type, nor do they use neurotransmitters as their mode of signaling.

Question 17

What type of tissue makes up the adenohypophysis,or anterior pituitary gland?

Accepted Answer

The adenohypophysis, or anterior pituitary gland, is composed of glandular epithelium, which secretes hormones into the bloodstream.

Question 18

What often serves as the second messenger when a hydrophilic amino-acid based hormone binds its receptor?

Accepted Answer

When a hydrophilic amino-acid based hormone binds its receptor, it often activates adenylate cyclase, which converts ATP into cyclic AMP (cAMP). cAMP then serves as a second messenger, activating downstream signaling pathways.

Question 19

What is a major function of the endocrine system?

Accepted Answer

The endocrine system's major function is to release hormones into the bloodstream to reach receptors on target cells, allowing for slower but longer-lasting effects on the body. This distinguishes it from the nervous system, which produces quick, short-lasting effects through the release of neurotransmitters. The endocrine system also differs from exocrine glands, which secrete their products into ducts that lead to body surfaces or cavities.

Question 20

Chemical messengers released by endocrine glands to regulate some functions of other cells are known as:

Accepted Answer

Chemical messengers released by endocrine glands to regulate some functions of other cells are known as hormones.

Quiz 16: The Endocrine System