Question 1

Neurohormones are hormones that specifically modify neural activity.

Accepted Answer

The answer of Neurohormones are hormones that specifically modify neural...

Question 2

Which statement concerning bone cells is correct?

Accepted Answer

Osteoclasts are bone cells that dissolve bone through a process called resorption. This allows for the removal of old or damaged bone tissue and the release of minerals such as calcium back into the bloodstream. Osteoblasts, on the other hand, are cells that make new bone cells. Chrondrocytes are not bone cells, but rather cells found in cartilage. Prolactin-inhibiting hormone does not directly affect bone cells.

Question 3

Specialization of target-cell receptors explains the specificity of hormonal action.

Accepted Answer

Hormones are chemical messengers secreted by endocrine glands and travel through the bloodstream to their target cells. The target cells have specific receptors on their surface that recognize and bind to the hormones, allowing them to receive the hormonal signal. The specificity of hormonal action is primarily due to the specificity of target-cell receptors, as only cells with the appropriate receptors can respond to the hormone's signal. Therefore, the specialization of target-cell receptors explains the specificity of hormonal action.

Question 4

Which of the following results in somatomedins being released from the liver?

Accepted Answer

Somatomedins are peptide hormones that are released from the liver in response to increased levels of plasma growth hormone. These hormones play an important role in promoting the growth and development of various tissues and organs in the body. Therefore, when plasma growth hormone levels increase, it leads to the release of somatomedins from the liver.

Question 5

Which disorders and hormonal imbalances are correctly matched?

Accepted Answer

Acromegaly is a disorder in which there is excessive growth hormone secretion even after the epiphyseal plates have closed, leading to enlargement of soft tissues and bones.

Answer: C 
 Diabetes mellitus is a disorder in which there is decreased insulin response, leading to high blood glucose levels.

Answer: A 
 Diabetes insipidus is a disorder in which there is decreased ADH secretion or response, leading to excessive urination and thirst.

Answer: None of the above 
 Dwarfism is a disorder in which there is inadequate growth hormone production or response, leading to short stature. Excessive cortisol production is associated with Cushing's syndrome.

Question 6

A deficiency in which of the following may result in dwarfism?

Accepted Answer

Dwarfism is often caused by a deficiency in growth hormone (GH), which is responsible for regulating body growth and development. Without enough GH, the bones and tissues don't grow properly, leading to shorter stature.

Question 7

The _____ is the main link between the nervous system and the endocrine system,due to its control over secretory activities of the _____ glands.

Accepted Answer

The hypothalamus is the main link between the nervous system and the endocrine system as it controls the secretory activities of the pituitary gland, which is often referred to as the "master gland" of the endocrine system. The thalamus is only responsible for relaying sensory information to the cerebral cortex and has no control over the endocrine system. The brainstem is responsible for regulating basic autonomic functions such as breathing and heart rate and does not directly control the endocrine system. The thyroid gland is controlled by the pituitary gland and the hypothalamus but is not considered the main link between the nervous and endocrine systems.

Question 8

What does excessive growth hormone secretion in an adult lead to?

Accepted Answer

Excessive growth hormone secretion in an adult leads to acromegaly, which results in disproportionate growth, thickened bones, and coarse features. Gigantism is the result of excessive growth hormone secretion in a child. Cushing's syndrome and central obesity are caused by excessive cortisol secretion.

Question 9

A hormone can influence the activity of another hormone at a given target cell in one of three ways: permissiveness,synergism and antagonism.Which statement concerning the above concept is correct?

Accepted Answer

Permissiveness refers to the situation in which one hormone must be present in adequate amounts for the full exertion of another hormone's effect.

Question 10

The same chemical messenger may be either a hormone or a neurotransmitter,depending on its source and mode of delivery to the target tissue.

Accepted Answer

This statement is true. For example, adrenaline (epinephrine) can act as a hormone when it is released from the adrenal glands into the bloodstream, but it can act as a neurotransmitter when it is released from nerve endings in certain parts of the body.

Question 11

In addition to GH,which other hormone is essential for normal growth?

Accepted Answer

Insulin is essential for normal growth as it promotes the uptake and utilization of nutrients such as glucose and amino acids, which are necessary for tissue growth and repair. While parathyroid hormone and calcitonin play important roles in regulating calcium levels in the body, they are not directly involved in growth. Glucagon regulates glucose levels but does not have a direct role in growth.

Question 12

Which statement concerning IGF is INCORRECT?

Accepted Answer

The answer of Which statement concerning IGF is INCORRECT?
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Question 13

How does growth hormone exert its effects on growth?

Accepted Answer

Growth hormone stimulates the liver to produce somatomedins, which are insulin-like growth factors (IGFs) that directly promote growth of tissues such as bone and muscle.

Question 14

Peptide hormones are often produced as prohormones.

Accepted Answer

Peptide hormones are often synthesized as longer precursor molecules called prohormones, which are then processed to release the active peptide hormone. This processing may involve modifications such as cleavage of specific amino acid residues or addition of carbohydrate or lipid groups.

Question 15

Which of the following are masculinizing hormones produced from the adrenal gland?

Accepted Answer

Androgens are the masculinizing hormones produced from the adrenal gland. Growth hormone, thyroid hormone, and cortisol are not specifically masculinizing hormones.

Question 16

Which factor does NOT increase growth hormone secretion?

Accepted Answer

Low blood amino acid levels actually stimulate growth hormone secretion, so this factor does not decrease it.

Question 17

The nervous system exerts considerable control over the endocrine system,but hormones have no influence over the nervous system.

Accepted Answer

While the nervous system does exert control over the endocrine system, hormones can also have an influence on the nervous system. For example, hormones such as cortisol and adrenaline can activate the sympathetic nervous system in response to stress.

Question 18

Which statement concerning osteoblasts is correct?

Accepted Answer

Osteoblasts are bone-forming cells that secrete organic matrix components, such as collagen, that make up the structure of bone. They are responsible for bone growth and repair.

Question 19

The hormones influence adjustments that require duration rather than speed,whereas the rapid coordinations of the body are controlled by the nervous system.

Accepted Answer

Hormones work gradually over time to make adjustments in the body, while the nervous system controls immediate responses and rapid movements.

Question 20

A single endocrine gland may produce many hormones.

Accepted Answer

This is true. For example, the pituitary gland produces at least 9 different hormones.

Quiz 5: Principals of Endocrinology; The Central Endocrine Glands