Question 1

Which of the following statements is true about the pancreas?

Accepted Answer

The islets of Langerhans, located in the pancreas, contain different types of cells that produce different hormones such as insulin, glucagon, and somatostatin. Therefore, option D is true. Option A is incorrect as the pancreas lies behind the stomach. Option B is incorrect as the pancreas also produces enzymes that aid in digestion. Option C is incorrect as it is the hypothalamus that produces stimulating hormones that control the pituitary gland. Option E is also incorrect as the pancreas does not store glucose, but instead regulates glucose levels through the production and release of hormones.

Question 2

The pancreatic hormone that causes blood sugar levels to fall is

Accepted Answer

Insulin is the pancreatic hormone that causes blood sugar levels to fall by increasing glucose uptake by cells and promoting the storage of excess glucose as glycogen in the liver and muscles.

Other options are incorrect:
A) Cortisol is a steroid hormone released by the adrenal gland in response to stress, and it increases blood sugar levels by promoting gluconeogenesis.
B) Somatotropin, also known as growth hormone, can indirectly affect blood sugar levels by promoting lipolysis and increasing circulating free fatty acids, which can then be converted to glucose in the liver. However, it does not directly cause blood sugar levels to fall.
D) Glucagon is a pancreatic hormone that causes blood sugar levels to rise by promoting glycogenolysis and gluconeogenesis in the liver. 
E) Aldosterone is a steroid hormone released by the adrenal gland that regulates salt and water balance in the body, but it does not directly affect blood sugar levels.

Question 3

When blood glucose levels fall,

Accepted Answer

When blood glucose levels fall, the hormone glucagon is released by the pancreas to stimulate the liver to break down glycogen into glucose and release it into the bloodstream, raising glucose levels. Insulin is released when blood glucose levels rise to help move glucose into cells for energy or storage. Peripheral cells taking up more glucose and protein synthesis increasing are not direct responses to falling blood glucose levels. Calcitonin is not involved in glucose regulation.

Question 4

Which of the following hormones stimulates skeletal muscle fibers to take in glucose from the blood?

Accepted Answer

Insulin is produced by the pancreas and helps to regulate glucose levels in the blood. It stimulates skeletal muscle fibers to take in glucose from the blood and store it as glycogen, thus lowering blood glucose levels.

Question 5

Type II diabetes is characterized by

Accepted Answer

Type II diabetes occurs when the body's target cells become resistant to insulin, which is the hormone that helps transport glucose into cells for energy. This results in high blood sugar levels.

Question 6

Which of the following is false concerning melatonin?

Accepted Answer

Exposure to light inhibits production of melatonin. It is produced by pinealocytes, made from serotonin and inhibits the release of GnRH.

Question 7

The adrenal medulla primarily secretes

Accepted Answer

The adrenal medulla primarily secretes epinephrine (adrenaline).

Question 8

In persons with untreated diabetes mellitus all of the following are true, except

Accepted Answer

Intracellular and tissue levels of glucose are not very high in untreated diabetes mellitus, as the glucose cannot be effectively transported into the cells without insulin. This leads to a state of cellular "starvation" and increased breakdown of fats and proteins for energy.

Question 9

All of the following may be functions of melatonin except that it

Accepted Answer

Melatonin has been found to have insulin-sensitizing effects, but it does not act as a direct insulin synergist. Therefore, option D is incorrect. Melatonin is involved in various functions such as regulating circadian rhythms, acting as an antioxidant, and protecting against free-radicals. It may also influence sexual maturation.

Question 10

Which of the following might occur in an overdose of insulin?

Accepted Answer

Insulin lowers blood glucose levels by promoting the uptake of glucose by cells and storage of glucose as glycogen in the liver and muscles. In an overdose of insulin, blood glucose levels can drop too low (hypoglycemia), leading to symptoms such as confusion, shakiness, sweating, and even loss of consciousness. Glycosuria (A) refers to the presence of glucose in the urine, which can occur in diabetes when blood glucose levels are too high. Ketoacidosis (B) is a serious complication of uncontrolled diabetes, characterized by high blood glucose, accumulation of ketones in the blood, and metabolic acidosis. High blood glucose (C) is the opposite of what happens in an insulin overdose, as insulin is supposed to lower glucose levels. Polyuria (E) refers to excessive urine production, which can occur in diabetes when glucose spills into the urine and drags water with it, leading to dehydration and increased thirst.

Question 11

Melatonin is produced by the

Accepted Answer

Melatonin is primarily produced by the pineal gland, which is located in the brain.

Question 12

A patient is receiving exogenous cortisol in the form of hydrocortisone shots for a sinus infection. Theirnatural adrenal secretion of cortisol will decrease due to negative feedback on the ________ reducing the secretion of ________.

Accepted Answer

Exogenous cortisol suppresses the anterior pituitary's secretion of ACTH through negative feedback.

Question 13

Each of the following is true of the pineal gland except that it

Accepted Answer

The pineal gland is a component of the epithalamus, not the hypothalamus.

Question 14

Alpha cells are to ________ as beta cells are to ________.

Accepted Answer

Alpha cells secrete glucagon and beta cells secrete insulin.

Question 15

The condition known as seasonal affective disorder (SAD) may be caused by

Accepted Answer

Seasonal affective disorder is linked to decreased exposure to sunlight, which can lead to an increase in the hormone melatonin. This increase in melatonin levels is believed to be a contributing factor in the development of SAD symptoms.

Question 16

The delta cells of the pancreatic islets produce

Accepted Answer

The delta cells of the pancreatic islets secrete somatostatin, which helps regulate various hormones in the body including insulin and glucagon.

Question 17

Excess production of hormones by the zona reticularis may lead to which disorder?

Accepted Answer

Excess production of hormones by the zona reticularis of the adrenal cortex can lead to adrenogenital syndrome, also known as congenital adrenal hyperplasia. This results in an excess production of androgens, which can cause masculinization of females and premature puberty in males.

Question 18

If a diabetic patient received too much insulin, the low blood sugar could be corrected by injecting

Accepted Answer

Glucagon can raise blood sugar levels by promoting the breakdown of stored glycogen in the liver and increasing gluconeogenesis. This is an effective treatment for hypoglycemia caused by an excess of insulin. GHIH (also known as somatostatin) regulates the release of insulin and glucagon and would not be useful in this situation. Thyroid hormone, aldosterone, and antidiuretic hormone do not have a direct effect on blood sugar levels.

Question 19

The beta cells of the pancreatic islets produce

Accepted Answer

Beta cells in the pancreatic islets are responsible for producing insulin.

Question 20

Which hormone may be prescribed in chronic inflammatory disorders such as Lupus?

Accepted Answer

Cortisol is a glucocorticoid hormone that has anti-inflammatory properties and is often prescribed in chronic inflammatory disorders such as Lupus. It helps to suppress the immune system and reduce inflammation.

Quiz 18: The Endocrine System