Question 1

Insulin and glucagon are two major hormones that regulate the level of nutrients circulating in blood. What are the other factors, in addition to low blood glucose level, that can shift the balance more toward activation of glucagon?

Accepted Answer

High protein, low carbohydrate meals can shift the balance toward activation of glucagon because glucagon is released in response to high amino acid levels in the blood, which often result from protein consumption, to maintain glucose levels by promoting gluconeogenesis and glycogenolysis.

Question 2

Where in the striated muscle cell would you find GLUT4 carriers about an hour after a meal?

Accepted Answer

After a meal, insulin stimulates the translocation of GLUT4 carriers from intracellular vesicles to the cell membrane, allowing glucose to enter the muscle cell for energy production or storage. Therefore, about an hour after a meal, GLUT4 carriers would be found in the cell membrane.

Question 3

Which of the hormones increases the activity of osteoclasts and causes faster resorption of bone?

Accepted Answer

Parathyroid hormone (PTH) is secreted by the parathyroid glands in response to low levels of calcium in the blood. PTH increases the activity of osteoclasts, the cells responsible for breaking down bone tissue, leading to faster resorption of bone. This helps to release calcium into the bloodstream to maintain appropriate levels. Vitamin K is important for bone health, but does not directly affect osteoclast activity. Insulin and thyroxine are also not directly involved in regulating bone resorption.

Question 4

Glucagon is a hormone that opposes the action of insulin. What are the target cells for glucagon?

Accepted Answer

Glucagon primarily acts on hepatocytes to stimulate glycogenolysis and gluconeogenesis, which increases blood glucose levels. While glucagon is also secreted by pancreatic alpha cells, these cells are not considered target cells for glucagon. Glucagon has no significant effect on intestinal epithelium cells.

Question 5

Binding of insulin to insulin receptor starts a signaling pathway that includes

Accepted Answer

Insulin binding to its receptor activates the intrinsic kinase domain of the receptor, leading to autophosphorylation and subsequent downstream signaling events.

Question 6

What hormones increase the activity of osteoblasts and bone growth during childhood?

Accepted Answer

Insulin like growth factors are released by the liver in response to growth hormone stimulation, and increase the activity of osteoblasts leading to bone growth during childhood. Glucocorticoids and sex hormones have a negative effect on bone growth. Anabolic steroids may increase bone growth, but their use is associated with several negative side effects.

Question 7

Identify the phase of General Adaptation Syndrome (aka stress response) in which degradation of stored glycogen occurs.

Accepted Answer

The Fight or Flight phase, also known as the alarm phase, is when the body prepares for immediate physical activity. This includes the release of adrenaline and other stress hormones, which among other effects, stimulate the degradation of stored glycogen to provide quick energy for the body to either fight the stressor or flee from it.

Question 8

Is insulin a hormone that supports catabolic or anabolic metabolism?

Accepted Answer

Insulin is an anabolic hormone that promotes the storage and synthesis of glucose, amino acids, and fatty acids into glycogen, proteins, and triglycerides. It is released in response to elevated blood glucose levels after a meal to facilitate glucose uptake by cells and reduce blood glucose concentration.

Question 9

Insulin like growth factors

Accepted Answer

Insulin like growth factors (IGFs) mediate the action of growth hormone on bones by promoting bone growth and mineralization. IGFs do not lower blood glucose levels (which is primarily the role of insulin), cause uterine contractions, or increase urine volume.

Question 10

Chronic stress can and will affect almost all body systems. Which of the following is NOT a common response of the body to long-term stress?

Accepted Answer

Stress can impair digestion, leading to symptoms such as indigestion, nausea, and gastrointestinal issues.

Question 11

Which of these statements concerning insulin is true?

Accepted Answer

Insulin is secreted by beta cells in the islets of Langerhans in the pancreas. It stimulates the uptake and storage of glucose, amino acids, and fatty acids, and helps regulate blood sugar levels. It works in opposition to glucagon, which stimulates the breakdown of glycogen stores to release glucose into the bloodstream. Insulin also has anabolic effects, promoting protein synthesis and muscle growth, rather than breakdown.

Question 12

The health of the bone depends on the balance between bone resorption and bone deposition. What modifiable factors contribute to the maintenance of healthy bones in adulthood?

Accepted Answer

Exercise is a modifiable factor that can contribute to the maintenance of healthy bones in adulthood by stimulating bone deposition and reducing bone resorption. Other modifiable factors that can contribute to bone health include nutrition, hormonal balance, and avoiding smoking or excessive alcohol consumption. Genetics and age are non-modifiable factors that can influence bone health. Gravity is an environmental factor that can affect bone health, but it cannot be modified.

Question 13

Exercise is often listed as a lifestyle factor that can slow down bone loss at old age. Which of the listed exercises is best for prevention of osteoporosis?

Accepted Answer

Lifting weights is the best type of exercise for preventing osteoporosis because it puts stress on the bones, which stimulates them to build more bone tissue. Water aerobics and swimming are low-impact exercises, which may help maintain bone density but are not as effective as weight-bearing exercise. Yoga can improve balance and flexibility, but it doesn't put enough stress on the bones to prevent osteoporosis.

Question 14

Acromegaly is caused by

Accepted Answer

Acromegaly is caused by the overproduction of growth hormone (GH) after puberty, most commonly due to a pituitary tumor. This excess GH leads to excessive growth of bones and tissues, particularly in the hands, feet, and face.

Question 15

Liver is the essential organ for regulation of glucose levels in blood through storage, release and production of "new" glucose from non-carbohydrate substrates. What type of receptors do hepatocytes express to fulfill this role?

Accepted Answer

Hepatocytes express both insulin and glucagon receptors to regulate glucose levels in blood. Insulin stimulates the storage of glucose in the liver, while glucagon promotes the release of glucose into the blood. Therefore, both receptors are necessary for the liver to maintain glucose homeostasis. GLUT 4 receptors are present on skeletal muscle and adipose tissue to facilitate glucose uptake, but not on hepatocytes.

Question 16

The hormone involved in the initiation of digestive tract peristalsis is

Accepted Answer

The answer of The hormone involved in the initiation of...

Question 17

Which of the following is produced in the adrenal medulla in the immediate reaction to a stressor?

Accepted Answer

The adrenal medulla produces epinephrine (also known as adrenaline) in response to a stressor as part of the immediate fight or flight response. Corticosteroids and glucosteroids are produced in the adrenal cortex in response to stress, but they are not part of the immediate response. Calcitriol, which is a form of vitamin D, is produced in the kidneys and is not directly involved in the stress response.

Question 18

The formation of bone is a never-ending process that happens even after we are done growing. Bones constantly remodel themselves. Remodeling of the bone involves

Accepted Answer

The remodeling of bone involves all of the choices. The mineral component provides strength and rigidity to the bone structure, while the protein and collagen fibers provide flexibility to the bone structure. Remodeling of the bone involves the continuous breakdown of old bone tissue and the deposition of new bone tissue. This process is controlled by specialized cells called osteoblasts and osteoclasts. Therefore, all of the choices- mineral, protein, and collagen fibers- are essential for the formation and remodeling of bone tissue.

Question 19

Insulin is known to practically everybody as a hormone that lowers blood sugar levels. Yet, it is a versatile hormone that has many other functions. What else does insulin do?

Accepted Answer

Insulin promotes the storage of fat by increasing triglyceride synthesis in adipose tissue, contrary to increasing fat breakdown or catabolism. It does not decrease fatty acid synthesis or directly increase the absorption of fat in the intestines.

Question 20

Each pancreatic islet contains how many types of hormone secreting cells?

Accepted Answer

Pancreatic islets contain four types of hormone-secreting cells: alpha cells (which produce glucagon), beta cells (which produce insulin), delta cells (which produce somatostatin), and PP cells (which produce pancreatic polypeptide).

Quiz 13: The Endocrine System