ENDOCRINE SYSTEM

Question 1

Which type of hormone is able to easily diffuse across the membrane?

Answer 1

Steroid

Question 1

True or False: Endocrine glands secrete chemical messages directly into the bloodstream

Answer 1

True

Question 2

True or false: The growth hormone axis contains at least one example of a negative feedback loop.

Answer 2

True

Question 3

GHRH directly triggers the release of which of the following hormones?

Answer 3

Growth Hormone

Question 4

A person has a genetic mutation in the receptor for GH that prevents the hormone from binding to target cells. What levels of IGF-1 do you find in the person?
A) Higher than Normal
B) Lower than Normal
C) Normal

Answer 4

Lower than Normal

Question 5

True or False: If an adult develops a tumor on their pituitary gland that causes a prolonged excessive release of GH, they are likely to develop the condition gigantism, in which they grow unusually tall.

Answer 5

False

Question 6

Growth hormone has which of the following effects on the body? Select all that apply.
A) Decreases amino acid uptake
B) Activates osteoblasts and chondrocytes
C) Decreases protein synthesis in muscle and bone
D) Triggers the release of IGF-1 by the liver

Answer 6

B) Activates Osteoblasts and Chondrocytes
and D) Triggers release of IGF-1 by the liver

Question 7

A person is lacking (through genetic mutations) the receptor for a steroid hormone. Which of the following observations are correct?
A) There are fewer receptors in the plasma membrane of the cell.
B) Even if the hormone is present, there will NOT be a change in gene expression.
C) There are more receptors in the cytoplasm.
D) The hormone fails to enter the cell.

Answer 7

B) Even if the hormone is present, there will NOT be a change in gene expression.

Question 8

Sometimes a child will begin puberty early (before age 8 or 9), called “precocious puberty’” What effect would this have on their stature? Think about the effect on bone growth.

Answer 8

They will be tall for their age at first but short as an adult

Question 9

A genetic mutation results in the suppression of rapid chondrocyte division. What is the result of the mutation?

Answer 9

Reduced intersitial growth

Question 10

Osteoporosis commonly occurs in older women as estrogen levels drop. Why?

Answer 10

Because estrogen stimulates osteoblasts

Question 11

Secretion of parathyroid hormone results in the activation of osteoclasts. This will have what effect?

Answer 11

Raise blood calcium levels

Question 12

A patient develops a tumor in one of their parathyroid glands, causing an increase in the release of parathyroid hormone into the blood. What would be the result?

Answer 12

High blood concentration than normal

Question 13

What and where is the parathyroid hormone?

Answer 13

The parathyroid glands are located behind the thyroid and these hormones help to regulate free calcium concentrations in our body

Question 14

What does too much calcium levels do to parathyroid release?

Answer 14

Inhibit by Hypercalcmia

Question 14

What does to little calcim do to parathyroid release?

Answer 14

Stimulated by hypocalcimia

Question 14

Overproduction of GH in children results in ____

Answer 14

Gigantism

Question 14

What happens at the closure of epiphyseal plates?

Answer 14

Osteoblasts outcompete chondrocytes and it is completely ossified

Question 15

Think back to our discussion about cell membrane transport from the beginning of the course. Based on the chart above and your own prior knowledge, which of the following hormones would be able to diffuse directly through the cell membrane?

Answer 15

Progesterone and Testosterone because they are steriod hormones

Question 16

True or False: Human growth hormone will bind to an intracellular receptor to create a hormone-receptor complex.

Answer 16

False; Human growth hormone is a protein hormone, so it cannot diffuse into a cell to reach an intracellular receptor. Instead, it will bind to a cell membrane receptor.

Question 17

A person has a genetic mutation in the receptor for GH that prevents the hormone from binding to target cells. What levels of IGF-1 do you find in the person?

Answer 17

Lower levels than normal; If GH cannot bind to target cells, then it will not be able to trigger the production of IGF-1 in target cells in the liver, leading to lower levels of IGF-1.

Question 18

The hypothalamus is a part of which region of the brain?

Answer 18

Diencephalon

Question 19

A patient develops a tumor in one of their parathyroid glands, causing an increase in the release of parathyroid hormone into the blood. What would be the result?

Answer 19

Higher blood calcium concentrations than normal (hypercalcemia). PTH stimulates osteoclasts to release calcium from the skeleton into the blood and prevents the kidneys from removing as much calcium from the blood. This has the effect of raising blood calcium levels.

Question 20

A patient develops a problem with their thyroid, where the thyroid is unable to produce calcitonin. What would be the result?

Answer 20

Hypercalcemia.
Calcitonin causes calcium to be stored in the skeleton and/or removed from the blood by the kidneys. Without calcitonin, calcium levels in the blood would therefore increase (hypercalcemia).