Endocrine System

Question 1

What is the chemical messenger used by the endocrine system?

Answer 1

Hormones

Question 2

How do nonsteroid hormones and steroid hormones differ?
How are they alike?

Answer 2

Non-Steroid - whole proteins, shorter chains of amino acids, or simply versions of single amino acids.
Steroid - small, lipid-soluble hormones. Nonsteroid hormones work as a second messenger mechanism, whereas steroid hormones pass directly through to a target cell

They both work with some form of receptor.

Question 3

What is a second messenger system?

Answer 3

A protein hormone acts as a first messenger, delivering a chemical message from the cells to highly specific membrane receptor sites on target cells. After connection with the specific receptor site, a number of chemical reactions occurs. These reactions activate molecules within the cells known as second messengers

Question 4

How does the lock-and-key method of chemical activity affect nonsteroid hormones?

Answer 4

The interaction between a hormone and its specific receptor site on the target cell’s plasma membrane is often compared with the fitting of a unique key into a lock. After the hormone successfully attaches to its specific receptor site, a number of chemical reactions occurs.

Question 5

How does negative feedback affect hormone levels in the blood?

Answer 5

Increase in blood glucose triggers secretion of insulin. Because insulin promotes glucose uptake by cells, the blood glucose level is restored to its lower normal level. Low blood sugar levels then cause endocrine cells in the pancreas to cease the production and release of insulin.

Question 6

Why are PGs called tissue hormones?

Answer 6

It is produced in a tissue and diffuses only a short distance to act on cells within that tissue.

Question 7

What are paracrine agents?
Give an example of one.

Answer 7

Prostaglandins (PGs), along with several other tissue hormones such as leukotrienes and thromboxane, are sometimes called paracrine agents. The term means “secrete beside,” which is appropriate for a regulatory agent that is released next to its target cell.

Question 8

How are the anterior pituitary and posterior pituitary different?
How are they alike?

Answer 8

The anterior pituitary gland secretes hormones just like the posterior pituitary gland. The anterior pituitary gland secretes hormones that stimulate another endocrine gland to grow and secrete hormones. The posterior pituitary gland secretes hormones that directly stimulate an organ. Both are controlled by the hypothalamus.

Question 9

What makes a hormone a tropic hormone?

Answer 9

They are stimulated by another endocrine gland to grow and secrete its own hormones.

Question 10

Name the hormones produced by the pituitary gland.

Answer 10

Growth hormone, adrenocorticotropic hormone, thyroid-stimulating hormone, gonadotropic hormones (FSH and LH), prolactin, oxytocin, antidiuretic hormone

Question 11

How does the hypothalamus control the pituitary gland?

Answer 11

Nerve stimulation, releasing and inhibiting hormones

Question 12

What hormone is being used by some people to keep feeling younger or to boost athletic performance?
Why is this not approved for safe use?

Answer 12

Human growth hormone (HGH) is used by some people to remain youthful or to boost athletic performance. This hormone has not been approved for this use and can have dangerous side effects by disrupting normal hormone balances in the body.

Question 13

Where are the thyroid and parathyroid glands located?

Answer 13

The thyroid lies in the neck just below the larynx; the parathyroid is found on the back of the thyroid gland.

Question 14

What gland stores its hormones for later use?

Answer 14

Thyroid

Question 15

CT and PTH both regulate the blood concentration for what important ion?

Answer 15

Calcium

Question 16

What hormones are exceptions to the general model of nonsteroid action requiring an internal second messenger?

Answer 16

T3 and T4 are small, nonsteroid hormones that are able to enter their target cells to find their receptors. This is an exception to the general model of nonsteroid action requiring an internal second messenger.

Question 17

Why is the adrenal gland often thought of as two separate glands?

Answer 17

Because it is actually two separate endocrine glands in one structure

Question 18

Name the hormones produced by the adrenal gland.

Answer 18

Mineralocorticoids (aldosterone), glucocorticoids (cortisol, hydrocortisone, epinephrine, and norepinephrine), and androgens

Question 19

How does the pituitary gland influence adrenal function?

Answer 19

In stress conditions the hypothalamus acts on the anterior pituitary gland to cause the release of ACTH, which stimulates the adrenal cortex to secrete glucocorticoids.

Question 20

Name the 2 primary hormones of the pancreatic islets.

Answer 20

Glucagon and insulin

Question 21

What effect does insulin have on the blood’s glucose concentration?

Answer 21

Insulin decreases blood glucose concentration

Question 22

How does diabetes produce glucose in the urine?

Answer 22

Excess glucose is filtered out of the blood by the kidneys and lost in the urine.

Question 23

Which hormones are produced by the male and female sex glands?

Answer 23

Female: Estrogen, progesterone; Male: Testosteron

Question 24

What is the role of thymosin?

Answer 24

Thymosin is the location where many of the body’s cells of immunity develop. The hormone thymosin is actually a group of several hormones that together play an important role in regulating the development and function of T cells – an important category of immunity agents in the body.

Question 25

Why is the placenta considered to be a gland?

Answer 25

It produces tropic hormones (chorionic gonadotropin).

Question 26

Why is the pineal gland sometimes called the timekeeper of the body?

Answer 26

Uses information regarding changing light levels to adjust its output of melatonin; melatonin levels increase during the night and decrease during the day, regulating sleep patterns.

Question 27

How many organs of the body are affected by hormone actions?

Answer 27

Every organ of the body is affected by hormone action.

Question 28

1. What is the difference between Endocrine and Exocrine glands?

Question 29

2. List the primary endocrine glands and identify the major hormones produced by each.

Question 30

3. Define the terms hormone, target cell, hypersecretion, and hyposecretion.

Question 31

4. Explain the mechanism of action of nonsteroid hormones.

Question 32

5. Explain the mechanism of action of steroid hormones.

Question 33

6. Explain & give an example of negative feedback loop for regulation of hormone secretion.

Question 34

7. Explain & give an example of a positive feedback loop for the regulation of hormone secretion.

Question 35

8. What is the difference between prostaglandins (PGs) and hormones?
   What body functions can be influenced by prostaglandins?

Question 36

9. Describe the structure of the pituitary gland and where it is located.

Question 37

10. Name the 4 tropic hormones released by the anterior pituitary gland and explain their functions.

Question 38

11. Explain the function of growth hormone.

Question 39

12. What is the function of ADH?

Question 40

13. Explain the function of Prolactin and Oxytocin.

Question 41

14. What is the function of the hypothalamus in the endocrine system?

Question 42

15. Explain the difference between T3 and T4. What is unique about the thyroid gland?

Question 43

16. Name the hormones produced by the zones or areas of the adrenal cortex.

Question 44

17. What is the function of aldosterone?

Question 45

18. Explain the function of glucocorticoids.

Question 46

19. What conditions may occur from hyposecretion and hypersecretion of the Growth Hormone (GH), Thyroid Gland, Adrenal Cortex and pancreas?