Endocrine System

Question 1

What are the two types of secretions of the endocrine system?

Answer 1

Steroid hormones and Non Steroid hormones

Steroid hormones can pass through the target cell’s membrane, while non-steroid hormones bind at receptors.

Question 2

How does the nervous system respond compared to the endocrine system in maintaining homeostasis?

Answer 2

Nervous system responds quickly through electrical impulses, while the endocrine system responds slowly with hormones released into the bloodstream

The nervous system’s response is short-lived, whereas the endocrine response is longer lasting.

Question 3

How do steroid hormones affect target cells?

Answer 3

Steroid hormones can pass through the target cell’s membrane, altering the action of the cell.

Question 4

How do nonsteroid hormones affect target cells?

Answer 4

Nonsteroid hormones bind at receptors since they cannot pass through cell membranes.

Question 5

What is the role of negative feedback mechanisms in hormonal secretions?

Answer 5

Negative feedback mechanisms stop or lower the input.

Question 6

Where is the anterior pituitary located?

Answer 6

In front of the posterior pituitary.

Question 7

List the hormones secreted by the anterior pituitary and their functions.

Answer 7

• TSH (Thyroid Stimulating Hormone) - stimulates the thyroid
• ACTH (Adrenocorticotropic hormone) - stimulates the adrenal glands
• GH (Growth Hormone) - stimulates growth (bone/muscle)
• MSH (Melanocyte-Stimulating Hormone) - stimulates melanocytes (melanin)
• Prolactin - stimulates milk production
• Gonadotrophs - stimulates sex hormones (testes, ovaries)

Question 8

Where is the posterior pituitary located?

Answer 8

Behind the anterior pituitary.

Question 9

List the hormones secreted by the posterior pituitary and their functions.

Answer 9

• AH (Antidiuretic hormone) - increases water retention in the kidneys, decreasing urination
• Oxytocin - stimulates breast milk production and labor contractions

Question 10

How is the secretion of each pituitary hormone regulated?

Answer 10

All are regulated by the hypothalamus.

Question 11

Where is the thyroid gland located?

Answer 11

In the neck.

Question 12

List the hormones secreted by the thyroid gland and their functions.

Answer 12

• Calcitonin - decreases calcium levels in the blood
• T3 & T4 (Thyroxine & Triiodothyronine) - regulate metabolism, body temperature, oxygen levels, blood pressure

Question 13

How is the secretion of thyroid hormones regulated?

Answer 13

By the hypothalamus through a negative feedback loop.

Question 14

Where are the parathyroid glands located?

Answer 14

On the posterior part of the thyroid.

Question 15

What hormone do the parathyroid glands secrete and what is its function?

Answer 15

• PTH (Parathyroid hormone) - increases calcium levels in the blood.

Question 16

How is the secretion of parathyroid hormone regulated?

Answer 16

By the hypothalamus.

Question 17

Where are the adrenal glands located?

Answer 17

Above the kidneys.

Question 18

List the hormones secreted by the adrenal glands and their functions.

Answer 18

• Glucocorticoids - regulate levels to recover (return back to level)
• Epinephrine & norepinephrine - regulate fight/flight response, blood flow, heart rate, oxygen levels, body temperature

Question 19

How is the secretion of adrenal hormones regulated?

Answer 19

By the hypothalamus.

Question 20

Where is the pancreas located?

Answer 20

In the abdominal cavity.

Question 21

List the hormones secreted by the pancreas and their functions.

Answer 21

• Insulin - lowers blood glucose levels
• Glucagon - increases blood glucose levels

Question 22

How is the secretion of pancreatic hormones regulated?

Answer 22

• Insulin - regulated by beta cells through negative feedback
• Glucagon - regulated by alpha cells through negative feedback

Question 23

Where is the pineal gland located?

Answer 23

In the posterior half of the brain.

Question 24

What hormone does the pineal gland secrete and what is its function?

Answer 24

• Melatonin - regulates sleep/wake cycle (circadian rhythm).

Question 25

Where is the thymus located?

Answer 25

In the upper chest behind the breastbone.

Question 26

List the hormones secreted by the thymus and their functions.

Answer 26

• Thymopoietin - development of immune system
• Thymic factor - development of immune system
• Thymosin - development of immune system

Question 27

What hormones do the ovaries secrete and their functions?

Answer 27

• Estrogen - maturation of sex organs, secondary sex characteristics
• Progesterone - controls menstruation, contributes to breast development (ability to produce milk)

Question 28

What hormone do the testes secrete and its function?

Answer 28

• Testosterone - maturation of sex organs, secondary sex characteristics, sperm production.

Question 29

How is the secretion of the hormones from the pineal, thymus, and other endocrine glands regulated?

Answer 29

By negative feedback loops and the hypothalamus.

Question 30

Hormonal Stimulus

Answer 30

glands are stimulated by a hormone secreted by the other glands
ex.) hypothalamus triggers pituitary

Question 31

Humoral stimulus

Answer 31

Levels of nutrients or ions in the gland trigger hormones to secrete
ex.) Ca+ levels increase/decrease from expected level trigger the parathyroid

Question 32

Neural stimuli

Answer 32

Nerve impulse causes a gland to secrete
ex.) sympathetic nervous System triggers adrenal glands (when stressed)