Week 6 - The Endocrine System

Question 1

What are the major endocrine glands?

Answer 1

Pineal gland, hypothalamus, pituitary gland, thyroid, parathyroid, pancreas, adrenal glands, ovaries, testes.

Question 2

Which hormone does the pineal gland secrete?

Answer 2

Melatonin.

Question 3

What is the function of melatonin?

Answer 3

Regulates sleep-wake cycles (circadian rhythm).

Question 4

What hormone-releasing functions does the hypothalamus have?

Answer 4

Produces releasing and inhibiting hormones that control the anterior pituitary and synthesizes oxytocin and ADH for posterior pituitary.

Question 5

Name two hormones released by the posterior pituitary.

Answer 5

Oxytocin and antidiuretic hormone (ADH).

Question 6

What is the “master gland” of the endocrine system?

Answer 6

The pituitary gland.

Question 7

What hormones are secreted by the anterior pituitary?

Answer 7

GH, TSH, ACTH, LH, FSH, and prolactin.

Question 8

What hormone does the thyroid gland produce?

Answer 8

Triiodothyronine (T3) and thyroxine (T4).

Question 9

What is the role of thyroid hormones?

Answer 9

Regulate metabolism, growth, and development.

Question 10

Where are the parathyroid glands located?

Answer 10

On the posterior surface of the thyroid gland.

Question 11

Which hormone regulates calcium levels in the blood?

Answer 11

Parathyroid hormone (PTH).

Question 12

What are the endocrine functions of the pancreas?

Answer 12

Secretes insulin and glucagon to regulate blood glucose.

Question 13

What hormones are secreted by the adrenal cortex?

Answer 13

Cortisol, aldosterone, and androgens.

Question 14

What hormones are secreted by the adrenal medulla?

Answer 14

Adrenaline (epinephrine) and noradrenaline (norepinephrine).

Question 15

Which glands secrete sex hormones?

Answer 15

Ovaries (estrogen, progesterone) and testes (testosterone).

Question 16

How do hormones travel in the blood?

Answer 16

Water-soluble hormones travel dissolved freely; lipid-soluble hormones travel bound to carrier proteins.

Question 17

Where are receptors for water-soluble hormones located?

Answer 17

On the cell membrane surface.

Question 18

Where are receptors for lipid-soluble hormones located?

Answer 18

Inside the cytoplasm or nucleus.

Question 19

Describe the action mechanism of water-soluble hormones.

Answer 19

Bind membrane receptors → activate second messengers (e.g., cAMP) → rapid cellular response.

Question 20

Describe the action mechanism of lipid-soluble hormones.

Answer 20

Diffuse through membrane → bind intracellular receptors → affect gene transcription → slower, long-lasting effects.

Question 21

What structural connection links the hypothalamus and the posterior pituitary?

Answer 21

Neural axons from hypothalamic neurons.

Question 22

How does the hypothalamus regulate the anterior pituitary?

Answer 22

Via releasing and inhibiting hormones through the hypothalamic-hypophyseal portal system.

Question 23

What hormone does TRH stimulate the anterior pituitary to release?

Answer 23

Thyroid-stimulating hormone (TSH).

Question 24

What triggers the release of oxytocin from the posterior pituitary?

Answer 24

Neural signals from the hypothalamus.

Question 25

What is the primary function of antidiuretic hormone (ADH)?

Answer 25

Regulates water retention by the kidneys.

Question 26

What is the role of the hypothalamic-hypophyseal portal system?

Answer 26

Carries hypothalamic hormones to the anterior pituitary.

Question 27

What is the main function of thyroid follicles?

Answer 27

Store thyroid hormone precursors in colloid.

Question 28

What mineral is essential for thyroid hormone synthesis?

Answer 28

Iodine.

Question 29

What effect do thyroid hormones have on metabolism?

Answer 29

They increase basal metabolic rate.

Question 30

What is the negative feedback loop in thyroid hormone regulation?

Answer 30

Elevated T3/T4 inhibit TRH and TSH secretion to reduce hormone levels.

Question 31

Define hyperthyroidism.

Answer 31

Excess thyroid hormone production causing increased metabolism.

Question 32

Define hypothyroidism.

Answer 32

Low thyroid hormone production causing decreased metabolism.

Question 33

What is a negative feedback loop?

Answer 33

A control system where the output inhibits the initial stimulus to maintain homeostasis.

Question 34

What is a positive feedback loop?

Answer 34

A control system where the output enhances the initial stimulus.

Question 35

Give an example of a hormone regulated by positive feedback.

Answer 35

Oxytocin during childbirth.

Question 36

How does oxytocin function in childbirth?

Answer 36

Stimulates uterine contractions, which trigger more oxytocin release.

Question 37

What is the role of growth hormone (GH)?

Answer 37

Stimulates growth and metabolism in tissues.

Question 38

What hormone stimulates cortisol release from the adrenal cortex?

Answer 38

Adrenocorticotropic hormone (ACTH).

Question 39

What hormone regulates sodium and water balance?

Answer 39

Aldosterone.

Question 40

What is the difference between endocrine and exocrine glands?

Answer 40

Endocrine glands secrete hormones into the blood; exocrine glands secrete substances via ducts.

Question 41

How does insulin affect blood glucose?

Answer 41

Lowers blood glucose by promoting cellular uptake.

Question 42

How does glucagon affect blood glucose?

Answer 42

Raises blood glucose by promoting glycogen breakdown.

Question 43

What is the primary function of follicle-stimulating hormone (FSH)?

Answer 43

Stimulates gamete production (sperm and ova).

Question 44

What hormone causes milk production?

Answer 44

Prolactin.

Question 45

What is the function of luteinizing hormone (LH)?

Answer 45

Triggers ovulation and testosterone production.

Question 46

What type of hormone is cortisol?

Answer 46

A steroid hormone.

Question 47

Which gland secretes adrenaline?

Answer 47

Adrenal medulla.

Question 48

How do hormones recognize their target cells?

Answer 48

Target cells have specific receptors for that hormone.

Question 49

Why do lipid-soluble hormones have longer-lasting effects?

Answer 49

Because they alter gene expression and protein synthesis.

Question 50

What hormone is involved in water retention by kidneys?

Answer 50

Antidiuretic hormone (ADH).

Question 51

What hormone triggers uterine contractions and milk ejection?

Answer 51

Oxytocin.

Question 52

What structure connects the hypothalamus and anterior pituitary?

Answer 52

The hypothalamic-hypophyseal portal blood vessels.

Question 53

How is the secretion of anterior pituitary hormones controlled?

Answer 53

By hypothalamic releasing and inhibiting hormones.

Question 54

Which hormone regulates calcium homeostasis?

Answer 54

Parathyroid hormone (PTH).

Question 55

What hormone does the adrenal cortex secrete in response to stress?

Answer 55

Cortisol.

Question 56

What is the role of the pancreas in the endocrine system?

Answer 56

Secretes insulin and glucagon to regulate blood sugar.

Question 57

What happens if thyroid hormone levels are low?

Answer 57

Hypothalamus and anterior pituitary increase TRH and TSH secretion.

Question 58

What does TSH stimulate?

Answer 58

The thyroid gland to produce T3 and T4.

Question 59

How does the body stop the oxytocin positive feedback loop?

Answer 59

When the baby is delivered, uterine stretch stimulus ends.

Question 60

What is the main function of the hypothalamus in the endocrine system?

Answer 60

To integrate neural and endocrine signals and control pituitary secretion.