The Endocrine System

Question 1

What are the three basic endocrine hormones?

Answer 1

1. Peptide hormones
2. Steroid hormones
3. Tyrosine derivatives

Question 2

Name the peptide hormones from the anterior pituitary gland.

Answer 2

1. FSH (follicle-stimulating hormone)
2. LH (leutinizing hormone)
3. ACTH (adrenocorticotropin)
4. hGH (human growth hormone)
5. TSH (thyroid-stimulating hormone)
6. Prolactin

Question 3

Name the peptide hormones from the posterior pituitary gland.

Answer 3

1. ADH

2. Oxytocin

Question 4

Name the parathyroid peptide hormone.

Answer 4

1. PTH

Question 5

Name the pancreatic peptide hormones.

Answer 5

1. glucagon

2. insulin

Question 6

Describe the function of a peptide hormone.

Answer 6

Peptide hormones are proteins that are water soluble, so they cannot diffuse through the cell membrane. They bind to receptors on the membrane and act through a second messenger.

Question 7

Describe the function of a steroid hormone.

Answer 7

Steroid hormones are lipids, and they can diffuse through the membrane and act on the nucleus.
They are derived from cholesterol.
The typical effect of a steroid hormone is to increase certain membrane or cellular proteins within the effector.

Question 8

Name the important steroid hormones:

Answer 8

(1) Glucocorticoids & mineral corticoids of the adrenal cortext: CORTISOL & ALDOSTERONE.
(2) The gonadal hormones: estrogen, progesterone, testosterone.

Question 9

Name the tyrosine derivatives:

Answer 9

(1) The thyroid hormones: T3 (triiodothyronine contains 3 iodine atoms), and T4.
(2) The catecholamines formed in the adrenal medulla: epinephrine and norepinephrine.

Question 10

If ADH holds water in the body, decreasing urine output and increasing blood pressure, does a person with high blood pressure have a high or low ADH blood level?

Answer 10

Low levels of ADH would be detected in the blood, as the ADH output responded to the body.
High levels of ADH is the incorrect answer, because that would mean that the ADH created the high blood pressure.

Question 11

A secondary effect of aldosterone is to increase blood pressure. Would expected aldosterone levels be high or low in a person with low blood pressure?

Answer 11

Aldosterone levels would be high. Since aldosterone increases blood pressure, and the body tries to bring blood pressure back to normal, the adrenal cortex should release more aldosterone into the blood.

Question 12

Describe the effect of the human growth hormone (hGH), released by the anterior pituitary.

Answer 12

The human growth hormone (hGH) is a peptide, and stimulates growth in almost all cells.

Question 13

Describe the effect of adrenocorticotropic hormone (ACTH), released by the anterior pituitary.

Answer 13

Adrenocorticotropic hormone (ACTH) is a peptide that stimulates the adrenal cortex to release glucocorticoids (stress hormones) via the second messenger system using cAMP.

Question 14

Describe the effect of the thyroid-stimulating hormone (TSH), released by the anterior pituitary.

Answer 14

The thyroid-stimulating hormone (TSH) is a peptide that stimulates the thyroid to release T3 and T4 via the second messenger system using cAMP. It also increases thyroid cell size, number, and the rate of secretion of T3 and T4.
IMPORTANT: T3 and T4 concentrations have a negative feedback effect on TSH release, both at the anterior pituitary and the hypothalmus.

Question 15

Describe the effect of Prolactin, released by the anterior pituitary.

Answer 15

Prolactin is a peptide hormone that promotes lactation (milk production) by the breasts.
Milk is not produced before birth, due to the inhibitory effects of progesterone and estrogen.
Milk production via prolactin is different than milk ejection, due to oxytocin.

Question 16

Describe the effect of oxytocin, released by the posterior pituitary.

Answer 16

Oxytocin is a small peptide that increases uterine contractions during pregnancy and causes milk to be ejected from the breasts.

Question 17

Describe the effect of the antidiuretic hormone (ADH), released from the posterior pituitary.

Answer 17

Antidiuretic hormone (ADH) is a small peptide hormone which causes the collecting ducts of the kidney to become permeable to water. This reduces the amount of urine, thus concentrating it. Since fluid is reabsorbed, ADH also increases blood pressure.