LO1 Endocrine System

Question 1

What method of communication does the endocrine system use?

Answer 1

chemical signaling

Question 2

Endocrine Glands

Question 3

Endocrine Gland Hormones ** See Chart 17.2 **

Question 4

Growth hormone (GH) - Gland/Effect/Chemical Class

Answer 4

• Promotes growth of body tissues
• Anterior Pituitary
• Protein

Question 5

Peptide Promotes milk production - Gland/Effect/Chemical Class

Answer 5

• Promotes milk production
• Pituitary (anterior)
• Peptide

Question 6

Thyroid-stimulating hormone (TSH) - Gland/Effect/Chemical Class

Answer 6

• Pituitary (anterior)
• Glycoprotein
• Stimulates thyroid hormone release

Question 7

Adrenocorticotropic hormone (ACTH) - Gland/Effect/Chemical Class

Answer 7

• Pituitary (anterior)
• Peptide
• Stimulates hormone release by adrenal cortex

Question 8

Types of Hormones ** See Chart 17.2 **

Answer 8

• Amine Hormone (Norepi)
• Peptide Hormone (Oxytocin)
• Protein Hormone (Growth Hormone)
• Steroid Hormone (Testosterone/Progesterone/Estrogen)

Question 9

Amine Hormones

Answer 9

Hormones derived from the modification of amino acids are referred to as amine hormones.

Question 10

Peptide Hormone Example

Answer 10

antidiuretic hormone (ADH), a pituitary hormone important in fluid balance, and atrial-natriuretic peptide, which is produced by the heart and helps to decrease blood pressure.

Question 11

Protein Hormone

Answer 11

• growth hormone, which is produced by the pituitary gland
• follicle-stimulating hormone (FSH), which has an attached carbohydrate group and is thus classified as a glycoprotein. FSH helps stimulate the maturation of eggs in the ovaries and sperm in the testes.

Question 12

Steroid Hormone

Answer 12

Estrogen/Testosterone
- Hydrophobic

Question 13

Pathways of hormone action

Answer 13

• Hormone Receptor
• Target Cell

Question 14

Pathways Involving Intracellular Hormone Receptors 17.2

Question 15

Pathways Involving Cell Membrane Hormone Receptors 17.2

Question 16

Downregulation

Answer 16

allows cells to become less reactive to the excessive hormone levels.

For example, the presence of a significant level of a hormone circulating in the bloodstream can cause its target cells to decrease their number of receptors for that hormone.

Question 17

Upregulation

Answer 17

When the level of a hormone is chronically reduced, target cells engage in upregulation to increase their number of receptors.

This process allows cells to be more sensitive to the hormone that is present. Cells can also alter the sensitivity of the receptors themselves to various hormones.

Question 18

The permissive effect

Answer 18

which the presence of one hormone enables another hormone to act.

Question 19

The synergistic effect

Answer 19

in which two hormones with similar effects produce an amplified response.

Question 20

The antagonistic effect

Answer 20

in which two hormones have opposing effects.
ex) Insulin and glucagon

Question 21

Humoral Stimuli

Answer 21

are changes in blood levels of non-hormone chemicals, such as nutrients or ions, which cause the release or inhibition of a hormone to, in turn, maintain homeostasis.

Question 22

Pituitary Hormones chart 17.3

Question 23

Anterior Pituitary Hormones and Chemical Class

Answer 23

• Growth Hormone (GH) (Protein) - Promotes growth of body tissues
• Prolactin (PRL) (Peptide) - Promotes milk production from mammary glands
• Thyroid-stimulating hormone (TSH) (Glycoprotein) - Stimulates thyroid hormone release from thyroid
• Adrenocorticotropic hormone (ACTH) (Peptide) - Stimulates hormone release by adrenal cortex
• Follicle-stimulating hormone (FSH) (Glycoprotein) - Stimulates gamete production in gonads
• Luteinizing hormone (LH) (Glycoprotein) - Stimulates androgen production by gonads

Question 24

Posterior Pituitary Hormones and Chemical Class

Answer 24

• Antidiuretic hormone (ADH) (Peptide) - Stimulates water reabsorption by kidneys
• Oxytocin (Peptide) - Stimulates uterine contractions during childbirth

Question 25

_____________ signal the posterior pituitary to release antidiuretic hormone (ADH)

Answer 25

osmoreceptors

Question 26

The target cells of ADH are located in the tubular cells of the _________

Answer 26

Kidneys

Question 27

Pituitary Gland

Question 28

Thyroid Gland

Question 29

Thyroid Hormones

Answer 29

Thyroxine (T4), triiodothyronine (T3) - (Amine) - Stimulate basal metabolic rate Calcitonin - (Peptide) - Reduces blood Ca2+ levels

Question 30

Parathyroid Gland

Question 31

Adrenal Gland

Question 32

Hormones of the Adrenal Glands

Answer 32

Adrenal gland Associated hormones Chemical class Effect Adrenal cortex Aldosterone Steroid Increases blood Na+ levels Adrenal cortex Cortisol, corticosterone, cortisone Steroid Increase blood glucose levels Adrenal medulla Epinephrine, norepinephrine Amine Stimulate fight-or-flight response

Question 33

Pineal Gland

Question 34

Pancreas

Question 35

Cells and Secretions of the Pancreatic Islets

Answer 35

The pancreatic islets each contain four varieties of cells: The alpha cell produces the hormone glucagon and makes up approximately 20 percent of each islet. Glucagon plays an important role in blood glucose regulation; low blood glucose levels stimulate its release. The beta cell produces the hormone insulin and makes up approximately 75 percent of each islet. Elevated blood glucose levels stimulate the release of insulin. The delta cell accounts for four percent of the islet cells and secretes the peptide hormone somatostatin. Recall that somatostatin is also released by the hypothalamus (as GHIH), and the stomach and intestines also secrete it. An inhibiting hormone, pancreatic somatostatin inhibits the release of both glucagon and insulin. The PP cell accounts for about one percent of islet cells and secretes the pancreatic polypeptide hormone. It is thought to play a role in appetite, as well as in the regulation of pancreatic exocrine and endocrine secretions. Pancreatic polypeptide released following a meal may reduce further food consumption; however, it is also released in response to fasting.

Question 36

Glucagon

Question 37

Insulin

Question 38

Hormones of the Pancreas

Answer 38

Associated hormones Chemical class Effect Insulin (beta cells) Protein Reduces blood glucose levels Glucagon (alpha cells) Protein Increases blood glucose levels Somatostatin (delta cells) Protein Inhibits insulin and glucagon release Pancreatic polypeptide (PP cells) Protein Role in appetite

Question 39

Reproductive Hormones

Answer 39

Gonad Associated hormones Chemical class Effect Testes Testosterone Steroid Stimulates development of secondary sex characteristics and sperm production Testes Inhibin Protein Inhibits FSH release from pituitary Ovaries Estrogens and progesterone Steroid Stimulate development of secondary sex characteristics and prepare the body for childbirth Placenta Human chorionic gonadotropin Protein Promotes progesterone synthesis during pregnancy and inhibits immune response against fetus

Question 40

Organs with Secondary Endocrine Functions and Their Major Hormones

Answer 40

Organ Major hormones Effects Heart Atrial natriuretic peptide (ANP) Reduces blood volume, blood pressure, and Na+ concentration Gastrointestinal tract Gastrin, secretin, and cholecystokinin Aid digestion of food and buffering of stomach acids Gastrointestinal tract Glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 1 (GLP-1) Stimulate beta cells of the pancreas to release insulin Kidneys Renin Stimulates release of aldosterone Kidneys Calcitriol Aids in the absorption of Ca2+ Kidneys Erythropoietin Triggers the formation of red blood cells in the bone marrow Skeleton FGF23 Inhibits production of calcitriol and increases phosphate excretion Skeleton Osteocalcin Increases insulin production Adipose tissue Leptin Promotes satiety signals in the brain Adipose tissue Adiponectin Reduces insulin resistance Skin Cholecalciferol Modified to form vitamin D Thymus (and other organs) Thymosins Among other things, aids in the development of T lymphocytes of the immune system Liver Insulin-like growth factor-1 Stimulates bodily growth Liver Angiotensinogen Raises blood pressure Liver Thrombopoietin Causes increase in platelets Liver Hepcidin Blocks release of iron into body fluids