Ch 10 Endocrine

Question 1

What are hormones?

Answer 1

Chemicals that alter the metabolic activities of many different tissues and organs

Chemical messengers that are released in one tissue and transported by the bloodstream to target cells in other tissues.

Question 2

Three groups hormones can be divided into based on chemical structure

Answer 2

amino acid derivatives

peptide hormones

lipid derivatives

Question 3

What are amino acid derivatives

Answer 3

AA derivatives are structurally similar to amino acids, relatively small molecules.

Epi, norepinephrine, thyroid hormones, and melatonin

Question 4

What are peptide hormones?

Answer 4

Chains of amino acids.

Range from short chain polypeptides such as antidiuretic hormone ADH and oxytocin

To small proteins such as growth hormone and prolactin..

Includes all hormones secreted by the hypothalamus, pituitary gland, heart, kidneys, thymus, digestive tract, and pancreas

Question 5

Endocrine system

Answer 5

Includes all the endocrine cells and tissues of the body.

Question 6

Endocrine cells

Answer 6

glandular secretory cells that release their secretions into the extracellular fluid.

Question 7

Exocrine cells

Answer 7

Secrete onto epithelial surfaces.

Sweat glands

Question 8

what are lipid derivatives

Answer 8

Two classes of lipid based hormones:
Steroid hormones:lipids that are structurally similar to cholesterol

eicosanoids: fatty acid based compounds derived from the 20 carbon fatty acid arachidonic acid. Affect blood clotting. they include prostaglandin.

Question 9

What are target cells?

Answer 9

Each hormone has one, they are specific cells that have the receptors that bind and read the hormonal message when it arrives.

Question 10

What is the first messenger hormone

Answer 10

Hormone that binds to a receptor on the plasma membrane surface.

Question 11

What is the second messenger hormone?

Answer 11

Intermediary molecule that forms due to hormone-receptor interaction.

Question 12

Hormones may circulate (blank) or be carried by transport (blank)

Answer 12

freely, Proteins

Free hormones are rapidly removed from the bloodstream.

Question 13

What is endocrine activity or hormone secretion mainly controlled by

Answer 13

Negative feedback

Question 14

What does the hypothalamus do?

Answer 14

It regulates the activities of the nervous site and endocrine system in 3 ways

1. synthesizes and secretes two hormones into the bloodstream at the posterior lobe of the pituitary gland.
2. Secretes regulatory hormones that control the activities of endocrine cells in the anterior lobe of the pituitary gland
3. exerts direct neural control over the endocrine cells of the adrenal medullae

Question 15

Pituitary gland (hypophysis)

Answer 15

Releases 9 important peptide hormones; all bind to membrane receptors, and most use cyclic-AMP as a second messenger

7 come from the anterior lobe and 2 from posterior.

Question 16

Hypophyseal Portal system

Answer 16

Ensures that all the blood entering the portal vessels will reach target cells in the anterior lobe of the pituitary gland before returning to the general circulation.

Question 17

7 hormones of the anterior lobe of the pituitary gland

Answer 17

1. thyroid stimulating hormone-thyroid hormones
2. adrenocorticotropic hormone-steroid hormones
3. FSH-sperm production
4. LH-ovulation/testosterone
5. Prolactin-milk production
6. GH-HGH
7. Melanocyte-stim. hormone

Question 18

2 hormones posterior lobe secrete

Answer 18

1. ADH released when body is low on water.

2. Oxytocin- promotes labor and delivery, stimulates contractions

Question 19

What are thyroid follicles and what do they release?

Answer 19

Spheres lined by a simple cuboidal epithelium

T4(thyroxine)
T3(triiodothyronine)

Question 20

What are C cells and what do they produce?

Answer 20

C cells, or parafollicular cells, are endocrine cells sandwiched between the follicle cells and their basement membrane.

C cells produce the hormone calcitonin. Helps regulate calcium concentrations in body fluids.

Question 21

Note*
The 4 parathyroid glands, embedded in the posterior surfaces of the thyroid gland, secrete parathyroid hormone to elevate blood calcium levels.

Question 22

Adrenal glands

Answer 22

superficial to kidneys
two parts with separate functions
outer adrenal cortex
inner adrenal medulla
secrete epic and norepi

Question 23

What does the adrenal cortex manufacture?

Answer 23

more than two dozen Steroid hormones collectively called corticosteroids.

In the blood stream, these hormones are bound to transport proteins.

Question 24

What are mineralocorticoids?

Answer 24

They affect the electrolyte composition of body fluids.

Question 25

What is aldosterone?

Answer 25

It is the principal MC (mineralocorticoids) of the adrenal cortex. It stimulates the conservation of sodium ions and the elimination of potassium ions by targeting cells that regulated the ionic composition of excreted fluids.

Specifically it causes the region of sodium by preventing the loss of sodium ions in urine, sweat, and saliva.

Question 26

adrenal medulla

Answer 26

Produces epinephrine and norepinephrine

Increases cardiac activity, blood glucose levels; release of lipids by adipose tissue

Question 27

What is the pineal gland?

Answer 27

The pineal gland lies in the posterior portion of the roof of the third ventricle. It contains neurons, glial cells, and secretory cells that synthesize the hormone melatonin.

Question 28

The pancreas, its location, and its characteristics

Answer 28

Lies in the J shaped loop between the stomach and proximal portion of the small intestine.
It contains both exocrine and endocrine cells
Its primarily a digestive organ whose exocrine cells make the digestive enzymes.

Question 29

Pancreatic islets

Answer 29

Cells of the endocrine pancreas form clusters called pancreatic islets, containing alpha cells and beta cells. Alpha cells produce glucagon, and beta produce insulin.

Question 30

what is calcitriol?

Answer 30

Secreted by the kidneys

Stimulates the absorption of calcium and phosphate ions across the intestinal lining of the digestive tract.

Question 31

What is erythropoietin (EPO)

Answer 31

released by the kidneys in response to low oxygen levels in kidney tissues.

EPO stimulates the red bone marrow to produce red blood cells.

Question 32

What is renin

Answer 32

Released by specialized kidney cells

In response to decline in blood volume, blood pressure, or both.

Renin activity leads to a formation of angiotensin II (vasoconstrictor) which is the hormone that stimulated the production of aldosterone in the adrenal cortex.

Question 33

The heart endocrine response

Answer 33

The endocrine cells in the heart are cardiac muscle cells in the walls of the right atrium; this chamber receives blood from the largest veins.

if blood volume becomes to great, these cardiac muscle cells are stretched, stimulating them to release the hormone atrial natriuretic peptide (ANP) which promotes the loss of sodium ions and water by the kidneys.

Question 34

the thymus

Answer 34

Produces several hormones called thymosins which play a role in developing and maintaining normal immune defenses.

Question 35

The testes

Answer 35

The interstitial cells of the testes produce the steroid hormones know as androgens. Testosterone is the most important androgen.

Question 36

Events that could happen if hormones interact with each other

Answer 36

1. antagonistic (opposite0
2. synergistic (additive)
3. permissive
4. integrative