Ch 10 Endocrine Flashcards by Brooks Lane

What are hormones?

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.

How well did you know this?

Not at all

Perfectly

Three groups hormones can be divided into based on chemical structure

amino acid derivatives

peptide hormones

lipid derivatives

How well did you know this?

Not at all

Perfectly

What are amino acid derivatives

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

Epi, norepinephrine, thyroid hormones, and melatonin

How well did you know this?

Not at all

Perfectly

What are peptide hormones?

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

How well did you know this?

Not at all

Perfectly

Endocrine system

Includes all the endocrine cells and tissues of the body.

How well did you know this?

Not at all

Perfectly

Endocrine cells

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

How well did you know this?

Not at all

Perfectly

Exocrine cells

Secrete onto epithelial surfaces.

Sweat glands

How well did you know this?

Not at all

Perfectly

what are lipid derivatives

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.

How well did you know this?

Not at all

Perfectly

What are target cells?

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

How well did you know this?

Not at all

Perfectly

What is the first messenger hormone

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

How well did you know this?

Not at all

Perfectly

What is the second messenger hormone?

Intermediary molecule that forms due to hormone-receptor interaction.

How well did you know this?

Not at all

Perfectly

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

freely, Proteins

Free hormones are rapidly removed from the bloodstream.

How well did you know this?

Not at all

Perfectly

What is endocrine activity or hormone secretion mainly controlled by

Negative feedback

How well did you know this?

Not at all

Perfectly

What does the hypothalamus do?

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

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

How well did you know this?

Not at all

Perfectly

Pituitary gland (hypophysis)

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.

How well did you know this?

Not at all

Perfectly

Hypophyseal Portal system

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.

7 hormones of the anterior lobe of the pituitary gland

thyroid stimulating hormone-thyroid hormones
adrenocorticotropic hormone-steroid hormones
FSH-sperm production
LH-ovulation/testosterone
Prolactin-milk production
GH-HGH
Melanocyte-stim. hormone

2 hormones posterior lobe secrete

ADH released when body is low on water.

2. Oxytocin- promotes labor and delivery, stimulates contractions

What are thyroid follicles and what do they release?

Spheres lined by a simple cuboidal epithelium

T4(thyroxine)
T3(triiodothyronine)

What are C cells and what do they produce?

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.

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

Adrenal glands

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

What does the adrenal cortex manufacture?

more than two dozen Steroid hormones collectively called corticosteroids.

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

What are mineralocorticoids?

They affect the electrolyte composition of body fluids.

What is aldosterone?

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.

adrenal medulla

Produces epinephrine and norepinephrine Increases cardiac activity, blood glucose levels; release of lipids by adipose tissue

What is the pineal gland?

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.

The pancreas, its location, and its characteristics

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.

Pancreatic islets

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

what is calcitriol?

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

What is erythropoietin (EPO)

released by the kidneys in response to low oxygen levels in kidney tissues. EPO stimulates the red bone marrow to produce red blood cells.

What is renin

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.

The heart endocrine response

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.

the thymus

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

The testes

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

Events that could happen if hormones interact with each other

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