Endo Exam 3

Comprehensive vocabulary flashcards covering endocrine concepts, hormone synthesis, regulation, and clinical pathologies from Endocrinology Exam 3.

*S phase

A cell passes through specific stage in it’s life cycle in which DNA is being duplicated.

Anterior pituitary

In which endocrine gland is growth hormone (GH) is produced.

Recombinant bovine growth hormone.

What does rBGH stand for?

Increase protein synthesis, inc mobilization of FA, dec rate of glucose utilization

We know that the major role of growth hormone is its effect on growth. However, even after cessation of somatic growth, GH exerts significant diverse actions in adult life. What are these major metabolic effects?

IGF-I

The effects of GH on growth are mediated indirectly by which hormone?

Liver

What is the major site of production of IGF-1?

What are the major target tissues for IGF-1?

required in glucose uptake and for inc incorporation of AA into muscles

While insulin is important in glucose homeostasis, it is also one of the “growth hormones”. Why is insulin required for anabolic effects for growth hormone to occur?

Prolactin

Which hormone, which shares a common ancestral gene with GH, is essential for ductile branching (pre- and post-pubertal) to form fully developed mammary glands and also stimulates milk production after parturition?

Placental lactogen

Which hormone is produced only during pregnancy (disappears from circulation immediately after delivery) and whose major role is to stimulate the development of the mammary gland during pregnancy without causing milk secretion during pregnancy?

Offer adequate supply of glucose, AA, and minerals to fetus in late pregnancy and it increases FA mobilization and utilization by the mother

Why would placental lactogen decrease insulin sensitivity during pregnancy?

*Erythropoietin

We discussed many growth factors in class. Three of these discussed were hematopoeitic growth factors. Which one is involved in red blood cell production and function?

*Epidermal growth factor (EGF)

Which growth factor has many functions, including epithlelial growth and development in many tissues and is a major growth promoting agent in human breast milk?

Accumlates iodine in great quantities and combine it into hormones; stores large amount of inactive hormone

Why is the thyroid gland considered to be such a unique gland compared to other endocrine glands?

false

T/F: The thyroid gland in humans is completely separated into two parts on either side of the esophagus.

iodine; tyrosine

The main function of the thyroid gland is to accumulate _____(element) and cause its attachment to ____(AA) in order to form the thyroid hormones.

Thyroglobulin

What is the large glycoprotein molecule necessary for thyroid hormone synthesis?

follicular cells

Where in the follicle is this large glycoprotein molecule synthesized?

Thyroid peroxidase (TPO)

The enzyme that catalyzes most of the steps in thyroid hormone synthesis.

Triiodothyronine ($T_3$)

The most biologically active thyroid hormone, formed by coupling monoiodotyrosine (MIT) with diiodotyrosine (DIT) or by the deiodination of $T_4$.

Thyroxine ($T_4$)

The thyroid hormone formed by coupling two diiodotyrosine (DIT) molecules; it is the thyroid hormone secreted in the largest quantity by the thyroid gland.

Colloid droplets

Droplets that transport thyroid hormones out of the follicular lumen to be released into circulation via enzymatic action.

Thyroid-stimulating hormone (TSH)

An anterior pituitary hormone that increases all thyroid gland activity.

Thyrotropin-releasing hormone (TRH)

A hypothalamic releasing hormone involved in the negative feedback loop from the thyroid gland that triggers the release of TSH.

Hyperthyroidism

A condition characterized by increased heart rate, cardiac output, weight loss, protruding eyeballs, fatigue with an inability to sleep, and an enlarged thyroid gland.

Hypothyroidism

A condition characterized by elevated serum cholesterol and suppressed hair growth.

Cassava

A plant known to act as a goitrogenic substance if consumed in high quantities.

Thyroxine-binding globulin

The primary thyroid hormone binding protein in cattle, sheep, swine, horses, and humans.

Chromaffin cells

Cells in the adrenal medulla where epinephrine and norepinephrine are synthesized and stored.

Tyrosine to DOPA

The rate-limiting enzymatic step in the synthesis of catecholamine hormones.

Phenylethanolamine N-methyltransferase

An enzyme induced by glucocorticoids that enhances the synthesis of epinephrine in the adrenal gland.

Desmolase

A mitochondrial enzyme that catalyzes the initial step of adrenal steroid hormone synthesis by converting cholesterol to pregnenolone.

Cortisol

The primary glucocorticoid in humans, sheep, horses, dogs, pigs, and cats.

Angiotensin-converting enzyme (ACE)

An enzyme required for the conversion of angiotensin I to angiotensin II, playing an important role in the regulation of aldosterone.

Atrial Natriuretic Factor (ANF)

A hormone secreted by the heart in response to elevated blood pressure that inhibits the angiotensin system and prevents aldosterone production.

Cushing's Disease

A disorder of the adrenal cortex marked by excess cortisol production, causing bone fractures, muscle weakness, and fat redistribution to the neck and abdomen.

Proopiomelanocortin (POMC)

A precursor protein encoding ACTH and MSH; its excess production in Addison's disease leads to increased skin pigmentation.

11-beta-hydroxysteroid dehydrogenase

An enzyme that converts cortisol to cortisone and is inhibited by the consumption of licorice.

Zilmax

The trade name of a $\beta$-agonist previously used in the beef cattle industry to promote lean muscle gain before being banned.

Paylean

The trade name for ractopamine hydrochloride used as a $\beta$-agonist in the swine industry.

Optaflexx

The trade name for ractopamine hydrochloride used as a $\beta$-agonist in the beef industry.