9/4 Edocrine Intro

Question 1

What are the organs that are traditionally associated with the edocrine system

Answer 1

pineal gland; hyothalamus; pituitary gland’ thyroid gland’ parathyroid glands (dorsal the thyroid). Thymus; adrenal glands; pancreas; ovary; testies.

Question 2

what are some non-traditional endocrine organs?

Answer 2

the heart, adipose tissue (leptin), the stomach etc.

Question 3

what is a parabiosis experiment?

Answer 3

A pairing of two mice together so that they share blood flow.

Question 4

describe the ob/ob and db/db mice

Answer 4

ob/ob+nomral = weight gain of ob/ob mouse suppressed. db/db+normal= normal mouse loses weight and dies; db/db+ob/ob = the mouse slowly loses weight and dies. therefore the ob gene must encode leptin hormone. the db gene codes the leptin receptor.

Question 5

how is endocrine like a radio signal

Answer 5

they go through out the entire body

Question 6

why do not all cells respond to the endocrine signals moving through the blood

Answer 6

not all of them have the receptors, and those that don’t ignore the receptor.

Question 7

describe the regulation of the thyroid hormone secretion

Answer 7

hypothalmus: TRH (thyrotropin releasing hormone) release stimulates the pituitary: Pituitary releases TSH (thyroid stimulating hormone) Thyroid releases T4,T3 (thyroid hormone). Then as the T4,T3 go up that inhibits the release of TRH and TSH.

Question 8

what is the axis of Thyroid hormone (what organs involved) and what do they release

Answer 8

Hypothalamus to pituitary to Thyroid

Question 9

what do we need to make thyroid hormone (in diet)

Answer 9

iodine

Question 10

How do we produce T3/T4

Answer 10

bring in iodine; thyroglobulin secretion (after it is translated and sent through the secretion system). thyrogloblin is secreted into the lumen of the folicle. thyroglobulin has lots of tyrosine, and these get iodine added to them (iodinated). then conjugation reaction and the tyrosine will conjugate into pairs! This is endocytose, and proteased and then you get thyroxin and triiodethyronine ( this is T3 and T4)

Question 11

what is an apparent mode of regulation of thyroid hormone based on the result of the production of thyroid hormone.

Answer 11

T4 is created in more abundance (thyroxine) and T3 is the active one (triiodothyronine).

Question 12

what signaling leads to the release of T3, (Thyroid hormone)

Answer 12

TSH binds to G-protien coupled receptor; protien kinase C pathway and then get synthesis of T4, T3

Question 13

how does thyroid hormone get activated? (from T3 to T4)

Answer 13

T4 is processed by a Deiodinase within the target cell itself

Question 14

why make more T4 (inactive) than T3?

Answer 14

to give the target cell the ability to control the level of active hormone

Question 15

how does T3 signal in a cell

Answer 15

it acts as a hormone receptor and act directly on a the DNA

Question 16

what are the major effects of thyroid hormone?

Answer 16

affeccts growth (up) / CNS (maturation of CNS)/ metabolic rate (up na/k atpase up O2 consulmption, up heat production, up BMR) / metabolism (up glusocse absorption up glycogenolysis up gluconoegenis etc.)/ cardiovascular output (increases it)

Question 17

what would a TSH receptor agonist lead to?

Answer 17

activate the receptor for TSH which would then activate the thyroid to produce the thyroid hormone, and this would lead to graves disease (hyerthyroidism). where you have elevated heart rate, and high metabolic rate, sweats etc.

Question 18

what would cause a Goiter and why?

Answer 18

overactive thyroid either because of a loss of regulation or a lack of enough iodine to produce the needed T3/T4 hormone.