Chemistry Unit 3.1

amine

tryptophan or tyrosine are modified to create amine hormone

peptide

considered to be an unbroken chain of amino acids of 50 or less

protein

made of chains of amino acids

glycoprotein

conjugated proteins bound to carbohydrates

steroid

derived from a lipid, typically cholesterol

follicle stimulating hormone and luteinizing hormone

secreted in the anterior pituitary gland and are both integral hormones in supporting reproduction

prolactin

peptide hormone secreted from anterior pituitary and primarily responsible for lactation and mammary gland development

androgens

produced as by-products of cortisol synthesis that are regulated by ACTH

progesterone

produced by the corpus luteum, a hormone secreting body formed from the ovary’s follicle after egg release

estrogens/estradiol/estriol

primarily metabolites of intraovarian and extraglandular conversion of androstenedione and testosterone

catechalomines

benzene ring with a catechol nucleus and 2 hydroxyl side groups linked to a sidechain amine

Thyroid hormone (T3, T4) and thyroid stimulating hormone (TSH)

activity of thyroid hormone depends on the location and number of iodine atoms

-circulates in the bloodstream where free T3 and T4 are available to travel across the cell membrane

posterior pituitary hormones

extension of the forebrain and represents the storage region for arginine vasopressin (AVP/ ADH) and oxytocin

calcitonin and procalcitonin

biomarker that aids in the risk assessment of critically ill patients on admission and continually for progression to severe sepsis and/or septic shock

parathyroid hormone (PTH)

increase the plasma calcium concentration by:

-increases bone resorption of calcium

-increase intestinal absorption of calcium

-increase removal of phosphate in the proximal and distal convoluted tubules in the kidneys

insulin

allows glucose to enter our peripheral cells and is the only hormone that decreases blood glucose concentrations

glucagon

helps the body to properly regulate the blood glucose concentration

gastrin and secretin

both help to regulate the acid-base balance in the lumen of the intestine

human chorionic gonadotropin (hCG)

hormone produced during pregnancy by the syncytiotrophoblast cells

serotonin

integral to regulating many of our behaviors, such as memory and mood

what are hormone metabolism processes?

alcohol consumption and adrenal steroid hormone synthesis

solubility

can be characterized as either water-soluble (hydrophilic) or fat-soluble (lipophilic)

carrier proteins

fat-soluble hormones are transported bound to a carrier protein

types of hormone transport

solubility and carrier-proteins

negative feedback mechanism

stimulus will feedback upstream to decrease the production itself

negative feedback mechanism example

thyroid

positive feedback mechansims

control mechanisms that increase the stimulus received until a distinct endpoint is achieved

positive feedback mechanisms can easily ______, as the mechanism exists to increase the stimulus

go out of control

positive feedback mechanism example

coagulation cascade

what are disorders of the endocrine glands characterized by?

the organ of disfunction

secondary or tertiary endocrine disorder

disorder affecting a regulating endocrine gland

primary endocrine disorder

final endocrine gland

what other factors can affect hormone levels?

emotional stress, time of day, menstrual cycle, menopause, food intake/diet, drugs

how can emotional stress affect hormone levels?

can lead to a well-adaptive or maladaptive endocrinologic response

hormones affected by psychological or emotional stress

glucocorticoids, catecholamines, growth hormone, and prolactin

how can time of day affect hormone levels?

usually regulates its function through external signals like light-dark changes or ratio of daylight to darkness

hormones affected by time of day

ACTH and TSH

how is menopause affected by hormone level?

the ovaries cease producing adequate levels of estrogen to continue fertility, thus signaling an end of the reproductive years

how can food intake/diet affect hormone level?

food and water intake will impact hormone secretion

how can drugs affect hormone levels?

change hormone secretion or activity

example of drugs affecting hormone

methimazole inhibits the enzyme thyroid peroxidase

three distinct parts of the pituitary

anterior pituitary or adenohypophysis; intermediate lobe or pars intermedialis; posterior pituitary or the neurohypophysis

posterior pituitary

responsible for the storage and release of oxytocin and AVP

how are the anterior pituitary hormones secreted?

pulsatile fashion

function of the pulsatile frequency for anterior pituitary hormones

regulated by neural modulation and specific for each hypothalamic pituitary end organ unit

TRH

release TSH and prolactin

GnRH

release LH and FSH

CRH

release ACTH

GHRH

release GH

somatostain

inhibits GH and TSH release

dopamine (prolactin inhibitory factor)

inhibits prolactin factor

hormones secreted from the anterior pituitary are _________ than those synthesized in the hypothalamus

larger and more complex

the pituitary hormones are either _____ or _____

tropic or direct effectors

tropic

their actions are specific for another endocrine gland

direct effectors

act directly on peripheral tissue

LH target gland

gonad (tropic)

LH feedback hormone

sex steroids (E2/T)

FSH target gland

gonad (tropic)

FSH feedback hormone

inhibin

TSH target gland

thyroid (tropic)

TSH feedback hormone

thyroid hormones (T3/T4)

ACTH target gland

adrenal (tropic)

ACTH feedback hormone

cortisol

growth hormone target gland

multiple (direct effector)

growth hormone feedback hormone

IGF-1

prolactin target gland

breast (direct effector)

prolactin hormone feedback hormone

unknown

pituitary is vital for ______

normal growth

what happens if the pituitary is removed?

growth stops and if the hormonal products from other endocrine glands that are acted on by the anterior pituitary are replaced

release of somatotropin

stimulated by hypothalamic peptide growth hormone, releasing hormone GHRH

GH influences

amphibolic → directly influences both anabolic and catabolic processes

GH directly antagonizes

effect of insulin on glucose metabolism, promotes hepatic gluconeogenesis, and stimulates lipolysis

Testing GH

baseline measurement is helpful

-when interpreted in conjunction with results from glucose suppression tests for the diagnosis of acromegaly or in conjunction with results from GH stimulation test for diagnosis of GH deficiency

prolactin

considered a stress hormone, it has vital functions in relationship to reproduction

prolactin major mode of hypothalamic regulation

tonic inhibition

prolactinoma

pituitary tumor that directly secretes prolactin

most common type of function pituitary tumor

prolactinoma

idiopathic galactorrhea

lactation occurring in women with normal prolactin levels

hypopituitarism

failure of either the pituitary or the hypothalamus results in the loss of anterior pituitary function

panhypopituiarism

complete loss of function of anterior pituitary

causes of hypopituiarism

pituitary tumors, parapituitary/hypothalamic tumors, trauma, radiation therapy/surgery, infarction, infection, infiltrative disease, immunologic, familial, idiopathic

posterior pituitary

extension of the forebrain and represents the storage region for AVP and oxytocin

oxytocin

has a critical role in lactation and major role in labor and parturition

arginine vasopressin

regulate renal free water excretion

tropic

target is gland

trophic

direct effector

tonic

produces a steady state