brain (hypothalamus)

brain (hypothalamus)

pituitary (pituitary level)

pituitary (pituitary level)

endocrine organs (body-level)

endocrine organs (body-level)

tissuestissues

levels of hormoneslevels of hormones

levels of hormoneslevels of hormones

brain (hypothalamus)

brain (hypothalamus)

pituitary (pituitary level)

pituitary (pituitary level)

endocrine organs (body-level)

endocrine organs (body-level)

tissuestissues

brain (hypothalamus)

brain (hypothalamus)

pituitary (pituitary level)

pituitary (pituitary level)

endocrine organs (body-level)

endocrine organs (body-level)

tissuestissues

brain (hypothalamus)

brain (hypothalamus)

pituitary (pituitary level)

pituitary (pituitary level)

endocrine organs (body-level)

endocrine organs (body-level)

tissuestissues

Thyrotropin-releasing hormone (TRH)Corticotropin-releasing hormone (CRH)Gonadotropin-releasing hormone (GnRH)Growth hormone-releasing hormone (GHRH)

FSH – Follicle-stimulating hormoneLH – luteinizing hormoneACTH – Adrenocorticotropic hormoneTSH – Thyroid-stimulating hormoneGH – growth hormonePRL -- prolactinOT -- oxytocinADH – antidiuretic hormone

FSH – Follicle-stimulating hormoneLH – luteinizing hormoneACTH – Adrenocorticotropic hormoneTSH – Thyroid-stimulating hormone

GH – growth hormonePRL – prolactin

OT -- oxytocinADH – antidiuretic hormone

TROPIC hormones(they activate some other endocrine gland

have effect on other body tissues (not directly on other endocrine glands

from the posterior pituitary

brain (hypothalamus)

brain (hypothalamus)

pituitary (pituitary level)

pituitary (pituitary level)

endocrine organs (body-level)

endocrine organs (body-level)

tissuestissues

• thyroid gland releases thyroxin• thyroxin causes most tissues to

increase their metabolic rate

thyroxin

• to make this happen, ant.pit. releases TSH – thyroid stimulating hormone

TSH

to make this happen, the hypothalamus releases TRH

what induces the hypothalmus to release TRH?

calcium in bones calcium in bloodstream

needed for strong and resilient bones, joints, teeth

needed for muscle contraction, fluid balance, many reactions all over body

calcium in bones calcium in bloodstream

needed for strong and resilient bones, joints, teeth

needed for muscle contraction, fluid balance, many reactions all over body

•skeleton is like a bank•when more calcium is needed in bloodstream, some bone is dissolved•this calcium circulates through the bloodstream•BALANCED against each other •homeostasis – NOT constant!

• too much: bone overgrowth, bone spurs

• too little: osteoporosis, brittle and fragile bones

• too much: kidney stones, fluid imbalance

• too little: weakness, unable to do muscular actions, shock and possible coma

bones

blood

bones

blood

PTH (parathyroid hormone)

• from parathyroid gland• in response to low blood Ca2+ levels

• (“get some Ca2+ from the bank”)

calcitonin• from thyroid gland• in response to HIGH blood Ca2+ levels

• (“put some Ca2+ IN the bank.”)

two very different parts of the adrenal gland

adrenal cortex (outside)secretes cortisol, aldosterone, other hormones

adrenal medulla (inside)connected directly to nerve fibers from the hypothalamussecretes adrenalin and noradrenalin

acromegaly• due to excess GH production• when that GH overproduction

begins AFTER adulthood• disproportionate growth of:

•skull (mostly jaw)•fingers + hands•feet + toes

• not much in the long bones

exophthalmiaprotruding eyeshypersecretion of thyroxineincreased pressure on eyesnote neck scar from thyroidectomy

•hyperthyroidism•increased pulse•excess perspiration•high BMR•shortness of breath•weight loss•flushed appearance•exophthalmia•nervous, anxious, restless•insomnia•tremors

Hypothyroidism•aka myxedema•if low thyroxin in adult•low BMR•lethargy•dry brittle hair•impaired memory•thick tongue•slow speech•voice deep and coarese•diminshished perspiration•reddened cheeks•megaloglossia•increased pigment elbows/knees

usually....•thyroid makes thyroxine•when thyroxine level too low, body signals thyroid gland to make more

but with goiter•thyroid can’t make thyroxine for some reason•but body is still telling thyroid to make more•therefore thyroid enlarges

cretinism•lack of thyroxine from birth

•or before birth•could be from lack of thyroid gland

•or lack of iodine in mother

•severe and irreparable mental defects

•stunted growth•reduced growth and function of many organs

Three different control mechanisms for Hormones

A

B

C“A” leads to “B” which leads to “C”“C” inhibits “A”

A B

C

A

C

1. feedback inhibition 3. pulsed release2. releasing/inhibiting

A releases CB inhibits C

A pulses out hormonehormone naturally breaks down over timethen A pulses out more hormone

A

C

A

C