the endocrine glands and their hormones anatomy chapter 11
TRANSCRIPT
The Endocrine Glands and Their Hormones
Anatomy Chapter 11
Oh, the Secretions I’ll Learn!
The Pituitary Gland
found at base of brain (sella turcica)
2 endocrine glands in one!attached to hypothalamus by stalk
once considered master gland, but is known to be controlled by hypothalamus
aka neurohypophoysis (neuro=nerve)composed of nerve cells/fibers & neuroglia
2 hormones:1. antidiuretic hormone-ADH- accelerates re-
absorption of water from urine in kidneysdecreases volume of urine released
2. oxytocin- secreted by females before and after birth of child
Posterior Pituitary Gland
aka adenohypophysis (adeno=gland)6-7 hormones many of these hormones will
stimulate another endocrine gland to grow & secrete its hormones (tropic hormones)will affect: thyroid, adrenal cortex,
ovarian follicles, corpus luteum
Anterior Pituitary Gland
1. thyroid stimulating hormone -TSH-acts on thyroidcauses it to secrete thyroid hormone
2. adrencorticotropic hormone –ACTh-acts on adrenal cortexcauses it to grow & secrete its hormones
Tropic Hormones
3. follicle-stimulating hormone-FSH-stimulates follicles to start to growcauses them to secrete estrogen (females)
(in males) stimulates cells to grow and form sperm
4. luteinizing hormone-LH-aka ovulating hormonestimulates follicles & ovum to grow & maturereleases estrogencauses ovulation(females) produces progesterone(males) testes develop; secrete testosterone
5. growth hormone –GH-stimulates cells to increase in size & divide frequentlypromotes normal growthhas to be balanced with blood glucose level
Non-tropic Hormones
Gigantism
Classic Acromegaly
Acromegaly
Dwarfism
6. melanocyte-stimulating hormone-MSH
causes synthesis & dispersion of melanin by melanocytesmay regulate ACTh
7. prolactin- stimulates milk production after birth
found in males, but purpose not known
Thyroid Gland
vascular below larynx & on sides & front of trachea
hypothalamus & pituitary gland controls
2 hormones released
Thyroid Gland
1. thyroxine aka tetraiodothyronine, T4 (contains 4 iodine atoms)
2. triiodothyronine, T3
(contains 3 iodine atoms)most potent & principle hormone(5x stronger)
purposes:regulate metabolism of carbs, lipids, proteins by: increasing rate which cells release energy from carbs
incr rate of protein synthesis stimulate breakdown & mobilization of lipids
basal metabolic rate (BMR) the amount of calories the body must consume to maintain life at restrequired for normal growth/developmentrequired for nervous sys to matureMUST have iodine*unique thyroid only gland to store hormonesinsufficient iodine = goiter
calcitonin- not actually considered true hormone• regulates conc of bld calcium & phosphate ions• the conc of calcium is what regulates release of calcitonin
Parathyroid Glandsfound on
posterior of thyroid gland
4 glandscomposed of
secretory cells covered in connective tissue
secrete parathyroid hormone –PTH-increases blood calcium concentration and decreases blood phosphate conc
affects bones, kidneys, intestines
increases a below normal bld calcium conc
Adrenal Glandsfound atop
kidney (cap)vascularconsists of 2
glands in oneeach releases
different hormones
composed of nerve cellscells connected with sympathetic
nervous systemhormones NOT VITAL for lifesecretes 2 hormones:
1. epinephrine (adrenalin)2. norepinephrine (noradrenalin)
adrenal medulla
epinephrine makes up 80% of secretions
both hormones have same effects as nerves on cell but lasts 10x longer
hypothalamus responds to stress, sends impulses to a.m.
body prepares for “fight or flight”
makes up bulk of adrenal glandcomposed of epithelial cellsvascularproduces > 30 steroidsmany VITAL to life
3 main hormones:
adrenal cortex
type of mineralocorticoidhelps regulate conc of mineral
electrolytesaffects kidneys to conserve Na+ and
excrete K+ stimulates water retention
conc levels of Na+, K+, or kidney will affect hormone’s release
1. aldosterone
aka-hydrocortisonetype of glucocorticoid- affects
glucose metabolism, and metabolism of fats and proteins
actions of hormone help blood glucose levels to stay within normal range between meals
2. cortisol
most male hormones (androgens), but changed to female hormones
stimulates early development of reproduction organs
3. adrenal sex hormones
Cushing’s disease
Pancreas2 glands in one!2 major secretory
cellsexocrine portion
secretes digestive enzymes
endocrine releases hormones
endo cells are grouped in clusters called: islets
islets contain 2 types cells:1. alpha – secrete hormone
glucagon
2. beta- secrete hormone insulin
glucagon – stimulates liver to breakdown glycogen into glucoseraises blood sugar level prevents hypoglycemia when glucose conc is low or used rapidly
insulin- stimulates liver to form glycogen from glucose & inhibits conversion of noncarbs into glucose
*only hormone to decrease blood sugar levels
normal bld sugar level 80-120mg
too little insulin-type I diabetes
abnormality of insulin type II diabetes
Pineal Glandaka - third eyenear thalamussecretes
melatonin which regulates circadian rhythms-
patterns of repeated activity associated with cycles of day and night
helps body tell difference between day and night
may control onset of puberty
resembles pine cone
Thymus Gland