ch 16- endocrine system Flashcards
37 slides
endocrine system function
secretes various hormones
hormones
long distance chemical messengers that can cause metabolic activity change, usually long lasting effects
hormones control-
reproduction, growth/development, immune system activation, various blood component maintenance
endocrine glands
highly vascularized, secrete hormones directly to blood. autocrines and paracrine r sometimes considered part of the endocrine system
autocrine
chemicalcmessage that affects she cell that produces message, a self message
paracrine
chemical message that is produced by one cell but affects a different one, both cells in same tissue and can affect dif cells in that same tissue
2 hormone classifications
amino acid based and steroid
amino acid based hormones
most frequent, water soluble, circulate without carrier (specific proteins that allows easy movement), molecular size varies here
steroid hormones 2 kindssss
synthesized from cholesterol, gonadal hormones and adrenocoortical hormones only ones. not water soluble and need a carrier for help-
specific weird ass hormone actions
a hormone can only affect target cells with receptors that can bind it. different cell types can have different receptors that can bind same hormone, but in target cell, these different cells can have dif receptors to same hormone. SHAPE CHANGES EFFECT!
major changes produced when hormone binds
alters plasma membrane permeability and membrane potential, stimulates synthesis of enzymes n proteins in cell, activates n deactivates enzymes, induces sensory activity, and stimulates mitosis
second messenger systems
use receptors found on surface of plasma membrane, this actually acts on cell. amino acid based hormones use this!! usually need a G protein coupled receptor, and its a very efficient system!
intracellular systems
steroid hormones use this bc they are lipid soluble, hormone enters cell first and then binds to intracellular receptors.
receptor hormone complex
binds specific DNA regions and DNA transcription will occur. SO certain proteins will be produced in larger numbers
5 steps to intracellular system
steroid hormone will diffuse through plasma membrane and bind to the intracellular receptor, then that receptor hormone goes in nucleus, then binds specific DNA region, and transcription of the gene to MRNA so finally protein synthesis
what feedback mechanism controls hormone release?
negative, it prevents extreme changes in response to binding a hormone. both synthesis and release r negative feedback mechanisms.
humoral stimuli
changing blood levels of critical ions and nutrients, like monitoring Ca2+ levels by parathyroid gland.
neural stimuli
nerve fibers stimulate hormone release, like NE and epinephrin e
hormonal stimuli
hormone released in response to other hormones, like hypothalamic hormones stimulating or inhibiting anterior pituitary gland
hormone concentration in blood depends on
how fast it is released by endocrine organ (more likely to interact with target cell) and how fast it is broken down.
hormones with shortest half life
water soluble hormones, they r easier to break down
cellular response variation
some hormones can bind to any cell type, others are limited to specific body parts. target cells only respond to a hoormone if a receptor protein is there
activation of cell depends on
blood levels of hormone, number of receptors for specific hormone on or in cell and affinity of receptor to hormone (how easy is It to bind)
each factor cell depends on for activation is determined by…
amt of hormome in blood, will tell how much and more means more likely for response
up-regulation
increase receptor number in response to low hormone levels, more receptors makes it easier to bind more sensitivity
down-regulation
decrease receptor number in response to high hormone levels, beaks and destroys the receptor for hormone so less sensitive.
if 2 or more hormones bind on same target cell, at the same tine, it may result in…
permissiveness, synergism, or antagonism
permissiveness
one hormone can have full effect without binding of a second hormone, or lack of second hormone may delay or completely inhibit effects of first hormone.ONE HORMONE PERMITS ANOTHER TO BIND
synergism
speeds up cell response, 2 or more hormones with similar effects bind target cell and amplification occurs.
antagonism
one hormone opposes effect of another. might compete for same receptor, or act through different metabolic pathway, or down regulate receptor of another hormone. so A WOULD BIDN AND THEN B’S RECEPTOR WOULD DISAPPEAR
are hormone effects always immediate
no, some can be hours or days or months even years after. like gonadal hormones
duration of hormone effects varies how
short: cellular response stops when thing is not in blood anymore like insulin
long: target cell may still carry response after hormone is removed
major endocrine organs (organs that only produce hormones)
pituitary gland, thyroid gland, parathyroid gland, and adrenal, pineal, pancreas.
pituitary gland
connected to hypothalamus, has anterior n posterior
anterior pituitary gland
won’t get AP, manufactures and releases several dif hormones
posterior pituitary gland
composed of neural tissue and nerve fibers. stores and releases neurohormones produced by hypoyhalamus. doesn’t actually produce any hormone- just NS tissue and neurons
release at pituoraty gland can happen 2 dif ways
AP from hypothalamus cause hormone release, sent to one part of pituitary. Thats in posterior bc its NS structure
OR
hypothalamic hormones released into hypophyseal portal system, stimulate or inhibit hormone release. that’s anterior bc blood is used to stimulate it
oxytocin (posterior pituitary)
stimulates uterine contraction, milk ejection, cuddle hormone acts as neurotransmitter
what type of feedback mechanism is stretching of cervix during childbirtth
positive. builds on contractions until infant is born.
antidiuretic hormone (ADH), posterior pituitary gland
how much water goes into urine- prevents water from being added to urine, slows down urine production. maintains water content of blood.dehydrated means more ADH, kidneys return more water
control of ADH release
osmoreceptors (measure solute concentration) in hyopothalamus. solute concentration is high when ADH is released to save as much water as possible.
anterior pituitary hormones have 4/6 of them being tropins- what does that do
affect activity of another endocrine gland, those 4 are growth hormones, TSH, ACTH, and gonadotropins
growth hormones, anterior pituitary
metabolic and growth effects. metabolic- decrease glucose uptake, mobilize fat storage by releasing fatty acids to blood, and increases amino acid uptake by blood.
growth- IGFS stimulate growth where a lot of GH is
IGF (insulin like growth factor)
increase nutrient uptake by tissue and form collagen and deposition of bone matrix. in order to grow, muscle build first
TSH (thyroid stimulating hormone), anterior pituitary
stimulates development and secretory activity of thyroid gland.
TRH (thyrotropin releasing hormone)
a tropin that stimulates TSH release.
adrenocorticotropic hormone (ACTH), anterior pituitary
stimulates adrenal cortex to relersase their own set of hormones.
corticotropin releasing hormone (CRH)
stimulates ATCH release.
gonadotropins
follicle stimulating hormone (FSH) and luteinizing hormone (LH)
follicle stimulating hormone (FSH), anterior pituitary
stimulates gamete production, ovaries and testes
luteinizing hormone (LH), anterior pituitary
stimulates gonadal hormone production, estrogen and testosterone
gonadotropin releasing hormone (GnRH), anterior pituitary
stimulates FSH and LH release, this negative feedback prevents too much estrogen or testosterone from going. ONLY RELEASE AFTER PUBERTY NOTHING PRIOR
prolactin , anterior pituitary
stimulates milk production in breast tissue and contributes to reproductive system. in males, its reproductive health and immune system. PRL rises and falls with blood estrogen
what controls the release of prolactin
dopamine, slows down PRL production
thyroid gland
only endocrine gland to produce, secrete, and store hormone. has 3 month supply of hormone
thyroid hormone
depends on presence of iodine if its released or not. affects every body cell.
how does TH affect every body cell
increases metabolic rate and body heat, regulates tissue growth and development, and maintains BP
hyperthyroidism
too much TH, too much heat body way too actin e
parathyroid gland
secretes parathyeroid hormone, PTH.
parathyroid hormone (PTH)
contributors to calcium hemostasis. blood calcium decreases.
how does decreasing blood Ca2+ levels stimulate PTH release?
stimulates osteoclasts to increase bone degradation, enhances Ca2+ reabsorption by kidneys, activates vitamin D so u can have more Ca2+
adrenal glands
stress response and electrolyte balance.
adrenal cortex
outermost region of adrenal gland, has 3 corticosteroids. mineralocorticoids, glucocorticoids, and gonadocorticoids
mineralocorticoids
regulate electrolyte concentration in ECF, Na+ and K+ especially
what do Na and K do in mineralcortiocids
Na influences water movement bc water follows Na, why ppl who retain so much water eat. a lot of salt.
K determines resting membrane potentials- imbalance will affect neuron response.
glucocorticoids
influence energy metabolism of cells, provide stressor resistance. cortisol, cortisone, and corticosterone
cortisol release stimulated by ATCH does what
negative feedback, stress affects cortisol release and CNS overrides negative feedback mechanism, more cortisol is released.
glucocorticoids
mobilizes body to store more glucose, provokes SNS. too much of this depresses bone formation, inhibits inflammation, depresses immune system, disrupts normal function overall in heart neurons and poop
gonadocorticoids
small androgen amounts released by adrenal cortex. some convert to testosterone some to estrogen. contribute to armpit and pubic hair- and in women can increase libido and ensures estrogen is produced post-menopause
adrenal medulla
innermost adrenal gland, synthesizes epinephrine and norepinephrine. unequal amounts tho, 80% is with more O2 and dilates airways, 20% is for blood vessel constriction for BP . released at SNS
hormones from adrenal medulla are not essential for fight or flight responses
they only add to it, not necessary tho. adds extra spice
pineal gland
secretes melatonin and affects circadian rhythm’s. release is controlled by light intensity
pancreas
hormones produced in pancreatic islets. makes blood sugar levels consistent.
2 hormones released at pancreas- first one is glucagon
produced by alpha cells. have hyperglycemic affect (increase blood glucose levels), also stimulates liver to break down glycogen and convert stuff to glucose. release is controlled by decreasing blood glucose levels
2 hormones released at pancreas- second one is insulin
beta cells produce it, hypoglycemic (lower blood glucose levels). increases glucose uptake of body cells, inhibits glycogen breakdown and stops non carb molecules to become glucose
what is insulin release controlled by
elevated blood glucose, rising blood levels of amino acids and fats, ACH from PNS release, any hyperglycemic hormone will eventually release hormone
pancreas homeostatic imabalnce- diabetes mellitus
inadequate or absent release of insulin by pancreas. causes consistently high blood sugar levels.
normal range of blood glucose vs diabetes
70-99 normal, 126+ is diabetic
type 1 diabetes
autoimmune disaorder, insulin is not produced at all. beta cells are destroyed by immune system, but insulin shots can help prior to meals. can lead to vascular and neural issues
type 2 diabetes
insulin resistance, its produced and released but cells do not respond. combination of genetics and lifestyle. overweight and inactive can cause it, but management is possible w diet and exercise.
gonads
females, ovaries produce estrogen and progesterone. estrogen matures reproductive organs, and sex characteristics . progesterone is boobs and mucosa lining for pregnancy
males, testosterone which matures and maintains reproductive organs. sex drive, secondary sex characteristics, and sperm
placenta
a temporary endocrine organ. needs estrogen progesterone and hCG (human chorionic gonadotropin) to maintain a pregnancy.
