Endocrine system Flashcards
what is direct communication
exchange of ions/molecules between adjacent cells via gap junctions
what is direct communication between
2 of the same cell
what is paracrine communication
chemical signals from cell to cell within the same tissue (both are PARt of a tissue)
what does transmission occur via
extracellular fluid
what is autocrine communication
occurs within itself
what is endocrine communication
releases hormones that are then transported to the blood stream
what is the definition of a hormone
chemical that controls and regulates cell or organs
what is endocrinology
study of hormones and endocrine organs
what is the tissue of endocrine and exocrine glands
glandular epithelium
what do exocrine glands do
release contents that leads to surface
what is merocrine
top of the cell releases contents by exocytosis (just the tip before marriage)
what is apocrine
part of the cell is pinched off/half gets torn away (apo = away)
what is halocrine
entire cell ruptures (in halo, when you shoot someone, they explode)
what are the 3 classes of hormones
amino acid, peptide hormone, lipid
what are 2 amino acid derivatives
tyrosine and tryptophan
what are peptide hormones synthesized as
prohormones
are peptide hormones short or long
short
are protein hormones short or long
long
what are 2 examples of polypeptide hormones
ADH and OXT
what are 2 examples of protein hormones
insulin and prolactin
what type of hormone is elcosanoids
lipid derivative
what do elcosanoids do
coordinate cellular activity and enzymes
what has contrasting effects on blood clots
omega 3 and 6
what are steroid hormones derived from
cholesterol
what steroid hormone do testes produce
androgens
what steroid hormone do the ovaries produce
estrogen and progesterone
what steroid hormone does the adrenal cortex produce
corticosteroid
what steroid hormone does the kidneys produce
calcitrol
what do steroid hormones bind to
transport proteins in plasma
are catecholamines and peptide hormones lipid soluble
no
where do catecholamines and peptide hormones bind to receptors
outside of membrane
are steroid and thyroid hormones lipid soluble
yes
where do steroid and thyroid hormones bind to receptors
inside of cell/membrane
what 2 things can hormones do in the blood
circulate freely and bind to carrier proteins
how long are free hormones functional
less than an hour
do bound hormones or free hormones remain functional longer
bound
when do free hormones become inactivated
diffuse out of blood and bind to receptors; absorbed by kidneys/liver; broken down by enzymes
what does the hormone in G protein coupled receptors use to activate the protein
intermediary
what happens once G protein is activated
cAMP levels increase
what is the secondary messenger
cAMP
what does activation of secondary messengers cause
accelerates metabolic activity
what does G protein inhibitory effect cause
decrease in cAMP levels
what does G protein activate to cause production of hormones
PLC
what hormones does the activation of PLC cause in secondary messengers
DAG and IP3
what does DAG and IP3 come from
PIP2
what diffuses into the cytoplasm in secondary messengers
IP3
what is released when IP3 is released into the cytoplasm
calcium
what does calcium activate in secondary messengers
PKC
how can steroid hormones affect DNA
alter DNA transcription
what else can steroid hormones alter other than DNA transcription
enzyme synthesis
where do thyroid hormones bind to receptors
mitochondria
what 3 things occur when thyroid hormones bind to receptors in the mitochondria
activates genes, increases ATP production, and nutrient breakdown
what happens to hormone receptors during down-regulation as there is a presence of hormone
they decrease
what happens to cell sensitivity as hormone levels increase
cell becomes less sensitive (it gets used to the hormones)
what happens to hormone receptors during up-regulation as there is an absence of hormones
they increase
what happens to cell sensitivity as hormone levels decrease
cell becomes more sensitive (in hopes of one attaching)
what is humoral stimuli
change in concentration
what is hormonal stimuli
arrival/removal or hormone
what is neural stimuli
neurotransmitters
what kind of stimuli is blood Ca2+ levels
humoral
what kind of stimuli is low TH releasing TRH
hormonal
what kind of stimuli is OXT
neural
how is the pituitary gland connected to the hypothalamus
infundibulum
what are the dark stains of the anterior lobe
grandular
what kind of hormone is cAMP
peptide
where are cell bodies of the posterior lobe neurons located
hypothalamus
where is the axon of the posterior lobe neurons located
infundibulum
what does SON release
ADH
what does PVN release
OXT
what is the function of hypophyseal portal system
ensures hormones reach cells in anterior pituitary before entering circulation
what is blood flow like in hypophyseal portal system
unidirectional
what does OXT stimulate
contractions and dilation
when are receptors more sensitive during pregnancy
at the end
what system causes the release of OXT
positive feedback system
what hormone is necessary for milk ejection
oxytocin
what hormone contributes bonding and feelings of love
oxytocin
what is the main thing that ADH causes
lack of urination
what in the hypothalamus triggers ADH release
osmoreceptors
what is the osmolarity levels that cause ADH to be released
increased
how does ADH raise blood pressure
blood vessels contract
how does alcohol effect ADH
it inhibits it –> seal broken
what is diabetes insipidus
chronic dehydration
how do ADH levels affect water reabsorption in kidneys
increased ADH levels, decreases water reabsorption in kidneys
what hormones are neurotransmitters
OXT and ADH
what is the general order of how FLAT hormones are secreted
releasing hormone –> stimulating H –> act on gland –> acts on cell
what is the general order of how PIG hormones are secreted
RH and IH –> stimulating H –> act on gland
where are stimulating hormones found
pituitary gland
where are RH and IH found
hypothalamus
what is the F in flat pig
follicle stimulating hormone
what is the L in flat pig
luteinizing hormone
what is the A in flat pig
adrenocorticotropic hormone
what is the T in flat pig
thyroid stimulating hormone
what is the P in flat pig
prolactin
what is the G in flat pig
growth hormone
what hormones of FLATPIG are GnRH
FSH and LH
what hormones of FLATPIG have inhibiting hormones
PIG
what does FSH stimulate
secondary sex hormones
what is FSH inhibited by
inhibin
what is inhibin released by
testes and ovaries
what does LH stimulate
primary sex hormones
what specific hormones does LH stimulate
estrogen and testosterone
what causes ovulation
surge in LH
where does corticotropin move to and from
hypothalamus to anterior pituitary
what does corticotropin moving cause to be stimulated
ACTH
where does ACTH move to
blood
what does ACTH moving to the blood cause to be stimulated
adrenal cortex
what does the adrenal cortex act on
zona G,F,R
what is zona glomerulosa associated with
salt
what is zona fasciculata associated with
sugar
what is zona reticularis associated with
sex
what is the order which thyroid hormone is secreted
TRH –> TSH –> TH
what does the thyroid hormone regulate
metabolism
how does hypothalamus decrease metabolism
decreases thyroid hormone
what does prolactin stimulate
milk production
what is prolactin inhibited by
dopamine
what is dopamine a derivative of
tyrosine
what does milk flow suppress
sex hormones
what happens when sex hormones are suppressed during breast feeding
libido and fertility
what does the release of GH result in
increase in tissue growth and metabolism
what is released in response to GH
somatomedins
what releases somatomedins
the liver
what do somatomedins do
stop growth hormone
what is pituitary gigantism
children have GH before fushion of epiphyseal plate
what is acromegaly
adults who have GH after fusion of epiphyseal plate
what secretes melanocytes stimulating hormones
pars intermedia
what does MSH result in
melanin production
where is the thyroid gland located
anterior to trachea
what is the medial region of the thyroid gland called
isthmus
what is the tissue of the thyroid gland
simple cuboidal lined
what regulates Ca2+ levels in blood
calcitonin
what is the active form of thyroid hormone
T3
what is the first step of thyroid hormone synthesis
TSH binds to receptors
what happens once TSH binds to receptors
iodide is moved into cytosol
what do the iodide ions undergo
oxidation
what is formed when iodide undergoes oxidation
I2 (iodine) is formed
what does iodine link to
tyrosine AA
where does iodine link to tyrosine AA
in the thyroglobulin
what is produced in the thyroglobulin
T3 and T4
what happens to T3 and T4 in the thyroid follicles
they go back into follicle cells
what causes T3 and T4 to move back into the follicle cells
TSH
what breaks down thyroglobulin colloid
lysosomal enzymes
what is released when thyroglobulin is broken down
T3 and T4 is diffused into the blood stream
what do low blood levels of TH stimulate
TRH
what is TRH released from
hypothalamus
what does TRH being released from hypothalamus lead to
TSH released
where is TSH released from
anterior pituitary gland
what does TSH cause the thyroid gland to secrete
T3 and T4
what organelle does T3 and T4 act on
mitochondria
what is the 1st function of thyroid hormones
metabolic rate
what do T3 and T4 bind to on mitochondria
intracellular receptor
what does T3 and T4 initiate in oxidation
transcription of genes
what is the 2nd function of thyroid hormones
protein synthesis
when is the critical period for brain development
1st trimester
what does protein synthesis increase sensitivity to
catecholamines
what is hyperthyroidism
antibodies mimic TSH and stimulate T3 and T4 in thyroid follicle cells
what is congenital iodine deficiency
insufficient maternal intake of iodine
what is myxedema
insufficient intake of iodine during adulthood
where is the parathyroid gland located
posterior to thyroid
what is the main function of the parathyroid gland
regulates Ca2+ levels
what happens when there is low blood calcium
muscle spasms and tetany
what is muscle and neural function like when there is low blood calcium
very excitable
what happens when there is high blood calcium
cardiac arrhythmias
what is muscle and neural function like when there is high blood calcium
depressed
where are the adrenal glands located
on top of the kidneys
where does blood flow and drain in the adrenal glands
flows to the cortex and drains to the medulla
what does zona glomerulosa act on
kidneys
what hormone does zona glomerulosa secrete
mineralocorticoids
what does zona glomerulosa cause to happen
increases renal absorption of Na+ and water
what is zona glomerulosa stimulated by
angiotensin 2
what do the kidneys secrete in response to low blood pressure
renin
what converts angiotensinogen to angiotensin 1
renin
what converts angiotensin 1 to angiotensin 2
ACE
what does angiotensin 2 do
regulate BP
how does angiotensin 2 regulate BP
releases Na+ to draw water in
what is aldosterone released by
adrenal glands
what hormone does zona fasciculata secrete
glucocorticoids
what is the hormonal effects of zona fasciculata
increase glucose and glycogen to utilize lipids
what is androgen secretion stimulated by
ACTH
what causes cushings disease
increase in glucose levels and glucocorticoids (too much sugar makes you cushiony)
what is cushings disease caused by
hyper secretion of cortisol due to pituitary tumor
what causes the hyper secretion of cortisol in cushings disease
due to pituitary tumor
what is Addisons disease
hyper secretion of corticosteroids
what hormone does zona reticularis secrete
androgens
what is the hormonal effect of zona reticularis
development of pubic hair
what controls the regulatory control of zona reticularis
ACTH
what do pinealocytes secrete
melatonin
what does melatonin come from
serotonin
what is the biggest effect on melatonin production
level of light
how does jet lag effect melatonin production
it disturbs the light and dark cycle
how is adiponectin affected by physical activity
it increases when engaging in physical exercise
what is adiponectin activated by
catecholamines
how does leptin effect appetite and energy
an increase in leptin = decrease in appetite, increase in energy
how does osteocalcin affect B cell proliferation
increases it
how does osteocalcin affect insulin
increases it
how does osteocalcin affect glucose uptake
increases it
how does osteocalcin affect adiponectin
increases it
what effect does osteocalcin have on cognitive function
improves it
what does osteoblasts secrete (OCN)
glaOCN inactive
where are glaOCN inactive sent
osteoclast
where is glaOCN active sent once it exits the osteoclast
pancreas, muscle, liver, adipose tissue, testes, brain
what gland is activated when there is high calcium levels in the blood
thyroid
what is released from the thyroid when there is high calcium
calcitonin (tone it down)
how does calcitonin act on the bones
it inhibits osteoclast activity
how does osteoclast activity affect levels of calcium in the blood
osteoclasts cause calcium to be reabsorbed into blood
how does calcitonin act on the kidneys
inhibits calcium reabsorption
what gland is activated when there is low calcium levels in the blood
parathyroid gland
what is released from the parathyroid when there is low calcium
parathyroid hormone
how does the parathyroid hormone act on bones
increases osteoclast activity
how does the parathyroid hormone act on kidneys
increase calcium reabsorption
how does the parathyroid hormone act on digestion
increases vitamin D –> increase calcium reabsorption
what gland is activated when there is high phosphate levels in the blood
thyroid gland
what is released from the thyroid when there is high phosphate
phosphatonin (FGF23) (tone it down)
how does the phosphatonin act on the parathyroid
blocks the function of it
how does the phosphatonin act on the kidneys
inhibits reabsorption of phosphate
how does the phosphatonin act on digestion
inhibits phosphate and calcium reabsorption
