endocrine Flashcards
Function of endocrine glands
Lack ducts and release hormones into the blood or surrounding tissues. Since hormones travel in the extracellular fluid, they can act on cells that are quite a distance away from the original secreting endocrine gland
major endocrine organs and structures
pineal gland, hypothalamus, pituitary gland, thyroid gland, parathyroid glands, thymus, adrenal glands, pancreas, gonads,
what are the 2 basic categories of hormones?
water soluble (hydrophilic) and lipid soluble (hydrophobic)
water soluble hormones or hydrophilic tend to be
amino acids based water soluble proteins.
lipid soluble hormones are usually
steroids and derived from cholesterol
what are the category of structures that are fatty acids that don’t fit the typical description of a hormone. they don’t travel in blood they function more locally
prostaglandins
Our two categories of hormones act differently
True
When a hormone binds to a cell it alters the cell’s activityA hormone may increase or decrease a particular cell’s activity and the affect a given hormone has on a cell is specific to the cell, not the hormone. This is called
target cell
Hormones have 2 basic mechanisms of action depending on whether they are
water or lipid soluble
things that move readily across the cell membrane are
lipid soluble
the things that do not move easily over the cell membrane
water soluble molecules
Something that is polar,____ ______ go across the phospholipid by layer.
does not
for water soluble cells the receptors are on the _____ of the cell
outside
water soluble hormones start a cascade effect once they bind to their receptors this is called _________
second messenger system or cyclic AMP - two atp
The first horomone that bonds to water soluble cell is called
first messenger
The hormone is called the first messenger and its binding to a receptor causes the activation of a
G protein
The activated G protein actives the enzyme, adenylate cyclase, which takes ATP and forms cAMP, cyclic AMP. cAMP, this is called the
second messenger
the second messenger, then floats in the cell and activates another enzyme,
protein kinase
Protein kinases are a group of enzymes that add a phosphate group to another
protein
The second messenger system is an example of a
cascade effect
what is cAMP
Cyclic AMP - Intracellular second messenger that mediates the effects of the first (extracellular) messenger (hormone or neurotransmitter); formed from ATP by a plasma membrane enzyme (adenylate cyclase).
Cyclic AMP is the
most common 2nd messenger in the body
Once the hormone get attached to the receptor the reaction is very
FAST
all hydrophyllic hormones work
FAST
What is the most common 2nd messanger
Cyclic AMP
Lipid soluble hormones or hormones that are hydrophobic have recepter that are
inside the cell since the cell.
a steroid hormone goes right across the cell membrane and the nuclear membrane as well.
T
Where are the receptors for lipid soluble hormones?
The DNA itself.
Lipid soluble hormones can increase and decrease the trancription or translation
production of proteins
Lipid soluble hormones affect your
DNA and protein Synthesis
Effecting the synthesis of a protein takes
a long time
epinephrine works ______, cortisone steroid works ______
fast, slow
Water soluble hormones have a shorter half-life, a fast onset and a short duration
True
Lipid-soluble hormones have a longer half life, slow onset and a longer duration
True
3 major ways to stimulate a cell?
Humoral, neural, hormonal.
What is a humoral stimulus?
hormone release caused by altered levels of certain critical ions or nutrients
What is an example of humoral stimulus?
Perithyroid hormone is secreted in response to low blood calcium levels
What is a hormonal stimulation
When a hormone stimulates another hormone
What is the neural stimulus
hormone relased caused by neural input.
example of the nervous system being the stimuls?
When there is an increase in sympathetic stimulation we see an increase in epinephrine.
What gland is a good example of a hormonal stimulus?
thyroid gland.
A given hormone can bind to more than one cell and a given cell can bind more than one hormone
True
humoral response is when a hormone is secreted in response to
changes in blood levels of specific ion and nutrients.
a rise in insulin levels following elevated blood glucose levels is an example of what kind of stimuli?
humoral stimuli
neural stimuli is a classic example of what kind of innervation
sympathetic nervous system stimulation.
The pituitary gland is connected to the _______ via the _________
hypothalamus, infundibulum.
What are the two lobes of the pituitary gland?
posterior and anterior lobes.
The posterior pituitary is derived from _______ and is actually considered part of the ________
nervous tissue, brain
the posterior pituitary is connected to the hypothalamus via a
nerve tract
hormones are made by the hypothalamus and then stored by the
posterior pituitary
the neurohormones in the posterior pituitary are released upon
sns stimulation
what are the two neurohormones secreted by the posterior pituitary gland
ADH and Oxytocin
What is ADH and what does it do?
Antidiuretic hormone
Hormone produced by the hypothalamus and released by the posterior pituitary; stimulates the kidneys to reabsorb more water, reducing urine volume.
What does oxytocin do
Hormone synthesized in the hypothalamus and secreted by the posterior pituitary; stimulates contraction of the uterus during childbirth and the ejection of milk during nursing.
The connection between the hypothalamus and the anterior pituitary is one of a
portal system
Releasing or inhibiting hormones are secreted by the hypothalamus and then travel thru a portal system to the anterior pituitary. The anterior pituitary will then response by
secreting or not secreting a second hormone into the blood
Adenohypophyseal Hormones
anterior pituitary hormone any of the protein or polypeptide hormones secreted by the anterior lobe of the pituitary gland, including growth hormone, thyrotropin, prolactin, follicle-stimulating hormone, luteinizing hormone, melanocyte-stimulating hormone, and corticotropin.
The release of 4 hormones from the anterior pituitary is controlled by the secretion of a second hormone from the hypothalamus. These hormones released from the hypothalamus are called
tropic hormones
All of the hormones secreted from the anterior pituitary gland are water-soluble and thus work through the
cAMP second-messenger system.
hypothalamus has it’s neurons and those neurons secrete hormones into a capillary bed then those hormones travel from that capillary bed to the anterior pituiatary causing the anterior pituitary to secrete a second set of hormones. These hormones are
neural hormones because they are secreted by neurons
some of the hormones that the hypothalamus secretes
a releasing hormone or an inhibiting hormone.
the hypothalamus is playing a role in directing the secretions from the anterior pituitary by secreting a
releasing hormone or an inhibiting hormone.
when a hormone is secreted from a gland or cell and it effects a secretin of a second hormone that is called a
tropic hormone
Funciton of Growth hormone GH
anabolic hormone, stimulates growth protein synthesis, mobilizes fats and has a glucose sparing effect.
what does it mean if a hormone is glucose sparing?
causes your body to utilize a different energy source other than glucose (typically fats) so that blood glucose levels and stay constant
One way to increase Growth Hormone is to increase
Growth Hormone Releasing Hormone
Another way to increase Growth hormone is low blood glucose because
GH has a glucose sparing effect it will allow you to break down lipids and use lipids as an energy source
Thyroid stimulating hormone is important for the
development and function of the thyroid gland
increase TRH which will increase TSH which will increase
T3 and T4
Hormones ultimately target most cells of the body producing widespread diverse effects. What are the major processes that hormones control and integrate
reproduction, growth and development, maintenance of electrolyte, water and nutrient balance of the blood, regulation of cellular metabolism and energy balance, mobilization of body defenses.
exocrine glanes produce
non hormonal substances such as sweat and saliva
endocrine glands produce are also called ductless glands, they produce
hormones and they lack ducts.
endocrine glands include
pituitary, thyroid, parathyroid, adrenal, and pineal glands
The hypothalamus produces and releases hormones so it is called a
neuroendocrine organ
The pancreas, gonads and placenta have what type of tissue
endocrine tissue
Most organs contain scattered
endocrine cells or small clusters of endocrine cells
autocrines are chemicals that exert their effects on
the same cells that secrete them
paracrines also act locally but
affect cell types other than the ones that secreted them.
What is the most common form of hormone that is usually water soluble and fast acting
amino acid based hormones
what type of hormone is less common, slower acting and lipid soluble and can cross the plasma membrane
steroids
all major hormones circulate to virtually all tissues but a hormone only influences the tissue cells that have
the receptor for that particular hormone
cells that have a receptor for specific hormones are called
target cells
A hormone typically produces one or more of the following changes
Alters plasma membrane permeability or membrane potential or both by opening or closing ion channels. stimulates synthesis of enzymes and other proteins within the cell. activates or deactivates enzymes, induces secretory activity, stimulates mitosis.
water soluble hormones act on receptors in the
plasma membrane
lipid soluble hormones act on receptors
inside the cell
Menopause
When there are low hormone levels, erratic periods, less menstruation and only in females.
Role of GnRH
From the hypothalamus and causes the increase in FSH and LH
Number of chromosomes in egg and sperm
23 because when they comes together you get 46
When the hypothalamus releases growth hormone releasing hormone to tells the
anterior pituitary to increase secretions of growth hormone.
when the hypothalamus releases growth hormone inhibiting hormone it tell the
anterior pituitary to decrease secretions of growth hormone
if the hypothalamus released thryroxin releasing hormone then there will be an
increase in thyroid stimulating hormone from the anterior pituitary.
if there’s an increase in cortical releasing hormone then there will be an
increase in adrenal cortical-tropic hormone.
if thre’s an increase in goanatropic releasing hormone then there will be an
increase in Luetenizing hormone and follical stimulating hormone
if there is an increase in prolactan inhibiting hormone there will be
less prolactin secreted from the anterior pituitary.
all hormones from the hypothalamus that affect a second hormone it’s called a
tropic hormone
the secretions from the posterior pituitary hormones are
nueral hormones, they are derived and secreted by the nuerons in the hypothalamus
the secretions from teh anterior pituitary are made in the AP and secretions can be influenced by the hormones of the hypothalamus by a
portal system
all AP hormones are
water soluble and very fast
If you increase thyroxin releasing hormone will increase thyroxin stimulating hormone which will travel to the thyroid to release
T3 and T4
corticoltropic releasing hormone and adrenal corticoltropic hormone will travel to the adrenal cortex and then it will
increase the sescretion like glucolcorticoids.
gonadatropins are FSH and LH. they effect
males and females, estrogen, progesterone and testosterone sescretion.
prolactin causes
milk production in pregnant females
you need oxytocin for milk to come out but you need prolactin to
make the milk.
Thyroid is a bilobed gland right underneath the
thyroid carteledge.
every cell in your body has receptors for
thyroid hormone
2 hormones secreted from the thyroid
T3 and T4
iodine from the blood is taken into the thyroid gland,, the iodine is then oxidized then there is this protein made in the thyroid gland called.
thyroglobolin.
thyroglobulin binds to
T3 and T4 to help them travel in the blood
T3 and T4 are lipid soluble and thats why the thyroidglobulin helps them travel through the blood. they effect
protein synthesis
T3 and T4 help in overall
metabolism.
low levels of T3 and T4 will lower your
metabolic rate. part of aging is a low metabolic weight.
parafollicular cells secrete
calcitonin
what does calcitonin do
it regulates blood calcium levels and is antagonistic with the action of Parathyroid hormone.
when you have elevatated calcium levels you will have an increase in
calcitonin to decrease calcium in blood
parythyroid glands secrete parathyroid hormone secretes in response to
low calcium levels.
What does parathyroid hormone do?
increase osteoclast activity, increases calcium reabsorption by the kidnesy and increases vitamin D. We also release phosphate which will be excreted in the urine.
phosphate gets excreted in the
urine
adrenal glands sit above the kidneys they have two parts
adrenal medulla which is nervous tissue and the adrenal cortex
secretions from adrenal medula
80% epi and 20% noepi - neuro hormones
adrenal cortex has three divisions and each one has a different secretion
zonas glomerulosa - mineral corticoids. zona fasciculata - glucocorticoids and zona reticularous - androgens
what is the major mineral corticoid from the zona gomerulosa?
aldosterone. secreted when there is low extra cellular sodium and high extra cellular potassium.
What is the major secretin from zona fasiaculata?
cortisol.
glucocorticoids have three basic roles
developmental, anti-inflamatory and metabolic
babies need glucocorticoids for
fetal lung development
glucocorticoids have what metabolic effect
glucose sparing effect
secretions of glucocorticoids are because of
long term stress
when you are exposed to long term stress you are more susceptible to being sick because you are
depressing the secretions from white blood cells
short term stress causes
epi and norepi
The major secretion for zona reticulularous
androgens
pancreas has both
endocrine and exocrine cells
in the endocrine portion of the pancreas we would see
insulin and glucogon
glucagon is secreted by
alpha cells
insulin is secreted by
beta cells
insulin promotes glucose uptake by cells and
stimulates protein or amino acids synthesis in muscle
diabetes melitus is an
autoimmune disease
type II diabes is
non-insulin dependent. often in adult life.
diabetes affects
microcirculation.
the gonads release
estrogen, progestrogone, testosterone
the pineal gland secretes
melatonin
