Endocrine Flashcards
why do we need hormones
homeostasis, metabolism, growth and development, body defences (immunity and stress response), reproduction, sleep
what are hormones
chemical messengers
what are hormones made of
amino acids or cholesterol
what are the three ways hormones can travel
travel in blood, dissolved in plasma, bound to a carrier protein
hormones have what type of receptors
specific
what happens after a hormone has served its purpose
it is removed, broken down and recycled or excreted in sweat or urine
what are some ways hormones can be monitored
non-invasive skin patch to detect hormones in sweat, urine testing in sport
what are the two main chemical classifications of hormones
water-soluble and lipid-soluble
what are molecular forms of water-soluble hormones
some amines, peptides and proteins
what are molecular forms of lipid-soluble hormones
some amines, steroids
how are water-soluble hormones transported in the blood
dissolved
how are lipid-soluble hormones transported in the blood
bound to carrier proteins
where are water-soluble hormones’ receptors found
in the cell membrane
where are lipid-soluble hormone receptors found
intracellular
protein in diet makes what type of hormones
water-soluble
cholesterol in diet makes what type of hormones
lipid-soluble
what is the action mechanism of water-soluble hormones
activates 2nd messenger which amplifies hormone response, binding of this triggers other existing messengers like dominoes of events, switch proteins on and off that were already present
what is the action mechanism of lipid-soluble hormones
alteration of gene transcription (to make new proteins)
which type of hormones are good for fast, acute responses
water-soluble
which type of hormones are good for slow, long-lasting responses
lipid-soluble
what is the neural link to the endocrine system
hypothalamus
where are the cell bodies of neurons involved in the endocrine system
hypothalamus
where are the axons of neurons involved in the endocrine system
posterior pituitary gland
where are hormones made
in the hypothalamus
where are hormones stored
axon terminals in posterior pituitary
what causes hormone release from posterior pituitary
action potentials
what is the connection from the hypothalamus to the posterior pituitary
axon connection
what is the connection from the hypothalamus to the anterior pituitary
blood vessel connection
releasing/inhibitory hormones are made in the __ and travel in the __ to affect anterior pituitary cells to release or inhibit release of anterior pituitary hormones
hypothalamus, blood
what are the growth hormones and where are they released from
GHRH from hypothalamus, growth hormone from anterior pituitary, IGF-1 from liver
where are growth hormones target cells
liver, skeletal muscle and adipose
what stimulates the release of the growth hormone axis
sleep and exercise
what connection does growth hormone axis use
blood vessel connection to anterior pituitary
the hypothalamus produce what hormones from the growth axis
GHRH (releasing), GHIH (inhibiting)
what are the effects of growth hormone
breakdown of fats/carbs to increase blood energy sources (fatty acids and glucose) fuel for cells to grow and divide, causes liver cells to release IGF-1
what is the effect of IGF-1
promotes growth of tissues, takes in glucose for energy to grow
how is IGF-1 like insulin
stimulates receptors to cause cells to intake glucose
what are the three ways in which growth hormone axis is stopped
GHIH in the hypothalamus, GH release negatively feeding back to hypothalamus, IGF-1 release negatively feeding back to anterior pituitary and hypothalamus
where are IGF-1 target cells
all body cells
what is TRH
thyrotropin releasing hormone
what is TSH
thyroid stimulating hormone
where is TSH released from
anterior pituitary
what stimulates the release of TRH from the hypothalamus
exercise, cold stress
which cells do thyroid hormone affect
most body cells
what effect does thyroid hormone have and how does it have these effects
increase metabolic rate, increase growth and development because it helps cells make ATP and build proteins faster, helps cells repair, grow and divide
how is thyroid hormone release stopped
negative feedback of thyroid hormone and TSH, remove the stimulus of cold or exercise
what are three ways the body deals with stress
makes fuel available for cells to use, ensures blood pressure is high enough, maintains ECF osmolarity
what is CRH
corticotropin releasing hormone
what is ACTH
adrenocorticotropin hormone
where are the adrenal glands
sitting on top of the kidneys
what stimulates the corticotropin axis
day/night rhythm, stress
are cortisol levels higher at day or night
day
what are the target cells for cortisol
muscle, fat, liver cells
what are the effects of cortisol
protein breakdown and glucose uptake in muscles, fat breakdown and glucose uptake in fat cells, glucose synthesis in liver cells, helps maintain normal blood pressure, increases immunity
how to stop cortisol release
remove the stress stimulus (can’t remove the day/night one), negative feedback of cortisol and ACTH
what pathway does the ADH hormone use
hypothalamus, posterior pituitary
what stimulates ADH release
dehydration (high ECF osmolarity, osmoreceptor stimulation in hypothalamus), stress
what are the target cells of ADH
kidneys, blood vessels, hypothalamus
what are the effects of ADH in the kidneys
stimulate reabsorption of water, increases blood volume, increases blood pressure
what are the effects of ADH in the hypothalamus
affects CRH and ACTH, increased cortisol release, increases blood pressure
what are the effects of ADH in the blood vessels
vasoconstriction, increases blood pressure
what is the risk of prolonged increased cortisol levels
high blood pressure leads to issues
what stops ADH release
remove the stimulus by increasing hydration and reducing stress, ECF osmolarity returns to normal which feeds back to osmoreceptors
is noradrenaline a hormone or a neurotransmitter
both
what stimulates adrenaline release
stress and exercise
where is adrenaline released from
hypothalamic neurons of the sympathetic nervous system stimulate the adrenal medulla to release adrenaline
when adrenaline is released a small amount of __ is also released
noradrenaline
where in the adrenal gland is cortisol released from
the cortex
where in the adrenal gland is adrenaline released from
the medulla
what are the target cells of adrenaline
lungs and airways, heart, blood vessels, liver, skeletal muscle, adipose
what are the effects of adrenaline
increased rate of breathing and airway dilation, increased heart rate and strength of contraction, increased blood pressure (vasoconstriction), increased glycogen breakdown and glucose synthesis in the liver, increased glycogen breakdown in skeletal muscle, increased fatty acid mobilisation in adipose
how is the release of adrenaline stopped
remove the stress, stop exercising, be calm and relax
is cortisol a long or short term response and what type of hormones are involved
long term, slow response that lasts hours to days, lipid-soluble
is adrenaline a long or short term response and what type of hormones are involved
short term, fast response that lasts seconds to minutes, water-soluble
what three hormone axes are involved in the stress response
CRH-ACTH-cortisol, adrenaline, ADH
what are catecholamines
adrenaline and noradrenaline
what are adrenergic receptors
receptors that are stimulated by catecholamines
what are the two receptors the adrenaline can bind to
alpha and beta, there are different responses when it binds to each
what is an example of something with both alpha and beta receptors that have different responses
blood vessels, vasoconstriction and vasodilation
what do adrenergic agonists do
mimic adrenaline, chemicals that stimulate or increase function of adrenergic receptors
what do adrenergic antagonists do
block or inhibit function of adrenergic receptors
what are called symapthomimetics
adrenergic agonists
what is an example of an adrenergic agonist
pseudoephedrine hydrochloride, acts on alpha and beta adrenergic receptors, decongestant, amphetamine (stimulant), banned in sports
what is an example of an adrenergic antagonist
propanolol, blocks beta adrenergic receptors, treats abnormal heart rhythm or high blood pressure, athletes use to calm nerves, banned in sports, competes with adrenaline to bind to receptors
what is normal blood glucose range
4-6mmol/L
glucagon is released from __ cells
alpha
insulin is released from __ cells
beta
what are the target cells for glucagon
liver
what are the target cells for insulin
liver, skeletal muscle, adipose
hormones are chemical signals that travel in the __ to all parts of the body
bloodstream
what is the connection between the hormonal and neural communication
hypothalamus
