endocrine flow charts Flashcards
insulin is secreted from where
the beta cells of pancreas
what causes insulin to be released
the increase of blood glucose concentration
insulin has an effect on what tissue cells
muscle cells and liver cells and adipose fat cells
what does insulin do to muscle and fat cells
muscle cell: causes net increase in uptake of glucose, as increased amino acid uptake and increased glycogen and protein synthesis.
fat cells sees increase in fat synthesis
what does insulin do to the liver cells
increases glycogen and fat synthesis, stops glucose output thereby increasing glucose intake.
whats the negative feedback for insulin release
the lowering of the blood glucose levels.
glucagon is secreted from where
the alpha cells of the pancreas
what is the stimulus for glucagon secretion
low blood sugar
what are the target cells of glucagon
the cells of the liver
what type of hormones are insulin and glucagon
peptide, water-soluble hormones
what does glucagon do to the target liver cells
increases breakdown of glycogen (glycogenolysis)
increases glucose synthesis (gluconeogenesis)
increases ketone synthesis
what is the negative feedback for glucagon secretion
the raise of blood glucose concentration and blood ketone concentration
what hormones can also raise blood glucose concentration
growth hormone, adrenaline and cortisol
what triggers the release of GH-RH
The stimulus for GH-RH release is neural input to the hypothalamus.
where is GH-RH hormone stored and secreted from
in GH-RH neurons in the hypothalamus
what are the target cells for GH-RH
the target cells are in the anterior pituitary gland.
what does the GH-RH signal cause in the anterior pituiary lobe
it signals the release of growth hormone from the anterior pituitary
what are the target cells for GH
muscle cells, liver cells, fat cells,
what does the hormone GH cause in the liver cells
it directly causes glucose synthesis in the liver, but also causes the secretion of another hormone, somatomedin C which has indirect effects
what inderect effects does IGF 1 have
somatomedin c, or IGF 1 promotes the growth of bones, muscle and other tissues, which promotes cell division
what effects does GH have on muscle cells
stimulates protein synthesis (long term) and inhibits, cellular uptake of glucose (short term)
what effect does GH have on fat cells
increases triglyceride breakdown in adipose tissue
(short term).
whats the negative feedback for the release of GH
the IGF-1 has negative feedback on the GH-RH neurons, slowing the release of GH-RH to the pituitary
what other effect does IGF-1 have
it causes positive feedback on the release of GH-IH from the somatomedin neurons
what does GH-IH do
it inhibits the release of GH from the anterior pituitary
what triggers the start of the thyroid hormone flow chart
external and internal stimuli lead
to CNS input to hypothalamus
what does CNS input to the hypothalamus cause in TH cycle
it causes the release of thyrotropin-releasing hormone from the hypothalamus
what are the receptor cells for TRH
the anterior pituitary cells
what does TRH cause in the anterior pituitary gland
it causes the release of thyrotropin-stimulating hormone from the anterior pituitary
what are the target cells for TSH
the thyroid gland cells
what does TSH cause in the thyroid gland
causes the release of thyroid hormones T3 and T4.
what are the main effects of thyroid hormone
an increase in basal metabolic rate via the synthesis and activity of K+ Na+ ion pump
what other effects does thyroid hormone have
stimulates growth in fetus and early childhood, it maintains normal alertness and reflexes
whats the negative feedback for the release of thyroid hormone
the release of thyroid hormone inhibits the release of TRH and TSH
low blood calcium concentration causes what
causes the parathyroid to secrete PTH
what are the target cells for PTH
kidney and bone cells
what does PTH cause in the kidneys
it increases the calcium reabsorption to the blood stream and causes vitamin D to be converted to calcitriol
what does calcitriol do
calcitriol amplifies the reabsorption of calcium to the blood, also amplifies the bone resorption by the osteoclasts, also increases calcium absorption from food
what is negative feedbakc for calcitriol prooduction and why
the negative feeback for calcitriol production is calcitriol itself, does this as it has an amplification effect on other processes caused by PTH
what does an increase in calcium reabsorption cause
it causes a decrease in calcium lost via urine
what does PTH cause in bone
it causes an increase in bone resorption by osteoclasts
what does an increase in bone resorption cause
an increase in blood calcium
what is the negative feedback for PTH release
the raising of blood calcium concentration
what is the stimulus for stress response
a stress acting on a person, the hypothalamus takes this stress and coordinates a response
what does the stress response of the hypothalamus cause
it causes the stimulation of preganglionic sympathetic nerves
what does stimukation of preganglionic nerve fibres cause
causes an action potential to propagate down the neuron
where does the AP of the preganglionic sympathetic neuron go
it goes to the adrenal medulla, ACh binding to the receptors
what does ACh binding to receptors on the adrenal meddula cause
causes the adrenaline to be secreted froim the adrenal medulla
what are the target cells for adrenaline
fat tissue, skeletal muscle and liver
what is the overall effect of adrenaline
Makes fuel (glucose & fatty acids) more readily available to cells. systems not crucial or short-term
survival are shut down
what does adrenaline cause in fat cells
causes an increase in breakdown of fat to fatty acids
what does adrenaline cause in liver and skeletal muscle fibres cause
incr breakdown of glycogen to glucose
whats the negative feedback for the release of adrenaline
there isnt really one, the only way to stop the release of adrenaline is to remove the stress causing this response.
what initiates the cortisol secretion cycle
non stress based neural inputs, like day night ryhtym and low blood glucose concentration
what does a non stress neural input cause
it causes the hypothalamus to secrete corticotropin releasing hormone
what does corticotropin-releasing hormone, CRH, cause
causes the anterior pituitary gland to release adrenocorticotropic hormone, ACTH
what are the target cells for corticotropin-releasing hormone, CRH
target cells are found in the anterior pituitary gland
what are the target cells for ACTH
adrenal cortex cells
what does ACTH cause in the adrenal cortex
the secretion of cortisol
what are the target cells for cortisol
muscle fat and liver cells
what does cortisol cause in muscle
an increase in protein breakdown and a decrease in glucose uptake
what does cortisol cause in fat
increase in fat breakdown, a decrease in glucose uptake
what does cortisol cause in liver cells
glucose synthesis
what are some other effects of cortisol
helps one to cope with stress, long term it supresses the immune system, its also essential for maintaining blood pressure
whats the negative feeback for cortisol release
the removal of the stress its self. or in a non stress case, the cortisol inhibits the release of CRH and ATCH
