Semester 2 L9: Hormone 3 Flashcards
insulin is linked too?
insulin
Ca2+ ions link too?
parathyroid hormone
what do hypothalamic neurone produce?
tropic hormones
Peptide hormones are ___ active.
fast
peptide hormones are synthesised as?
preprohormones
preprohormones are cleaved to form?
prohormones
what are prohormones packaged into?
secretory vesicles by golgi
prohormone cleaved to form?
an active hormone
what stem stages of insulin being synthesised?
pre-pro-insulin (arrow) proinsulin (arrow) insulin
where does protein synthesis happen?
endoplasmic reticulum
pro hormones are packaged in too _____.
vesicles
steroid hormones has to be what?
synthesised
steroid hormones is derived from?
cholesterol
cholesterol is derived from..
low density lipoprotein
where is cholesterol converted to steroid ?
in mitochondria and SER
RER links too?
protein synthesis
what enzyme is used in the mitochondrial, during steroid hormone synthesis?
cytochrome P450
steroid hormones diffuse out of cell into what?
into interstitial fluid and blood
How is a steroid hormone produced?
- cell receives signal to produce steroid hormones.
- singling causes lipid droplets to release the cholesterol
- cholesterol travels to mitochondria and SER
- This produces the steroid hormone which goes back to the mitochondria then diffuses into the blood
where is the pituitary gland located?
below hypothalamus at the base of the brain
what connects the hypothalamus to the pituitary?
infundibulum (stalk)
what does the infundibulum contain?
nerves and vessels
what do hypothalmo-pituitary portal vessels do?
deliver hypothalamic hormones to pituitary
pituitary gland has two may lobes ?
2
the anterior lobe of the pituitary is linked too?
the tissue in the roof of the mouth
the posterior pituitary gland originates from where?
embryonic Brian tissue
How does the anterior pituitary gland produce hormones ?
- Hormone is released form the hypothalamus, via a cluster of nuclei, it travels down axons.
- to the blood vessels which are in the median eminence
- it then travels to the anterior pituitary, simulating the follicle cells to produce new hormones that’s released into the blood vessels.
How does the posterior pituitary gland produce hormones ?
supraoptic nuclei and paraventricular nuclei axons go to the posterior pituitary gland, where the hormone enter the blood stream and go to where they are needed.
what are the two nuclei involved in he posterior pituitary gland ?
supraoptic nuclei
paraventricular nuclei
the axons of the supraoptic nuclei, paraventricular nuclei end at the ?
posterior pituitary.
what’s a typical 3 hormone sequence ?
hypothalamus (hormone 1 secretion), anterior pituitary (hormone 2 section), third endocrine gland (hormone 3 secretion), target cell.
insulin can be referred to as a ?
storage hormone
insulin is a _____ hormone
1.peptide
where is insulin produced?
pancreas by beta cells of islets of Langerhans
what two cells do islets of Langerhans have?
alpha and beta
what do the alpha cells of islets of Langerhans produce?
glucagon
what does insulin act on?
muscle, adipose tissue and liver.
give an example of humeral control.
insulin is released in response to changes in glucose levels, as plasma levels increase, beta cells produce insulin. Blood insulin increases and then travel to the target cells. insulin is removed from the blood and stored in cells.
How does insulin work?
insulin binds to the receptor on the target cell, sets off signalling pathways, there’s vesicles with glucose transporter molecules in them. these vesicles move to the cell membrane and glucose transporter molecules fuse to membrane, they allow glucose to diffuse into the cell.
what san insulin target cell?
The cell thats going to store all the glucose
what do glucose transporter proteins increase?
increase rate of glucose entry in to the cells.
How do muscles respond to an increase in insulin?
glucose is taken up then its converted into glycogen or amino acid uptake and protein synthesis
How do fats respond to an increase in insulin?
glucose is taken up and leads to the synthesis or triglycerides
How does the liver respond to an increase in insulin?
glucose is taken up its stored as glycogen, there’s synthesis of triglycerides but no ketone synthesis.
How do muscles respond to a decrease in insulin?
Glucose uptake is reduced, net glycogen catabolism net protein catabolism net amino acid release fatty acid uptake
How do fats respond to an decrease in insulin?
Glucose uptake is reduced,
net triglyceride catabolism and release of glycerol and fatty acids
How does the liver respond to an decrease in insulin?
glucose is released due to net glycogen catabolism and gluconeogenesis.
ketone synthesis increases.
After food what increases?
plasma glucose levels
what can stimulate insulin production?
plasma glucose increase, plasma amino acid increase, increases in parasympathetic activity.
insulin can be controlled by the?
autonomic nervous system
what can stop insulin production?
sympathetic activity
where is Glucose-dependent insulinotopic peptide produced?
intestine
Glucose-dependent insulinotopic peptide (GIP) responds to?
eating
Glucose-dependent insulinotopic peptide produces insulin at a ___ level so you don’t get a ____ spike of insulin.
- low
2. huge
Glucose-dependent insulinotopic peptide is known as?
GIP
what 3 systems control insulin?
humeral control, autonomic nervous system and GIP
what secretes GIP?
endocrine cells in the GI tract
what inhibits insulin secretion?
sympathetic stimulation and increased adrenaline
whats the Role of glycogen in glucose control?
low plasma glucose leads to islet alpha cells producing glucagon, plasma glucagon levels increase which leads to the production of glucose because amino acids, triglycerides and glycogen break down. Also increase in plasma ketone.
if you’re failing to secrete insulin this means you have?
type 1 diabetes
If you have an impaired response to insulin?
type 2 diabetes
insulin deficiency can lead to pathway 1 which is?
You start depending on fatty tissue (lypolisis). You start producing ketones, hydroxybutyric acid andacetoacetic acid.
results in acidosis and coma.
insulin deficiency can lead to pathway 2 which is?
High glucose levels (hyperglycaemia), induced diuresis (los of water) which means loss of sodium, blood volume decreases, results in low blood pressure, which can lead to a coma as inadequate blood delivery to brain.
what are some treatments for low insulin?
- Administer insulin
- Administer Sulfonyl Ureas
- transplant (pancreas, islet cells, stem cells)
why does Sulfonyl Ureas help with low insulin?
stimulate beta cells to produce insulin
