Module 6: Endocrine System Flashcards
What is the condition:
Occurs after a woman gives birth, develops low blood pressure and reduced blood flow to the pituitary gland and can result in severe depression with SI?
Sheehan’s syndrome
In Sheehan’s syndrome, what gland is under perfused?
The pituitary gland
which 3 are hormones and neurotransmitters?
Serotonin, norepinephrine, and epinephrine
What three glands in the brain are where the nervous and endocrine system comes together?
The hypothalamus, the pituitary gland, and the pineal gland.
what are hormones?
secreted circulating chemical mediators
what do autocrine mediators do?
they help regulate the cell that secreted it
what do paracrine mediators do?
influence cells nearby
Name the 4 steroid hormones
aldosterone, cortisol, estrogen, and testosterone
Name 3 amino acid hormones
insulin, adrenocorticotropic hormone (ATH), and prolactin
Name 3 amine hormones
thyroid hormone, epinephrine, and norepinephrine
what are amine hormones derived from?
built/derived from the amino acid tyrosine
what are steroids made out of?
made of cholesterol (fat) and are lipid soluble
where do steroids bind to?
they bind to receptors inside the cytosol or the nucleus
what is the “interface” between the nervous and endocrine system/
the hypothalamus
what 3 endocrine glands does the hypothalamus communicate with?
adrenal medulla (gland), anterior pituitary (adenohypophysis), and the posterior pituitary (neurohypophysis).
what is another name for the anterior pituitary?
adenohypophysis
how does the hypothalamus communicate with the adenohypophysis?
the hypothalamus communicates with the anterior pituitary with chemical signals via the blood stream.
what is another name for the posterior pituitary?
neurohypophysis
how does the hypothalamus communicate with the posterior pituitary?
the hypothalamus communicates with the posterior pituitary via a nerve track
what kind of hormones are released from the hypothalamus?
releasing-factor hormones
how many hormones are released from the anterior pituitary ?
5 hormones
what are the 5 hormones secreted by the anterior pituitary?
- adrenocorticotropic hormone
- growth hormone
- prolactin
- follicle stimulating hormone/luteinizing hormone
- thyroid stimulating hormone
what is the ACTH?
adrenocorticotrophic hormone
what is TSH?
thyroid stimulating hormone
what is GH?
growth hormone
what is FSH/LH ?
follicle stimulating hormone/ luteinizing hormone
what is PRL?
Prolactin hormone
what does the adrenal cortex describe?
it means outside of the organ
what does the adrenal medulla describe?
inside the organ
what does the adrenal cortex secrete?
corticosteroids
what is the primary corticosteroid the adrenal cortex releases?
cortisol
what is a mineralocorticoid released from the adrenal cortex?
aldosterone
what is the function of aldosterone?
retain sodium, excrete potassium
what is the 3 glucocorticoids?
cortisol, cortisone, and corticosterone
what is the most abundant glucocorticoid?
cortisol
Emotional and physical stress is communicates to the hypothalamus via what system of the CNS?
the limbic system
what is cholesterol a component of and where does it come from?
it is a component of glucocorticoids and comes from the liver.
**it is delivered to the adrenal cortex where it its used to produce glucocorticoids
When is cortisol level the highest throughout the day?
In the morning, when waking up
what pattern does cortisol have?
It has a diurnal or circadian pattern
what is muscle protein catabolism?
breakdown of muscle protein which leads to loss of functional muscle
what is lipolysis?
breakdown of fat
what is gluconeogenesis?
making new glucose out of amino acids and lactate
what is anabolism?
building up or synthesizing of complex chemical structures
what is catabolism?
the breakdown of complex chemicals into simple chemical products
What is Cushing’s disease associated with?
Too much or excess cortisol
what type of cancer is a frequent cause of ectopic excess of ACTH?
small cell lung cancer
what are the s/s of Cushing’s disease?
muscle wasting, hyperglycemia, increased infection, hypertension, bruising, central redistribution of fat
What is Addison’s disease associated with?
A deficit or too little cortisol
what are the s/s of Addison’s disease?
hypoglycemia, weakness, weight loss, hypotension, lethargy, mental confusion, possible seizures
aldosterone is under partial influence of what hormone?
adrenocorticotropic hormone (ACTH)
aldosterone secretion is under dual control by?
the hypothalamus and the renin-angiotensin system
Describe the Renin-angiotensin-aldosterone system:
The liver produces angiotensinogen which is secreted when the renal artery pressure is low, there is increased sympathetic activity. the juxtaglomerular cells of the kidneys secrete renin into the circulation. Renin breaks down angiotensinogen to angiotensin 1. the angiotensin 1 circulates to the lung in which the enzyme ACE converts angiotensin 1 to angiotensin 2.
what is renin?
an enzyme that breaks down angiotensinogen to angiotensin 1.
what cells of the kidneys secrete renin?
the juxtaglomerular cells
what does ACE stand for?
angiotensin converting enzyme
where in the body does the ACE enzyme convert angiotensin 1 to angiotensin 2?
the lungs
aldosterone is regulated by: (2)
adrenocorticotrophic hormone (ACTH) and angiotensin II
what happens in hyperaldosteronism?
think fluid and electrolyte imbalance
hypernatremia and hypokalemia
HTN, cardiac hypertrophy, and HF occur
what is the function of the thyroid gland?
Helps control growth and maintain energy (metabolism) homeostasis
what two hormones does the thyroid gland secrete?
T3 and T4
what is another name for T4?
thyroxine
what is another name for t3?
triiodothyronine
how many iodines does thyroxine have?
4 iodines
how many iodines does triiodothyronine have?
3 iodines
T3 and T4: which is more abundant and more potent?
T3 is more potent but less abundant.
T4 is less potent but more abundant.
what are the thyroid hormone functions?
increase carbohydrate and lipid catabolism (breakdown), increased protein synthesis, thermogenesis, stimulate growth and development with GH, and increases reactivity of the nervous system
what are the symptoms of hypothyroidism?
myxedema, lethargy, memory impairment, slow deep tendon reflexes, anovulation, menstrual irregularities, infertility, constipation, depression, hypercholesterolemia, high LDL, goiter.
what is grave’s disease associated with?
hyperthyrodisim
what are the s/s of hyperthyroidsim?
exophthalmos, goiter, weight loss, tachycardia, hypertension, hyperreflexia, and diarrhea
what is a normal TSH range?
0.30–3.0
In hypothyroidism, what labs are expected for TSH and T4?
TSH is high and T4 is low
in hyperthyroidism, what labs are expected for TSH and T4?
TSH is low and T4 is high
what is the ratio for T4 to T3?
20 to 1
what is another name for the growth hormone?
Somatotropin
At what part in life is somatotropin the most secreted?
During puberty or adolescence
growth hormone targets what organ?
the liver
what does hormone does the liver secrete?
somatomedin
Deficiency of the growth hormone in neonates can result in what?
Hypoglycemia
why: somatotropin is not available to tell the liver to release glucose from glycogen
Deficiency of the growth hormone in infants and children can result in what?
slow growth, delayed puberty and bone growth or maturity, dwarfism, slow muscle development and delayed motor skills
deficiency of the growth hormone in adults results in what?
muscle wasting and weakness, reduced bone density–osteoporosis, increased insulin resistance, increased central obesity, dyslipidemia
Excess growth hormone in children can result in what?
accelerated growth and gigantism
Excess growth hormone in adults can result in what ?
Acromegaly and type 2 diabetes
what is acromegaly?
enlargement or increased bone thickening particularly in the hands, feet, jaw.
Growth hormone targets what tissues?
The skeleton, skeletal muscle, adipose tissue
Follicle stimulating hormone and lutenizing hormone targets what gland?
Ovary and testes
prolactin targets what glands?
the mammary glands
what type of connection does the posterior pituitary have with the hypothalamus?
Neural connection, does so by nerve transmission
what 2 hormones does the posterior pituitary secrete?
Oxytocin and anti-diuretic hormone (also called vasopressin)
what does ADH (anti-diuretic hormone) target?
the kidneys
what does oxytocin help control (2)?
the uterus and mammary glands
After ADH is transported to the kidney, where is water reabsorbed?
distal tubule and the collecting duct
what are the 4 functions of ADH?
Increase water reabsorption, decrease perspiration (inhibit sweat glands), conserve fluid volume, and raises blood pressure.
what is the deficiency of ADH called?
Diabetes Insipidus
what are the 3 main symptoms of diabetes insipidus?
Polydipsia (increased thirst), dehydration, and increased/excessive urination
what does the adrenal medulla secrete?
catecholamines: epinephrine and norepinephrine
what is the communication between the hypothalamus and the adrenal medulla?
it has a direct (neural integration) relationship/communication
of the two catecholamines which is more potent?
epinephrine (it is more abundant and potent)
where on the adrenal gland are the glucocorticoids and the catecholamines produced?
adrenal cortex: glucocorticoids
adrenal medulla: medulla
Describe the effects of the catecholamines on:
- blood vessels
- airway
- respiratory rate
- digestion
- blood sugar
The effects are sympathomimetic
Constricts blood vessels–increases blood pressure
increased HR, RR, slowed digestion, increased blood sugar, and airway dilation
What is an agoinst?
something that binds to receptors and activates it
what is pheochromocytoma ?
it is a tumor of the adrenal gland–usually benign
what can pheochromocytoma cause?
malignant hypertension (due to excess catecholamine)
what are s/s pheochromocytoma?
systemic vasoconstriction, HTN, elevated HR, nervousness, anxiety, tremors, excessive sweating, weight loss, volume depletion
What system relays emotional stress to the hypothalamus?
the limbic system
what system relays physiological stress to the hypothalamus?
the reticular system
when the hypothalamus sends out the corticotropin releasing hormone/factor what cells does it activate?
mast cells
what role does mast cells have?
they are a major line of defense against invading pathogens, they can eat microbes and release cytokines to destroy foreign invades, helps mediate inflammation.
what gland is affected by light and dark cycles?
the pineal gland
the pineal gland secretes which 5 hormones?
melatonin, adrenoglomerulotropic hormone (aldosterone stimulating), norepinephrine, serotonin, gonadotropin releasing factor
when does the thymus stop increasing?
It stops after puberty
what is the thymus made out of ?
lymphoid tissue
The release of what hormone inhibits the production of immunoglobulin production and the maturation of NK T lymphocytes?
Somatostatin or Growth Hormone
what does VIP stand for?
Vasoactive intestinal peptide
what is an exocrine gland?
an exocrine gland produces a substance which is secreted into a duct
what is an endocrine gland?
an endocrine gland produces a substance which is secreted into circulation
what gland/organ has both endocrine and exocrine properities?
the pancreas
Name the endocrine and exocrine properties of the pancreas?
endocrine properties is the islets of Langerhans
exocrine properties are the digestive enzymes from the pancreatic duct
where are the alpha and beta cells secreted from?
the Islets of Langerhans
what do the alpha cells of the pancreas secrete?
the alpha cells secrete glucagon
When do the alpha cell secrete?
they begin secreting when glucose levels are low which helps increase blood glucose levels
what process is used for alpha cells to increase glucose?
Hepatic gluconeogenesis (liver helps make new glucose which is made out of lactate (a metabolite of glucose) and amino acids
what is glycogenolysis?
it is the breakdown of glucose–catabolism of glycogen that has been stored in the liver
what is lipolysis?
the breakdown of fat.
what is the released from lipolysis?
fatty acids are released from fat breakdown into circulation.
what do beta cells secrete (2)?
insulin and amylin
what do delta cells of the pancreas secrete?
somatostatin
what is one of the main determinants of blood glucose levels?
muscle uptake of glucose
what are the functions of insulin?
increase muscle uptake of glucose, promote glucose storage as glycogen, increase lipogenesis, and protein synthesis
the main organs for converting glucose to fatty acids are:
the liver and adipose tissue
The rise in ATP to ADP ratio closes the potassium ATP channel into the cell and it opens what?
the calcium channel, calcium influx stimulates the release and synthesis of insulin.
what are the 3 functions of amylin?
decrease hepatic glucose release, regulate gastric emptying into duodenum, and may suppress feeding by signaling leptin to the hypothalamus
what is leptin?
a hormone secreted by fat cells that is an integral part of energy regulation in signaling satiety to the hypothalamus. (amylin helps increase the hypothalamic sensitivity to leptin.
what is the drug pramlintide (simillnitide)?
it is a synthetic form of amylin and it can be used as an adjuvant therapy at mealtime with insulin–given subcutaneously for Type 1 or 2 DM. Can’t be mixed in the same syringe as insulin.
what is the function of the delta cell hormone, somatostatin?
it counterbalances the growth hormone by curbing or slowing down growth
what is aldosterone deficiency?
diabetes insipidus
what is the cause of type 1 diabetes mellitus?
damaged pancreatic insulin secretion, insulin deficient
what is the cause of type 2 diabetes mellitus?
insulin resistance, increased insensitivity to insulin
what is gestational diabetes?
diabetes type 2 (insulin resistance) that develops during pregnancy
when does gestational diabetes usually occur?
usually occurs in the 2nd half of pregnancy
what is the diagnostic criteria for diabetes?
- Hemoglobin A1C greater 6.5%
- a fasting plasma glucose greater than 126mg/dL (with no caloric intake for at least 8hrs)
- oral glucose tolerance test that has a b.g. greater than 200mg (after 2 hours on ingestion)
- random plasma glucose greater than 200 with s/s: polyuria, polydipsia, and polyphagia with weight loss
what 3 tests for diabetes needs to be confirmed with a 2nd test?
Hemoglobin A1C, fasting blood glucose, oral glucose tolerance test
what is hyperinsulinemia and what is it characterized with?
increased insulin in the blood
it is associated with early on in diabetes because the body wants glucose to be taken up by the muscles to turn off gluconeogenesis in the liver
what cell is associated with destroying beta cells in type 1 diabetes?
T cells
glycosuria leads to what?
Polyuria due to the sugar in the urine acting as an osmotic diuretic
what process make a hemoglobin A1C result possible?
Glycosylation of RBCs, it tests over the lifespan of a RBC which is 3 months (120 days)
what a ketones?
they are the byproduct of lipid breakdown
what is ketosis?
lipid breakdown resulting in small fatty acids in the blood
what is ketoacidosis, hyperkalemia, and hyperglycemia associated with?
Type 1 diabetes mellitus
what are long term complications associated with diabetes?
microvascular and macrovascular changes, nephropathy, neuropathy, hyperglycemia/hypoglycemia, blindness, atherosclerosis
retinopathy is associated with what type of complication in diabetes?
it is a microvascular change that can lead to blindness
atherosclerosis is associated with what type of complication in diabetes ?
it is a macrovascular change that can lead to blindness
In type 2 diabetes, amylin will activate what system to increase vasoconstriction and makes patients prone to hypertension?
the renin-angiotensin aldosterone system
what medications are given to inhibit the renin-angiotensin aldosterone system?
Angiotensin converting enzyme (ACE) inhibitors
what do ACE inhibitors specifcially act on?
They block the end stages of the RAAS by preventing conversion of angiotensin 1 to angiotensin 2
what are the 5 reactive oxygen species (ROS) –free radicals that cause damage in type 2 diabetes?
superoxide, hydrogen peroxide, hydroxyl radical, and peroxynitrite
what causes oxidative stress in type 2 diabetes?
altered glucose and fat metabolism with chronic inflammation
what are 2 signs of chronic inflammation in type 2 diabetes?
increased fibrinogen and C-reactive protein
what effects does chronic inflammation have on the lipid profile?
elevated triglycerides
low density lipoproteins (LDL)
low levels of high density lipoprotein (HDL)
what is the good cholesterol (lipoprotein)?
HDL (high density lipoprotein)
what is visceral obesity?
the deposition of adipose tissue in the abdomen (apple shaped body)
what are complications associated with type 2 diabetes?
macrovascular and microvascular disease, neuropathy, nephropathy, nonalcoholic steatohepatitis (fatty liver), and hyperglycemia, hyperosmolar nonketotic condition
what is hyperosmolar nonketotic condition ?
extremely high hyperglycemia which leads to serious dehydration and hyperosmolar condition
