Endocrine- Pt 1-3 Flashcards
this type of hormone produces a rapid response and accounts for most hormones
peptide hormones
list the steps of peptide hormone synthesis
DNA–> mRNA–> preprohormone–> prohormone–> hormone
what kind of hormones are these:
insulin
glucagon
ghrelin
leptin
peptide hormones
this type of hormone is derived from tyrosine?
amine hormones
what 2 major categories of hormones are amine hormones?
1- catecholamines
2- thyroid hormones
catecholamines have a ________ response, while thyroid hormones have a _________ response
rapid
slow
thyroid hormones are __________, which allow them to diffuse across membranes to bind cytosolic or nuclear receptors
lipophilic
this type of hormone is derived from cholesterol
steroid hormones
do steroid hormones have a slow or fast response?
slow
what type of hormones are these:
cortisol
aldosterone
estradiol
progesterone
testosterone
calcitriol
steroid hormones
are steroid hormones lipophilic?
yes
does the short or long feedback loop feed back to the HPA axis?
long
does the short or long feedback loop feed back to the hypothalamus to inhibit secretion of hypothalamic releasing hormone?
short
this connects the pituitary and hypothalamus
infundibulum
this part of the pituitary is composed of neural tissue
posterior pituitary
what 2 hormones does the posterior pituitary release?
ADH and oxytocin
2 actions of ADH
V1- potent vasoconstrictor
V2- increases reabsorption in late DCT and collecting duct
what 2 factors inhibit ADH release?
decreased serum osmolarity
ethanol
cause of central diabetes insipidus
failure of ADH release from the pituitary
cause of nephrogenic diabetes insipidus
cells of collecting duct not responsive to ADH
this disease is excessive ADH release and leads to the production of small volumes of concentrated urine
SIADH
this hormone is released from the posterior pituitary and is responsible for the “letdown” reflex and emotional bonding
oxytocin
what inhibits oxytocin?
opioids
this part of the pituitary gland is a collection of endocrine cells activated by the hypothalamic tropic hormones
anterior pituitary
what stimulates the pituitary to release stimulating hormones?
releasing hormones from the hypothalamus
what type of cells in the anterior pituitary release GH?
somatotrophs
what type of cells in the anterior pituitary release prolactin?
lactotrophs
what class of hormone are prolactin and GH?
peptide hormones
list 5 effects of GH
1- increases protein synthesis
2- antagonizes effects of insulin
3- mobilizes fatty acids from storage
4- stimulates gluconeogenesis in the liver
5- increased linear growth
what hormone inhibits GH and where is it released from?
somatostatin (SRIF) released from the hypothalamus
this condition is caused by a lack of GH
dwarfism
this condition is caused by defective GH receptors
Laron dwarfism
this condition is caused by a GH secreting tumor
acromegaly
what hormone from the hypothalamus stimulates prolactin release?
thyrotropin releasing hormone (TRH)
list 4 effects of prolactin
1- breast development at puberty
2- development of mammary alveoli in pregnancy
3- synthesis of milk components (lactose, casein, lipids)
4- inhibits ovulation
what substance released from the hypothalamus via hypothalamic-hypophyseal portal veins is inhibitory of prolactin?
dopamine
this substance is a dopamine agonist
bromocriptine
list the 3 layers of the adrenal cortex and what they release
zona glomerulosa- aldosterone
zona fasciculata- cortisol
zona reticularis- androgens
all adrenocortical steroids are derived from _______
cholesterol
this is the rate limiting step in adrenocortical steroid synthesis
cholesterol desmolase
*stimulated by ACTH from anterior pituitary
this stimulates aldosterone production at the last enzymatic steps which is unique to the aldosterone pathway
angiotensin 2
this molecule is required for glucocorticoid synthesis
11-beta hydroxylase
this molecule from the anterior pituitary stimulates adrenal cell growth and activity, processing of cholesterol via CYP450 and is highest in the morning
ACTH
list 5 major effects of cortisol
1- gluconeogenesis
2- protein catabolism
3- lipolysis
4- immunosuppression
5- anti-inflammatory
what 2 androgenic compounds does the zona reticularis release?
DHEA
androstenedione
what is the main regulator of aldosterone secretion?
RAA system
does high K+ lead to increased or decreased cholesterol desmolase?
increased–> increased Na/K pumps
what are 3 major actions of aldosterone?
1- insertion of Na/K pumps (increased Na+ reabsorption and increased K secretion)
2- increased hydrogen ATPase (increased H secretion)
3- fluid volume expansion and increased BP
excess aldosterone leads to increased _________ reabsorption and increased _________ secretion, leading to ____________ and increased BP
Na+
K+
hypokalemia
low aldosterone leads to decreased ___________ reabsorption and decreased ____________ secretion, leading to decreased BP
Na+
K+
this disease is destruction of all zones of the adrenal gland
Addison disease
Addison’s disease leads to a decrease in these 3 factors. List them and their effects.
1- cortisol: hypoglycemia, anorexia, weight loss
2- aldosterone: hyperkalemia, metabolic acidosis, hypotension
3- androgens: decreased pubic and axillary hair
this syndrome is excess production of glucocorticoids (cortisol)
cushing syndrome
this thyroid hormone accounts for 90% of TH production
T4 (thyroxine)
this thyroid hormone is the most ACTIVE
T3 (triiodothyronine)
are TH lipophilic or hydrophilic?
lipophilic
this molecule makes up a large portion of colloid
thyroglobulin
thyroglobulin has high amounts of this a.a.
tyrosine
this enzyme puts tyrosine and iodine together
thyroid peroxidase
this inhibits thyroid peroxidase function
propylthiouracil
how does TH move in the blood?
bound to thyroxine binding globulin (TBG)
small amount bound to albumin or free floating
is active TH free and unbound or protein bound?
free/ unbound
liver failure may reduce _____ which leads to an increase in levels of free TH–> negative feedback will inhibit synthesis and lead to ___________ (hyper or hypo thyroidism)
TBG
hypothyroidism
starvation decreases the conversion of _____ to _____ in the body, but NOT in the brain
body
does T3/ T4 bind to receptors outside or inside cells?
inside
this disease is a type 2 hypersensitivity in which antibodies stimulate TSH receptors
Graves disease
list 4 causes of goiter
1- graves disease
2- TSH secreting hormone
3- autoimmune thyroiditis
4- iodine deficiency
what do alpha cells from the pancreas release?
glucagon
what do beta cells from the pancreas release?
insulin
what do delta cells from the pancreas release?
somatostatin
is oral or IV glucose a more effective stimulator of insulin release?
oral- increases intestinal factors
what does insulin increase?
glucose uptake into cells
glycogen formation
protein synthesis
fat deposition
K+ uptake into cells
what does insulin decrease?
glycogenolysis
gluconeogenesis
lipolysis
list 2 insulin effects on adipose tissue
1- increases glucose and fatty acid uptake and triglyceride synthesis
2- decreases lipolysis
list insulin effects on skeletal muscle
increases uptake of glucose, glycogen storage and uptake of a.a. and protein synthesis
list 2 effects of insulin on the liver
1- increases glycogen synthesis and triglyceride synthesis
2- decreases gluconeogenesis
glucose binds to receptors on beta cells which leads to _________ of the beta cell–> insulin release
depolarization
list the MOA of insulin
1- binds to alpha subunit–> activation
2- GLUT insertion into membrane
true or false- insulin downregulates its own receptor
true
this is a type 4 hypersensitivity that causes autoimmune destruction of beta cells
type 1A insulin dependent diabetes mellitus
are type 1 or type 2 diabetes more prone to ketoacidosis?
type 1
in this condition, the pancreas produces insulin but the insulin has little or no effect and over time, beta cells become damaged
type 2 diabetes mellitus
______ is the antagonist to insulin
glucagon
list 3 effects of glucagon
1- glycogenolysis
2- gluconeogenesis
3- lipolysis
this hormone inhibits secretion of insulin and glucagon via paracrine action
somatostatin
do you get hyperreflexia with hypo or hyper calcemia?
hypocalcemia
- less polarization of cell (easier to depolarize)
forms of calcium in the blood
40% bound to albumin
10% bound to phosphate
50% ionized and free in the blood
_____ and Ca2+ compete for spots on albumin
H+
in acidosis, blood Ca2+ levels are _____
high
in alkalosis, blood Ca2+ levels are ______
low
this is the main hormone involved in increasing blood Ca2+ levels
PTH
what major 3 effects does PTH have?
1- increased resorption of bone
2- increased Ca2+ reabsorption from kidney
3- activation of vit D in kidney
how does PTH increase Ca2+ resorption from bone?
increased osteoclast activity
what 3 major impacts does PTH have on the kidney?
1- Ca2+ reabsorption in DCT
2- inhibits phosphate reabsorption
3- activation of vit D
this hormone reduces bone resorption by inhibiting osteoclasts
calcitonin
3 effects of active vit D
1- increases bone resorption and Ca2+ and phosphate used to rebuild new bone
2- increased Ca2+ and phosphate absorption in intestines
3- stimulates Ca2+ and phosphate reabsorption in the kidney
this is a vit D deficiency
rickets