✅PHYSIOLOGY - Endocrine Flashcards
Hormones that are derivatives of tyrosine
T3, t4, epinephrine, norepinephrine dopamine
What hormone attaches to a cytoplasmic receptor (instead of a nuclear) for transcription?
Cortisol
2nd messenger of glucagon
Camp
2nd messenger of insulin
Tyrosine kinase
Protein complex subunits in GPCR
Alpha (most impt)
Beta
Gamma
GTP is stimulated by
Guanine nucleotide exchange factors (GEFs)
GTP is inhibited by
GTPase accelerating proteins (GAPs) RGS Proteins (Regulatin of G protein signalling)
G-protein with alpha(t) subunit is responsible for
Hyperpolarization of the eye
Alpha(t) subunit is also called
Transducin
Messengers associated with phospholipase C
DAG
Ip3
DAG activates
Protein kinase C
cAMP activates
Protein kinase A
Examples of water soluble hormones
Insulin
Glucagon
Catecholamines
Lipid soluble hormones
Steroids
Calcitriol
Thyroxines
Retinoic acid
Other name for IGF-1
Somatomedin
EPO uses what 2nd messenger
Tyrosine associated kinase receptors
Tyrosine kinase receptors
Growth factors
NGF EGF PDGF IGF-1 Insulin
All hypothalamic hormones except _____ use the IP3 DAG mechanism
CRH
Transport of steroid hormones
Bound to proteins
Active form of steroid hormones
Free unbound form
Main site of inactivation of hormones
Liver
Main site of excretion of hormones
Liver
Kidneys
Hormone receptors are constant. T or F
False
Variable
Minimum amount of a hormone to produce an effect
1 picogram per ml
Hormone interaction that uses upregulation of receptors in response to another hormone
Permissive effects
2 types of synergistic effects
Additive and complementary
What type of hormone interaction does NE and E have?
Additive effect
3 moments where positive feedback of hormone is seen
LH surge
Oxytocin in delivery
Oxytocin in milk secretion
Example of negative feedback that does not use HPA
Insulin
The pituitary gland is connected to the _______ of the hypotahalamus via the pituitary stalk
Median eminence
Parts of the pituitary gland
Adenohypophysis
Neurohypophysis
Pars intermedia
Avascular portion of the pituitary gland
Pars intermedia
The anterior pituitary is derived from the
Oral ectoderm or
Rathke’s pouch
Hormones produced in the neurohypophysis
Vasopressin
Oxytocin
The posterior pituitry is derived from the
Neural ectoderm
2 types of cells in the anterior pituitary
Basophilic and acidophilic cells
Acidophilic cells produce
GH
Prolactin
Basophilic cells produce
B FLAT Major
FSH LH ACTH TSH MSH
If the pituitary stalk is damaged, all hormones would decrease except
Prolactin
In terms of number, what are the top 2 cells in the anterior pituitary
Somatotropes (40%)
Corticotropes (20%)
Hormones derived from POMC
MSH
ACTH
Hormone family in the anterior pituitary with the same alpha unit but unique beta subunits
TSH
LH
FSH
3 hormone classes
Steroids
Protein
Derivatives of tyrosine
Growth hormone is both catabolic and anabolic. T or F
t
Other name for growth hormone
Somatotropin
Other name for IGF
Somatomedin
Growth hormone is released in a ________ fashion
Pulsatile (every 2 hrs)
Nocturnal peak of GH
1 hour after stage 3 or 4 sleep
4 diabetogenic hormones
Glucagon
GH
Epinephrone
cortisol
GH secretion requires normal plasma levels of this hormone.
Thyroid hormones
Decreased GH
MCC of dwarfism
Achondroplasia
Achondroplasia is a defect in
FGF 3 receptor
Inc GH with skeletal deformities
Acromegaly
Symmetrical
Inc GH
Gigantism
Lactational amenorrhea duration
6mos
What is one possible side effect of antipsychotic drugs that involve prolactin?
Amenorrhea
Galactorrhea
Prolactin is stimulated mainly by
Pregnancy (estrogen)
Breast feeding
Prolactin is inhibited by
Dopamine
Bromocriptine
Other names of vasopressin
AFH
AVP(arginine vasopressin)
Vasopressin is secreted byvthe
Supraoptic nuclei in the hypothalamus
Vasopressin responds to ECF changes detected by osmoreceptors in the
Organum vasculosum
Most poteng stimulus for vasopressin release
Increased plasma osmolality
Vasopressin acts on what type of receptors in the kidney?
V2 receptors
Causing the insertion of AQP2 in the late distal tubule and CD
Peripheral vasoconstriction is mediated by which receptor of ADH
v1
Treatment in central diabetes insipidus
DDAVP
Treatment of peripheral diabetes insipidus
Thiazide diuretics
Treatment for SIADH
Demeclocycline
Rapid correction of hyponatremia results in
Central pontine myelenosis
Oxytocin is from the
Paraventricular nuclei of the hypothalamus
2 actions of oxytocin
Milk ejection (contraction of myoepithelial cells) Uterine contraction
Only hormones that we can store
Thyroid hormones
Thyroid hormones are synthesized by the
Follicular epithelial cells of the thyroid
Thyroid gland can produce and store hormones for up to how many mos?
3 mos
What thyroid hormone is more active?
T3
Percent of T3 and T4 synthesized
T4 93 %
T3 7 %
How do thyroid hormones regulate basal metabolic rate?
Increases mitochondria and NaKATPase activity
Effect of thyroid hormones that causes fine muscle tremors
Increases muscle vigor
Important in regulation of thyroid hormones
Temperature
Cold temperature stimulates what thyroid regulation process
TRH secretion
Exophthalmos is pathognomonic for which disease
Graves
Whole body myxedema is seen in hypo or hyperthyroidism?
Hypo
Hyper- pretibial myxedema
RDA of iodine per day
150 ug
What is the WOLFF-CHAIKOFF EFFECT?
High levels of iodine inhibiting organification and iodine thyroid hormone synthesis
TBG levels in kidney and liver failure
Decreased
TBG levels in estrogen or pregnancy
Increased
Enzyme that converts T4 to T3
5 iodinase
T4 can also be converted to
rT3 (inactive)
What is theJod-Basedow phenomenon?
Hyperthyroidism following administration of iodine
Where is cortisol produced?
Zona fasciculata
Main catecholamine produced in the adrenal medulla
Epi 80%
Norepi 20%
Inhibits 11 beta hydroxylase
Metyrapone
Inhibits desmolase
Ketoconazole
Significance of adrenal androgens in males and females respectively
Inisgnificant
Significant
Diabetogenic hormones
GH
Epi
Glucagon
Cortisol
Primary adrenal insufficiency
Addison’s disease
Primary adrenal hyperplasia
Cushing syndrome
Treatment for cushing’s syndrome
Ketoconazole
Metyrapone
11 depxycorticosterone is a _____ hence there is increased BP with accumulation
Weak mineralocorticoid like aldosterone
Most abundant cells in the islets of langerhans
Beta cells 60%
Name the secretion of each cell:
Beta
Alpha
Delta
f cell /PP cell
Beta - insulin and amylin
Alpha - glucagon
Delta - somatostatin
f cell /PP cell - pancreatic polypeptide
Half life of insulin
6 minutes
Structure of insulin
A chain and B chain joined by disulfide bonds
Effect of insulin on potassium uptake
Inc potassium uptake of the cells
Percentage of beta cell lost to manifest with DM type 1
80-90%
2nd messenger of insulin
TK
Effects if insulin on the brain
None
GLUT transporter found in beta cells
GLUT 2
Calcium is ___ in bone
Hydroxyapatite
Where are PTH receptors located
Osteoblasts
What is secreted by osteoblast to inhibit osteoclastic activity in hyperparathyroidism?
Alkaline phosphatase
Active vitamin D
1,25 OH2 cholecalciferol
PTH is secreted
Chief cells of the parathyroid gland
Calcitonin is secreted by
Parafollicular cells (c-cells) of the thyroid gland
Stimulus for clacitonin release
High plasma Ca
Mnemonic calcitonin
“Calcium in”
Net effect of vit d on serum level of Calcium and phosphate
Inc calcium and phosphate
Net effect of PTH on serum level of calcium and phosphate
Inc calcium
Dec phosphate
Effect of pth on the kidneys
Inc calcium reabsorption in the DCT
Dec phopshate reabsorption in the PCT