Endo Flashcards
Thyroid hormones
T3t4
Parafollicular calcitonin
Proteins and peptides
Stored in secretory vesicles until needed
Water soluble
Amines
Derived from tyrosine
Steroids
Synthesized from cholesterol
Lipid soluble
Not stored
More protein binding
Less metabolic clearance long plasma half life
Little protein binding
Lots of metabolic clearance
Little protein binding
Adenylate cyclase mechanism
ACTH, LH, FSH, TSH, hCG, MSH, CRH, PTH, calcitonin, glucagon
Gs
Phospholipase C
GnRH, TRH, GHRH, oxytocin
Gq, a bound to GTP, activate phospholipase C and get PIP2 then get DAG, IP3
DAG-PKC
IP3-ca release from er or sr
Steroid hormone mechanism
Thyroid hormones, glucocorticoids, aldosterone, estrogen, testosterone, 1,25 D
Cytoplasmic receptor and into nucleus where dimerize and bind to steroid responsive element
Anterior pituitary embryo
Oral ectoderm-epithelial
Posterior pituitary embryo
Neuroectoderm
Posterior pituitary nerves
PP is a collection of axons whose cell bodies are located int he hypothalamus
-SON, PVN
ADH from
SON
Oxytocin from
PVN
Anterior pituitary to hypothalamus
Neural and hormonal
-hypothalmic release and inhibit hormones into hypothalamic hypophysial portal vessels which go to anterior lobe which release into blood
Anterior pituitary is a collection of endocrine cells
Connected t hypothalamus by hypothalamic hypophysial portal vessels
Primary, secondary, tertiary disorders
Primary peripheral endocrine gland
Secondary pituitary
Tertiary hypothalamus
What are the families of anterior lobe hormones
ACTH
TSH, fsh, lh
GH, prolacitn
Growth hormone is secreted in a pulsation manner, when is most secreted
Sleep
Who is GH secretion higher in
Pubertal growth than in kids and adults
Describe GH secretion
Increased by GHRH , inhibited by somatostatin
Get IGF which - anterior pituitary
IGF and GH + hypothalamus
GHTH - hypothalamus
What does GH hormone do
Diabetogenic effect
Increase protein synthesis and organ growth
Increase linear growth
Diabetogenic effect GH
Increase blood glucose
Insulin resistance
Decrease glucose uptake, increase lipolysis in adipose tissue
INCREASE BLOOD INSULIN
GH increase protein synthesis and organ growth
Increase uptake of aa
Stimulate synthesis of DNA, RNA and protein
done by IGF-1
GH increase linear growth
Stimulates DNA, RNA protein synthesis
Increase metabolism inc artilage forming cells and chronrocytes proliferation
Done by IGF-1
Fasting effect on gh, IGF1 and insulin
Increase GH, decrease IGF1, decrease insulin
Increase caloric mobilization
ADH precursor
Preprossophysin
Oxytocin precursor
Prepro-oxyphysin
ADH action
V1-vasoconstriction
V2-increase reabsorption kidney
Urea can pass with water but electrolytes cant
Overall increase bp and blood volume
What causes secretion ADH
Plasma osmolarity 1% increase
(>280mOsm)
Decrease bp, by, angII, symp, dehydration
How sense osmolarity
Hypothalmic receptors and interneuron send to hypothalamus
How detect arterial stretch (look volume)
Atrial stretch receptors to sensory neuron to hypothalamus
How detect bp
Cardiac and aortic baroreceptors send sensory neuron to hypothalamus
DI
Lack ofAH on renal collecting duct
What causes central DI and how treat
Damage to pituitary and destruction of hypothalamus
Desmopressin
What causes nephrogenic DI and how treat
Lithium, chronic disorders
No desmopressin
Water deprivation test
For DI
Allow fluids overnight before test and give breakfast with no fluid
Weigh
Allow no fluid for 8 hours, every 1-2 hours weigh (stop test is drop more than 5%)
Measure urine volume and osmolarity
Measure plasma osmolarity (stop if over 300 )
If indicate DI give after and desmopressin
Measure plasma and urine osmolarity urine volume
17 a hydroxylase defiency
Increase mineralocorticoids, decrease cortisol, decrease sex hormones
High bp
Low K
Decrease androstenedione
Male-undescended testes
Female-lack of secondary sexua development
21 b defiency
Decrease mineralocorticoids, decrease cortisol, increase sex hormones,
Decrease bp increase K
Increase renin and 17 hydroxyprogesterone
Salt wasting , precocious puberty, virtualization
11b defiency
Decrease aldosterone, increase DOC, decrease cortisol, increase sex hormone, increase bp, decrease k , decrease renin
Virluisation
Cortisol release
Cortisol inhibit acth and CRH, long loop negative feedback
When is cortisol secreted
Morning
Cushing syndrome
Adrenal tumor, increase cortisol
Cushing disesase
Pituitary tumor increase cortisol
Addison
Autoimmune adrenal gland
Decrease cortisol
Secondary adrenal insuffiency
Glucocorticoid drugs suppressing H and P
Primary adrenal excess
Increase cortisol, decrease CRH, decrease ACTH, no hyperpigmentation
Secondary cortisol excess
Increase cortisol, decrease CRH, increase ACTH, hyperpigmentation
Primary defiency cortisol
Decrease cortisol, increase CRH, increase ACTH, hyperpigmentation
Secondary defiency
Decrease cortisol increase CRH, decrease ACTH, no hyperpigmentation
Steroid administration
Decrease cortisol but symptoms of excess, decrease plasma CRH, decrease acth, no hyperpigmentation
When secrete aldosterone
Decrease bp get renin
Stress
Decrease na k in blood,
Paracrine mechanisms in pancreas
Delta cells send to alpha and beta
Alpha and beta send to each other
Explain glucose regulat of insulin
Glucose bind glut2 and glycolysis so get ATP which close K channel (inward rectifying k channel), depolarization opens ca channel and exocytosis
Sulfonylurea receptor
Sulfonylurea drugs (tolbutamide, glyburide) promote closing of the ATP dependent k channel: increase insulin secretions used in treatment of type 2 DM
Insulin and insulin receptor
When bind, autophosphorylation and other proteins (insulin receptor substrate) which activate MAP PI3K which mediate the metabolic and mitogenic activities
Internalized
Insulin downregulates its own receptor
Insulin on striated muscle
Increase glucose uptake
Increase glycogen synthesis
Increase protein synthesis
Insulin liver
Decrease gluconeogenesis
Increase glycogen synthesis
Increase lipogenesis
Insulin on blood glucose
Decrease
Insulin of glycogen
Increase formation
Insulin on gluconeogenesis
Decrease
Insulin on glycogenolysis
Decrease
Insulin on protein synthesis
Increase, decrease aa in blood
Insulin on fat deposition
Increase, decrease FFA
Insulin on lipolysis
Decrease, decrease ketoacid
Insulin K
Increase uptake into cells, decrease K
What stimulates insulin
Glucose, aa, FA, ketoacid, glucagon, cortisol, GIP, vagal, K, sulfonylurea, obesity, somatotataton, diazoxide, exercise
Associated conditions with type 1 DM
Autoimmune thyroid disease
Addison’s disease
Associated with type 2 DM
Obesity, lipid abnormalities, PCOS, NAFLD
Glycogen effect
Increase lipolysis and inhibit FA synthesis, which shunts substrates toward gluconeogenesis
Ketoacid are produced from FA
Glucagon on glucose, FA, ketoacid
Increased, increased, increased
Where is most ca
Bone
Biologically active form Ca
Free ionized (50% of total)
Sign of hypocalcemia
Tetany
Chvostek sign
Trousseau sign
Hypercalcemia
Long QT, constipation, not hungry, polyuria, polydipsia, weak, hyporeflecia, coma
Low Ca
Reduces activation threshold for Na
Increases membrane excitability
Tingling numbness and muscle twitches
High ca
Decrease membrane excitability, reflex response slowed
How alter ionized concentration
Change fraction bound to albumin
Changes in anion concentration
If increase phosphate conc, decrease ca concentration
Changes in plasma protein conc
No change in ionized
PTH effect
Bone-resorption
Kidney, decrease P reabsorption, increase ca reabsorption, increase urinary camp
Intestine-increase ca ab via vitamin d
How parathyroid sense ca
CASR
CASR
Gq, Gi to PTH gene decrease
Chronic hypercalcemia
Decrease synthesis and storage of PTH, increase breakdown of stored PTH and release of inactive PTH fragment into the circulation
Chronic hypoglycemia
Increase synthesis and storage of PTH and hyperplasia of parathyroid glands
Vitamin d make
See
Cyp1a
1a hydrozylase
PTH short term
Bone formation, receptors on osteoblasts not osteoclast (direct action on osteoclast)
—-use PTH synthetic in osteoporosis
Long term PTH
Bone resorption (inc=direct on osteoclasts from cytokines released from osteoclast
Vd
Stimulate osteoclast
PTH kidney
Stimulates 1 a hydrozylase
How PTH get osteoblast
M-CSF, RANKL and OPG production
VD
SI-increase ca and P absorption
Bone-sensitize osteoblast to pth, regulates osteodystrophy production and calcification
Kidney-P reabsorption proximal tube by NPT2a expression,
PTH-inhibits PTH gene expression and stimulates CASR
Hyperparathyroidism
Stones, bones, groans(constipation)
Primary hyperparathyroidism
Increase PTH, increase Ca, decrease Pi, increase VD
Secondary hyperparathyroidism
Low ca
Renal failure, VD defiency
Renal failure vs vitamin d defiency
Renal-increase PTH, decrease ca, increase P, decrease VD
VD def-increase PTH, decrease ca, decrease Pi, decrease VD
Hypoparathyroidism
Decrease PHT, decrease Ca, increase pi, decrease Vd
Albright hereditary osteodystrophy(pseudopohypoparathyroidism type 1a
AD, Gs for PTH in bone and kidney defective
Hypocalcemia and hyperphosphatemia
Increase PTH
-give pth no phosphaturic response and no increase in urinary camp
Phenotype Albright hereditary osteodystrophy
Short, short neck, obese, subcutaneous calcification, short metatarsals, and metacarpals
Increase PTH, decrease Ca, increase pi, decrease VD
Hypercalcemia of malignancy
PTHrP-n terminal to PTH
Decrease PTH, increase Ca, decrease Pi, decrease Vd
Familial hypocalcemia hypercalcemia FHH
AD, mutation in CaSR in parathyroid and ascending limb of kidney
-decrease urinary Ca excretion and increase serum ca
Maybe increase PTH, incrase Ca serum, decrease urine ca, no change in p or VD
Pseudovitamin d deficient rickets or vitamin d dependent rickets type I
Decrease 1a hydroxylase
Pseudovitamin d deficient rickets or vitamin d dependent rickets II
Decrease VD receptor
Vd defiency
Increase PTH, decrease P, increase urine P and camp, decrease VD< increase osteomalacia and resorption
Enough hormone is stored as iodinated TG int he follicular colloid to last the body 2-3 months
Iodine is stored iodinated as tyrosine of thyroglobulin
Peripheral conversion T4 to T3
Deiodinase
Defiency of deiodinase
Mimics dietary I defiency
High levels I
Inhibit organification and synthesis of thyroid hormones: Wolff chaikoff effect
PTU
Effective treatment for hyperthyroidism
Transport T3 t4
Thyroxine binding protein -synthesized in liver, higher affinity for T2
Trnasytherin
Albumin
Hepatic failure
Decrease TBG, increase free t2m t4
Inhibition of T2 t4 synthesis from neg feedback
Pregnancy tbg
Increase
Decrease free
Increase in secretion and synthesis t2 t4
Increase total levels of T3 and t4 but levels of free physiologically active thyroid hormones normal (clnicalll. Euthyroid)
T3 t4 inhibit
TSH
Is TSH pulsation Luke gh
No steady state
Stimulate thyroid
TSH, the=triode stimulating immunoglobulins, incrase tbg
Inhibit thyroid hormone
I defiency, deiodinase defiency, intake I, perchlorate, thiocyanate, PTU, decrease TBG
PTU
Propylthiouracil
Thyroid hormone action
Growth, cns maturation, increase BMT, increase metabolism, increase cardiac output and upregulate b1 receptors, diarrhea
Goiter
Hyper or hypo