Endo Flashcards
Thyroid GLand hormones
T4, T3, calcitonin; thyroid hormones are amino acid derived
Ovary hormones
Estrogen, progesterone, relaxin
Testis hormones
testosterone, inhibin
Placenta hormones
hCG, heman somatomammotropin
Peptide/protein hormones
surface receptors
Steroid hormones
nuclear receptors/ genomic effect to activate/repress genes for protein synthesis
positive feedback occurs in
oxytocin during birth, menstrual cycle
Hypothalamus
releases hypothalamic releasing hormones - GHRH, GnRH, TRH, CRH
Anterior pituitary
synthesizes hormones; simulating hormones - TSH, ACTH, FSH/LH - tropic; direct-PRL(secretion controlled by PIH-DA), GH
Posterior pituiray
stores hormones made in AP; Oxytocin, ADH, MSH
ADH
conserve water, released from PP, aka vasopressin; inserts aquaporins; plasma osmolarity sensed by hypo osmoreceptors - stimulate ADH; inc by dec blood vol
Diabetes insipidus
ADH defiecency - hypothalamic/central where def in secretion of ADH from PP
nephrogenic - kidney not responsive to ADH
excess urine production
Oxytocin
synth in neurons of hypo; sotred in PP; stimulates smooth muscle uterine contractions and stimulates smooth muscles in mammary glands during suckling
Growth hormone/somatrotropin
involved in growth; synth by somatrophs in AP; stimulates secretion of IGF, bone/soft tissue/cartilage growth, anabolic hormone- proteins synth, fatty acid utilization and dec glucose utilization; anti-insulinic hormone - high levels lead to insulin resistance -
GHRH –> GH
Regualtion of GH
starvation increases GH levels; stimulate by hypoglycemia and protein depletion;
Dwarfism
GH deficiency during childhood
Giantism
GH excess - child
Acromegaly
GH excess - adults, enlargement of extremities
Insulin like growth factors IGF
stimulated by GH, prod in liver, promore cartilage and bone growth,
PRL
AP, promotes milk production, reproduction, suppressed by dopamine, after parturition - needed for milk synth and milk secretion w/ cortisol and insulin; breast tissue differentiation, lactogenesis/milk prod; excess blocks GNRH to inhibit FSH and LH; high lvls lead to menstrual irreg and fertility problems - blocks ovulation, menstruation, spermatogenesis
Prolactinoma
inc PRL levels, lack of menstruation, secretion of milk, erectile dystfn, breast enlargement in males
Beta cells
secrete insulin and amylin
Alpha cells
secrete glucagon
d cells
secrete somatostatin - inhibits both glucagon and insulin
Insulin regulated by
inc plasma gluc, inc plasma AA, gut hormones,
Insulin
anabolic - promotes uptake of glucose causing glucose lvls to fall; glucose –> glycogen, nurtient uptake, inc storage of glucose, fatty acids, and AAs
inhibits glucose breakdown, glycogen breakdown and lipid breakdown, promotes glucose uptake by liver - stimulates glycogen synthetase –> glycogen,
Glucagon
target organ -liver; secreted when plasma gluc falls; inhibited by insulin; increase plasma gluc levels; stimulates glycogen –> glucose in liver; inc uptake of AA by liver adn coverts to gluc
Hyperglycemia
underproduction of insulin, diabetes mellitus, high blood gluc lvls
Hypoglycemia
overproduction of insulin, low blood gluc lvls
insulin resistance
abnormal cell response to insuling - Type II diabetes
DM Type I
pancreas stops producing enough insulin, automimmune destruction of beta cells, insulin deficiency, insulin dependent/juvenile diabetes,
C-peptide
pancrease normally releases c-peptide and insulin in equal amts
DM Type Ii
insulin-resistant, change life-style
Gestational diabets
insulin resistance
Insulin resistance
reduces action of insulin, causes pancreas to produce more insulin, hyperinsulinemia,
Hypoglycemia
low levels of blood glucose, • Cold, clammy skin • Trembling or feelings of nervousness • Lack of motor coordination and fatigue • Irritability or confusion • Blurred vision • Headache or dizziness • Nausea or stomach pain • Fainting or unconsciousness
Outer adrenal cortex
secretes hormones
Inner adrenal medulla
secretes catecholamines
Inner zona reticularis
androgens/sex hormones
Middle zona fasciculate
corticosteroids - metabolic hormones
outer zone glomerulosa
aldosterone
Lyase
cleaves side chains of cholesterol
hydrozylese
add oh groups
aromatase
converts ring to phenolic structure
Cortisol regulation
synth on demand, binds CBG in circulation,
Glucocorticosteroid
Fight/flight, protects heart and brain from glucose starvation, mediates long-term stress, prevents hypoglycemia - inc gluc in body in response to stress, cortisol needed for glucagon, catabolic hormone - • Promotes gluconeogenesis, glycolysis and lipolysis
• Causes breakdown of skeletal muscle proteins
• Suppresses the immune system, thus works as an anti-inflammatory agent
• Causes negative calcium balance
• Influences brain function negatively
Actions of cortisol
Protein metabolism/breakdown to provide AA for gluconeogenesis, Carb metabolism - elevated gluc concentration, lipid metabolism - conserve glucose and glycogen
Effects of cortisol
negative Ca - inc excretion and decrease absorption; break down bone matrix, inhibits Na loss and inc K excretion; inc hunger; alters mood, memory and learning changes, cataracts; suppress immune sys;
Cushing’s syndrome
hypercorisolism, adrenal tumor, primary, high cortisol
Cushing’s disease
hypercortisolism - pituitary tumor, high acth, secondary
Addison’s disease
hypocortisolism, autoimmune destruction of adrenal gland, dec ACTH secretion/loss of pituitary fn; dec aldosterone, decrease cortisol
COngenital adrenal hyperplasia
androgen steroids are elevated, inherited deficiency, hypercortisolism, hyperplasia of adrenal, masculinization of external genitalia in female newborns - androgenital syndrom
Androgenital syndrome
- Extremely high levels of adrenal androgens produced in response to overstimulation of the adrenal by ACTH
- In males, leads to early puberty
- In females, leads to ambiguous genitalia at birth
- In females, leads to virilization and hirsuitism later in life
Aldosterone
maintains Na and K balance and BP, works on distal and collecting duct of nephrons in kidney, Na reabsorption adn K excretion; regulated by ACTH and angiotensin II; excess-> hypokalemia; low –> hyperkalemia
Hypokalemia
excess aldo, low K; • Increase in plasma volume • Hypertension • Increased cardiac output • Impaired skeletal muscle function • Muscle weakness, muscle cramps • Muscle paralysis
Hyperkalemia
aldo def, high K; • Cardiac toxicity
• Abnormal heart rhythms
• Cardiac arrest
• Weak contractions and arrhythmia
• Decrease in plasma volume, decrease in BP
• Circulatory shock
• Muscle paralysis due to suppression of normal electrical stimulation of skeletal muscles
11 β-HSD
converts cortisol to cortisone
Thyroid GLand
follicular cells and C cells, supply TH
Follicular cells
produce THs,
C-cells
produce Calcitoninn
Synth of TH
Hypo - TRH
AP - TSH
Thyroid Gland – Thyroglobulin, released into colloid space where tyrosine residues are iodinated
TH
catabolic; stimulates fat metabolism; increases gluconeogenesisa dn glycogeneolysis to generate free glucose; inc insulin-dependent glucose uptake into cells; inhibits protein synthesis
TH reproductive syst
needed for follicular developmen and ovulation in female syst; normal maintainance of pregnancy; spermatogenesis in males
Graves disease
hyperthyroidism; autoimmune; goiter, swollen eyeballs/exopthalamos
Goiter
Excessive stimulation of the thyroid gland by TSH causes the gland to enlarge
Cretinism
hypothyroidism; children, stunted physical and mental growth, poor length growth, bone maturation and puberty delayed, ovulation impeded, infertility,
Myxedema
Adult hypothyroidism, mental impairment, depression, cold intollerance
hashimoto;s disease
autoimmune thyroiditis, destruction of thyroid gland, unable to prod TH, hypothyroidism
Tissue growth
GH, IGFs, TH - permissive, Insulin stimulates protein synthesis and provides energy
Bone growth
Ca
Calcium
Calmodulin binds Ca, needed in bone growth
Hypocalcemia
Ca and Vit D deficiency, causes Tetany, seizures, overexcitation of muscles
Hypercalcemia
opp, psychiatric problems
Phosphate
build strong bones, bone mineralization
PTH
inc Ca - when Ca lvls dec, then PTH is secreted - inc Ca by • Directly mobilizes calcium from bone (resorption)
• Directly stimulates renal re-absorption of Ca++ (and inhibits PO4 re-absorption
• Indirectly increases intestinal absorption of Ca++
PO4 - reduces re-abs, inc excretion of PO4, enhances uptake from bones
Calcitonin
lowers Ca
Calcitriol/1,25-dihydroxy-vitamin D3
inc Ca
Hyperparathyroidism
PTH exces,, leads to hypercalcemia; • Bone pain or tenderness
• Depression and forgetfulness
• Feeling tired, ill, and weak
• Fragile bones of the limbs and spine that can break easily
• Increased amount of urine produced
• Kidney stones
• Nausea and loss of appetite
Hypoparathyroidism
PTH def, hypocalcemia;
Calcitonin
secreted by C-cells in thyroid gland; opposes PTH - dec bone resorption, Ca inc then CT is released; increases renal Ca excretion; end goal is dec high Ca levels in blood
VitD
active form 1-a-25-dihydroxyvitamin D3 ; enhances Ca uptake; renal Ca reabsorption; Ca mobilization out of bone; regulated by PTH; inc serum Ca levels
Inhibin
inhibits FSH, doesn’t inhibit GnRH, sertoli cells
Sertoli cells
nourish developing sperm, inhibin synth, FSH receptors, produces AMH - prevents uterus from forming
TUrner syndrome
girls born with 1 1/2 X chromosomes; short, low ears, webbed neck, swelling hands and feet, sterile,
Klinefelter
men, XXY, hypogonadism, infertility, less facial hair and body hair, weaker, shy,
Cryptochordism
genital problem in pediatrics, hidden/obscured testes - dunacn,
aromatase
converts T to E
