Endocrine Flashcards
What are the characteristics of peptide hormones?
Water soluble, large in size, charged, cannot pass through cell membrane freely, requires 2nd messenger system.
Examples include insulin, glucagon, FSH, LH, ADH, GH, PTH, etc.
What are the characteristics of steroid hormones?
Lipid soluble, derived from cholesterol, can pass through phospholipid barrier, binds to receptors in the cell.
Examples include testosterone, estrogen, progesterone, aldosterone, cortisol, gonad corticoids, etc.
What is the G Protein-Coupled Receptor (GPCR) pathway for peptide hormones?
G receptor activates G protein by removing GDP and adding GTP, involves Gs and Gq protein receptors.
Gs receptors activate adenylate cyclase leading to cAMP production, while Gq receptors activate phospholipase C.
What is the function of Gs protein receptors?
Activates adenylate cyclase, converts ATP to cAMP, activates protein kinase A (pkA), leads to phosphorylation of multiple proteins.
What is the function of Gq protein receptors?
Activates phospholipase C, divides PIP2 into DAG and IP3, leading to increased intracellular calcium and activation of calmodulin.
Where can steroid hormone receptors be located?
Can be intra cytosolic or intranuclear.
What do activated steroid hormone receptors bind to?
Bind to hormone response element (HRE) to stimulate cell proliferation and synthesis of proteins.
What connects the hypothalamus to the pituitary gland?
Infundibulum.
What are the two parts of the pituitary gland?
Anterior pituitary and posterior pituitary.
What hormones does the Supraoptic Nucleus (SON) secrete?
Antidiuretic hormone (ADH).
What stimulates the release of ADH?
↓ blood volume, ↑ plasma osmolality, pain.
What hormones does the Paraventricular Nucleus (PVN) secrete?
Oxytocin.
What stimuli trigger the release of oxytocin?
Birthing process, breastfeeding, male ejaculation.
What does the anterior pituitary secrete in response to Corticotrophin-releasing hormone?
Adrenocorticotropic hormone (ACTH) and alpha melanocyte stimulating hormone (a-MSH).
What is the role of Gonadotropin Releasing Hormone (GnRH)?
Stimulates gonadotropes to produce follicle stimulating hormone (FSH) and luteinizing hormone (LH).
What is the effect of increased frequency of GnRH release?
Stimulates LH secretion.
What does decreased frequency of GnRH release lead to?
Stimulates FSH secretion.
What is one effect of oxytocin during childbirth?
Increases contractions by binding to receptors in the myometrium.
What is the mechanism of action for oxytocin in milk letdown reflex?
Stimulates myoepithelial cells through Gq protein mechanism.
What are the symptoms of oxytocin hyposecretion?
Uterine inertia or postpartum hemorrhaging.
What triggers the release of Antidiuretic Hormone (ADH)?
↓ blood volume, ↓ blood pressure, ↑ plasma osmolality.
What is the role of aquaporin 2 in the kidneys?
Facilitates water reabsorption into the bloodstream.
What are the two types of Diabetes Insipidus?
Central and nephrogenic.
What causes Central Diabetes Insipidus?
Sheehan Syndrome, pituitary apoplexy, macroadenomas, unintentional surgical removal.
What are the complications of Diabetes Insipidus?
Hypernatremia, polyuria, polydipsia, dehydration.
What is SIADH?
Syndrome of Inappropriate ADH production.
What characterizes SIADH?
Overproduction of ADH leading to concentrated urine and hyponatremia.
What is the primary function of Growth Hormone (GH)?
Stimulates growth and metabolism.
What does IGF-1 do in the body?
Increases amino acid uptake and protein synthesis, enhances bone growth.
What hormone controls milk production?
Prolactin.
What inhibits prolactin secretion?
Prolactin inhibiting hormone (PIH)/dopamine.
What stimulates the release of thyroid hormones?
Thyrotropin-releasing hormone (TRH) from the hypothalamus.
What is the synthesis process of thyroid hormones?
TRH → TSH → thyroglobulin synthesis → iodide trapping and oxidation → iodination and coupling → endocytosis and cleavage → exocytosis.
What is hypothyroidism?
Decreased levels of thyroid hormone.
What are common symptoms of hypothyroidism?
Goiter, weight gain, cold intolerance, lethargy, bradycardia, menstrual irregularities.
What causes hyperthyroidism?
Hyperfunctioning of the thyroid, autoimmune disorders, exogenous thyroid supplementation.
What are symptoms of hyperthyroidism?
Weight loss, heat intolerance, tachycardia, menstrual irregularities.
What is the main secretion of parathyroid glands?
Parathyroid hormone (PTH).
What does parathyroid hormone (PTH) do?
Increases calcium and phosphate removal from bones, increases calcium absorption in kidneys.
What are the two types of parathyroid disorders?
Hypoparathyroidism and hyperparathyroidism.
What is a sign of hypoparathyroidism?
Hypocalcemia.
What is a complication of hyperparathyroidism?
Hypercalcemia.
What is primary hyperparathyroidism?
A condition characterized by excessive secretion of parathyroid hormone (PTH) leading to hypercalcemia.
What are the complications associated with hypoparathyroidism?
Hypocalcemia, tetany, perioral numbness and tingling, Chvostek’s sign, Trousseau’s sign, and arrhythmias.
What is Chvostek’s sign?
A facial spasm elicited by tapping the facial nerve.
What is Trousseau’s sign?
Wrist flexion that occurs when a blood pressure cuff is inflated above systolic pressure.
What are the symptoms of hyperparathyroidism?
Hypercalcemia, nephrolithiasis, osteopenia/osteoporosis, pancreatitis, nephrogenic diabetes insipidus, and bradycardia.
What is the treatment for hypoparathyroidism?
Replenish calcium, magnesium, and increase PTH with recombinant PTH.
What is the role of aldosterone?
Stimulates sodium reabsorption and potassium excretion in the kidneys.
What stimulates the secretion of cortisol?
Corticotropin releasing hormone (CRH) → adrenocorticotropic hormone (ACTH) → adrenal cortex.
What are the effects of cortisol on the body?
Increases plasma glucose levels, inhibits inflammatory immune response, and promotes protein catabolism.
What hormones are produced by the adrenal medulla?
Catecholamines: epinephrine and norepinephrine.
What is adrenal insufficiency?
A condition characterized by insufficient production of adrenal cortex hormones.
What is the most common cause of primary adrenal insufficiency in the US?
Autoimmune adrenalitis.
What are the symptoms of adrenal crisis?
Increased stress response, lethargy, hypotension, hyponatremia, hyperkalemia, and acidosis.
What is Cushing’s syndrome?
Hyperfunction of the adrenal gland leading to increased cortisol secretion.
What causes Cushing’s disease?
Increased ACTH release due to hyperpituitarism or paraneoplastic syndrome.
What are the complications of Cushing’s syndrome?
Secondary hypertension, diabetes mellitus, osteoporosis, and increased risk of infection.
What is hyperaldosteronism?
Increased secretion of aldosterone due to adrenal gland mass or increased renin-angiotensin system activity.
What are the effects of glucagon?
Stimulates glycogenolysis and gluconeogenesis in the liver, activates lipolysis in adipose tissue.
What is the pathophysiology of Type I diabetes mellitus?
Beta cell destruction leading to insulin deficiency and hyperglycemia.
What is diabetic ketoacidosis (DKA)?
A condition more common in Type I diabetes, characterized by ketogenesis and metabolic acidosis.
What are the symptoms of hyperglycemic hyperosmolar syndrome (HHS)?
Severe hyperglycemia, dehydration, total body potassium depletion, and encephalopathy.
What are the macrovascular complications of diabetes mellitus?
Atherosclerotic diseases including TIA, CVA, CAD, MI, PAD, and intermittent claudication.
What are the microvascular complications of diabetes mellitus?
Nephropathy, retinopathy, and peripheral neuropathy.
What is the treatment for Type I diabetes mellitus?
Insulin replacement therapy.
What is metabolic syndrome?
A cluster of conditions including obesity, hypertension, and dyslipidemia.
What is the classification of obesity based on BMI?
Class I: 30-35; Class II: 35-40; Class III: > 40.
What is the effect of obesity on insulin sensitivity?
Increases insulin resistance leading to hyperglycemia.
What is the role of insulin in the body?
Facilitates glucose uptake, glycogenesis, and lipogenesis.
What is the effect of catecholamines on the heart?
Increases contractility and heart rate.
What stimulates catecholamine release?
Short-term stress activated by the sympathetic nervous system.
What is the function of the adrenal cortex’s zona glomerulosa?
Produces mineralocorticoids, primarily aldosterone.
What is the function of the adrenal cortex’s zona fasciculata?
Produces glucocorticoids, primarily cortisol.
What is the function of the adrenal cortex’s zona reticularis?
Produces gonadocorticoids, primarily androgens.
What is the primary treatment for hyperaldosteronism?
Suppress hyperplasia with spironolactone or eplerenone.
What is the effect of cortisol on the immune system?
Inhibits inflammatory immune response.
What is the most common treatment for chronic adrenal insufficiency?
Replacement of cortisol with corticosteroids.
What is the primary hormone responsible for sodium reabsorption in the kidneys?
Aldosterone.
What are the key features of Type II diabetes mellitus?
Insulin resistance, obesity, and metabolic syndrome.
What is the role of the Islets of Langerhans in the pancreas?
Secretes insulin and glucagon to regulate blood glucose levels.
What is the relationship between RAAS activity and hypertension?
↑ RAAS activity leads to hypertension.
RAAS stands for Renin-Angiotensin-Aldosterone System.
How does VLDL production in the liver affect triglyceride levels?
↑ VLDL production in liver results in ↑ triglycerides.
VLDL stands for Very Low-Density Lipoprotein.
What happens to HDL levels in the bloodstream in the context of metabolic syndrome?
↓ HDL levels in bloodstream.
HDL stands for High-Density Lipoprotein.
What is the significance of waist circumference in metabolic syndrome?
↑ fat distribution in central portion of the body leads to increased waist circumference.
Central obesity is a criterion for metabolic syndrome.
What criteria must be met to diagnose metabolic syndrome?
At least 3 obesity criteria must be met.
Criteria include hypertension, dyslipidemia, and high blood sugar.
How is obesity classified based on BMI?
Class I: 30-35; Class II: 35-40; Class III: > 40.
BMI stands for Body Mass Index.
What are the fasting glucose and blood pressure criteria for metabolic syndrome?
Fasting glucose > 100; BP > 130/85.
Blood pressure is measured in mmHg.
What triglyceride level is associated with metabolic syndrome?
Triglycerides > 150.
Triglycerides are a type of fat found in the blood.
What are the HDL level criteria for males and females in metabolic syndrome?
HDL: < 40 (males) or < 50 (females).
Low HDL is a risk factor for heart disease.
What waist circumference measurements are indicative of metabolic syndrome for males and females?
Waist circumference > 40 in males or > 35 in females.
Abdominal obesity is a significant risk factor.
What complication is characterized by increased RAAS and SNS activity?
Hypertension.
SNS stands for Sympathetic Nervous System.
What is the relationship between obesity and Type II Diabetes Mellitus?
Obesity leads to ↑ insulin resistance and ↓ glucose uptake.
Insulin resistance is a key feature of Type II Diabetes.
What cardiovascular diseases are associated with atherosclerotic disease?
CVA/TIA, CAD/MI, PAD.
CVA: Cerebrovascular Accident, TIA: Transient Ischemic Attack, CAD: Coronary Artery Disease, MI: Myocardial Infarction, PAD: Peripheral Artery Disease.
What condition is caused by upper airway compression and leads to nocturnal hypoxia?
Obstructive Sleep Apnea (OSA).
OSA is common in individuals with obesity.
What is the progression of Nonalcoholic Fatty Liver Disease (NAFLD)?
↑ insulin resistance → ↑ free fatty acid uptake by liver → steatosis → inflammation → nonalcoholic steatohepatitis (NASH) → cirrhosis.
NAFLD is increasingly recognized as a liver condition related to obesity.
What are the main treatment options for obesity/metabolic syndrome?
Lifestyle modifications, medications, bariatric surgery.
Medications include orlistat, GLP-1 agonists, Wellbutrin, naltrexone.
What types of bariatric surgery are mentioned?
Vertical sleeve gastrectomy, gastric banding, gastric bypass, duodenal switch.
Bariatric surgery is indicated for severe obesity.
Endocrine vs exocrine
Exocrine glands secrete their substances through ducts onto your body’s surfaces. On the other hand, endocrine glands secrete their substances directly into your bloodstream
