Question | Answer |
Hormones of the anterior pituitary gland | ACTH, GH, TSH, LH, FSH, and Prolactin |
Hormones of the posterior pituitary gland | Stores and releases ADH, Oxytocin |
Anatomy of the thyroid gland | 2 lateral lobes connected by isthmus;follicles that produce the glycoprotein thyroglobulin;Colloid (thyroglobulin + iodine) fills lumen of follicles and the precursor of thyroid hormone;Parafollicular cells produce calcitonin |
Up-regulation | Up-regulation—target cells form more receptors in response to the hormone |
Down-regulation | target cells lose receptors in response to the hormone |
Prolactin | milk production |
Calcitonin | Antagonist to parathyroid hormone; PTH—most important hormone in Ca2+ homeostasis;
Negative feedback control: rising Ca2+ in the blood inhibits PTH release; Elevated Ca2+ depresses NS and contributes to formation of kidney stones |
Hormones of the Adrenal Cortex | Zona glomerulosa—mineralocorticoids
Zona fasciculata—glucocorticoids
Zona reticularis—sex hormones, or gonadocorticoids (androgens) |
Hormones of the Adrenal Medulla | Epinephrine and norepinephrine |
Mineralcorticoids | Regulate electrolytes (primarily Na+ and K+) in ECF
Aldosterone is the most potent mineralocorticoid
Stimulates Na+ reabsorption and water retention by the kidneys |
Glucocorticoids | Keep blood sugar levels relatively constant
Maintain blood pressure by increasing the action of vasoconstrictors |
Cortisol | Major glucocorticoid
Released in response to ACTH, patterns of eating and activity, and stress
Prime metabolic effect is gluconeogenesis—formation of glucose from fats and proteins
Promotes rises in blood glucose, fatty acids, and amino acids |
Hypersecretion of glucocorticoid | Depresses cartilage and bone formation
Inhibits inflammation
Depresses the immune system
Promotes changes in cardiovascular, neural, and gastrointestinal function |
Cushing's syndrome | Hypersecretion of glucocorticoid |
Hyposecretion of glucocorticoid | Also involves deficits in mineralocorticoids
Decrease in glucose and Na+ levels
Weight loss, severe dehydration, and hypotension |
Addison’s disease | Hyposecretion of glucocorticoid |
Hormones of the hypothalamus | Hypothalamic hormones stimulate the release of most anterior pituitary hormones;oxytocin and ADH |
Growth Hormone | Stimulates liver, skeletal muscle, bone, and cartilage to produce insulin-like growth factors
Mobilizes fats, elevates blood glucose by decreasing glucose uptake and encouraging glycogen breakdown (anti-insulin effect of GH) |
Erythropoietin | Signals production of red blood cells |
Insulin | Lowers blood glucose levels
Enhances membrane transport of glucose into fat and muscle cells
Participates in neuronal development and learning and memory
Inhibits glycogenolysis and gluconeogenesis |
Glucagon | Major target is the liver, where it promotes
Glycogenolysis—breakdown of glycogen to glucose
Gluconeogenesis—synthesis of glucose from lactic acid and noncarbohydrates
Release of glucose to the blood |
Insulin action on cells | Activates a tyrosine kinase enzyme receptor
Leads to increased glucose uptake and enzymatic activities
Catalyze the oxidation of glucose for ATP production
Polymerize glucose to form glycogen
Convert glucose to fat (particularly in adipose tissue) |
Diabetes mellitus | Due to hyposecretion or hypoactivity of insulin
Three cardinal signs of DM
Polyuria—huge urine output (osmolality)
Polydipsia—excessive thirst (ADH)
Polyphagia—excessive hunger and food consumption
(No insulin to put glucose in the cells) |
Diabetic Ketoacidosis | resulting from large amounts of ketoacids from less insulin production and greater fat metabolism |
Hyperinsulinism | Excessive insulin secretion; results in hypoglycemia, disorientation, unconsciousness |
Hormonal synergism | more than one hormone produces the same effects on a target cell (FSH and LH) |
Hormonal permissiveness | one hormone cannot exert its effects without another hormone being present (Thyroid hormone and Epinephrine) |
Hormonal antagonism | : one or more hormones opposes the action of another hormone (GnRH blockers, sex change) |
Glyconeogenesis | Production of glycogen from noncarbohydrate molecules such as amino acids, fatty acids, or lactate |
Glycogenolysis | Breakdown of stored glycogen into glucose |
Glycogenesis | the synthesis of glycogen from glucose from the blood |