The Endocrine System

Hormones of posterior pituitary

ADH and Oxytocin

Hormones of the hypothalamus and anterior pituitary

• GH

• Prolactin

• Gonadotropins (FSH and LH)

• TSH

• ACTH

Growth Hormone

• Controlled by hypothalamic GHRH and somatostatin

• Liver releases IGF-1, negative feedback.

• Increases protein synthesis, decreases protein catabolism, slows carbohydrate utilization, increases the mobilization of fats and use of fats as energy

Thyroid Hormones

T3 and T4

Lipid Soluble

Increase metabolic rate, essential for normal growth and development

Catecholamines

Adrenal medulla releases epinephrine and norepinephrine in response to SNS stimulation.

Mineralcorticoid Aldosterone

Produced by outer zona glomerulosa in response to angiotensin II

Glucocorticoid Cortisol

Produced by middle zona fasciculata in response to ACTH

Androgen DHEAS

Produced by inner zona reticularis in response to ATCH

The steroid hormones are produced in the _______ and regulate _______

Adrenal Cortex, the three S’s, sugar (cortisol), salt (aldosterone), and sex (androgens)

Aldosterone is released in response to

Hypotension, reduced renal perfusion, and high serum potassium level

Cortisol Action on Target Cells

Primary effect on glucose metabolism, opposite effects of insulin

Pituitary Gigantism

GH excess in childhood before the skeletal epiphyses close

Acromegaly

GH excess in adulthood

Which hormone is considered diabetogenic

Growth Hormone (GH)

Hashimoto’s Disease

Acquired hypothyroidism, autoimmune

Myxedema is a result of

Hypothyroidism

Grave’s Disease

Hyperthyroidism

Autoantibodies bind and stimulate TSH receptors leading to diffuse toxic goiter (mimic TSH, increased T3 and T4 production)

Addison’s Disease

Primary Adrenocortical Insufficiency (low aldosterone and cortisol)

Congenital Adrenal Hyperplasia

In pediatric, enzymatic defect in biosynthesis of cortisol in adrenal, high ACTH, high Androgens

Cushing’s Syndrome

Any condition of hypercortisolism for long period

Exogenous steroids most common cause in the United States

Cushing’s Disease

Secondary Hypercortisolism caused by a benign tumor on the pituitary (elevated ACTH, elevated Cortisol)

Low calcium levels cause

PTH release

High calcium levels cause

PTH suppression

Calcitonin effects

Released from thyroid

Decreased blood calcium, opposes PTH effects

Promotes conservation of hard bone matrix

Conn Syndrome

Primary Hyperaldosteronism, usually caused by aldosterone secreting tumors

Pheochromocytoma

Benign adrenal medulla tumor, excess production and release of catecholamines

Diabetes Insipidus

Insufficient ADH activity

Excess loss of water

Syndrome of Inappropriate ADH (SIADH)

Excessive ADH from tumor’s ectopic production