Pituitary Gland “The Master Gland”

• 2 Functional Lobes *Anterior Lobe *Posterior Lobe • Interacts closely with the Nervous System through the . • Protected by what structure?

• Regulated through humoral stimulation from the hypothalamus. • Many of the released are Trophic Hormones. Anterior Pituitary Hormones • GH – Somatotropin – promotes mitosis – Too much = Gigantism or – Too little = • PRL – – promotes breast milk production during gestation and nursing – Hyperprolactinemia = can disrupt fertility and menstruation – Hypo-secretion = lack of milk production • ACTH - Adrenocorticotropic – promotes the to release its hormones – Hypersecretion = Cushing’s Syndrome – Hyposecretion = loss of release by adrenal glands Anterior Pituitary Hormones • TSH - Stimulating Hormone – promotes the thyroid gland to release its hormones – Hyposecretion can lead to hyperactive thyroid – Hypersecretion can lead to hypoactive thyroid and production of a Goiter • GRN – Releasing Hormone – promotes activity in gonads – Hyper- and hypo- secretion can both lead to infertility Too Much

• Acromegaly is caused by too much growth hormone AFTER puberty has completed.

• Gigantism is caused by too much growth hormone during and puberty. Too Little Growth Hormone

• The girl below is pictured with her father at the age of 5 years.

• The man on the left is 25 years old. The man on the right is 22 years old. Abnormal TSH secretion

Goiter formation due to inadequate iodine consumption. Hormones • – stimulates labor contractions during delivery – Lack of oxytocin during labor and delivery requires administration of PITOCIN to prompt contractions. • ADH – Antidiuretic Hormone – prevents loss of water from kidneys to bladder during times of dehydration. – Diabetes insipidis – loss of too much water – Polydipsia – excessive thirst Thyroid Gland • Located in the anterior portion of the neck, just below the throat. • Releases hormones that act on the metabolic rate.

*T3:

*T4: thyroxine • – maintains blood calcium levels Thyroid Gland

• T3: triiodothyronine & T4: thyroxine – High levels of these hormones can increase metabolic rates – Low levels of these hormones can decrease metabolic rates • Calcitonin – Low levels can result osteoporosis and stones since blood calcium is not being placed into the • Located on the posterior surface of the Thyroid gland. • (PTH) Parathyroid Gland Parathyroid Hormone (PTH) • The MOST important regulator of blood calcium levels. • Low levels of PTH result in muscle spasms and palpitations • High levels of PTH result in osteoporosis, too much calcium is being taken from bones Adrenal Glands • Located on the superior aspect of each kidney • 2 functional parts * Cortex * Medulla Each part secretes a specific type of hormone. Adrenal Gland Divisions CORTEX MEDULLA • MINERALOCORTICOID • CORTICOSTEROIDS – controls fluid and – Controls sympathetic/ electrolyte balance parasympathetic – Example - function • Produces sex hormones – Example – cortisol and epinephrine – Example – androgens and () • Located in abdominal cavity behind . • Produces hormones for the use and storage of glucose – – allows glucose to absorb into cells – – removes stored glucose from and fat cells Pancreas Insulin – Too little – diabetes mellitis – inability to use sugar to make ATP – Too much – hypoglycemia – low blood sugar Glucagon – Too much – glucagonoma caused by tumor of pancreas leads to symptoms much like diabetes – Too little – chronic low blood sugar due to inability to release glucose from liver and fat cells • Close to the optic nerve in the brain. • Produces - sleep-wake cycles.

Disorders of Pineal Gland • Decreased melatonin levels are associated with – • Chronic Fatigue Syndrome – Panic Disorders – Depression • SAD – Seasonal Affective Disorder – Peptic ulcers Gland

• Located behind the sternum. • Decreases in size as you age. • Produces Thymosin needed for the production of T- lymphocytes.

T-cells are needed for protection against viral infections, fungal infections, and cancer development Thymus Gland

• Both high and low levels of thymosin cause immune dysfunction. – Too little thymosin results in lack of immune response – Too much thymosin causes havoc for the and it does not respond correctly Gonads: and Testes • Hormone producing glands of the female and male reproductive systems. • Controls fertility, reproduction, and gestation.

Testes produce

Ovaries produce Other Hormone-Producing Organs/Tissues

• • Skin • Stomach • Adipose/Fat • Intestines • Liver • Heart • Kidneys • Striated muscles • Uterus