ANAPHY ENDO PART 2

Thyrotropic hormone (TH) also called thyroidstimulating hormone (TSH)

Influences growth and activity of the thyroid gland

Adrenocorticotropic hormone (ACTH)

Regulates endocrine activity of the adrenal cortex

Pineal Gland

• Hangs from the roof of the third ventricle of the brain

• Secretes melatonin. Believed to trigger the body's sleep/wake cycle

Thyroid Gland

• Found at the base of the throat, inferior to the Adam's apple (thyroid cartilage)

Produces two hormones

• Thyroid hormone

• Calcitonin

Thyroid hormone

• Major metabolic hormone

• Controls rate of oxidation of glucose to supply body heat and chemical energy (ATP) - Needed for tissue growth and development

Composed of two active iodine-containing hormones

• Thyroxine (T4)

• Triiodothyronine (T3)

Thyroxine (T4)

secreted by thyroid follicles

Triiodothyronine (T3)

formed from the conversion of T4 at target tissues

Calcitonin

• Decreases blood calcium levels by causing calcium deposition on bone

• Released in response to rising blood calcium levels

• Antagonistic to parathyroid hormone

Parathyroid Glands

• Tiny masses on the posterior of the thyroid gland

• Most important regulator of calcium ion (Ca2+) homeostasis of the blood

• Stimulates osteoclasts to remove calcium from bone

Thymus

• Located in the upper thorax, posterior to the sternum

• Largest in infants and children

• Decreases in size throughout adulthood

• Produces a hormone called thymosin

thymosin

• Matures some types of white blood cells

• Important in developing the immune system

Adrenal Glands (Suprarenal Glands)

Sit on top of the kidneys

Adrenal cortex

outer glandular region has three layers that produce corticosteroids

Adrenal medulla

inner neural tissue region; secrets epinephrine and norepinephrine

Mineralocorticoids (mainly aldosterone)

• Produced in outer adrenal cortex (Glomerulosa)

• Regulate mineral (salt) content in blood, particularly sodium and potassium ions

• Regulate water and electrolyte balance

• Target organ is the kidney

atrial natriuretic peptide (ANP)

a hormone produced by the heart when blood pressure is too high

Glucocorticoids (including cortisone and cortisol)

• Produced by middle layer of adrenal cortex (Fasciculata)

• - Promote normal cell metabolism

• - Help resist long-term stressors by increasing blood glucose levels (hyperglycemic hormones)

• - Anti-inflammatory properties (decrease edema and pain) - Released in response to increased blood levels of ACTH

Sex hormones

• Produced in the inner layer of the adrenal cortex (Reticularis)

• Small amounts are made throughout life

• Most of the hormones produced are androgens (male sex hormones), but some estrogens (female sex hormones) are also formed

Pancreas

• Located in the abdomen, close to stomach

• Mixed gland, with both endocrine and exocrine functions