Hormones

ANTERIOR PITUITARY: increases bone and muscle growth, increases cell turnover rate, rate of mitosis & protein synthesis. 

Lowers blood glucose and oxidizes fatty acids for energy instead. Lowers the breakdown of protein.

ANTERIOR PITUITARY -> MAMMARY GLAND: milk production

Normally inhibited by progesterone and estrogen.

ANTERIOR PITUITARY -> THYROID: increases synthesis and release of thyroid hormone (tropic)

Experiences negative feedback effect from T3 and T4  

ANTERIOR PITUITARY -> ADRENAL GLAND: increases growth and secretory activity of adrenal cortex

Stimulated by stress

ANTERIOR PITUITARY -> OVARY/ TESTES: ovulation or testosterone synthesis

ANTERIOR PITUITARY -> OVARY / TESTES: follicle development or spermatogenesis

POSTERIOR PITUITARY -> KIDNEY: water retention

Increase BP

POSTERIOR PITUITARY -> BREAST & UTERUS: milk letdown and uteral contractions

THYROID: in the child it is necessary for physical and mental development; in the adult, it increases metabolic rate and temperature

*Increase the transcription of many genes in many cells in the body

THYROID C CELLS -> BONE, KIDNEY, SMALL INTESTINE: lowers serum [Ca2+] by decreasing osteoclast acivity

PARATHYROIDS -> BONE, KIDNEY, SMALL INTESTINE: raises serum [Ca2+]

Stimulates osteoclast proliferation and Ca2+ resorption

THYMUS: is involved in T-cell development during childhood.

• ADRENAL MEDULLA: sympathetic stress response (rapid)
• Vasoconstrictors of  internal organs and skin but vasodilators of skeletal muscles

• ADRENAL CORTEX--->results in a longer-term stress response;
• increased blood [glucose]; stimulates gluconeogenesis in the liver;
• increased protein catabolism;
• increased fat catabolism
• decreased inflammation and immunity

Steroid (glucocorticoid)

• ADRENAL MEDULLA--> KIDNEY-->Increased Na+ reabsorption to increase blood pressure, K secretion
• Steroid hormone

ADRENAL CORTEX: not normally important, but an adrenal tumor can overproduce these, causing masculinization or feminization.

BETA CELLS OF THE ISLETS OF LANGERHANS IN THE PANCREAS: decreases blood [glucose]; increases glycogen and fat storage; it is activated at high blood [glucose] and is absent or ineffective in diabetes melitus

Bonds to membrane receptors to exert action and increase permeability to cells to glucose

ALPHA CELLS OF THE ISLETS OF LANGERHANS IN THE PANCREAS: secreted at low blood [glucose] and results in an increase in blood [glucose] and decrease in glycogen and fat storage

Stimulates glycogenolysis and glunegenesis in the liver

SIGMA CELLS OF THE ISLETS OF LANGERHANS IN THE PANCREAS: inhibits many digestive processes

TESTES: male characteristics; spermatogenesis

OVARIES / PLACENTA: Female characteristics, endometrial growth

OVARIES / PLACENTA: leads to endometrial secretion, pregnancy

HEART -> KIDNEY: increases urination to decrease blood pressure

KIDNEY -> BONE MARROW: increases RBC synthesis

Parathyroid hormone and Calcitonin

Insulin and Glucagon

Oxytocin and Prolactin

Glucagon (alpha) & Insulin (beta) & Somatostatin (sigma)

Oxytocin, Prolactin, Progesterone, Estrogen, LH, FSH

Atrial natriuretic factor (ANF) & Aldosterone

Glucagon (polypeptide derivative), Epinepherine (amino acid derivative), Cortisol (steroid / glucocorticoid)

Exocrine glands: release enzymes into environment through ducts

Endocrine glands: release hormones directly into body fluids, are not released directly to tissues but are released into the general circulation

It is both an endocrine AND an exocrine gland

By binding to specific cellular receptors, which are found either on the membrane OR within the cell

• 1. Peptide 
• 2. Steroid
• 3. Tyrosine derivatives

• 1. Synthesized by the ER as a preprohormone 
• 2. Cleaved into a prohormone in the ER lumen
• 3. Sent to Golgi where they are cleaved & modified
• 4. Secreted into blood stream via exocytosis

May be an ion channel or a second-messenger pathway instigator once hormone binds

1. Aderal cortex - cortisol (glucocorticoid) & aldosterone (mineralcorticoid)

2. Gonads/placenta - estrogen, progesterone, testosterone

Require a protein transport to be carried through blood stream. 

• Freely diffuse through plasma membrane because nonpolar.
• Combine with a cytosolic receptor to diffuse into the nucleus, where they act at the transcription level.

Steroids usually affect the synthesis of proteins within the target cell.

Thyroid: T3 & T4

Adrenal Medulla: Catecholamines epinephrine & neuroepinephrine

Via cytosolic enzymes or on the rER.

Tyroid hormones = lipid soluble, have long latent period

Catecholamines: water soluble, act though cAMP

Remember that hormones RESPOND to irregularities in the body if they arise --- they don't create them! 

Think about the physiological situation and then think about how the body would then respond to it via hormone release to compensate.

Ctx: steroid hormone secretion 

Medulla: catecholamine secretion

• 1. T3 & T4
• 2. Calcitonin