Growth Hormone (hGH)
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.
Thyroid-stimulating hormone (TSH)
ANTERIOR PITUITARY -> THYROID: increases synthesis and release of thyroid hormone (tropic)
Experiences negative feedback effect from T3 and T4
Adrenocorticotropic hormone (ACTH)
ANTERIOR PITUITARY -> ADRENAL GLAND: increases growth and secretory activity of adrenal cortex
Stimulated by stress
ANTERIOR PITUITARY -> OVARY/ TESTES: ovulation or testosterone synthesis
Follicle-stimulating hormone (FSH)
ANTERIOR PITUITARY -> OVARY / TESTES: follicle development or spermatogenesis
Antidiuretic hormone (ADH, vasopressin)
POSTERIOR PITUITARY -> KIDNEY: water retention
POSTERIOR PITUITARY -> BREAST & UTERUS: milk letdown and uteral contractions
Thyroid hormone (TH, thyroxine)
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
Parathyroid hormone (PTH)
PARATHYROIDS -> BONE, KIDNEY, SMALL INTESTINE: raises serum [Ca2+]
Stimulates osteoclast proliferation and Ca2+ resorption
THYMUS: is involved in T-cell development during childhood.
Epinephrine & Norepinephrine
- 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
- 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
Atrial natriuretic factor (ANF)
HEART -> KIDNEY: increases urination to decrease blood pressure
KIDNEY -> BONE MARROW: increases RBC synthesis
Regulation of [Ca2+]
Parathyroid hormone and Calcitonin
Regulation of blood [glucose]
Insulin and Glucagon
Milk production and letdown
Oxytocin and Prolactin
Secreted by the Pancreas
Glucagon (alpha) & Insulin (beta) & Somatostatin (sigma)
Involved in Pregnancy Prepping
Oxytocin, Prolactin, Progesterone, Estrogen, LH, FSH
Regulation of B.P.
Atrial natriuretic factor (ANF) & Aldosterone
Hormones that increase blood [glucose]
Glucagon (polypeptide derivative), Epinepherine (amino acid derivative), Cortisol (steroid / glucocorticoid)
Difference between endocrine and exocrine glands
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
What kind of gland is the pancreas?
It is both an endocrine AND an exocrine gland
How do hormones exert their actions on cells?
By binding to specific cellular receptors, which are found either on the membrane OR within the cell
What are the three types of hormones?
- 1. Peptide
- 2. Steroid
- 3. Tyrosine derivatives
Where are protein hormones synthesized and how are they processed?
- 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
Receptors of protein hormones
May be an ion channel or a second-messenger pathway instigator once hormone binds
What are the steroid hormones?
1. Aderal cortex - cortisol (glucocorticoid) & aldosterone (mineralcorticoid)
2. Gonads/placenta - estrogen, progesterone, testosterone
How do steroid hormones exert their actions?
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.
What are the tyrosine derivative hormones?
Thyroid: T3 & T4
Adrenal Medulla: Catecholamines epinephrine & neuroepinephrine
Where in the cell are tyrosine derivative synthesized?
Via cytosolic enzymes or on the rER.
Solubility to tyrosine derivatives
Tyroid hormones = lipid soluble, have long latent period
Catecholamines: water soluble, act though cAMP
Key for hormone questions
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.
Adrenal ctx vs Adrenal medulla
Ctx: steroid hormone secretion
Medulla: catecholamine secretion
Hormones the thyroid gland secretes