18-9 Organs With Secondary Endocrine Functions

Gonads

-Produce hormones responsible for gender-related differences in Skeletal proportions Secondary sex characteristics -testes -ovaries

Heart (cardiovascular system)

-Produces natriuretic peptides (ANP and BNP) When blood volume becomes excessive Results in a reduction in blood volume and blood pressure Actions opposes those of angiotensin II

Organs with secondary endocrine functions:

1. Intestines 2. kidneys 3. heart 4. thymus 5. Gonads 6. adipose tissue

Testes (gonads of the male reproductive system)

Interstitial endocrine cells produce testosterone Nurse cells (Sertoli cells) -Support sperm production -Secrete inhibin for negative feedback

Adipose tissue

Produces leptin (a peptide hormone) Provides feedback control of appetite Maintains normal levels of GnRH and gonadotropin synthesis

Thymus (lymphatic system)

Produces thymosins (blend of several hormones) Promotes development and maturation of lymphocytes -Important in coordinating the immune response

Intestines (digestive system)

Release numerous hormones that coordinate digestive activities

Kidneys (urinary system)

Release the hormones calcitriol and erythropoietin (EPO) -CALCITRIOL increases intestinal absorption of Ca2+ Along with the actions of calcitonin and PTH, calcitriol promotes absorption of calcium salts from the digestive system and into the blood for deposition in bone Inadequate levels result in weak, flexible bones EPO causes the red bone marrow to increase red blood cell production -release the ENZYME RENIN

RAAS (renin-angiotensin-aldosterone system)

Renin is released by kidneys in response to decreased blood volume; In BLOOD causes ANGIOTENSINOGEN to split & produce ANGIOTENSIN I; lungs convert angiotensin I to angiotensin II; angiotensin II stimulates adrenal gland Angiotensin II is a hormone that causes in increase in ADH and aldosterone and leads to: water retention, increased blood volume, increased blood pressure

Renin

hormone secreted by the kidney; it raises blood pressure by influencing vasoconstriction (narrowing of blood vessels)

Ovaries (gonads of the female reproductive system)

produce estrogens and progesterone