MajorEndocrine Glands
I. Hypothalamus
II. Pituitary gland
III. Thyroid gland
IV. Parathyroid glands
V. Pancreas
VI. Adrenal glands
VII. Gonads
VIII. Pineal gland
II. Pituitary Gland = “The Master Gland”
• Stimulates all other endocrine glands
• Two parts: posterior and anterior
Posterior Pituitary:1. Antidiuretic hormone (ADH) –
promotes retention of water by kidneys
2. Oxytocin (OT) – responsible for contractions during labor and milk ejection
Anterior Pituitary Gland1. Growth hormone (GH) – promotes growth2. Prolactin (PRL) – stimulates milk
production
3. Follicle-stimulating hormone (FSH) – stimulates secretion of estrogen, development of follicle cells in ovaries, sperm maturation
4. Luteinizing hormone (LH) – promotes ovulation, secretion of estrogen, progesterone and testosterone
5. Thyroid-stimulating hormone (TSH) – triggers secretion of thyroid hormones
6. Adrenocorticotropic hormone (ACTH) – stimulates production of glucocorticoids
Chapter 18
The Endocrine System Cont.
.
MajorEndocrine Glands
I. Hypothalamus
II. Pituitary gland
III. Thyroid gland
IV. Parathyroid glands
V. Pancreas
VI. Adrenal glands
VII. Gonads
VIII. Pineal gland
V. The Pancreas
• Secretes hormones insulin and glucagon
The Pancreas Cont.
1. Insulin - ↓ blood glucose levels by enhancement of glucose utilization
2. Glucagon - ↑ blood glucose level by stimulating glycogen and fat breakdown, and glucose production at the liver
Diabetes Mellitus
• Consistent increased blood glucose levels
• Type I - Insulin-Dependent Diabetes Mellitus • rapid onset of symptoms prior to age 15 • lack of insulin activity – patients need daily, frequent
dosages of insulin
• Type II - Non-Insulin-Dependent Diabetes Mellitus • usually in overweight individuals• some insulin is produced • management by diet, exercise and antihyperglycemic drugs
VI. Adrenal Glands
• Adrenal glands (2) sit on top of kidneys
• Produce mineralocorticoids, glucocorticoids, and epinephrine/norepi-nephrine
Adrenal Glands Cont.
1. Mineralocorticoids - ↑ absorption of sodium and water; ↑ blood V and blood p
2. Glucocorticoids - ↑ blood glucose level (insulin antagonist); anti-inflammatory effect
3. Epinephrine/norepinephrine - stimulated by the Sympathetic Division of the ANS; ↑ muscular strength in skeletal and cardiac muscles; ↑ breakdown of glucose, fats, and glycogen
VII. Gonads
• Testes - produce testosterone
• Testosterone - promotes production of sperm, determines male secondary sexual characteristics, maintains glands of the male reproductive system, and stimulates growth
Ovaries produce estrogen, progesterone, and relaxin
1. Estrogen – responsible for maturation of eggs, growth of uterine lining, and development of female secondary sexual characteristics
2. Progesterone - prepares uterus for the arrival of embryo and enlarges mammary glands
3. Relaxin - produced during pregnancy to loosen pubic symphysis, expand uterus, and stimulates mammary gland development
VIII. Pineal Gland
• Produces melatonin
• Melatonin - involved in maintenance of wake and sleep cycles, effective antioxidant