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.

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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