Major Endocrine Glands I. Hypothalamus II. Pituitary gland III. Thyroid gland IV. Parathyroid glands V. Pancreas VI. Adrenal glands VII. Gonads VIII. Pineal.

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