1. Endocrine System at a Glance
glands that secrete hormones- chemicals that regulate body activities such as:
Metabolic rate
Water and mineral balance
Immune system reactions
Sexual functioning

2. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.

3. Anatomy and Physiology
Secrete hormones directly into bloodstream to act on target organs
Increase or decrease target organ’s activity level
Essential in maintaining homeostasis
stable internal environment

4. Types of Glands Two types of glands in body Exocrine glands
Exocrine glands and endocrine glands
Exocrine glands
Release secretions into duct that carries them to outside of body
Example: sweat glands
Endocrine glands
Release hormones directly into bloodstream
Have no ducts AKA ductless glands

5. Glands of the Endocrine System
Pituitary gland
Pineal gland
Thyroid gland
Parathyroid glands – four
Thymus gland
Adrenal glands – two
Pancreas
Ovaries – two in females
Testes – two in males

6. 1. Pituitary Gland Referred to as “master gland”
Secretes hormones that regulate other endocrine glands
Regulated by hypothalamus in brain
Divided into anterior and posterior lobes

7. Anterior Pituitary Thyroid-stimulating hormone (TSH)
Regulates function of thyroid gland
Adrenocorticotropin hormone (ACTH)
Regulates function of adrenal cortex
Growth hormone (GH)
Also called somatotropin
Stimulates cells to grow and divide

8. Anterior Pituitary Prolactin (PRL)
Stimulates milk production in breast
Melanocyte-stimulating hormone (MSH)
Stimulates melanocytes to produce more melanin

9. Anterior Pituitary Gonadotropins Follicle-stimulating hormone (FSH)
Responsible for development of ova and sperm
Also stimulates ovary to secrete estrogen
Luteinizing hormone (LH)
Stimulates secretion of sex hormones
Plays a role in releasing ova in females

10. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 11.7 – The different hormones and target tissues for the anterior pituitary.

11. Posterior Pituitary Antidiuretic hormone (ADH) Oxytocin
Also called vasopressin
Promotes water reabsorption by the kidneys
Oxytocin
Stimulates uterine contractions during birth
After birth stimulates release of milk from breast

12. 2. Pineal Gland Small pine cone-shaped gland
Part of thalamus region of brain
Secretes melatonin (your body’s natural sedative)
Not well understood, but plays a role in regulating body’s circadian rhythm
24-hour clock that governs periods of wakefulness and sleepiness

13. 3. Thyroid Gland Located on either side of trachea
Resembles a butterfly in shape
Divided into right & left lobes

14. Thyroid Gland Thyroid hormones Needs iodine to make hormones
Thyroxine (T4)
Triiodothyronine (T3)
Needs iodine to make hormones
These hormones:
Regulate energy production
Adjust metabolic rate

15. Thyroid Gland Also secretes calcitonin
Regulates level of calcium in bloodstream
If calcium levels in blood rise too high:
Calcitonin levels in blood increase
Increases deposition of calcium into bone
Lowers levels of calcium in bloodstream
Its action is opposite of parathyroid hormone

16. 4. Parathyroid Glands Four tiny glands
Located on dorsal surface of thyroid gland

17. Parathyroid Glands Secretes parathyroid hormone (PTH)
Regulates level of calcium in bloodstream
If calcium levels in blood fall too low:
PTH in the blood increase to stimulate bone breakdown & release more Ca+ into bloodstream

18. 5. Thymus Gland Located in mediastinum of the chest
Part of immune system but also an endocrine gland
Secretes thymosin

19. Thymus Gland
Thymosin
Essential for growth and development of thymic lymphocytes or T cells for immune system
Present at birth and grows to largest size during puberty
At puberty begins to shrink and eventually is replaced with connective and adipose tissue

20. 6. Adrenal Glands Two glands, one located above each kidney
Each gland is composed of two sections:
Adrenal cortex
Adrenal medulla

21. Adrenal Cortex
Outer portion that secretes hormones referred to as corticosteroids
Mineralocorticoid
Example: aldosterone
Regulates Na+ and K+ levels
Glucocorticoid
Example: cortisol
Regulates carbohydrates
Steroid sex hormones
Androgens, estrogen, and progesterone
Regulate secondary sexual characteristics

22. Adrenal Medulla Inner portion Secretes epinephrine and norepinephrine
Epinephrine is also called adrenaline
Critical during fight or flight response
Increases blood pressure
Increases heart rate
Increases respiration rate

23. 7. Pancreas Located along lower curvature of stomach
Only organ that has both endocrine and exocrine functions
Exocrine portion
Releases digestive enzymes through duct into duodenum
Endocrine sections of the pancreas
Islets of Langerhans
Produce insulin and glucagon

24. Pancreas Insulin Produced by beta cells
Stimulates cells of body to take in glucose from bloodstream
Lowers blood sugar level
Occurs after eating a meal and absorbing carbohydrates

25. Pancreas Glucagon Produced by alpha cells
Stimulates liver to release stored glucose into bloodstream
Raises blood sugar levels
Occurs when body needs more glucose

26. Diabetes Mellitus Non-insulin- dependent diabetes mellitus (NIDDM)
Also called Type 2
Develops later in life
Person makes enough insulin, but it has lost ability to regulate cells
Do not take insulin
Treated by diet, exercise, and oral medications
Insulin-dependent diabetes mellitus (IDDM)
Also called Type 1
Develops early in life
Destruction of islet cells
Person makes too little insulin
Must take insulin injections

27. 8. Ovaries Two ovaries located in pelvic cavity of females
Secrete female sex hormones, estrogen and progesterone
Estrogen is responsible for:
Female sexual characteristics
Regulation of menstrual cycle
Progesterone
Maintains suitable uterine environment for pregnancy

28. 9.Testes Two oval glands located in scrotum of males
Secrete male sex hormone testosterone
Testosterone
Produces male secondary sexual characteristics
Regulates sperm production