1. Anatomy and Physiology, Sixth Edition
Rod R. Seeley Idaho State University
Trent D. Stephens Idaho State University
Philip Tate Phoenix College
Chapter 18
Lecture Outline*
*See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes.
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. Chapter 18
Endocrine Glands

3. Endocrine System Functions
Metabolism and tissue maturation
Ion regulation
Water balance
Immune system regulation
Heart rate and blood pressure regulation
Control of blood glucose and other nutrients
Control of reproductive functions
Uterine contractions and milk release

4. Pituitary Gland and Hypothalamus
Where nervous and endocrine systems interact
Pituitary gland/hypophysis
Secretes 9 major hormones
Hypothalamus
Regulates secretory activity of pituitary gland through neurohormones and action potentials
Posterior pituitary is an extension of

5. Pituitary Gland Structure
Posterior or neurohypophysis
Continuous with the brain
Secretes neurohormones
Anterior or adenohypophysis
Consists of three areas with indistinct boundaries: pars distalis, pars intermedia, pars tuberalis

6. Relationship of Pituitary to Brain

7. Hypothalamus, Anterior Pituitary and Target Tissues

8. Pituitary Gland Hormones
Posterior
Antidiuretic hormone (ADH)
Oxytocin
Anterior
Growth hormone (GH) or somatotropin
Thyroid-stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
Melanocyte-stimulating hormone (MSH)
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
Prolactin

9. Antidiuretic Hormone Also called vasopressin
Promotes water retention by kidneys
Secretion rate changes in response to alterations in blood osmolality and blood volume
Lack of ADH secretion is a cause of diabetes insipidus

10. Oxytocin Promotes uterine contractions during delivery
Causes milk ejection in lactating women

11. Growth Hormone (GH)
Stimulates uptake of amino acids and conversion into proteins
Stimulates breakdown of fats and glycogen
Promotes bone and cartilage growth
Increased secretion in response to increase amino acids, low blood glucose, or stress
Regulated by GHRH and GHIH or somatostatin

12. TSH, ACTH, MSH ACTH TSH or thyrotropin MSH
Stimulates cortisol secretion from adrenal cortex
MSH
Increases skin pigmentation
TSH or thyrotropin
Causes release of thyroid hormones from thyroid gland

13. LH, FSH, Prolactin Prolactin LH and FSH
Both hormones regulate production of gametes and reproductive hormones
Testosterone in males
Estrogen and progesterone in females
GnRH from hypothalamus stimulates LH and FSH secretion
Prolactin
Stimulates milk production in lactating females

14. Thyroid Gland One of largest endocrine glands Highly vascular
Histology
Composed of follicles
Parafollicular cells
Secrete calcitonin which reduces calcium concentration in body fluids when levels elevated

15. Biosynthesis of Thyroid Hormones

16. Thyroid Hormones Include Transported in blood
Triiodothryronine or T3
Tetraiodothyronine or T4 or thyroxine
Transported in blood
Bind with intracellular receptor molecules and initiate new protein synthesis
Increase rate of glucose, fat, protein metabolism in many tissues thus increasing body temperature
Normal growth of many tissues dependent on

17. Regulation of T3 and T4 Secretion

18. Thyroid Hormone Hyposecretion and Hypersecretion
Hypothyroidism
Decreased metabolic rate
Weight gain, reduced appetite
Dry and cold skin
Weak, flabby skeletal muscles, sluggish
Myxedema
Apathetic, somnolent
Coarse hair, rough dry skin
Decreased iodide uptake
Possible goiter
Hyperthyroidism
Increased metabolic rate
Weight loss, increased appetite
Warm flushed skin
Weak muscles that exhibit tremors
Exophthalmos
Hyperactivity, insomnia
Soft smooth hair and skin
Increased iodide uptake
Almost always develops goiter

19. Parathyroid Glands Embedded in thyroid Secrete PTH
Increases blood calcium levels
Stimulates osteoclasts
Promotes calcium reabsorption by kidneys

20. Regulation of PTH Secretion

21. Adrenal Glands Functions as part of sympathetic nervous system
Composed of medulla and cortex (3 layers)
Hormones
Medulla secretes epinephrine and norepinephrine
Cortex secretes mineralocorticoids, glucocorticoids, androgens

22. Hormones of Adrenal Cortex
Mineralocorticoids
Zona glomerulosa
Aldosterone produced in greatest amounts
Increases rate of sodium reabsorption by kidneys increasing sodium blood levels
Glucocorticoids
Zona fasciculata
Cortisol is major hormone
Increases fat and protein breakdown, increases glucose synthesis, decreases inflammatory response
Androgens
Zona reticularis
Converted to androgen and testosterone

23. Pancreas Located along small intestine and stomach Exocrine gland
Produces pancreatic digestive juices
Endocrine gland
Consists of pancreatic islets
Composed of
Alpha cells secrete glucagon
Beta cells secrete insulin
Delta cells secrete somatostatin

24. Insulin and Glucagon Insulin
Target tissues: liver, adipose tissue, muscle, and satiety center of hypothalamus
Increases uptake of glucose and amino acids by cells
Glucagon
Target tissue is liver
Causes breakdown of glycogen and fats for energy

25. Regulation of Insulin Secretion

26. Regulation of Blood Nutrient Levels After a Meal

27. Regulation of Blood Nutrient Levels During Exercise

28. Hormones of the Reproductive System
Female: Ovaries
Estrogen and Progesterone
Uterine and mammary gland development and function, external genitalia structure, secondary sex characteristics, menstrual cycle
Inhibin
Inhibits FSH secretion
Relaxin
Increases flexibility of symphysis pubis
Male: Testes
Testosterone
Regulates production of sperm cells and development and maintenance of male reproductive organs and secondary sex characteristics
Inhibin
Inhibits FSH secretion

29. Pineal Body In epithalamus Produces Melatonin Arginine vasotocin
Enhances sleep
Arginine vasotocin
Regulates function of reproductive system in some animals

30. Effects of Aging on Endocrine System
Gradual decrease in secretory activity of some glands
GH as people age
Melatonin
Thyroid hormones
Kidneys secrete less renin
Familial tendency to develop type II diabetes

31. Diabetes Mellitus
Results from inadequate secretion of insulin or inability of tissues to respond to insulin
Types
Type I or IDDM (Insulin-dependent)
Develops in young people
Type II or NIDDM (Non-insulin dependent)
Develops in people older than 40-45
More common