This slideshow is intended for students in Mr. Hildebrandt's anatomy & physiology classes.

1. Essentials of Human Anatomy & Physiology
Seventh Edition
The Endocrine System
Anatomy & Physiology II

2. Developmental Aspects of the
Endocrine System
• Most endocrine organs operate smoothly
until old age
• Menopause is brought about by lack of
efficiency of the ovaries
• Problems associated with reduced estrogen
are common
• Growth hormone production declines with age
• Many endocrine glands decrease output with
age
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.41

3. Sometimes there are problems…

4. Endocrine System Function:
• Second messenger system of the body
• Uses chemical messages (hormones)
that are released into the blood
• Hormones control several major
processes
• Reproduction
• Growth and development
• Mobilization of body defenses
• Maintenance of much of homeostasis
• Regulation of metabolism
Slide 9.1

5. Hormone Overview
• Hormones are produced by specialized
cells
• Cells secrete hormones into
extracellular fluids
• Blood transfers hormones to target sites
• These hormones regulate the activity of
other cells
• Three types: Amino acid, Steroid, & Lipid
based

6. Mechanisms of Hormone Action
• Hormones affect only certain tissues or
organs (target cells or organs)
• Target cells must have specific protein
receptors
• Hormone binding influences the working
of the cells
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.4

7. Control of Hormone Release
• Hormone levels in the
blood are maintained by
negative feedback loop
• A stimulus (3 types)
triggers the release of
more hormone
• Hormone release stops
once an appropriate level
in the blood is reached
Slide 9.10

8. Hormonal Stimuli of Endocrine
Glands
• Endocrine glands
are activated by
other hormones
Figure 9.2a
Slide 9.11

9. Humoral Stimuli of Endocrine
Glands
• Changing blood
levels of certain
ions stimulate
hormone release
Figure 9.2b
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.12

10. Neural Stimuli of Endocrine Glands
• Nerve impulses
stimulate hormone
release
• Most are under
control of the
sympathetic nervous
system
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.13

11. Location of Major Endrocrine Organs
Figure 9.3
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12. Pituitary Gland “the master gland”
• Grape-sized, hangs
by a stalk from the
hypothalamus
• Protected by the
sphenoid bone
• Two functional lobes
• Anterior pituitary –
glandular tissue
• Posterior pituitary –
nervous tissue

13. Pituitary - Hypothalamus
Relationship
• Release of hormones is controlled by
releasing and inhibiting hormones
produced by the hypothalamus
• Hypothalamus produces two hormones
that are transported to neurosecretory
cells of the posterior pituitary
• The posterior pituitary is not strictly an
endocrine gland, but does release
hormones
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.21

14. Hormones of the Anterior Pituitary
Figure 9.4
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.17

15. Hormones of the Posterior Pituitary
Figure 9.5
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.22b

16. Thyroid Gland
• Found at the base of
the throat
• Two lobes and a
connecting isthmus
• Produces two
hormones
• Thyroid hormone
• Calcitonin
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.23a

17. Parathyroid Glands
• Tiny masses on posterior
thyroid
• Secrete parathyroid hormone

18. Adrenal Glands
• “Two glands in one”
• Cortex – outer
glandular region in
three layers
• Medulla – inner
neural tissue region
• Sits on top of the
kidneys

19. Pancreatic Islets
• The pancreas is a mixed gland
• The islets of the pancreas produce
insulin and glucagon

20. Pineal Gland
• Found on the third
ventricle of the brain
• Secretes melatonin
• Helps establish the body’s
wake and sleep cycles
• May have other as-yet-
unsubstantiated functions
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.34

21. Thymus Gland
• Located posterior
to the sternum
• Largest in infants
and children
• Produces
thymosin
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 9.35

22. Hormones of the Ovaries
• Estrogens
• Progesterones
Hormones of the Testes
• Interstitial cells of testes are
hormone-producing
• Produce several androgens
• Testosterone most significant
Slide 9.36

23. Hormones to know…
ACTH Glucagon PTH
ADH Insulin Growth hormone
Aldosterone LH Testosterone
Cortisol Melatonin Thymosin
Epinephrine Oxytocin Thyrocalcitonin
Estrogen Progesterone Thyroxine
FSH Prolactin TSH
Slide 9.36