The document presents an overview of the endocrine system, detailing the various glands, their locations, and the hormones they secrete, along with their functions. It explains key concepts such as hormone feedback mechanisms, stress responses, and common endocrine disorders. Additionally, it emphasizes the importance of hormones in regulating bodily functions and maintaining homeostasis.

1. © 2009 The McGraw-Hill Companies, Inc. All rights reserved
The Endocrine System
The Endocrine System
PowerPoint® presentation to accompany:
Medical Assisting
Third Edition
Booth, Whicker, Wyman, Pugh, Thompson

2. 34-2
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Learning Outcomes
34.1 Define the term endocrine glands.
34.2 Describe the general functions of the endocrine
system.
34.3 Define the term hormone.
34.4 Explain the difference in hormone control by
positive and negative feedback loops.

3. 34-3
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Learning Outcomes (cont.)
34.5 Describe the locations of the hypothalamus,
pituitary gland, pineal body, thyroid gland,
parathyroid glands, adrenal glands, pancreas,
thymus, and gonads.
34.6 List the hormones released by the pituitary gland
and give the functions of each.
34.7 List the hormones released by the thyroid gland
and parathyroid glands and give the functions of
each.

4. 34-4
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Learning Outcomes (cont.)
34.8 List the hormones released by the adrenal glands
and give the functions of each.
34.9 List the names of the endocrine cells of the
pancreas, the hormones released by them, and the
function of each hormone.
34.10 List the hormones released by the pineal body,
thymus, and gonads, and give the functions of
each.

5. 34-5
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Learning Outcomes (cont.)
34.11 Name the hormones produced by the kidneys and
heart, listing which organ produces the hormone,
and the hormone’s function.
34.12 Describe stressors and their effect on the body.
34.13 Describe the causes, signs and symptoms, and
treatment of various endocrine disorders.

6. 34-6
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target tissues
Introduction
 The endocrine system includes the organs of the
body that secrete hormones directly into body fluids
such as blood
 Regulates chemical reaction in cells and therefore control
functions of the organs, tissues, and other cells
Glands
secrete
hormones
into
bloodstream
to

7. 34-7
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Hormones
 Endocrine glands
 Ductless
 Release hormones
 Directly into target tissues
 Into bloodstream to be carried to target tissues
 Hormones – chemicals secreted by a cell that
affect the functions of other cells

8. 34-8
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Hormones (cont.)
 Many are derived from steroids that easily
cross the cell membrane
 Examples of steroid hormones
 Estrogen
 Progesterone
 Testosterone
 Cortisol
hormones

9. 34-9
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Hormones (cont.)
 Nonsteroidal hormones
 Made of amino acids or
proteins and cannot cross
the cell membrane easily
 Bind to receptors on the
surface of the cells
 G-protein – activated by the
hormone-receptor complex
 Activates enzymes inside
cell
 Prostaglandins
 Local, or tissue, hormones
 Derived from lipid molecules
 Do not travel in the
bloodstream
 Target tissues are located
close by
 Produced by organs such as
 Kidneys
 Heart
 Stomach
 Uterus
 Brain

10. 34-10
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Negative and Positive
Feedback Loops
 Control hormone levels
 Negative feedback loop
 Hormone release stops in response to decrease in
stimulus
 Stimulus (eating) raises blood glucose levels
 Pancreas releases insulin in response to elevated blood
glucose
 Blood glucose decreases as it is used by the body or
stored in the liver
 Insulin release stops as blood glucose levels normalize

11. 34-11
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Negative and Positive
Feedback Loops (cont.)
 Positive feedback loop
 As long as stimulus is present, action of hormone
continues
 Infant nursing at mother’s breast  stimulates
hypothalamus  stimulates posterior pituitary
 Oxytocin released  stimulates milk production and
ejection from mammary glands
 Milk release continues as long as infant continues to
nurse

12. 34-12
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Apply Your Knowledge
Match the following:
___ Chemicals that effect cell function A.Nonsteroidal
hormone
___ Easily cross cell membranes B. Steroidal hormone
___ Made of amino acids C. G-protein
___ Target nearby cells D.Prostaglandins
___ Activated by hormone-receptor E. Hormones
complex
___ Cannot cross cell membranes easily
___ Estrogen and cortisol
B
A
D
C
A
B
E
ANSWER:

13. 34-13
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Hypothalamus
 Hormones
 Oxytocin
 Antidiuretic hormone (ADH)
 Hormones transported to the posterior
pituitary for storage
 Directs posterior pituitary to release hormones
Glands

14. 34-14
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 Controlled by the hypothalamus
 Located at the base of the brain
 Protected by a bony structure called the sella turcica
 The optic chiasm is located just above the pituitary gland
 Carries visual information to the brain for interpretation
 Two lobes
 Anterior lobe
 Posterior lobe
Pituitary Gland
Glands

15. 34-15
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Anterior
Lobe
Growth hormone Prolactin
Adrenocorticotropic
Thyroid-stimulating
Follicle-stimulating
Luteinizing
Stimulates milk
production
Stimulates the adrenal cortex
to release its hormones
Stimulates the thyroid
gland to release its
hormones
Females: stimulates estrogen
production and maturation of the ova
Males: stimulates sperm production
Females: stimulates ovulation
and estrogen production
Males: stimulates testosterone production
Pituitary Gland (cont.)
Stimulates increase in size
of muscles and bones

16. 34-16
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Posterior
Lobe
Antidiuretic hormone (ADH)
Oxytocin
Stimulates the kidneys to
conserve water
Females: causes
contraction of the
uterus and ejection of
breast milk
Males: stimulates
contraction of the
prostate and vas
deferens during
sexual arousal
Pituitary Gland (cont.)

17. 34-17
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Apply Your Knowledge
Match the following:
___ Stored in posterior pituitary A. Follicle-stimulating hormone
___ Milk production B. Prolactin
___ Produced by hypothalmus C. Luteinizing hormone
___ Stimulates sperm production D. ADH
___ Maturation of ova E. Oxytocin
___ Stimulates ovulation
___ Conservation of water
___ Production of testosterone
___ Contraction of uterus
E
D
B
D, E
C
A
A
C
D, E
ANSWER:
Super!

18. 34-18
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T3 T4
Thyroid Gland and
Parathyroid Glands
Thyroid Gland
 Located below the larynx
 Divided into follicles that store some of the hormones
Major hormones
Stimulate protein synthesis and
increase cellular energy
production
Lowers blood calcium levels
by activating osteoblasts that
build new bone tissue Glands

19. 34-19
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Thyroid Gland and
Parathyroid Glands (cont.)
 Parathyroid glands
 Four located on the posterior surface of the
thyroid gland
 Secrete parathyroid hormone (PTH)
 Agonist to calcitonin by raising blood calcium levels
through activation of osetoclasts (dissolve bone)
 As bone dissolves, calcium levels in blood increase
Glands

20. 34-20
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Apply Your Knowledge
True or False:
__ Thyroid hormones stimulate protein synthesis.
__ The thyroid gland does not store hormones.
__ PTH activates osteoblasts.
__ Calcitonin increases cellular energy production.
__ The four parathyroid glands are located on the thyroid gland.
__ Calcitonin lowers blood calcium levels.
F
F
F
T
T
T
ANSWER:
PTH activates osteoclasts.
Thyroid hormone
increases cellular
energy production.
Thyroid follicles store
some hormones.

21. 34-21
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Adrenal Glands
 Located on top of each kidney
 Divided into the adrenal medulla and adrenal cortex
 Adrenal medulla
 Central portion
 Hormones
 Epinephrine
 Norepinephrine
 Same effects as sympathetic nervous system
Glands

22. 34-22
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Adrenal Glands (cont.)
 Adrenal cortex
 Outermost portion
 Secretes many hormones, but main ones are
 Aldosterone
 Stimulates body to retain sodium and water
 Important in maintaining BP
 Cortisol
 Released when stressed
 Decreases protein synthesis, resulting in slowed tissue repair
 Decreases inflammation

23. 34-23
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Apply Your Knowledge
Match the following:
____ Adrenal medulla A. Cortisol
____ Sodium retention B. Epinephrine
____ Decreases inflammation C. Aldosterone
____ Sympathetic effects D. Norepinephrine
____ Maintains blood pressure
____ Released during stress
____ Adrenal cortex
A, C
B, D
A
C
A
C
B, D
ANSWER:
Excellent!

24. 34-24
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Pancreas
 Located behind the
stomach
 Both exocrine gland and
endocrine gland
 Exocrine – secretes
digestive enzymes into a
duct leading to the small
intestine
 Endocrine – secretes
hormones into
bloodstream Glands

25. 34-25
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Pancreas (cont.)
 Islets of Langerhans secrete hormones into
bloodstream
 Alpha cells secrete glucagon
 Beta cells secrete insulin
Blood glucose
concentrations
Protein synthesis
Blood glucose
concentrations
Protein synthesis

26. 34-26
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Apply Your Knowledge
What are the effects of insulin and glucagon?
ANSWER: Insulin decreases blood glucose concentration
and increases protein synthesis.
Glucagon does just the opposite. It increases blood
glucose and decreases protein synthesis.
Yippee
!

27. 34-27
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Other Hormone-Producing Organs
 Pineal body
 Small gland
 Located between
cerebral hemispheres
 Melatonin
 Regulates circadian
rhythms
 May play a role in
onset of puberty
 Thymus gland
 Located between
lungs
 Thymosin
 Promotes
production of
T lymphocytes
Glands

28. 34-28
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Other Hormone-Producing
Organs (cont.)
 The gonads
 Ovaries
 Estrogen
 Progesterone
 Testes
 Testosterone
 Stomach
 Gastrin
 Small intestine
 Secretin
 Cholecystokinin
 Heart
 Atrial natriuretic
peptide – regulates BP
 Kidneys
 Erythropoietin –
stimulates blood cell
production Glands

29. 34-29
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Back
Back

30. 34-30
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Apply Your Knowledge
Match the following:
___ Between lungs A. Pineal body
___ Melatonin B. Heart
___ Estrogen/testosterone C. Kidneys
___ Gastrin D. Thymus gland
___ Secretin E. Small intestine
___ Erythropoietin F. Stomach
___ Atrial natriuetic peptide G. Gonads
___ Thymosin
___ Cholecystokinin
C
E
F
G
A
E
D
B
D
ANSWER:

31. 34-31
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The Stress Response
 Stressor
 Any stimulus that
produces stress
 Types
 Physical factors
 Psychological
factors
 Positive stimuli

32. 34-32
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The Stress Response (cont.)
 Physiologic response to stress caused by
hormone release
 General stress syndrome
 Increased heart rate, respiratory rate, and BP
 Increase in glucose and fatty acids in blood, which
leads to weight loss
 Increase in cortisol if stress prolonged
 Decreased body repair
 Susceptibility to illness

33. 34-33
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
Apply Your Knowledge
Match the following:
___ Extreme heat A. Physical stress
___ Death of friend B. Psychological stress
___ Fractured leg C. Positive stimulus
___ Wedding
___ Exam
___ Hearing an explosion nearby
___ “A” on an exam
___ Flu
___ Car stolen
B
B
B
A
A
C
B
C
A
ANSWER:

34. 34-34
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Common Diseases and Disorders
Disease/Disorder Description
Acromegaly Too much growth hormone produced in adults;
enlargement of bones and thickened skin
Addison’s disease Adrenal gland fails to produce enough
corticosteroids
Cretinism Extreme form of hypothyroidism present prior
to or soon after birth
Cushing’s disease Hypercortisolism; over-production of cortisol
Diabetes insipidus Kidneys fail to reabsorb water, resulting in
excessive urination; hyposecretion of ADH

35. 34-35
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Common Diseases and Disorders (cont.)
Disease/Disorder Description
Diabetes mellitus
Type I
Type II
Gestational
Chronic disease characterized by elevated
blood glucose levels
Insulin-dependent diabetes mellitus; usually develops
in childhood
Noninsulin-dependent diabetes mellitus; primarily in
adults but increased incidence in teens
Occurs during pregnancy; usually temporary
Dwarfism Too little growth hormone (somatotropin)
produced during childhood

36. 34-36
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Common Diseases and Disorders (cont.)
Disease/Disorder Description
Gigantism Too much growth hormone produced during
childhood
Goiter Enlargement of thyroid gland, causing
swelling in neck; deficiency of iodine in diet
Grave’s disease Hyperthyroidism; antibodies attach to thyroid
gland, causing it to produce too much thyroid
hormone
Myxedema Thyroid gland produces inadequate amounts of
thyroid hormone; common in females over 50

37. 34-37
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Apply Your Knowledge
True or False:
___ Acromegaly develops as a result of too much growth hormone in a child.
___ In diabetes insipidus, the kidneys fail to reabsorb water.
___ Too little growth hormone in childhood results in dwarfism.
___ Myxedema is the result of hyperthyroidism.
___ Addison’s disease is the result of too little corticosteroid.
___ Cushing’s disease is the result of too little ACTH.
___ Cretinism is an extreme form of hyperthyroidism present at birth.
F
T
T
T
F
F
ANSWER:
F
hypothyroidism
too much ACTH
hypothyroidism
in an adult
Correct!

38. 34-38
© 2009 The McGraw-Hill Companies, Inc. All rights reserved
In Summary
 The organs of the
endocrine system
secrete hormones
directly into blood and
other body fluids.
 Hormones secreted by
the endocrine system
control the functions of
other cells.
 Endocrine organs
 Hypothalamus
 Pituitary gland
 Thyroid gland
 Parathyroid glands
 Adrenal glands
 Pancreas
 Pineal body
 Thymus gland
 Gonads, stomach small
intestine, heart, kidneys

39. 34-39
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Its not stress
that kills us,
it is our
reaction to it.
~ Hans Selye