1. Interest Grabber Fast and Slow Messages
Section 39-1
Fast and Slow Messages
Your endocrine (hormonal) system is the slow message system of your body. Its messages consist of chemicals released by glands into the bloodstream. Your nervous system, on the other hand, is the fast message system of the body. Its messages consist of electrical signals that travel along the membranes of nerve cells.
1. Describe a situation in which the body could use the endocrine system to deliver a “slow” message.
2. Describe a situation in which the body could use the nervous system to deliver a “fast” message.
3. Develop an analogy that illustrates this difference between these two systems.

2. Section Outline 39–1 The Endocrine System A. Hormones B. Glands
C. Hormone Action
1. Steroid Hormones
2. Nonsteroid Hormones
D. Prostaglandins
E. Control of the Endocrine System
1. Controlling Metabolism
2. Maintaining Water Balance
F. Complementary Hormone Action

3. Hormone Action Section 39-1 Nonsteroid hormone (first messenger)
Target cell membrane
Receptor
Target cell membrane
Receptor
cAMP (second messenger)
Hormone-receptor complex
Altered cellular function
Nucleus
Enzyme activities
DNA
Altered cellular function
Protein synthesis
Nucleus
Cytoplasm
Cytoplasm
mRNA

4. Hormone Action Section 39-1 Nonsteroid hormone (first messenger)
Target cell membrane
Receptor
Target cell membrane
Receptor
cAMP (second messenger)
Hormone-receptor complex
Altered cellular function
Nucleus
Enzyme activities
DNA
Altered cellular function
Protein synthesis
Nucleus
Cytoplasm
Cytoplasm
mRNA

5. Figure 39–2 The Endocrine Glands
Section 39-1
Hypothalamus
The hypothalamus makes hormones that control the pituitary gland. In addition, it makes hormones that are stored in the pituitary gland.
Pineal gland
The pineal gland releases melatonin, which is involved in rhythmic activities, such as daily sleep-wake cycles.
Thyroid
The thyroid produces thyroxine, which regulates metabolism.
Pituitary gland
The pituitary gland produces hormones that regulate many of the other endocrine glands.
Pancreas
The pancreas produces insulin and glucagon, which regulate the level of glucose in the blood.
Parathyroid glands
These four glands release parathyroid hormone, which regulate the level of calcium in the blood.
Ovary
The ovaries produce estrogen and progesterone. Estrogen is required for the development of secondary sex characteristics and for the development of eggs. Progesterone prepares the uterus for a fertilized egg.
Thymus
During childhood, the thymus releases thymosin, which stimulates Tcell development.
Testis
The testes produce testosterone, which is responsible for sperm production and the development of male secondary sex characteristics
Adrenal glands
The adrenal glands release epinephrine and nonepinephrine, which help the body deal with stress.

6. Interest Grabber A Grizzly Scenario
Section 39-2
A Grizzly Scenario
Imagine that you are hiking in the Rocky Mountains, and you happen upon a grizzly bear and her cubs. The mother grizzly looks as if she is about to attack you. Terrified, you back away slowly to get out of the bears’ “territory.” You desperately want to turn and run, but you know that might cause the mother bear to attack you.
1. When you are frightened, it triggers the “fight-or-flight” response. Describe the changes that took place in your body the last time you were in a scary situation.
2. Which body structures do you think become readied for this “fight-or flight” response? Why do you think this happens to these structures?
3. Which body structures do you think are slowed down during this “fight-or-flight” response? Why do you think this happens?

7. Section Outline 39–2 Human Endocrine Glands A. Pituitary Gland
B. Hypothalamus
C. Thyroid Gland
D. Parathyroid Glands
E. Adrenal Glands
1. Adrenal Cortex
2. Adrenal Medulla
F. Pancreas
G. Reproductive Glands

8. Calcium and glucose levels
Concept Map
Section 39-2
The Endocrine System
regulates
Growth
Water balance
Reproduction
Metabolism
Calcium and glucose levels
Response to stress
by means of the
by means of the
by means of the
by means of the
by means of the
by means of the
Pituitary
Ovaries
Testes
Thyroid
Pancreas
Adrenals
Parathyroids

9. Figure 39–10 Actions of Insulin and Glucagon
Section 39-2
Beta cells release insulin into the blood
Body cells absorb glucose
Blood glucose level increases
Liver converts glycogen to glucose
Blood glucose level decreases
Homeostasis: Normal blood glucose level
Blood glucose level increases
Blood glucose level decreases
Liver converts glycogen to glucose
Alpha cells release glucagon into blood

10. Interest Grabber A Soprano Becomes a Tenor
Section 39-3
A Soprano Becomes a Tenor
Many changes take place in the human body between the ages of about 9 to 15 years. Think about the changes that you have noticed in yourself and your friends in the last few years. Then, answer the following questions.
1. How does an eight-year-old male’s voice compare to that of an adult male? How does an eight-year-old female’s voice compare to that of an adult female?
2. What do you think causes the differences in the voices? Explain your answer.
3. Another change that occurs between 9 and 15 is a growth spurt, which is a rapid increase in height. Do you think growth spurts occur earlier in males or in females? Explain your answer.

11. Section Outline 39–3 The Reproductive System A. Sexual Development
B. The Male Reproductive System
1. Sperm Development
2. Sperm Release
C. The Female Reproductive System
1. Egg Development
2. Egg Release
D. The Menstrual Cycle
1. Follicular Phase
2. Ovulation
3. Luteal Phase
4. Menstruation

12. The Menstrual Cycle
Section 39-3

13. Figure 39–14 The Male Reproductive System
Section 39-3
Large intestine
Rectum
Seminal vesicle
Prostate gland
Bulbourethral gland
Epididymis
Testis
Scrotum
Penis
Urethra
Vas deferens
Pubic bone
Urinary bladder

14. Figure 39–15 The Female Reproductive System
Section 39-3
Fallopian tube
Ovary
Urinary bladder
Pubic bone
Urethra
Vagina
Uterus
Cervix
Rectum

15. Interest Grabber More Than One
Section 39-4
More Than One
Fertilization is the fusion of a sperm and an egg to form a zygote, the single cell from which all cells of the human body are derived. When an egg is fertilized, the remarkable process of human development begins.
1. If two eggs are released during ovulation, each can be fertilized by a sperm. What do you think would be the result? Explain your answer.
2. If one zygote splits into two, each can continue development on its own. What do you think would be the result? Explain your answer.
3. Triplets are three babies born at the same time. Describe three ways that triplets could develop.

16. Section Outline 39–4 Fertilization and Development A. Fertilization
B. Early Development
1. Gastrulation
2. The Placenta
C. Later Development
D. Childbirth
E. Early Years
1. Infancy
2. Childhood
3. Adolescence
F. Adulthood

17. Fertilization and Implantaton
Section 39-4
Uterine wall
Blastocyst
Morula
4 cells
2 cells
Zygote
Ovary
Fallopian tube
Day 3
Day 2
Day 1
Day 4
Fertilization
Day 0
Day 7
Implantation of blastocyst
Egg released by ovary

18. Figure 39–20 The Placenta Section 39-4 Amniotic sac Placenta
Umbilical cord
Uterus
Amnion
Fetal portion of placenta
Maternal portion of placenta
Maternal artery
Maternal vein
Umbilical arteries
Umbilical vein
Villus in chorion