1. Endocrine System
Big Idea: How does the body use chemical signals to maintain homeostasis?

2. Describe how this person feels walking on the bridge
Describe how this person feels walking on the bridge. List situations in your life that cause stress. Describe how your body reacts to this stress.

3. Nervous vs Endocrine
If you wanted to send information to ONE person, what would you do?
If you wanted to send information to MANY people, what would you do?

4. Nervous vs Endocrine
The nervous system sends messages quickly and directly via neurons
The endocrine system is the slow message system that delivers messages to every cell of the body by releasing chemicals called hormones.

5. The Endocrine Glands Section 39-1 Hypothalamus Pineal gland
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. 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

7. 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 glucose to glycogen
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

8. Reproductive System
The function of the human reproductive system is to produce, store, nourish and release sex cells (gametes – eggs and sperm).
In addition, the function of the female reproductive system is to nourish a developing embryo.
The fusion of egg and sperm produces a zygote.

9. What would happen if you removed a person’s circulatory system?
What would happen if you removed a person’s reproductive system?
Why is the reproductive system important if a person can survive without it?
Does every member of a species have to reproduce?

10. 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

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

12. Female reproductive system
Contrary to males, who are able to produce about 1000 sperm per minute, females produce one egg per month.
All the eggs a woman will ever have are formed while she is in her mother’s uterus (about 5 million eggs) by the time she is a five month old fetus.
Only about 400 eggs will be ovulated.

13. Your period starts a cycle that usually produces a single egg that can be fertilized.
Cycle lengths are from 21 – 35 days, but usually are 28 days.
FSH and LH reach the ovaries and signal them to produce estrogen. Estrogen causes the egg to ripen.
The egg ripens in a sac called the follicle. When an egg is ripe, it is released from the follicle into the abdomen where it is picked up by the fimbria of the Fallopian tube.

14. Ovulation, which takes about 2 minutes to complete, usually occurs 14 days AFTER the onset of the period in a 28 day cycle.
Ovulation always occurs 14 days BEFORE the onset of the period (bleeding).
Therefore, if you have a 35 day cycle, you will ovulate on day 21 and if you have a 20 day cycle, you will ovulate on day 6.

15. What happens next?
After the egg is in the Fallopian tube, it continues to ripen and prepare itself for the sperm.
The egg is capable of being fertilized for 24 hours.
Sperm can live in the vagina, cervix, uterus and Fallopian tubes for days.

16. How the gametes meet
During sexual intercourse a small amount of seminal fluid containing millions of sperm cells is expelled through the man’s penis and deposited below the woman’s uterus. Helped by the movements of the woman’s vagina and uterus, some of the sperm cells manage to swim through the cervix to the uterus. Many get no further and either die of exhaustion or the warmth of the uterus. Only the strongest sperm pass through the uterus to the Fallopian tubes. And only half of these enter the correct tube where an egg may be waiting. Eventually a few hundred sperm approach the egg. An egg is fertilized when one sperm enters it.

17. If fertilization occurs…
Fertilization occurs in the Fallopian tube.
One sperm penetrates the egg’s protective outer layer. Once this happens, a chemical reaction occurs that makes it impossible for any other sperm to penetrate the egg.
The fertilized egg becomes a dividing ball of cells which implants into the uterine wall.

18. Fertilization and Implantation
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

19. Embryo development
Male and female embryos are identical for the first 6 weeks.
After the 7th week of development, the embryo’s reproductive organs produce sex hormones that make it either male or female. The male testes produces androgens and the female ovaries produce estrogens.

20. What triggers a female to become female is not so much the presence of estrogen as the absence of testosterone. Without testosterone, both male and female embryos would develop as female.
The mother produces so much estrogen that diffuses across the placenta, that the amount the embryo produces is insignificant.
The testosterone produced by the male embryo is the essential difference between males and females. Male and female reproductive organs develop from the same embryonic tissue.

21. Testicular feminization syndrome – Y chromosome present, but externally female due to either lack of testosterone production, or problem with testosterone receptor cells.
Female androgenital syndrome – Genetic female with male characteristics (enlarged clitoris).

22. 6 week old embryo

23. 7 week embryo
12 weeks weeks Full term

24. 12 weeks

25. Fetus After 8 weeks of development, the embryo is called a fetus.
On average it takes 9 months (40 weeks after the last menstrual period) for a fetus to become full term. Babies born before 8 months (37 weeks after the last menstrual period) are premature.

26. Fetuses older than 23 weeks can be viable

27. 20 weeks

28. 28 weeks
36 weeks

29. 40 weeks – Full term

31. After birth, the testes and ovaries continue to produce hormones that influence the development of reproductive organs.
Testes and ovaries produce gametes after puberty (starts between ages 9 – 15).

32. Secondary sexual characteristics in females: development of breasts,
widening of hips and an increase in body fat.

33. Secondary sexual characteristics in males:
deepening of the voice, broadening of the chest and shoulders
and development of facial and body hair

34. If fertilization does not occur…
The egg dies and the lining of the uterus is shed, resulting in a period (menstruation/bleeding)

35. Mythical Methods of Birth Control
OR, THE ONES THAT DON’T WORK
Withdrawal (a small amount of semen can escape from the penis before ejaculation, plus you have to trust that he will pay attention and “pull out”)
Rhythm (counting days and only having sex when it is “safe” – you really need to have a regular cycle and know your body)
Intercourse during menstruation (if you have a short or erratic cycle you can be ovulating during your period)
The First Time (yes, virgins CAN get pregnant)
Standing up immediately after sex
Douching with Pepsi or Coke
Praying