1. Hormones & Reproduction

2. What are hormones?
Chemicals released in one part of the body that travel through the bloodstream and affect the activities of target cells.

3. Where are hormones made?
Hormones are made in endocrine glands. The glands release the hormones directly into the bloodstream.
Hormones travel to their site of action to perform their function.
Endocrine glands are scattered throughout the body.

4. Major glands of the Endocrine System
Glands can secrete one or more hormones each with different functions
Lets look at some examples to demonstrate the diversity of functions

5. Major glands of the Endocrine System
Hypothalamus
Portion of the brain that connects the nervous system with the endocrine system
Controls the secretions of the pituitary gland

6. Major glands of the Endocrine System
Pituitary Gland
Secretes 9 hormones!
Some are involved in production of sperm and egg
Others are involved in water absorption

7. Major glands of the Endocrine System
Parathyroids
Secretes Parathyroid Hormone (PTH) to regulate calcium levels in the blood

8. Major glands of the Endocrine System
Thyroid
Regulates the body’s metabolism

9. Major glands of the Endocrine System
Adrenals
“Fight or flight” response
Release of epinephrine & norephinephine

10. Major glands of the Endocrine System
Pancreas
An organ made up of two types of glands
Exocrine gland- releases digestive enzymes into stomach
Endocrine gland-releases the hormones insulin and glucagon into bloodstream

11. Major glands of the Endocrine System
Testes
Produce testosterone
Ovaries
Produce estrogen & progesterone

12. Although the testes and ovaries are called the “reproductive glands”, the human body relies on hormones from the pituitary gland to help regulate the reproductive process.

13. How do humans reproduce?
By the union of a male and a female gamete.
Gametes are produced in the sex organs.
Males produce sperm in the testes.
Females produce eggs in the ovaries.

14. Let’s talk reproduction!!!
Are you born with the capability to reproduce?
What has to happen first?
No!
PUBERTY!

15. MALE FEMALE ONSET OF PUBERTY
Two hormones released from the pituitary gland causes the onset of puberty.
Testes begin making testosterone.
Results in development of male characteristics
Ovaries begin making estrogen.
Results in the development of female characteristics.

16. MALE FEMALE GAMETE PRODUCTION
Follicle stimulating hormone (FSH) and testosterone stimulates the production of sperm.
Sperm are haploid.

17. MALE FEMALE GAMETE PRODUCTION
Born with all the egg cells they will ever produce.
Eggs are haploid.
FSH causes maturation of the egg.
Progesterone signals for a thickening of the uterus lining.
Follicle stimulating hormone (FSH) and testosterone stimulates the production of sperm.
Sperm are haploid.

18. Now we have our male and female gametes, what happens next?
FERTILIZATION
When the sperm is deposited in the female reproductive system, the sperm swim until they encounter an egg, or until they die.
If sperm does not reach the egg, fertilization does not occur.
If the egg is not fertilized within hours, it dies.

19. Is this sexual or asexual reproduction?
Why?
HAPLOID + HAPLOID = DIPLOID

20. Sexual Reproduction- NOT JUST FOR HUMANS
Aquatic animals release male and female gametes near one another in the water, where fertilization occurs.
This is called external fertilization because the egg is fertilized outside the female body.

21. Sexual Reproduction
Most land animals reproduce sexually by internal fertilization, the union of sperm and egg within the female’s body.
Once fertilization occurs, developing eggs must be kept moist. How?
Shells protect them from drying out! OR
Eggs develop internally.