1. The Endocrine System & The Reproductive System
Ms. Edwards

2. The Endocrine System
Produces chemicals that control many of the body’s daily activities.
Regulates long-term changes like growth and development.
Made up of glands that do not connect to tubes
Endocrine glands- produce and release chemicals directly into the blood stream.

3. Hormones
Hormones- chemical messengers that are made by endocrine glands.
Hormones direct the activities of different tissues and organs.
Carried throughout the body in the bloodstream.
Can act rapidly or be long-lasting
Target cells- cells that recognize a hormone’s chemical structure.

4. Glands of the Endocrine System

5. Glands of the Endocrine System

6. Functions of Endocrine Glands
Endocrine glands: hypothalamus, pituitary, thyroid, parathyroid, adrenal, thymus, pancreas.
Hypothalamus
Tiny part of the brain that links the nervous and endocrine systems.
Controls sleep, hunger, and other basic body processes.
Maintains homeostasis by sending nerve impulses and hormones.

7. Pituitary Gland Below hypothalamus, about the size of a pea
Communicates with hypothalamus to control many body activities.
Also releases hormones that turn other endocrine glands “off” and “on.”
Pituitary hormones control growth and water uptake in kidneys.

8. The Endocrine System

9. Negative Feedback
Type of regulation where the system is turned off by the condition it produces.
Endocrine system uses negative feedback to maintain homeostasis.
Through negative feedback, when the amount of a hormone reaches a certain level, the endocrine system tells the body to stop the release of that hormone.
Similar to the thermostat in your house.

10. Negative
Feedback
The Endocrine System

11. Sexual Reproduction
Ovaries and Testes control many bodily changes as a child matures.
Egg- female sex cell
Sperm- male sex cell
Fertilization- joining of sperm and egg
Zygote- fertilized egg

12. Sexual Reproduction Sex cells contain chromosomes, which contain DNA
Every cell in the body that has a nucleus has 46 chromosomes.
Sex cells have half the number of chromosomes, 23.
During fertilization, egg (23 chrom.) + sperm (23 chrom). = zygote (46 chrom.)

13. Male Reproductive System
Functions: to produce sperm and the hormone testosterone.
Testes- organs where sperm are produced.
Testosterone- hormone that controls the development of physical traits of men.
Scrotum- external pouch of skin that houses the testes. Keeps the testes (and the sperm) 2-3 degrees cooler than the body.

14. Sperm Production Begins in males during the teenage years.
Composed of a head (contains DNA) and tail (allows for movement).
Semen- mixture of sperm cells and fluids. One drop has 5-10 million sperm!
Urethra- tube through which semen exits the body.
Penis- male sexual organ

15. The Male and Female Reproductive Systems

16. Female Reproductive System
Functions: produce eggs, nourish baby until birth.
Ovaries- female reproductive organs.
Estrogen- hormone that controls development of female traits.
Fallopian tubes- also called oviducts, passageways for eggs from ovaries to uterus. Fertilization usually happens here.

17. Female Reproductive System
Uterus- hollow, muscular organ about the size of a pear.
Fertilized egg implants and grows in the uterus.
Vagina- muscular passageway leading to the outside of the body. Also the passageway through which a baby leaves the mother’s body.

18. The Male and Female Reproductive Systems

19. Menstrual Cycle
The monthly cycle of changes that occur in the female reproductive system.
Starts during female’s teenage years.
Ovaries contain about 400,000 undeveloped eggs, but only about 500 will leave the body.
During the menstrual cycle, an egg develops in an ovary and the uterus prepares for the arrival of an embryo.

20. Menstrual Cycle
Egg starts to mature in ovaries, lining of uterus thickens
Ovulation- the process of an egg leaving the ovaries.
Egg can only be fertilized during ovulation.
If egg is not fertilized, it breaks down and is shed, along with the lining of the uterus, from the body during menstruation.
Menstruation lasts about 6 days, at the same time a new egg is maturing in the ovaries.

21. The Male and Female Reproductive Systems
Menstrual Cycle

22. Human Life Cycle Before birth zygote  embryo  fetus
zygote is no larger than a period.
embryo- until 8th week of development
fetus- 9th week until birth
Amniotic sac- fluid-filled, protects baby
Placenta- link between mother and baby. Oxygen, nutrients, and wastes are exchanged here.
Umbilical cord- between fetus and placenta, another link between mother and baby.

23. 4 wks- heart beat, eyes, ears 24 wks- fingerprints, complete eye
Zygote
2 days
24 wks- fingerprints, complete eye
8 wks- heart chambers

24. The Human
Life Cycle

25. Birth 3 stages: labor, delivery, afterbirth
Labor- muscular contractions of uterus
cervix dilates
may last 2 to 20 hours
Delivery- baby is pushed out of mother’s body
baby is connected to placenta by umbilical cord
Afterbirth- 15 minutes after delivery
placenta is pushed out of body

26. The Human
Life Cycle

27. Growth and Development
Changes take place between infancy and adulthood include physical, mental, and emotional changes.
Infancy
First 2 years of life
Large head, small body, rapid growth
Gain coordination, begin to walk
Begin to speak, follow directions, and play

28. Childhood Adolescence
Ages 2 to about 12
Increase mental abilities, language skills
Adolescence
Stage when children physically and mentally become adults.
Somewhere between ages
Puberty- period of sexual development

29. Adulthood Ages 18 to death
Aging- begins about at 30. Skin wrinkles, eyesight weakens
Aging becomes most noticeable around ages
Menstruation stops, sperm count lowers.