1. OR YOUR LIFE AS YOU KNOW IT
PUBERTY
OR YOUR LIFE AS YOU KNOW IT

2. Reproduction Purpose of life… Survival
Reproduction to ensure the continuation of species

3. Stages of Human Development
Sexual reproduction requires the fertilization of an ovum (from the mother) by a spermatozoan (from the father)
Fertilization is the fusion of an ovum and a spermatozoa
Genetic material becomes fused and produces a cell made of 23 pairs of chromosomes for a totral of 46(half from mom and half from dad)
This cell is called a Zygote

4. Life Stage
Approx. Age
Stages during Pregnancy
Zygote
Fertilization to 2 weeks
Embryo
2 to 9 weeks
Fetus
9 weeks to birth
Stages after Birth
Baby
Birth to 2 years
Early Childhood
2 to 6 years
Childhood
6 to 10 years
Adolescence
10 to 18 years
Adulthood
18 to 70 years
Old Age
70 years to death

5. Puberty The reproductive system becomes functional during adolescence.
Puberty is when the body undergoes physical, anatomical and psychological changes to prepare for the ability to reproduce.
Generally, occurs between the ages of 10 and 14 years old
The beginning of puberty is marked by an increase of hormones.
Sperm and ova production begins at the onset of PUBERTY

6. Puberty continued…
Hormones are chemical messengers, transported by the blood and control the activity of one or more organs
They are secreted (made) by glands, released into the bloodstream and stimulate activity in an organ or tissue somewhere else in the body

7. More on Puberty!
Hormones and the glands that make them are part of endocrine system.
The endocrine system regulates the body’s activities, growth, response to stress, reproduction and regulation of metabolism

8. Glands
Puberty is triggered by two hormones secreted by the pituitary gland
Pituitary gland: it is the size of a grape and found at the base of the brain.
The two hormones produced are FSH (follicle- stimulating hormone) and LH (luteinizing hormone).
These stimulate the maturation of the ova or the production of spermatozoa.

9. Glands continued…
In women: FSH and LH also stimulate the ovaries to produce the female sex hormones: estrogens and progesterone
In men: FSH and LH stimulate the testicles to produce the male sex hormone, testosterone.
This causes several physical and psychological changes: the primary and secondary sexual characteristics

10. Effect of hormones on the Body TB p. 142, fig. 5.22
OVARIES
-Stimulate maturity of ova
-Stimulate production of female sex hormones
Estrogens and Progesterone
FSH and LH
ORGANISM
-Primary sexual characteristics develop
-Secondary sexual characteristics develop
Pituitary Gland
TESTICLES
-Stimulate production of spermatozoa
-Stimulate production of male sex hormones
FSH and LH
Testosterone

11. Sexual Characteristics in Females TB p. 142, fig. 5.23
Types of changes
Observable phenomena
Physiological
(primary)
Menstrual Cycle begins
Genital organs mature
Anatomical
(Secondary)
Silhouette changes (fatty tissue accumulates(breasts and hips)
Pelvis widens
Underarm and Pubic hair appears
Psychological
Physical attraction
Libido
Need for autonomy
Sense of responsibility to reproduce

12. Sexual Characteristics in Males TB p. 143, fig 5.24
Types of changes
Observable phenomena
Physiological
(primary)
Testicles mature and lower
Anatomical
(Secondary)
Skeletal & muscle growth
Bone density increases
Larynx enlarges
Facial, Underarm and Pubic hair appears. General hairiness increases
Psychological
Physical attraction
Libido
Need for autonomy

13. Male Hormones
In puberty, the release of FSH stimulates spermatogenesis (the production of sperm)
The cells that line the testicles undergo meiosis to produce spermatozoa (sperm)
Since these cells are under constant renewal, the testicles can produce roughly 120 million sperm per day.

15. The travel of Sperm:
Seminiferous Tubules–Epididymis -Vas deferens- Ejaculatory duct -Urethra

16. Erection and Ejaculation
Once formed the sperm enter the vas deferens for collection until they are expelled through the urethra
The penis contains elastic spongy tissue that fills with blood during sexual arousal. This causes swelling of tissues and causes an erection.

17. More on Erection and Ejaculation
With stimulation, the sperm is then pushed down towards the urethra, mixes with the seminal fluid to create semen until the resulting pressure causes ejaculation (the expulsion of semen by the penis)
The acid in urine kills sperm, so it is important that the two do not mix
So during an erection, two ring-shaped muscles contract, making it impossible to urinate

18. FYI
Need erection to ejaculate, but do not need to ejaculate if an erection occurs.
There is approximately 350 million sperm/ejaculation.
Sperm can live in a woman for 24 to 72 hours

19. Hormones and the Female Body
Estrogen
Involved in the menstrual cycle (the changing of the endometrium)
Affects body shape and growth
Breasts, wider hips, body hair
Progesterone
Prepares the uterus for implantation
Causes the mammary glands (produce milk) to develop in pregnant women

20. Oogenesis
Between 3 and 7 months of fetal life, cells near surface of ovaries undergo mitosis
They enter meiosis, but stop halfway through (meiosis I)
They are called primary oocytes and are enveloped in protective cells called follicles.
Starting at puberty, one oocyte per menstrual cycle can reach maturity and develop into an ovum.
This process is called oogenesis (the production of ovum through meiosis)

21. TB p. 144
At puberty: there are about oocytes capable of becoming ova.
About 400 of these oocytes will become ova throughout a female’s lifetime.
To be considered fertile, a woman must be able to produce mature ova.

22. Series of changes that ovarian follicles undergo every month.
Ovarian Cycle: TB p. 145
Series of changes that ovarian follicles undergo every month.
Process by which a single ovarian follicle matures in order to release an ovum and changes into a corpus luteum to encourage the implantation of the ovum in the uterus.

23. Ovarian Follicle (Days 1-13)
FSH stimulates maturation of ovarian follicle containing oocyte.
Follicle releases more estrogen, which stimulates release of more FSH and LH
Estrogen thickens the lining of uterus

24. Ovulation (14th day)
Increase in LH and FSH causes the ovarian follicle to burst and releases the oocyte into the fallopian tube.

26. Corpus Luteum (days 15-28)
LH promotes the healing of the ovarian follicle and transforms the follicle into the corpus luteum.
The corpus luteum produces progesterone to prepare the body to receive a fertilized ovum and stops production of FSH and LH so more ova won’t mature and be released.
Thickens the uterine lining (endometrium).

27. Fertilization or not
If ovum is fertilized, it will then implant in the uterus (The woman becomes pregnant).
If ovum is not fertilized, menstruation starts. Uterine lining and unfertilized ovum are expelled, and corpus luteum disintegrates, causing progesterone production to decrease. (day 1-5 of menstrual cycle)

28. Ovum
Ovarian follicles
Haploid oocyte
Endometrium

29. The Menstrual Cycle (TB p. 147)
The menstrual cycle represents all the periodic changes that take place in the uterus.
Phase
Event
Hormones
Menstrual Phase (days 1 to 5)
Bleeding occurs- expulsion of the uterine lining and unfertilized ovum
Progesterone production decreases
Proliferation Phase (days 6 to 14)
Lining of the uterus begins to thicken
Production of estrogen increases
Secretory Phase (days 15 to 28)
Lining of the uterus continues to thicken
Progesterone production increases

30. p. 148
The ovarian cycle and the menstrual cycle are controlled by the hormonal cycle!!