Reproductive System Ch 19

General Functions of reproductive system.  Produce and nurture sex cells  Gametes  Sperm  Eggs  Transport them to sites of fertilization.

Meiosis - Overview  Creates sex cells with half the number of chromosomes as normal cells.  Haploid  Two divisions  Males: Spermatogenesis  Females: Oogenesis

Meiosis - Sperm

Meiosis - Egg

Locate and describe the general functions of each part of the male reproductive system  testes  epididymis  scrotum  bulbourethral gland  prostate gland  seminal vesicle  ductus deferens  urethra  corpus cavernosum  corpus spongiosum  penis  glans penis

Outline the process of spermatogenesis.  spermatogenesis – formation of sperm  Spermatogenic cells (spermatogonia) formed in the testes (46 chromosomes)  At puberty when testosterone production resumes...  Form primary spermatocytes  Meiosis takes place  First division makes secondary spermatocytes  Second division makes spermatids (23 chromosomes)

Outline the process of spermatogenesis.  When spermatids reach the epididymis, they are non- motile.  By the time they are pushed through the epididymis, they have matured into sperm cells and can move independently.

Describe semen production and exit from the body.  Production takes place in four parts:  Testes – sperm  Seminal vesicles  Prostate gland  Bulbourethral glands  Exits by ejaculation through the penis.

Vocabulary  spermatogenesis  spermatogonia  spermatid

Explain how hormones control the activities of the male reproductive organs…  GnRH – released in hypothalamus  Pituitary gland– secretes gonadotropins  In males, these are androgens  LH (leutinizing hormone)  FSH (follicle-stimulating hormone)  Testosterone

…and the development of male secondary sex characteristics  Body hair  Lower voice  Thickening of skin  Increased muscular growth  Thickening/strengthening of bones

More about hormones  There’s a negative feedback system that controls the amount of testosterone released.

Locate and describe the general functions of each part of the female reproductive system  Ovaries  Uterine tube  Uterus  Cervix  Vagina  Clitoris  Endometrium  Myometrium  Perimetrium

Outline the process of oogenesis.  What is oogenesis?  Primordial follicles are formed during fetal development. These are also calle primary oocytes.  At puberty, primary oocytes continue meiosis.  Cytoplam is distributed unevenly, so only one secondary oocyte is formed.

Meiosis - Egg

Outline the process of oogenesis.  Secondary oocyte is released from the ovary – Ovulation  Uterine tubes – fertilization  IF it’s fertilized, it will go through Meiosis II and become a zygote.  Only have about a day!  Uterus – receives embryo and sustains development  Three layers  Endometrium  Myometrium  Perimetrium  Vagina – birthing purposes and receives sperm

Explain how hormones control the activities of the female reproductive organs...  Puberty – FSH is released and ovaries enlarge  LH triggers ovulation.  Two main types of female hormones – estrogens and progesterones.  Ovaries are the major source of estrogens.  They stimulate enlargement of vagina, uterus, uterine tubes, and ovaries.  They develop secondary sex characteristics.

...and the development of the female secondary sex characteristics.  Development of breasts and ductile system of mammary glands  Increased deposition of adipose tissue generall, and specifically in the breasts, thighs, and buttocks.  Increased blood vessels in skin.  Females also have a low androgen concentration that stimulates hair growth in pubic and axillary regions.

Vocabulary  Spermatogenesis  Spermatid  Spermatogonia  Oogenesis  Oocyte  Ovulation  Androgen  Testosterone  Estrogen  Progesterone

Describe the major events of the reproductive cycle.  FSH and LH released from pituitary gland.  FSH causes follicle to become primary oocyte.  Follicular cells secrete estrogen causing endometrium to thicken.  More LH from pituitary gland stimulates ovulation.  More estrogen and progesterone is released – waiting for fertilization.

Describe the major events of the reproductive cycle.  If fertilization does not occur, estrogen and progesterone stop – causes endometrium to quit building.  Uterine lining disintegrates and sloughs off.  Cylce repeats with LH and FSH being released from pituitary.