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Human Reproduction
Chapter 23

 

I. Male Reproductive System

A. Testes - are male gonads

1. Contain seminiferous tubules that produce sperm
-extremely sensitive to heat energy

2. Secrete testosterone(hormone) that are responsible for male secondary sex characteristics

3. Epididymus - stores sperm

4. Vas Deferens - a tube from each testis in which sperm leave the epididymus into the lower abdomen & into the urethra

B. Scrotum - sac in which Testes are located

1. located outside the body in order to keep temperature lower than body heat temperature for production of sperm

C. Urethra - 2 vas deferens join at the urethra & then into the penis

D. Seminal vesicles - solution of sugar(fructose)

E. Prostate gland - secrete alkaline solution

F. Cowper's gland - lubricating fluid

II. Female Reproductive System

A. Ovaries - female gonads

1. Each contains about 200,000 follicles (tiny egg sacs) which contain an immature egg
2. Secrete estrogen (hormones) responsible for secondary sex characteristics

B. Fallopian tubes or Oviduct - leads from each ovary (neither in contact)

1. site for fertilization
2. eggs are not motile; they get pushed along the fallopian tube by cilia

C. Uterus or Womb - site where the egg implants it's self if fertilized

D. Vagina - birth canal, leads to the outside of the body

E. Cervix - dilates to 10 cm during labor

III. Menstrual Cycle - mature egg develops & is released approximately 28 days

A. Stages:

1. Follicle Stage - FHS(follicle stimulating hormone) secreted by the pituitary causes several follicles to develop in the ovaries. As a follicle develops, it releases estrogen which stimulates the uterine lining to thichen with blood (10-14 days).

2. Ovulation - FHS decreases, LH (lutenizing hormone) from the pitutary gland increases which causes a mature egg to release from the follicle & from the ovary. Occurs in the middle of the cycle (14 day).

3. Corpus Luteum Stage (yellow body stage) - After ovulation the follicle fills with cells forming the corpus luteum. Corpus luteum secretes progesterone which maintains the continued growth of the uterin lining.

4. Menstration - if fertilization does not occur, secretion of the LH decreases & the corpus luteum breaks down. Progesterone levels decrease & the lining of the uterus breaks down & is given off. Lasts 3-5 days.

VI. Implantation, Developement

A. After fertilization, the zygote undergoes cleavage & becomes an embryo. The embryo arrive in the uterus about 5-10 days after fertilization. The embryo implants (blastula stage) in the uterus. [now woman is pregnant]

B. Placenta - a temporary organ develops in the uterus to nourish the embryo.

C. Umbilical Cord - attaches embryo to the placenta

D. Amnion - embryo develops inside the amnion & amnionic fluid.

E. Gestation Period - length of pregnancy.

F. Birth

1. Multiple Births

a. Identical - formed when 1 egg is fertilized and splits during the first division.

b. Fraternal - formed when 2 eggs are fertilized at the same time.

G. Menopause - The perminant cessation of the menstrual cycle which occurs approximately between 45-50 years of age.

 

Play Jeopady (Power Point) on Animal Development

Biology Trivia

1. What determines the sex of the Philippine crocodile? answer

return to Mr. Via's syllabus