1. The Male And Female
Reproductive
Systems
(Let’s Keep it clean,
people!)
2. Sex Cell Production
In most animals cells are produced in 2
ways:
Mitosis – cell reproduction; asexual
Meiosis – sex cell production; produces 4
gametes that are genetically non-identical
3. Variations
Mainly during Meiosis:
– Crossing Over – recombination of genes
– Independent assortment of chromosomes
– Mutation – produces new characteristics that
can be passed – only in sex cells
5. Parts to the System
PARTS AND FUNCTIONS:
In Scrotum
– Testes – produce sperm in tightly coiled tubes:
Seminiferous Tubules - meiosis
– Interstitial Cells – in between seminiferous tubules:
produce TESTOSTERONE
– Epididymis – stores maturing sperm
Tubes
– Vas Deferens – carries sperm from epididymis to urethra.
– Urethra – in penis. Exit point for sperm
Food and Travel -
– Seminal Vesicles – releases “sugars”
– Prostate Gland – releases alkaline solution
– Cowper’s Gland – fluid to lubricate urethra, flush out urine
Hormones:
– GnRH stimulates production of FSH and LH(ICSH)
6. HORMONES and NEGATIVE
FEEDBACK
GnRH stimulates the pituitary to release LH and FSH
LH stimulates the production of testosterone.
FSH works on “sartoli’ cells to provide nourishment for
sperm.
Sartoli cells produce a hormone “inhibin” which inhibits
the pituitary and hypothalamus resulting in lower levels
of FSH
HIGH LEVELS OF TESTOSTERONE PRODUCES NEGATIVE
FEEDBACK ON THE PITUITARY GLAND DECREASING
LEVELS OF LH (ICRH).
15. Parts and Functions
Parts and Functions:
– Ovaries –eggs produced in cavities:
FOLLICLES. Released at Ovulation.
– Oviduct – passageway for egg. SITE of
fertilization
– Uterus – muscular, pear shaped. Holds
developing organism
– Cervix – lower end of uterus
– Vagina – entry point for sperm. Exit
point for Fetus. Birth Canal.
19. General: Hormones from Glands control cycle:
– Hypothalamus(in brain): GnRH…….secreted to
Pituitary:
FSH –
– Stimulates growth of egg
– Stimulates secretion of estrogen
LH –
– Stimulates ovulation
– Stimulates empty follicle to convert to corpus luteum
– Stimulates corpus luteum to secrete estrogen and progesterone
– Ovary
Estrogen
– Stimulates repair and growth of the uterus
Progesterone
– Stimulates and maintains growth of the uterine lining
20. Stages of Menstruation
Menstruation – (5 days)
– Egg not fertilized
– Inner Uterine lining (endometrium) breaks down and passes out of the
vagina(with the egg).
Follicle Stage – (9 days)
– FSH production increases
– Follicles in ovaries develop. (oocyte)
– Estrogen secreted to heal, repair, and thicken endometrium with blood
vessels
Ovulation – Middle of Cycle--- 1 day
– High level of estrogen decreases FSH and stimulates secretion of LH
– High level of LH – Follicle ruptures and egg is released.
Corpus Luteum Stage – ( 13 days)
– Corpus Luteum is produced in ruptured follicle…stimulates progesterone
production.
– Maintains endometrial growth.
– Egg implantation if fertilization takes place
21.
22. Hormones: – and + feedback
ESTROGEN
– Negative feedback on pituitary to block FSH
release.
– Positive feedback on pituitary to signal release
of LH
Progesterone
– Negative feedback to block FSH release
– Negative feedback to block LH release
24. Copulation vs. Fertilization
Copulation –
– Coupling
– Physical contact between male and female
needed for sperm to move from male to
female: intercourse
Fertilization
– Fusion of male and female nuclei to produce a
zygote
28. After Fertilization
MALE AND FEMALE GAMETES LINE UP AT THE
EQUATOR
PREPARE FOR 1ST MITOTIC DIVISION
NO CELL GROWTH
“CLEAVAGE DIVISION”
AFTER SEVERAL DIVISIONS:
– BALL OF CELLS = MORULA
REACHES UTERUS IN APPX. 4 DAYS
Implantation – into wall of the
endometrium
35. Parturition
Prostglandin – hormone- like substances; help to
stimulate contractions.
Oxytocin – hormone – released by pituitary gland
POSITIVE FEEDBACK SYSTEM
Parturition – process of delivering the fetus and
placenta. Includes
– Labour – dilation of cervix, vagina
– Expulsion – Birth
– Afterbirth – delivery of placenta
40. Amniocentesis and CVS
Amniocentesis –
•inserting a needle
into the uterus
through a very
small incision in
the abdomen
• needle takes
amniotic fluid –
contains embryonic
cells.
• used to detect
genetic defects
41. In vitro fertilization
Approximately 1 of 6 couples
Used mainly as a way to overcome a
female infertility (physiological)
issue: blocked oviducts or timely
ovulation
Cannot be used in the case of low
sperm count.
43. IVF Process
1. Drug given to stop menstrual cycle.
2. Large doses of FSH given – 2 weeks
3. HCG given 48 hours before collection – matures eggs
4. Man provides semen.
5. Eggs extracted through the vagina
6. Each egg is mixed with some sperm in a petri dish –
incubated 24 hours
7. Check to see if fertilized!
8. Embryo’s selected and placed in uterus
9. Wait approximately 2 to 3 weeks and take pregnancy
test – implantation
10. Scan as normal for any developmental issues
44. Ethical Issues of IVF
Pro: Against:
Environmental infertility Fate of extra embryos?
will not affect offspring Long term storage of
Not developed – no pain embryos – stem cells?
to embryo Multi pregnancy places
Genetic screening before stress on family
transferring Expensive
Parents have strong High rate of failure
desire for child religious
46. Permanent Contraception
– Female sterilization (tubal
ligation)
– Vasectomy
Mechanical
– Diaphragm
– Intra Uterine Device
– Condom
Chemical
– Spermicide
– Birth control pill*
– “day-after” pill*
Other
– Rhythm - cycle
– Withdrawal before ejaculation
– Abortion
47. Birth Control and “Day After” Pill
Birth Control – synthetic estrogens and
progesterone(s) that prevent release of
GnRH ---- FSH & LH
Morning After –
– Blocks progesterone receptors in uterus.
– altering the lining of the womb, so a fertilized
egg can't embed itself there.
48. Ethics of Family Planning and
Contraception
Pro Against
Can choose to get Most not 100%
pregnant effective
A few methods 100% Promotes promiscuity
effective Abstinence difficult in
Population control marriage
Irreversible
50. Puberty in Males
Marked by a sharp increase in
testosterone production:
Production of sperm: primary!!
Secondary:
Enlargement of penis and testes
Growth of body hair: face, underarm, pubic
Deepening of voice
Broad shoulders - muscle
51. Puberty in Females
Marked by the onset of the menstrual
cycle
Egg production: primary!
Secondary:
– Breast Development
– Body curve – placement of tissue
– Hair: underarm, pubic
52. Developmental Terms to Know
Zygote – newly fertilized egg
Cleavage – first series of cell divisions; multiple
rounds of mitosis
Morula – 4-16 cells; solid ball of cells
Blastomere – cells of the morula
Blastocyst – after 5 days; develops a hollow
cavity
Implantation – blastocyst penetrates
endometrium
Endometrium – uterine lining
Gestation – pregnancy, 40 weeks
55. Implantation
Blastocyst contains fluid filled cavity called
blastocoel.
Blastocyst:
– Two parts:
– Inner mass cells - will develop into the embryo
– Trophoblast – releases HCG hormone; digests a hole into
the endometrium
HCG helps to maintain progesterone levels
during pregnancy. Pregnancy test.