Chapter 28

The Reproductive System

100 keys, pg. 1038

“Meiosis produces gametes that contain half the number of chromosomes found in somatic cells. For each cell entering meiosis, the testes produce four spermatozoa, whereas the ovaries produce a single ovum.”

male anatomyand hormones

female anatomyand hormones

female cycles

fertility/contraception/birth control

Hermes

male

site of spermatogenesisseminiferous tubules in

testes

begins after puberty

continues throughout life

male

spermatogonia divide mitotically

begins meiosis Iprophase Imetaphase Ianaphase Itelophase I with cytokinesis

primaryspematocyte

2 secondaryspermatocytes

male

2 secondaryspermatocytes

begins meiosis IIprophase IImetaphase IIanaphase IItelophase II with cytokinesis

4 spermatids

male

4 spermatids

4 spermatozoa

spermiogenesis

fig 28-8

fig 28-7

male hormones

LH acts on interstitial cells

testosterone

FSH acts on Sertoli cells

promotesspermatogenesis

testosterone regulates

spermatogenesis2º sex. char.

100 keys, pg. 1039

“Spermatogenesis begins at puberty and continues until relatively late in life (past age 70). It is a continuous process, and all stages of meiosis can be observed within the seminiferous tubule.”

(it takes over 2 months from beginning to end)

Aphrodites

female

site of oogenesiswithin follicles in the ovary

begins before birth arrested until later

continues cyclically from puberty to ~50

menstrualcycle

menopause

female

oogonia divide mitotically

begins meiosis Iprophase I

arrested here before birth

primaryoocyte

metaphase Ianaphase Itelophase I with cytokinesis

2º oocyte + polar body

female

secondaryoocyte

begins meiosis IIprophase IImetaphase II (another arrest)anaphase IItelophase II with cytokinesis

1 ovum+ 2nd polarbody

fig. 28-15

female hormones

LH luteinizing hormone

FSH follicle stimulating hormonepromotes

maturation of follicles

progesterone

promotes developmentof corpus luteum

estrogen rebuild endometrium2º sex. char.

prepare/maintain endometrium

100 keys, pg. 1052

“Oogenesis begins during embryonic development, and primary oocyte production is completed before birth. Each month after puberty, the ovarian cycle produces one or more secondary oocytes form the pre-existing population of primary oocytes. The number of variable and responsive primary oocytes declines markedly over time, until the ovarian cycles end at age 45-55.”

the menstrual cycle

proliferatoryphase

day 0

menses secretoryphase

fig. 28-26e

2814

the menstrual cycleday 0

fig. 28-26b, c

2814

luteal phase

follicular phase

the menstrual cycleday 0

fig. 28-26c, d

2814 luteal phase

follicular phase

the menstrual cycleday 0

fig. 28-26d, e

2814 luteal phase

follicular phase

the menstrual cycleday 0 2814

fig. 28-26

luteal phase

follicular phase

fig. 29-2 hCG (human chorionic gonadotropin)

the menstrual cycleday 0 2814

ovu

lati

on

fert

iliza

tion

embryoimplants

hCG

fig. 28-26

100 keys, pg. 1065

“Cyclic changes in FSH and LH levels are responsible for the maintenance of the ovarian cycle; the hormones produced by the ovaries in turn regulate the uterine cycle. Inadequate hormone levels, inappropriate responses to circulating hormones, or poor coordination and timing of hormone production or secondary oocyte release will reduce or eliminate the chances of pregnancy .”

100 keys, pg. 1067

“Sex hormones have widespread effects on the body. They affect brain development, and behavioral drives, muscle mass, bone mass and density, body proportions, and the patterns of hair and body fat distribution. As aging occurs, reductions in sex hormone levels affect appearance, strength, and a variety of physiological functions.”

FERTILIZED EGG(ZYGOTE)

BLASTULA

GASTRULA

NEURULA

FETUS

NEWBORN

SEXUALMATURITY

cleavage

gastrulation

neurulation

organogenesis

parturition

growth anddifferentiation

gametogenesis

senescence

EGG / SPERM d. 5

d. 16

w. 8

w. 38

w. 750

hollowball

threelayers

3.5 weeks:brain formingheart beating

HumanLife

“Cycle”w. 4321

R.I.P.

Unable to get pregnantafter trying for one year

age decreased fertility with age

anatomical blockage scar tissue (STD)

low sperm count temperature?environment?

infertility

assisted reproduction

assisted gamete production (hormones)

artificial insemination

In vitro fertilization…

Assisted reproduction

assisted gamete production hormones

artificial insemination

In vitro fertilization…

surrogate pregnancy legal ??

adoption

GIFT, ZIFT

BABI

population growth control

Population control

Birth control

operating at the level of the population

“operate by preventing births one at a time”

population growth control

Birth control

before fertilization (conception)

after fertilization

aka., contraception

Timeline (this is your life):

conception birth death

egg

sperm

1st 2nd 3rd

contraception

birth control

Contraception

Abstinence

Avoid sexual activity and you won’t get pregnant

(or contract STD’s)

Behavior

(complete)

Contraception

Abstinence

Avoid sexual activity around the time of ovulation…

Behavior

Rhythm

(complete)

(partial)

Contraception

Abstinence

Coitus interputus

Behavior

Withdrawl

(complete)

(partial)Rhythm

Contraception

Chemical:

spermicidesthe “Pill”

Contraception

Barriers:

condomsdiaphragm

spermicides

Contraception

Surgery:

vasectomy

tubal

egg

sperm

fertilization(conception)

birth

contraceptionbirth

control

timeline-your life…

Birth Control(not contraception)

Works after conception

IUD prevent implant.

Ru 486 cause menses

Abortion remove embryo/fetus

All methods of contraception are birth control…

but not all methods of birth control prevent conception.

Abortion “a highly charged issue”

Roe v. Wade (1973, Supreme Court)

States rights to regulate/prohibit abortion

pictures of embryos and fetuses

Roe v. Wade (1973, Supreme Court)

Even after viability (the ability of the fetus to live outside the uterus on its own) a mother can still have an abortion

When does life begin?

life: it doesn’t begin…

When does a new human life begin?

When does a embryo/fetus/baby become a person with rights?

Japan

West Africa

Formosa

Truk

baby is not a person until its first cry

baby is not a person until it’s a week old

baby named when 2-3 years oldbaby with defects were drowned or burned

Roe v. Wade (1973, Supreme Court)

1st Trimester

2nd Trimester

3rd Trimester

States cannot regulate;Decision between woman and doctor

States can regulate (who, where…),but cannot prohibit

States still cannot prohibit if the motherslife or health is at risk