bio chapter 16.3

Uterus (womb)

Largest organ in female reproductive system

• Muscular, hollow organ

•Shaped like an inverted pear

• Site where embryo (until 9th week of

development) and fetus develop, is composed of

2 major tissues

Myometrium

Muscular outer lining of uterus

• Provides support for developing embryo

Endometrium

Glandular inner lining of uterus

• Provides nourishment for developing embryo

• If pregnancy does not occur, is shed

• Menstruation

Oviduct (Fallopian Tube)

Once mature, an egg will

enter oviduct through

wide, open ends called

fimbriae

• As egg is moved along

It by cilia, it goes

through its final stages of

development

Fertilization of egg occurs in it

Vagina

Connects uterus with outer environment

•Sexual intercourse (copulation)

•Birth canal

•During last phase of pregnancy, strong muscular

contractions help move baby into birth canal

•Strongly acidic

•Hostile environment for microbes, but also sperm

Cervix

Muscular band

• Separates vagina from uterus

• Holds fetus in place

• Dilation during birth permits fetus to enter birth canal

Oogenesis

formation of an egg

•Formation of eggs

Occurs in specialized cells of ovary called follicles

Primary oocyte

contains 46 chromosomes

•Present at birth, prophase I of meiosis I.

•At age of puberty, completes rest of meiosis I and II.

•Transforms into a mature oocyte, or ovum, following fertilization

Granulosa cells

Provide nutrients for oocyte; form follicle wall

corpus luteum

Secretes hormones essential for pregnancy