FEMALE REPRODUCTIVE SYSTEM PRIMARY FUNCTIONS OF THE FEMALE REPRODUCTIVE SYSTEM ARE:-  PRODUCTION OF FEMALE HORMONES  FORMATION OF THE OVUM  DEVELOPMENT OF THE OFFSPRINGS
2 FEMALE REPRODUCTIVE SYSTEM THE ORGANS AND THEIR FUNCTIONS:- OVARIES:- PRODUCE HORMONES & OVA UTERINE TUBES:- TRANSPORT THE OVA UTERUS:- OFFSPRING DEVELOPMENT CERVIX:- PROTECTION OF UTERUS VAGINA:- BIRTH CANAL & THE FEMALE ORGAN OF COPULATION EXTERNAL GENITALIA:- CLITORIS, LABIA MAJORA AND LABIA MINORA
Hymen – partially closes the vagina until it is ruptured
OOGENESIS IS THE PROCESS OF OVA FORMATION OOGONIA > PRIMARY OOCYTE > FIRST MEIOTIC DIVISION > SECONDARY OOCYTE & THE FIRST POLAR BODY. IF FERTILIZED, SECONDARY OOCYTE > SECOND MEIOTIC DIVISION > ZYGOTE & SECOND POLAR BODY. BOTH POLAR BODIES DEGENERATE.
OVERIAN CYCLE FOLLICULAR PHASE:- THE DEVELOPMENT OF ONE PRIMARY FOLLICLE TO FORM A MATURE FOLLICLE OVULATION:- RUPTURE OF THE MATURE FOLLICLE TO RELEASE THE OVUM LUTEAL PHASE:- FORMATION OF THE CORPUS LUTEUM FROM THE RUPTURED MATURE FOLLICLE. DEATH OF THE CORPUS LUTEUM WILL FORM A CORPUS ALBICANS
The Ovarian Cycle The follicular phase: is the period of follicle growth, as lasting from the first to the fourteenth day of the cycle The luteal phase: is the period of corpus luteum activity, days 14-28 Typical ovarian cycle repeats at intervals of 28 days, with ovulation occurring midcycle
The follicular phase PRIMORDIAL FOLLICLE > PRIMARY FOLLICLE > SECONDARY FOLLICLE > MATURE FOLLICLE > OVULATION & RELEASE OF OVUM > CORPUS LUTEUM > CORPUS ALBICANS
THE OVARIAN CYCLE Primordial follicle Primary follicle primary oocyte arrested in prophase I + 1 layer of squamouslike cells primary oocyte that has resumed meiosis I + 1 layer of cuboidal follicle cells enclosing the oocyte Late secondary follicle Secondary follicle Two or more layers of granulosa cells surround the oocyte Layer of connective tissue condenses around the follicle forming theca folliculi Thick extracellular layer called zona pellucida
Mature (Vesicular) follicle Ovulation Fluid filled pockets coalesce to form central fluid filled cavity called an antrum The antrum isolate the oocyte with its surrounding capsule cells called a corona radiata Each month one of the ripening follicles ejects its oocyte from the ovary Secondary oocyte surrounded by its corona radiata
Corpus luteum remnants of follicle cells after ovulation Remaining granulosa cells increase in size and along with internal thecal cells 80% granulosa cells, 20% thecal cells Secrete progesterone and some estrogen Corpus albicans = scarred over corpus luteum
Oogenesis Events of Oogenesis: Left flow chart of meiotic events, Right correlation with follicle development and ovulation in the ovary
OOGENESIS Mitosis in fetal life 2 meiotic arrests Total number of ova 6 months in utero birth number of germ cells (millions) puberty menopause 7 million at 5th month 2 million at birth 250,000 at puberty ~480 ovulations = ~13 per year for 37 years age oögonium (2n) primary oöcyte (2n) enters meiosis arrested in prophase I first meiotic division polar body 1 (1n) Stages of oögenesis secondary oöcyte (1n) Hormones arrested in metaphase II Gn-RF FSH LH estrogen fertilization completes meiosis II polar body 2 (1n) oötid (1n) + sperm (1n) = zygote
Differences between Spermatogenesis and Oogenesis Differences between Spermatogenesis and Oogenesis In females, mitotic proliferation of germ cells occurs prior to birth. In males, spermatogonia proliferate only after puberty. In female, meiotic divisions of oocyte produces only one mature ovum. In male, meiotic divisions of primary spermatocyte produces 4 mature spermatozoa In female, second meiotic division is completed only upon fertilization. In male, the products of meiosis (spermatids) undergo substantial differentiation in the maturing process.