The Female Reproductive System. The Female Reproductive Cell Egg ( ovum )
Notes - Female Reproductive System
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Transcript of Notes - Female Reproductive System
REPRODUCTIVE SYSTEM: FEMALE
Ovary = primary sex organ: paired, Produce eggs (ova) &
secretes estrogen & progesterone
Posterior pelvic wall Supported parietal
peritoneum = broad ligament
Ovary – cont.
Consists of four layers; 1. Superficial (Germinal)
Epithelium - single layer of cuboidal cells, thin outermost
2. Tunica Albuginea - a collagenous C.T.
3. Cortex – primary substance of the ovary
4. Medulla - innermost, vascular area
Oogenesis: egg formation
http://wps.aw.com/bc_martini_eap_4/0,11295,2680298-content,00.html
Before birth - Ovary contains about one million oogonia (immature egg cells, 46 chromosomes).
At birth - SOME of the oogonia grow and begin into the 1st Meiotic division but stop in Prophase I = Primary Oocytes.
Primordial Follicle = The immature Primary Oocyte + flattened, randomly-arranged Follicle Cells
Oogenesis
Puberty – (Primary Follicleformation) FSH stimulates some Primordial Follicles to grow bigger by developing numerous layers of uniformly-arranged,\ cuboidal Follicle Cells surrounding a Primary Oocyte
Oogenesis
Secondary Follicle formation -LH stimulates, the Follicle Cells to secrete a nutritive fluid which collects into several fluid-filled cavities called Vesicles which aggregate together to form an Antrum (fluid-filled cavity). Also, a protective layer develops around the Primary Oocyte = Zona Pellucida. The Primary Oocyte plus the Antrum, multiple layers of Granulosa Cells, and the Zona Pellucida = Secondary Follicle.
Oogenesis
With continued hormonal stimulation, the Granulosa (Follicle) Cells continue to increase in number and to secrete the nutritive fluid, and the Antrum enlarges to its maximum size. At this stage, the follicle is known as a Graafian (Mature, Vesicular) Follicle.
In the Graafian Follicle, under the influence of LH, the Primary Oocyte undergoes completion of the 1st meiotic division & begins into the 2nd meiotic division, but stops in Metaphase II = Secondary Oocyte
Oogenesis -menstruation
Once a month (at approximately day 14 of the normal 28 day cycle), under the influence of LH, the Graafian Follicle is induced to rupture = Ovulation.
A Secondary Oocyte is released, surrounded by: 1. Zona pellucida - a protective gel
layer made by the granulosa cells 2. Corona radiata - two layers of
granulosa cells
The remaining portion of the Graafian Follicle, under the influence of LH, is induced enlarge and to form a Corpus Luteum. It will produce Estrogen & Progesterone which thickens the stratum functionalis of the uterus.
Secondary Sex Organs –Fallopian tubesFallopian tubes: 4 parts;
fimbriae, infundibulum, ampulla, isthmus, transport Oocyte to uterus 1. Fimbriae - motile
processes which hang over ovary. Draw secondary oocyte into Uterine Tube
Secondary sex organs- Uterus 3 Parts; Fundus, Body, &
Cervix Histology:
a. Endometrium i. Stratum functionalis -
shed during menses, implantation occurs here
ii. Stratum basale - deep, very vascular, never shed, replaces Stratum Functionalis
b. Myometrium - middle, smooth m.
c. Perimetrium - outer, C.T.
Secondary sex organs - Vagina Vagina: copulatory organ, opening = Vaginal Orifice,
in most newborns it is covered by a hymen (vascular connective tissue)
Secondary sex organs - Vulva
External Genitalia = Vulva Mons pubis - hair covered fat
pad Labia majora - hair covered
skin folds Labia minora - smaller,
hairless skin folds. Anteriorly, they fuse to form a prepuce (over Clitoris)
Vestibule: space between labia minora. Contains: a. Vaginal orifice b. Urethral orifice c. Openings for Vestibular
(Bartholin's) glands Clitoris: contains 2 columns of
erectile tissue = corpora cavernosa
Secondary sex cells – Mammary Glands Mammary glands: modified
sweat glands. Divided into lobules which are
subdivided into lobules. The lobules contain Alveolar Glands
Milk flows through the Lactiferous ducts & is stored in the Lactiferous sinuses just below the areola.
Milk leaves the sinuses via Lactiferous Ducts to Nipple
Areola - pigmented area around nipple, many oil glands