Microsoft word - female_reproductive_system.doc

A. Oogenesis is the formation of the egg (ovum) in the female.
1. During fetal development females have oogonia which are diploid sex
a. While still in the womb the oogonia divide by mitosis to form ½- 1 million primary oocytes.
b. These primary oocytes will begin the first meiotic division but c. The female is born with these primary oocytes. 2. By the time the female reaches puberty approximately 40,000 of the 3. Beginning during puberty, each month hormones from the anterior pituitary stimulate a primary oocyte to complete the first meiotic
division generating two secondary oocytes of unequal size.
a. The smaller secondary oocyte is called a polar body, containing
b. The larger secondary oocyte is the ovum (egg) that will be
released from the ovary for fertilization by the spermatozoa. i. Only if the ovum is fertilized will it continue the second ii. If fertilized the ovum divides again to produce a second polar body, with the fertilized ovum forming the diploid zygote. iii. If the ovum is not fertilized within 24 hours after release it B. The vulva (external genitalia)
1. The labia majora
a. Consist of longitudinal folds of skin with adipose tissue that enclose and protect the other external organs. b. Develops from the same embryonic tissue as the scrotum. 2. The labia minora
a. Two folds of skin inside the labia majora.
b. Anteriorly, form a hood over the clitoris.
c. Merge posteriorly with the labia majora.
d. Covers the region of the vestibule.
3. The clitoris
a. Consists of two columns of erectile tissue that is richly supplied b. Plays a role in initiating sexual excitation and orgasm in the 4. The hymen
a. A fold of mucous membrane that partially closes the vaginal 5. Paraurethral glands
a. Located in the wall of the urethra. b. Secrete mucous for lubrication. c. Develop from the same tissue as the prostate gland in the male. 6. Bartholin’s glands
a. Located on either side of the vaginal opening. b. The primary source of mucous for lubrication during intercourse. c. Are similar to the bulbourethral glands in the male. 1. The vagina
a. A canal that extends from the exterior of the body to the cervix b. Functions as the birth canal and the female organ of copulation i. Lined by a mucous membrane with stratified squamous ii. Includes smooth muscle capable of contraction during intercourse and dilation during childbirth. 2. The uterus
a. A hollow, muscular organ where the fetus develops and is the b. Consists of a fundus, body and cervix.
i. The fundus is the dome shaped portion of the uterus ii. The body is the central portion of the uterus. iii. The cervix is the portion of the uterus that extends into the (a) Is typically plugged with mucous to block the (b) Cervical cancer is highly linked to the Human
Papillomavirus, the virus that causes genital warts.
c. The wall of the uterus consists of three layers. i. The outermost layer is the perimetrium.
(a) Is synonymous with the visceral portion of the peritoneum, the serous membrane that covers organs within the abdominal and pelvic cavities. (b) Covers the uterus and forms the broad and round
ligaments that attach the uterus to the pelvic wall.
ii. The middle layer is the myometrium.
(a) Consists of 3 layers of smooth muscle that forms the (b) Contraction of this muscle help to expel the fetus iii. The innermost layer is the endometrium.
(a) Consists of a mucous membrane with simple columnar epithelium at the free surface. (b) Is divided into the stratum functionalis and the
stratum basalis.
(i) The stratum functionalis is the superficial layer (ii) The stratum basalis is the deeper mitotic layer that regenerates the stratum functionalis. (c) Forms the maternal portion of the placenta.
(d) Endometriosis is a condition where endometrial
tissue is deposited and grows outside the uterus. The tissue enters the pelvic cavity by way of the fallopian tubes and implants on other organs within the abdominopelvic cavity. fluctuations and bleed monthly leading to scarring and inflammation. (iii) A leading cause of female infertility. 3. The uterine (fallopian) tubes
a. Carry the ovum from the ovaries to the uterus. b. Typically where fertilization of the ovum occurs. c. Are twice as wide as a human hair and lined by ciliated d. End in fingerlike projections known as fimbriae that surround,
i. Brush over the surface of the ovary to draw the ovum into 4. The ovary
a. Where oogenesis occurs.
b. Produces the hormones progesterone and estrogen.
c. Are covered by the germinal epithelium consisting of cuboid
d. The tunica albuginea is fibrous tissue deep to the germinal
e. The inner portion of the ovary is divided into a cortex and a
medulla.
i. The cortex contains ovarian follicles in different stages of
(a) The ovarian follicle is the developing ovum surrounded by follicular cells producing estrogen. (b) The Graafian follicle is a mature follicle that
(c) Once the Graafian follicle has released the ovum the remnant of the follicle is known as a corpus luteum
which produces progesterone.
ii. The medulla consists of connective, vascular and lymphatic D. The female breast
1. Are the location of mammary glands, modified sweat glands that
a. Each mammary gland consists of 15-20 lobes of glandular tissue with ducts that lead to an ampulla (milk reservoir) beneath the
nipple and adipose tissue.
2. Hormones associated with breast development and function. a. Estrogen stimulates duct formation, adipose deposition and b. Progesterone stimulates the development of the glandular tissue. i. Since progesterone is not produced until the female is ovulating, glandular development does not begin until the female has reached sexual maturity. c. Prolactin produced during pregnancy, along with estrogen and
progesterone, cause breast enlargement and help prepare the breast for milk production. i. After the child is born the reduced levels of estrogen and progesterone (due to loss of the placenta) allow prolactin to stimulate milk production by the glands. ii. Suckling stimulates continued production of prolactin. d. Oxytocin is also released due to suckling of the nipple and
stimulates the ejection of the milk by the ductile system. E. Hormones of the female reproductive cycle 1. The hypothalamus secretes gonadotropin-releasing hormones
(follicle-stimulating hormone releasing hormone and leuteinizing
hormone releasing hormone) to the anterior pituitary glands which
stimulates the release of the hormones follicle stimulating hormone
(FSH) and leuteinizing hormone (LH).
i. Targets developing follicles stimulating growth of the ii. Stimulates the production of estrogen from the follicular i. Stimulates final maturation of the follicle and the full production of estrogen by the follicular cells. ii. A surge of LH at midcycle stimulates ovulation, release of the developed ovum from the Graafian follicle. iii. Once the ovum is released LH maintains the follicular cells iv. LH stimulates the corpus luteum to produce progesterone i. Is the primary female sex hormone produced by the follicle cells, the corpus luteum and the placenta. ii. Responsible for the production and maintenance of the female primary and secondary sex characteristics. iv. Targets the uterus stimulating the build up of the i. Produced by the corpus luteum and the placenta. ii. Targets the uterus with estrogen to prepare the endometrium for implantation and maintains the endometrium during the early stages of pregnancy. iii. If implantation does not occur a drop in progesterone 1. Menstrual phase
a. Represents the first 5 days of the cycle. b. The stratum functionalis of the endometrium sloughs off during i. Low levels of progesterone cause the uterine arteries to ii. The loss of blood flow to the stratum functionalis causes the cells to die and eventually slough off. 2. Proliferative (preovulatory) phase
i. Follows the menstrual phase and continues from day 6 to ii. Controlled primarily by high levels of estrogen. iii. The stratum functionalis of the endometrium regenerates 3. Secretory (postovulatory) phase
i. Begins with ovulation on day 14 and continues to day 28. ii. Controlled primarily by progesterone. iii. The stratum functionalis continues to thicken in preparation iv. If implantation does not occur the corpus luteum begins to degenerate and progesterone levels drop, resulting in the beginning of the menstrual phase.

Source: https://www.rtc.edu/Programs/GeneralEducation/Biology/Biology221/files/Female_Reproductive_System.pdf