Female Reproductive System 2

blastomeres; morula

The zygote produced by fertilization undergoes mitotic cleavages as it is moved toward the uterus, with its cells called ________ in a compact aggregate called _______

blastocyst stage

About 5 days after fertilization the embryo reaches the uterine cavity, by which time blastomeres have rearranged to form a central cavity in the morula and the embryo enters the ______ of development

trophoblast; embryoblast or inner cell mass

The blastomeres then develop as two groups: a peripheral layer called the ______ surrounding the cavity, and a small cluster of cells just inside this layer, the _____ or ______

Implantation or nidation

Involves attachment of the blastocyst to the surface epithelial cells of the endometrium and its proteolytic penetration through this epithelium into the underlying stroma, a process lasting about 3 days

Amniotic cavity and yolk sac

The trophoblast cells drive the events of implantation, during which time cells of the embryoblast rearrange to form two cavities, the future _____ and ______

bilaminar embryonic disc; epiblast, hypoblast

Where the cells lining amniotic cavity and the yolk sac make contact, the ______ develops with its ______ layer continuous with the amnion and its ______ layer part of the yolk sac

cytotrophoblast

a layer of mitotically active cells immediately around the amnion and yolk sac

blastocyst

The embryo enters the uterus as a ______ about 5 days after ovulation or fertilization, when the uterus is in the secretory phase and best prepared for implantation

syncytiotrophoblast

a more superficial, nonmitotic mass of multinucleated cytoplasm that invades the endometrium and eventually surrounds the developing embryoblast and the cytotrophoblast.

syncytiotrophoblast layer

It is the developing _______ that produces increasing amounts of hCG, maintaining the corpus luteum and providing the basis for pregnancy tests.

9th

By about the ____ day after ovulation, the trophoblast and embryo complete implantation into the endometrium and derive nutrients primarily from maternal blood there

Decidual cells; decidua

The endometrial stroma undergoes histologic changes in the period following implantation. Fibroblasts become enlarged, polygonal, more active in protein synthesis, and are now called ______ and the whole endometrium now becomes the ______

decidua basalis

the area between the implanted embryo and the myometrium;

decidua capsularis

region immediately around the embryo and the extraembryonic structures that thins as these structures grow

decidua parietalis

layer of decidua on the side of the uterus away from the embryo

placenta

soon develops as the organ for exchange for nutrients, wastes, O2 and CO2 between the mother and the embryo, containing tissues components from each.

chorion

represents the embryo’s contribution, derived from the trophoblast and embryonic mesodermal cells; the maternal part develops from the decidua basalis.

Primary villi

first appear 2 days after implantation as simple cords of proliferating cytotrophoblast cells covered by syncytiotrophoblast that extend into lacunae containing maternal blood.

Secondary villi

begin to form on about the 15th day of embryonic development as the cores of primary villi are invaded by extraembryonic mesenchyme.

Tertiary villi

develop within a few more days as these mesenchymal cells in the secondary villi differentiate as capillary loops continuous with the embryonic circulatory system.

Cervix

makes up the lower, cylindrical part of the uterus

Endocervical mucosa; cervical glands

_________ is a simple columnar epithelium on a thick lamina propria, with many large, branched, mucus-secreting _______

exocervical mucosa; nonkeratinized stratified squamous epithelium

The cervical region around the external os projects slightly into the upper vagina and is covered by the ______ with _______ continuous with that of the vagina.

transformation zone

An abrupt change from this squamous epithelium and the mucus-secreting columnar epithelium of the endocervix occurs in a ______, an area just outside the external os that shifts slightly with the cyclical changes in uterine size

progesterone; cervical mucus

Under the influence of _______, the consistency of ______ changes cyclically and plays a significant role in fertilization and early pregnancy

watery mucus; viscous mucus; highly viscous mucus

Around ovulation abundant, ______ facilitates sperm movements into the uterus. In the luteal phase, more ______ hinders sperm passage. During pregnancy the cervical glands proliferate and secrete ______ that forms a plug in the cervical canal

lactic acid

When the cells desquamate, bacteria metabolize glycogen to _____, causing a relatively low pH within the vagina, which helps protect against pathogenic microorganisms

External genitalia or vulva

include several structures, all having many Meissner and Pacinian corpuscles and covered by stratified squamous epithelium

Labia majora

consist of thick lateral folds of skin, homologous to and similar histologically to the skin of the scrotum

Labia minora

Smaller paired folds, medial and parallel to the labia majora with richly vascular loose connective tissue, numerous sebaceous glands and melanocytes.

vestibule

occupies the space between the labia minora and encompasses the urethral and vaginal openings

Greater Vestibular Glands

The wall of vestibule includes numerous small tubuloacinar vestibular glands and paired ______ which are homologous to the male bulbourethral glands.

clitoris

small erectile structure, homologous to the penis with paired corpora cavernosa.

Mammary glands

develop embryologically as invaginations of surface ectoderm along two ventral lines, the milk lines, from the axillae to the groin

15-20 lobes

Each mammary gland consists of ______ of the compound tubuloacinar type which secrete nutritive milk for newborns.

lactiferous duct; nipple

Each lobe, separated from the others by dense connective tissue and much adipose tissue, represents a separate gland with its own excretory ______ that emerge independently at the _____

lactiferous sinuses

Before puberty the mammary glands in both sexes consist only of ______ near the nipple, with very small, branching ducts emerging from these sinuses.

terminal duct lobular units (TDLU)

In nonpregnant adult women each mammary gland lobe develops many smaller lobules, sometimes called ______

stratified cuboidal epithelium; simple cuboidal epithelium

The lactiferous sinuses are lined with ______, but the lining of the lactiferous ducts and terminal ducts is ______ with many myoepithelial cells.

areola

Continuous with the mucosa of the lactiferous sinuses and contains sebaceous glands and abundant sensory nerves

alveoli

During pregnancy mammary glands undergo growth due to the synergistic action of several hormones, mainly estrogen, progesterone, prolactin, and the placental lactogen. These cause cell proliferation in the secretory _____ of TDLUs

stroma

While the alveoli and duct system grow and develop during pregnancy in preparation for lactation, the _____ becomes less prominent

Glandular alveoli

develop completely only during pregnancy and begin milk production near the end of pregnancy.

lactation

During _____, secretory cells of the mammary gland become more columnar and very active in milk production. .

colostrum

Late in pregnancy the glandular alveoli and ducts dilate with accumulated ______, a fluid rich in proteins produced under the influence of prolactin

lactation

Following parturition, the mammary TDLUs start active milk production, or ______, stimulated primarily by prolactin from the anterior pituitary

merocrine

Large amounts of protein are synthesized and packaged into secretory vesicles that undergo _____ secretion into the lumen

Lipid droplets

form initially from short-chain fatty acids synthesized in the epithelial cells and grow by accretion of longer fatty acids and cholesterol originating from the diet or fat stores.

apocrine secretion

They eventually undergo ________, during which the droplets become enveloped with a portion of the apical cell membrane

Lactose

the major carbohydrate and energy source in milk, is synthesized by Golgi apparatus enzymes regulated by α-lactalbumin

Breast cancer

originates from epithelial cells in the terminal lobules of the glands.