Female Reproductive System Flashcards
Uterine tubes or oviducts or fallopian tubes
Paired ducts that:
Catch the ovulated secondary oocyte.
Nourish both the oocyte and sperm.
Provide the microenvironment for fertilization.
Transport the embryo to the uterus.
Tubal ligation
A common surgical type of contraception.
Salpingitis
The uterine tube mucosa can become inflamed if infectious agents ascend from the lower genital tract
Uterus
Supported by the set of ligaments and mesenteries also associated with the ovaries and uterine tubes, the uterine wall has three major layers
Perimetrium
Myometrium
Endometrium
Perimetrium
An outer connective tissue layer, which is a type of serosa covered by mesothelium.
Myometrium
A thick layer of highly vascularized smooth muscle.
Endometrium
A mucosa lined by simple columnar epithelium. It has a basal layer and a functional layer.
Vulva
Consists of the external female sex organs
Clitoris
Has a tunica albuginea, glans, and prepuce, as does
the penis. The crura are attached to the pubic bone. The erectile tissue is the
paired corpora cavernosa, which are composed of trabeculae (spongy
tissue) and smooth muscle.
Bulb of vestibule (vestibular bulbs)
Erectile tissue
Ovaries
Each ovary is covered by a simple surface (or
germinal) epithelium overlying a layer of dense
connective tissue capsule, the tunica albuginea.
Made up of cortex and medulla
Ovary Cortex
highly cellular connective tissue and many
ovarian follicles after menarche (first menstrual
period).
Ovary Medulla
Loose connective tissue and blood vessels.
Primordial follicle
At puberty, with follicle-
stimulating hormone (FSH) causes primordial
follicles each month begin follicular growth.
Unilaminar primary follicle
Follicular cells divide
and form a simple cuboidal epithelium (unilaminar,
or one layer of cells) around the growing oocyte.
The follicle is now called primary.
Multilaminar primary follicle
The follicular cells
proliferate, forming a stratified (multicell layer)
epithelium with granulosa cells (= follicular cells).
Stromal cells outside each follicle form the follicular theca interna and externa.
Secondary or antral follicles
The follicle cells secrete
follicular fluid. The granulosa cells form a cavity called
the antrum. Follicular fluid contains several substances,
including high concentrations of steroid hormones (progesterone, androstenedione, and estrogens).
Mature follicle
The single large antrum of a mature or Graafian follicle expands to a diameter of 2 cm or more. A mature follicle can be imaged with ultrasound. It develops from a primordial follicle over a period of about 90 days.
Corpus luteum
After ovulation, the
granulosa cells and theca interna of the follicle form a temporary endocrine gland, the corpus luteum.
Corpus albicans
The scar of connective tissue that forms at the site of a corpus luteum after its
involution. It contains mostly collagen, and gradually becomes
very small and lost in the ovarian stroma.
Ovulation
The hormone-stimulated process by which the oocyte is released from the ovary. It normally occurs around the 14th day of a typical 28-day cycle. In humans usually only one oocyte is liberated during each cycle.
PCOS (polycystic ovary syndrome)
A common cause of infertility in women.
Growing primary follicles can become involved
in PCOS, which is characterized by enlarged
ovaries with numerous cysts and with no
follicles completing maturation successfully.
Ovarian and Menstrual Cycle
- Day 1-13: FSH stimulates follicle growth (follicular phase); the follicles produce
estrogen, which stimulates the proliferative phase of the uterine cycle and peaks near ovulation. - Day 14: LH induces ovulation and also
formation of the corpus luteum. - Day 15-27: After ovulation the corpus luteum
forms and produces both progesterone and
estrogens (follicular phase), which together promote growth and development, the secretory phase of the endometrial functional
layer. - Day 17-25: The estrogens produced by the corpus luteum inhibit FSH release.
- Day 1-5: Unless fertilization and implantation
of an embryo occur, regression of the corpus
luteum leads to declining levels of the steroid
hormones and the new endometrial tissue is not
maintained. This tissue sloughs off as the menstrual flow, the first day of which is taken to mark day 1 of both the ovarian cycle and the
uterine cycle.
Pregnancy and HCG (human chorionic gonadotropin)
If pregnancy occurs, the
uterine mucosa must not be allowed to undergo
menstruation because the embryo would be lost. To
prevent the drop in circulating progesterone, the implanted embryo produces human chorionic
gonadotropin (HCG).
HCG maintains and promotes further growth of the corpus luteum, stimulating secretion of
progesterone to maintain the uterine mucosa.
Embryo Implantation
After fertilization of the ovum by a spermatozoan, the zygote begins to divide,
forming a hollow ball of cells, the blastocyst.
At this time the uterus is in the secretory phase and best prepared for implantation. The blastocyst forms two parts, the
trophoblast and the embryoblast, which will
form the embryo.
During implantation, the part of the trophoblast
in contact with the uterus differentiates into the
cytotrophoblast, which will form part of the placenta, and the syncytiotrophoblast, an outer layer that invades the endometrium.
Implantation
The attachment of the blastocyst to the surface cells of the endometrium and its penetration into the underlying stroma, a process that lasts about 3 days
Mammary Gland
The main structures are the lobes (15-25), each with its own lactiferous (excretory) duct, which consists of lobules and smaller alveoli. The lactiferous ducts
empty into lactiferous sinuses that collect milk and release it through the nipple.
The structure of the mammary glands is similar to
Apocrine sweat glands
What is the significance of the substances of the zone pellucida?
They activate the acrosome of the spermatozoa for fertilization.
When in the menstrual cycle does ovulation take place?
Around day 14