Histology Flashcards
What are the two roles of the ovary?
Produce gametes and produce steroids
What tissues are in the medulla of the ovary?
Loose connective tissue, contorted arteries, veins, lymphatics and nerves
What tissues are in the cortex of the ovary?
Scattered ovarian follicles in highly cellular connective tissue with stromal cells and scattered muscle fibres.
What is the name of the group of arteries that enter the hilum from the broad ligament and supply the ovary?
Helicine arteries of the ovarian artery
what are the 2 outermost layers of the ovary?
Germinal epithelium (single layer cuboidal cells) sits on top of tunica albuginea (dense connective tissue) - outermost layers
Around what week do germ cells invade the ovaries and proliferate by mitosis to form oogonia?
Week 6
Define oogenesis
Development of oocytes from oogonia
Define folliculogenesis
Growth of the follicle
At 7 months in utero, approx. How many oogonia are present?
5,000,000
At birth how many oocytes are there that have developed from oogonia by meiosis?
1,000,000
By puberty how many follicles are there that have developed from primary oocytes?
500,000
What is atresia?
Loss of oogonia and oocytes by apoptosis
What happens before birth in terms of follicular developemt?
Meiosis begins in the oocytes but halts at Prophase I. If oocyte develops further than meiosis will restart, this restarts in puberty
What are the 5 forms of follicular development?
Starts as primordial follicle - then primary follicle - then late primary follicle - then secondary follicle - then mature graffian follicle
Which forms of follicle are pre-antral and which antral?
Pre-antral are primordial, primary and late primary and antral are secondary and mature graffian follicles
What happens to an oocyte if it fails to associate with pregranulosa cells in the fetal ovary?
It will die
What defines the change of primordial follicle into primary follicle?
Squamous pregranulosa cells becoming cuboidal granulosa cells (zona granulosa)
In follicular development the theca folliculi forms from what?
Stromal cells associating with the outside of the primary follicle
What is the name of the extracellular matrix layer that forms between the oocyte and granulosa cells in the primary follicle?
Zona pellucida
What changes occur in the primary follicle to become the late primary follicle?
Granulosa cell layer proliferates, inner stroma cells outside granulosa develop into theca interna and outermost stroma cells become theca externa
What layer formed in the late primary follicle will go on to secrete oestrogen precursors and where will these be converted?
Theca interna and will be converted to oestrogen by granulosa cells
What changes occur in the late primary follicle to form the secondary follicle?
Antrum forms in granulosa cell layer and fills with follicular fluid and overall follicle enlarges with all cell layers proliferating
When does the secondary follicle become the Graafian follicle?
When the first meiotic division has completed and antrum grows and cumulus oophorus forms
What is the cumulus oophorus?
Cluster of cells that surround the oocyte in antral follicles
What happens in the largest Graafian follicle one day before ovulation?
Oocyte in largest graafian follicle will complete meiosis 1 BUT will not produce two equal cells, will produce one cell called secondary oocyte and one tiny polar body that carries away the second nucleus to degenerate
The secondary oocyte will begin second phase of meiosis but will stop at metaphase II. When will it complete meiosis to become a fully mature oocyte?
After ovulation and fertilisation
What is the follicle stigma?
The bulging of the tunica albuginea that shows imminent rupture of the follicle
What do the granulosa cells become known as after ovulation?
Corona radiata
What happens to the follicle after ovulation?
Becomes corpus luteum with theca & granulosa cells secreting oestrogen and progesterone. If no implantation it becomes corpus albicans. If implantation HCG produced by placenta keep corpus luteum around for a while
How does the ovum move down the uterine tubes after ovulation?
Peristalsis and currents created by ciliated epithelium
What secretes nutrients for the ovum in the uterine tubes?
Secretory cells in epithelium
Describe the layers of the ampulla of the uterine tube.
Mucosa is highly folded, lined by simple columnar epithelium with ciliated cells and secretory cells. Mucosa surrounded by smooth muscle
How do the layers of the isthmus differ to that of the ampulla.
Lining epithelium is mostly secretory with few ciliated cells. 3 smooth muscle layers in isthmus as opposed to 2 in ampulla
What tissues make up the endometrium of the uterus?
Inner secretory mucosa made up of tubular secretory glands embedded in connective tissue stroma
What tissues make up the myometrium of the uterus?
3 layers of smooth muscle combined with collagen and elastic tissue
What tissue makes up the perimetrium and what covers this?
Loose connective tissue and is covered by mesothelium
What are the 2 layers of endometrium and their functions?
Stratum functionalis - grows and sheds during periods & stratum basalis regenerates the functionalis
What happens in the endometrium during proliferative phase of ovarian cycle?
Stratum basalis proliferates and glands, stroma and vasculature grow to increase thickness of functionalis
What happens in the endometrium during secetory phase of ovarian cycle?
Glands become coiled with corkscrew appearance and secrete glycogen
What happens in the endometrium during menstrual phase of ovarian cycle?
Arterioles in stratum functionalis constrict causing ischaemia and tissue breaks down
Describe the cell layers of the cervix
Mostly fibrous connective tissue covered by stratified squamous epithelium on vaginal surface. Transitions to mucous secreting simple columnar epithelium further up into uterus.
What are the endocervical glands?
Furrows in the mucous secreting epithelium of cervix that secretes different mucous at different stages of menstrual cycle
What is the name of the cyst caused by blockage of endocervical glands?
Nabothian cyst
What are the four layers of vaginal tissue?
Non-keratinised stratified squamous epithelium, lamina propria (connective tissue rich in elastic fibres and thin-walled blood vessels), fibromuscular layer (inner circular and outer longitudinal smooth muscle) and adventitia
Where does the vagina get its lubrication from?
Endocervical glands and fluid from thin-walled blood vessels in lamina propria
How is growth of pathogenic bacteria inhibited in the vagina?
Commensal bacteria metabolises the glycogen and lactic acid
Describe the tissues of the mons pubis
Skin with highly oblique hair follicles that overlies subcutaneous fat pad over the pubic symphysis
Describe the tissues of the labia majora
Extensions of mons pubis rich in apocrine sweat glands, sebaceous glands, small bundles of smooth muscle and hair follicles on outer surface only
Describe the tissues of the labia minora
Thin tissue rich in vasculature and sebaceous glands that secrete directly onto skin surface. Keratinised epithelium extends into opening of vagina to hymen. Lack subcutaneous fat and hair follicles
Describe tissues of clitoris
Contains two tubes of erectile vascular tissue (corpora cavernosa), covered by fibrocallgenous sheath covered by skin with rich innervation and thin epidermis
