Histology Flashcards
what are the two roles of the ovaries
produce gametes (oogenesis) produce steroids (osterogens and (mainly) progesterone)
what is the medulla of the ovary like
forms the core
contains loose connective tissue
contorted arteries, veins and lymphatics
is continuous with the hilum of the organ
what is the cortex of the ovary like
contains scattered ovarian follicles
highly cellular connective tissue stroma
the outer shell of cortex has dense connective tissue layer = tunica albuginea which is covered by single layer of cuboidal cells called the germinal epithelium
does the corpus luteum leave the ovary
no, stay and becomes corpus albicans when it degenerates
what are the arteries in the ovaries
helicine arteries enter the hilum from the broad ligament
what happens to germ cells at week 6
go from the yolk sac to the ovaries
begin to proliferate by mitosis to form oogonia
what do oogonia form
via development and meiosis form mature oocytes/ ova
what is oogenesis
the development of oocytes from oogonia
what is folliculogenesis
the growth of the follicle
what makes up a follicle
oocyte and associated support cells
what is atresia
loss of oogonia and oocytes - an apoptosis based process (cell is resorbed following cell death)
describe meiosis in follicles
before birth meiosis begins in the oocytes but halts at prophase 1
can stay like this for several decades and then restart development
in a 20 y/o 15 follicles restart development per day
how many divisions in meiosis
2- reductive and equatorial
what are the stages of follicular development
starts as primordial follicle - primary - late primary (these three forms are the pre-antral follicles) - secondary - mature graafian these last 2 forms are antral follicles
what are pregranulosa cells
follicle cells
are squamous then become cuboidal if follicle enters the growth phase
what forms the zona granuloa
follicle cells
what forms the theca folliculi
stromal cells associating with the outside of the follicle
what is the zona pellucida
a layer of special extracellular matrix between the oocyte and granulosa cells
what type of cell are granulosa cells
cuboidal
what is the theca interna
formed from inner layer of stromal cells adjacent to follicle
goes on the secrete oestrogen precursors
what cells convert the precursors from the theca interna into oestrogen
granulosa cells
what is the theca externa
outer layer formed by stroma cells
what is the order of conents from the theca externa in
TE theca interna basal lamina GC zona pellucida oocyte
what is an antrum and what does it do
as the follicle enlarges a space, called the antrum which is filled with follicular fluid forms in the granulosa cell layer
this forms a secondary follicle
as the follicle enlarges so too does the antrum
what happens to the granulosa and thecal layers as the follicle enlarges
continue to proliferate
what are the largest antral follicles called
graafian follicles
what is the cumulus oophorus
areas of granulosa cells that attaches the oocytes to the basal lamina when antrum gets v large
what happens to the oocyte one day before ovulation
complete meiosis 1
but instead of producing two equal cells, it will produce one cell called a secondary oocyte, similar in size to the original primary oocyte, and one tiny polar body that carries the second nucleus away to degenerate.
The secondary oocyte will then begin the second phase of meiosis but stops as metaphase II
when will the secondary oocytes complete meiosis
after ovulation and fertilisation
when is a second polar body formed by the oocyte
when it is fertilised
what layer does the follicle have to go through to be ovulated
tunica albuginea
what does the follicle become after ovulation
(still in ovary without egg) corpus luteum with the theca and granulosa cells secreting oestrogens and progesterone, which helps prepare the uterus for implantation
what happens to the corpus luteum without implantation
becomes a white coloured connective tissue called the corpus albicans
what happens to the corpus luteum when implantation occurs
, the placenta secretes HCG which prevents degeneration of the corpus luteum for a time and so maintains progesterone levels, which in turn maintains the pregnancy
what moves the ovum down the fallopian tubes
peristalsis and currents created by ciliated epithelium
both these are cyclic
what do the secretory epithelium in the uterine (fallopian) tubes do
secrete nutrients
where does fertilisation occur
in the ampulla (end of fallopian tube closest to the fimbrae)
what makes up the lining of the ampulla of the uterine tube
high folded mucosa like by simple columnar epithelium within ciliated and secretory cells
this is surrounded by smooth muscle
how does the uterine tube changes as it goes from the ampulla to the isthmus
epithium becomes mostly secretory gains another (now 3) layer of smooth muscle
what is the endometrium
an inner secretory mucosa in the uterus - is shed during menstruation
made of secretory glands embedded in a connective tissue stroma
what is the myometrium
3 layers of smooth muscle, collagen and elastic tissue in the uterine wall
what is the perimetrium
the outer visceral layer of the uterus, made of connective tissue covered by mesothium
what are the two parts of the endometrium
stratum functionalis (what is shed via vasoconstriction which cuts of blood supply) stratum basilis (reserve tissue that regenerates the functionalis)
what hormone causes the stratum basilis of the endometrium to proliferate
oestrogen
when is the proliferative phase of the endometrium
day 5 to day 14 (one day after ovulation)
what happens to the glands in the endometrium during the secretory pphase
become coiled and secrete glycogen
what is the cervix made of
fibrous connective tissue covered by stratifies squamous epithelium on its vaginal surface and mucous secreting simple columnar epithelium further up
(transition site common area to get dysplasia and neoplasms)
what can form when endocervical glands get blocked
nabothian cyst
what do the endocervical glands secrete
thin watery mucous when in proliferative stage (fertile)
thick vicous mucous following ovulation
why are cell in vagina stratified squamous
as low vaginal pH
what are the layers from in out of the vagina
non keratinised stratified squamous epithelium
lamina propria (connective tissue, elastic fibres, thin wall blood vessels)
fibromusclar layer (inner circular and outer longitudinal smooth muscle)
adventitia
what lubricas the vagina
no gland in wall of vagina
lubricated by mucous from cervical glands and fluid from blood vessels in lamina propria
what inhibits the growth of pathogenic bacteria in the vagina
commensal bacteria (metabolised glycogen to lactic acid) lower pH
what is the mons pubis
skin will oblique hair follicles that covers the pubic symphysis and subcutaneous fat pad
describe the features of the labia majora
extension of mons pubis
similar in structure- lots of apocrine sweat glands, sebaceous glands, bundles of smooth muscle, hair follicles on outer surface
describe the features of the labia minora
think skin folds
lack subcutanous fat an hair follicles
rich in vasculatory and sebaceous glands
keratinised epithelium extends into the opening of the vagina to the level of the hymen where it transitions to non keratinised stratified squamous
what makes up the clitoris
two tubes of erectile vascular tissue (corpora cavernosa) covered by fibrocollagenous sheath and skin with rich innervation and thin epidermis
