Flashcards in Repro 5 Female Anatomy Deck (116):
How are the oocytes stored?
In the follicles in the outer cortex of the ovaries (1 oocyte per follicle). Each oocyte is surrounded by stromal cells (follicular cells) forming primordial follicles (pale staining nucleus)
Where do oocytes originate from?
Outside the ovary from the primordial germ cells that colonise the ovary during early embryonic development
What happens to the primordial germ cells in the ovary?
Divide by mitosis to form oogonia which develop into oocytes by undergoing meiosis
When does meiosis of oocyte complete?
After fertilisation - if not fertilised, meiosis is not completed
At what stage of division does the oocyte halt meiosis?
Diplotene phase of 1st meiotic prophase until just before ovulation.
How many oocytes mature each month?
Several begin to develop each month but generally only one (sometimes 2) develop to primary oocytes just before ovulation and are released.
What happens to the primary ooctye at ovulation?
The first meiotic division completes to form a haploid secondary oocyte and a polar body
How many follicles persist at puberty and what happens to the rest?
Many follicles undergo degeneration (atresia) in the fatal and postnatal ovary
Approximately how many oocytes will develop fully and be released in menstruation of a woman's life?
What are the 2 different populations of follicles?
Reserve pool of non-gorwing follicles (larger) and a smaller pool of growing follicles, derived periodically from the former group.
What happens to the reserve pool of follicles?
Constantly depleted as no new follicles are made after birth therefore stores are exhausted around the age of 50-55
What is folliculogenesis?
Entry of follicles into the growth phase and their subsequent development
What transformations occur to form a primary follicle from a primordial follicle?
The single layer of flattened follicular cells transform into a layer of cuboidal granulosa cells
Glycoproteins secreted by the granulosa cells that contribute to the formation of the zona pellucida surrounding the oocyte appear at this time and form a thick amorphous layer as the follicle grows
How are secondary pre-antral follicles formed?
Granulosa cells form multiple layers and transformation of the surrounding stromal layers to theca folliculi which comprises the oestrogen secreting theca interna and a fibrous theca externa
What signals the formation of a tertiary or astral follicle?
Appearance of a fluid-filled cavity - antrum. These follicles enlarge by an increase in the fluid volume and proliferation of the granulosa and thecal cells
What are Graafian and ovulatory follicles?
Graafian follicles are large antral follicles and only one of the most advanced of these will become the ovulatory follicle
What happens to the ovum at ovulation?
The follicle ruptures to release the ovum, the granulosa and theca interna cell show structural (and functional) transformation. The entire mass of the tissue becomes highly vascularised via the growth and infiltration of blood vessels from the surrounding tissue
What is the appearance of the granulosa cells in the corpus luteum?
undergo hypertrophy and form a thick and folded layer of granulosa lutein cells which have a spherical nucleus and pale stained vacuolated cytoplasm containing numerous lipid droplets
What happens to the internal thecal cells in the corpus luteum?
Transformed into theca lutein cells and occupy depressions formed by the granulosa lutein cells accompanied by blood vessels.
What is in the central cavity of the corpus luteum?
Undifferentiated connective tissue
From what are ovarian cysts derived?
When are cystic ovaries associated with infertility?
Polycystic - more than 10
Where do tumours in the ovary most commonly arise from?
Epithelial components or germ cells
What is the suspensory ligament?
Attachment of the ovary to the posterior uterine wall
What is the ovarian ligament?
Attachment of the ovary to the uterus
What is the round ligament?
Attachement of the uterus to the labia majora, passing through the inguinal canal
What is the broad ligament?
Base of the peritoneum
What is the uterosacral ligament?
Attachment of the uterus posteriorly to the sacral spine
What is the cardinal ligament?
Attachment of the uterus to the lateral abdominal wall
What is the pubouterine ligament?
Attachment of the uterus to the pubic symphysis
What is the function of the mesovarium?
Attaches the ovary to the posterior of the broad ligament
Which ligament passes from the ovary to the uterus posteroinferior to the uterotubal junction?
Why does the ovarian artery originate from the renal level of the aorta?
Embryonic origin is at this level
What is the venous drainage of the ovaries?
R ovarian -> IVC
L ovarian -> L renal vein -> IVC
(same as testicular venous drainage in male)
What is the lymphatic drainage of the ovaries?
drains to para-aortic nodes
How does the surface appearance of a pre-pubertal ovary compare to that of a post-pubertal ovary?
Pre-pubertal surface is smooth, post-pubertal surface epithelium becomes progressively scarred and distorted because of repeated rupture of ovarian follicles and discharge of oocytes during ovulation
What is the function of the uterine tubes?
Transfer and transport of the ovum from the ovary to the uterus
What are the sections of the uterine tube?
Funnel shaped abdominal opening - ostium with fingerlike projections called fimbria
Isthmus (narrowest part) opens into the uterine cavity
Describe the lumen of the oviducts.
Mucous membrane is thrown into complex folds thus the lumen in cross section appears as a labyrinthine system of narrow spaces
Describe the epithelia of the fallopian tubes.
Simple columnar with ciliated and non-ciliated (secretory) cells
What is the function of the fimbria and cilia?
Movement of the fimbria over the surface of the ovary and ciliated cells are thought to assist in the transfer of the ovum from the surface of the ovary into the uterine tube and cilia throughout move the ova along the tube
What is the function of the secretory cells in the fallopian tube?
Provide nutrients to the early conceptus following fertilisation
What are the layers of the fallopian tube?
What is the function of the muscular layer of the fallopian tube?
Contractions of the smooth muscle layer assists with the transport of sperm to the site of fertilisation and the transport of the conceptus to the uterus
What is salpingitis?
Inflammation of the uterine tube caused by microorganisms.
What are the complications of salpingitis?
Infertility due to fusions or adhesions of the mucosa and thus partial or complete block of the lumen
May also result in ectopic pregnancy
Where does the uterine tube lie?
In the edge of the broad ligament
What mechanisms facilitate the movement of an ovum along the duct?
Smooth muscle contraction
How can infection spread to the peritoneum from the female reproductive tract?
Opening of the uterine tube at infundibulum into peritoneal cavity -> infection from anywhere in the reproductive tract
What are common sites of implantation of ectopic pregnancies?
fimbrial, isthmic, ampullary, interstitial (uterine tube), ovary
What are rare sites of implantation of ectopic pregnancies?
Pouch of Douglas
Where is pain from an ectopic pregnancy likely to be felt?
Lower abdominal quadrants due to stretching and tearing of the peritoneum
Why might pain be felt in the shoulder after the rupture of an ectopic pregnancy?
When lying down, blood may accumulate under the diaphragm, irritating the phrenic nerve which originates C3,4,5 so pain may be referred to the dermatomes of these segments - shoulder
From where would the blood passing through the vagina be originating after rupture of an ectopic pregnancy?
Withdrawal bleed (not from site of rupture) caused by the reduction of hCG which maintains the corpus luteum and hence maintains the endometrium
What is the blood supply to the uterine tubes?
Anastomotic of the ovarian and uterine arteries.
What covers the uterus?
Peritoneum - serous membrane
What is the myometrium?
Mass of smooth muscle in the uterine wall
What happens to the myometrium in pregnancy?
Undergoes considerable hypertrophy and hyperplasia in preparation to expel the fetus at birth
What lines the uterine cavity?
Endometrium - mucous membrane
What type of glands are in the endometrium?
Uterine glands - tubular glands that extend from the surface into the connective tissue. Long, narrow and straight and often slightly dilated.
In the deepest part of the endometrium the glands show some bifurcation in the zone adjacent to the myometrium and occasionally they penetrate a short distance among the muscle bundles
What are the layers of the endometrium?
Stratum functionalis (functional layer)
Why is the stratum functional is the 'functional' layer?
It is subject to cyclical growth, degeneration and shedding of the dead tissues
What is the function of the stratum basalis?
regeneration of the upper endometrium
What regulates the cyclical changes of the stratum functionalis?
Hormones secreted by the ovary:
Oestrogen secreted during folliulogenesis stimulates the proliferative phase
Corpus luteum secretes progesterone which stimulates the secretory phase
What happens to the endometrium in the proliferative phase?
Growth and proliferation
What happens to the endometrium in the secretory phase?
Corpus luteum secretes progesterone which stimulates the endometrial glands to secrete glycogen and causes extensive coiling and enriches vascular supply to the mucous membrane
What is the purpose of the proliferative and secretory phase of the endometrium?
Preparation for receipt and embedding (implantation) of the conceptus following fertilisation
What happens to the endometrium if the conceptus fails to implant?
Enters the menstrual phase - brought about by withdrawal of hormonal support (degeneration of the corpus luteum) and changes in the vascular supply of the endometrium. Degeneration and breakdown of the stratum functionalis, bleeding and shedding of the dead tissues -> menses
What type of epithelium lines the uterine cavity?
Simple columnar, mixed ciliated and secretory cells
Describe the stroma of the uterus
Stellate cells surrounded by a fine reticular network
Where are the spiral arteries of the uterus located?
Mostly in the lower part of the endometrium and appear transversely sectioned
How does the uterus appear in the secretory phase?
The endometrial glands have enlarged to become more tortuous and have developed marked sacculation, resulting in a relatively wide lumen of irregular outline containing secretion.
Endometrial Stroma appears oedematous and some of the stromal cells have undergone hypertrophy
Arteries are present in the superficial region due to extension of the blood supply
Basal layer is essentially unaltered
How does the uterus appear in the menstrual phase?
The endometrium has undergone extensive necrosis and shows ruptured blood vessels
What is the cervix?
A fibromuscular neck which protrudes into the upper vagina and contains the endocervical canal which links the uterine cavity with the vagina
What is the function of the cervix?
Allows the sperms deposited in the vagina at coitus to enter the uterine cavity to proceed to the site of fertilisation
Protects the uterus and upper genital tract from bacterial invasion
What are the 2 regions of the cervix?
Describe the epithelia of the cervix.
Endocervix lined with tall columnar epithelia with basally placed nuclei and the greater part of the cytoplasm filled with mucus
The exocervix is covered with stratified squamous non-keratinised epithelium
The abrupt change from columnar to stratified squamous is at the transition zone (endothelium -> exothelium).
Describe the muscosa of the cervix.
Contains numerous large glands that are also lined with tall, mucus-secreting columnar cells
What orientation is the smooth muscle of the cervix?
Circularly arranged smooth muscle fibres lying in abundant dense connective tissue
What is endometriosis?
A condition in which ectopic endometrial tissue is dispersed to various sites alone the peritoneal cavity and beyond. May be associated with severe period pain (dysmennorrhoea), infertility or both
When does endometrial carcinoma usually occur?
(malignancy of the endometrium) postmenopausal women
What is the major symptom of endometrial carcinoma?
Abnormal uterine bleeding
Where do the majority of neoplasms form in the cervix?
How may the broad ligament be subdivided?
Mesometrium - suspends the uterus
Mesosalpinx - suspends the uterine tube
Mesovarium - suspends the ovary
What are the 3 layers of the uterus?
Perimetrium - serosa
Myometrium - 3 muscle layers
Endometrium - stratum basalis and functionalis
How do the glands change over the course of the endometrial cycle?
From simple to highly coiled
What type of glands are in the cervix?
When are the various uterine phases in relation to the menstrual cycle?
Days 1 - 14 proliferative
Days 14 - 28 secretory
Why is the ureter in danger of being damaged during hysterectomy?
In clamping of the uterine artery, the ureter may be damaged as it passes just under the artery
What is the lymphatic drainage of the funds of the uterus?
What is the lymphatic drainage of the body of the uterus?
External iliac nodes
What is the lymphatic drainage of the cervix?
sacral nodes, external and internal iliac nodes
What is the normal position of the utreus?
Anteverted to the vagina
Anteflexed to the cervix
What is assessed in bimanual examination?
Insertion of one or two fingers into the vagina to examine the cervix
The external hand palpates the uterus (and ovaries if enlarged) from the anterior surface of the body to assess for pregnancy or irregularity
Uterus is assessed for size, consistency, pain, mobility, regularity, position etc.
On average, what size is a uterus?
Similar size to a plum
If the uterus is retroverted, which structure would be the presenting part on a speculum or vaginal examination?
OS or posterior lip (rather than anterior lip) of the cervix
What are the constituents of cervical mucus?
How does the cervical mucus change during the uterine cycle?
Production greatest during the follicular phase in preparation for ovulation. It changes from cloudy to clear at ovulation - clear acellular mucus with high stretchability. Following ovulation, the mucus again becomes thick and cloudy in diminishing quantities.
What happens to the cervical mucus during pregnancy?
Forms a thick mucus plug, the loss of which may indicate labour
From what cells of the cervix do Nabothian cysts develop and what are they?
Cervical glandular ducts
Infection of the endocervical gland (as in chronic cervicitis) can result in blockage of the duct and result in cyst formation (2mm - 1cm). There presence, especially if infected can reduce chances of pregnancy by making the cervix inhospitable to sperm
What is the vagina?
A distensible muscular tube
From where does the vagina extend?
Vestibule of the female genitalia to the cervix of the uterus
What are the layers of the vagina?
Fibrous connective tissue layer - adventitia
Describe the mucous membrane of the vagina.
Consists of stratified squamous epithelium with underlying lamina propria composed of dense connective tissue which projects (papillae) in places into the covering epithelium. The lamina propria is looser towards the muscular layer and in this region it contains large veins
Describe the epithelium of the vagina.
Appears vacuolated because of the loss of some of the cytoplasmic components (mainly glycogen) during tissue preparation for microscopy
What type of glands are in the vagina?
None - the mucus lubricating it originates from the cervical glands
Describe the arrangement of the muscular layer of the vagina.
Smooth muscle bundles arranged circularly and longitudinally.
Longitudinally arranged bundles are numerous in the outer half of the muscle layer
How is the low pH of the vagina maintained?
Bacteria in the vagina utilise the glycogen as a substrate for lactic acid production thus maintaining the low pH
What is the purpose of maintaining a low pH in the vagina?
Natural barrier against infection - many microorganisms cannot thrive in these acidic conditions.
What are the anatomical relations of the vagina?
Anteriorly, the funds of the urinary bladder and urethra
Posteriorly, the anal canal and rectum and rectouterine pouch
Laterally, the levitator any and ureters (just superior to lateral fornices
What structures may be palpated in a vaginal examination?
Anteriorly, bladder, urethra and pubic symphysis
Posteriorly, rectum, prolapsed uterine tube and ovary
Laterally, ovary and uterine tube, sidewall of pelvis
Apex, cervix (ante or retroverted)
In pelvic examination, which of the cervical fornices is usually the largest and why?
Posterior is usually deepest as the uterus is usually anteverted and anteflexed (more of the posterior part of the cervix enters the vagina compared to anteriorly)
What is the lymphatic drainage of the vagina?
Inguinal lymph nodes
How does the vaginal epithelia reflect its function?
stratified squamous - external layers shed with friction
Which bony and fibrous structures form the boundary of the perineum?
Pubic symphysis anteriorly
Inferior pubic rami anterolaterally
Ischial rami anterolaterally
ischial tuberosities laterallu
sacrotuberous ligaments posterolaterally