Week 1- Anatomy and development of reproductive system Flashcards
where is the pelvic cavity?
the pelvic cavity is between the inlet and outlet of the bony pelvis
where do the ossa coxae articulate?
posteriorly: with sacrum at the sacroiliac joint
anteriorly: at the pubic symphysis
what are the three parts of the os coxae?
ilium, ischium, pubis
what are the borders of the pelvic inlet
posterior: sacral promotory and ala
lateral: arcuate and pectineal line
anterior: pubic symphysis
what are the borders of the pelvic outlet?
posterior: tip of coccyx
lateral: ischial tuberosities
posterolateral: sacrotuberous ligament
anterior: pubic arch
what are the differences between the male and female pelvis?
male: deep and narrow; heart shaped, narrow pelvic inlet; smaller subpubic angle- <70
female- wide and shallow; oval, wide pelvic inlet; bigger subpubic angle- 80-90
what are the layers of the uterus and their function?
endometrium- innermost layer, lines uterus, shed during menstruation
myometrium- middle smooth muscle, contains blood vessels and nerves, contracts during childbirth
perimetrium- layer of peritoneum overlying uterus
what is the internal and external os of the cervix?
the internal os is the opening of the cervix into the uterine cavity
the external os is the opening into the vaginal cavity
what are vaginal fornices?
gutters around the margin of the cervix and wall of the vagina created where the cervix bulges into the vagina
what are the angles of the uterus?
angle of anteversion: angle between the axis of the vagina and the axis of the cervix
angle of anteflexion: angle between the axis of the uterine body and the axis of the cervix
the uterine angles are maintained by …
cardinal ligaments- cervix to iliac vessels
uterosacral ligaments- cervix to sacrum
what are the parts of the uterine tube?
from medial to lateral: isthmus, ampulla, infundibulum and the fimbriae
what is the function of the fimbriae of the uterine tube?
the fimbriae sweep the ovum into the uterine tube
where does fertilisation usually take place?
in the ampulla of the uterine tube
ovarian vessels and nerves are found within….
the suspensory ligament of the ovary
true/ false- the urethra is fused to the anterior wall of the vagina
true
which peritoneal pouch is the posterior vaginal fornix closely associated with?
the recto-uterine pouch
what is the vestibule of the perineum?
the vestibule is the region between the labia minor where the vagina opens into
describe the route of sperm through the male reproductive tract?
sperm is produced in the testes and moves to the epididymis to mature before entering the ductus deferens. the ductus deferens enters the abdominal cavity via the inguinal canal and then passes posteriorly and medially to the pelvic brim into the pelvic cavity. it unites with the seminal vesicle and forms the ejaculatory duct which passes into the prostate and joins with the urethra. the urethra then travels down the penis
what is the function of seminal vesicles?
seminal vesicles contribute seminal fluid (containing fructose, prostaglandins, coagulants, etc.) to the semen.
where is sperm stored prior to ejaculation?
the sperm is stored first in the epididymis and then in the ampulla of the ductus deferens just prior to ejaculation
what are the lobes of the prostate and their composition?
isthmus (anterior)- anterior to urethra, fribromuscular
right and left- glandular ( can be subdivided into 4 indistinct lobes: inferoposterior, inferolateral, anteromedial, superomedial)
what is the arterial supply of the prostate?
mainly inferior vesicle artery, also middle rectal and pudendal artery
what is the venous drainage of the prostate?
prostate venous plexus drains into the internal iliac veins
what is the innervation of the prostate?
sympathetic- T12-L3
parasympathetic- S2-S3
what are the glands within the prostate called?
inner periurethral- open directly into the urethra outer periurethral (submucosal glands)- ducts transfer secretion into urethra external/ peripheral zone glands- open into urethra via long ducts.
what is the epithelium of the glands and ducts of the prostate?
glands- tall/ cuboidal columnar epitheilium
ducts- columnar or cuboidal, get more cuboidal and transitional closer to the urethra.
what are the signs and symptoms of a malignant prostate?
signs- enlarged with irregular nodules
symptoms- urination difficulties
what is a mesentery, momentum and ligament?
they are double folds of peritoneum arising from peritoneal reflections
mesentery- between viscera and abdominal wall
momentum- between viscera and other viscera
ligament- can be either
are pelvic viscera intraperitoneal, retroperitoneal or subperitoneal?
pelvic viscera are subperitoneal- they only have peritoneum on their superior surface
what are the peritoneal pouches in a male pelvis?
there is the rectovesical pouch between the bladder and rectum
what are the peritoneal pouches in a female pelvis?
vesicle-uterine pouch- anterior, between bladder and uterus
recto-uterine pouch- posterior, between uterus and rectum
what is a culdocentesis?
drainage of a fluid from recto-uterine pouch through an incision in the posterior vaginal fornix
what is the broad ligament?
a double layer of peritoneum (mesentery) extending from the sides of uterus to the lateral walls and floor of pelvis
what are the subdivisions of the broad ligament?
mesometrium- between lateral pelvic walls and body of uterus
mesoalpinx- most superior pair, suspends the uterine tube
mesovarium- posterior extension of the broad ligament attached to the ovary
what is the ovarian ligament and the suspensory ligament of the ovary?
suspensory ligament of the ovary- connects ovary to the wall of pelvis, contains ovarian nerves and vessels.
ovarian ligament- connects ovary to uterus (joins at uterotubal junction)
what is the round ligament and what is its function?
this runs from the uterotubal junction through the inguinal canal to the labia major. it is continuous with the ovarian ligament. it is an embryological remnant of the gubernaculum. function- maintains position of uterus in pregnancy
where do the gonadal arteries branch from?
the abdominal aorta
what do the gonadal arteries supply?
the gonads (ovaries and testes) and the lateral half of the uterine tube in females.
which division of the internal iliac artery supplies the pelvic viscera?
the anterior division
what are the branches of the anterior division of the internal iliac and what do they supply?
- umbilical artery branches into superior vesicle artery which supplies the bladder and urethra
- obturator- moves towards obturator foramen
- vaginal (female) or inferior vesicle (male)
- uterine artery (female)
- middle rectal- supplies rectum
- inferior gluteal- supplies gluteal region
- internal pudendal- supplies perineum (external genitalia)
what does the ascending and descending branch of the uterine artery supply?
ascending branch- uterine body
descending branch- cervix and vagina
what does the uterine artery anastomose with, where does it happen and what does it supply?
the uterine artery anastomoses with the ovarian artery in the broad ligament to contribute to uterine tube supply.
what is a fistula?
an abnormal connection between two hollow spaces
what is an internal and external fistula and give an example.
external- one of the spaces is the skin. example- anal fistula (usually after draining of an anal abscess)
internal- between 2 hollow organs. example- colo-vesical or recto vaginal (during labour)
what is a bimanual exam?
fingers inserted into vagina and other hand pressed above pelvic brim to palpate the cervix (pain) and to check if the uterus is palpable above the pelvic brim (pregnancy, large fibroids, large cancers)
what are the steps of a rectal examination?
- inspection- for haemorrhoids, anal fissure/fistula, prolapse
- neuromuscular function- superficial anal reflex (L1/2), levator ani, external anal sphincter and internal anal sphincter
- digital examination- rectum palpated for masses, prostate and rectovesical pouch (men), rectouterine pouch (women)
at what stage do primordial follicles appear in the ovary of a foetus?
32 weeks
where does follicular development take place in the adult ovary?
the cellular stroma of the outer cortex
what are the steps of fertilisation?
- sperm capacitation
- penetration of corona radiata
- attachment to zone pellucida
- activation: acrosome reaction, penetration of zone pellucida
- sperm fuses to plasma membrane and entry
- blocks to polyspermy
what happens to the follicle after ovulation?
luteinisation of granulose and thecal cells by LH. this produces granulosa lutein cells and theca lutein cells which secret progesterone and a small amount of oestrogen. the follicle is now a corpus luteum. this shrinks and stops producing hormones becoming a corpus albicans
what is capacitation and where does it occur?
capacitation is the removal of glycoproteins and sterols from plasma membrane. it occurs post ejaculation in the female genital tract
what is sperm activation?
morphological event. includes acrosome reaction: release of hydrolytic enzymes from the acrosome
what are the two blocks to polyspermy?
fast block- electrical depolarisation of plasma membrane of the ovum, prevents sperm fusing to membrane
slow block- oocyte secretes lysozymes ceasing the cortical reaction- formation of impenetrable membrane and zone reaction- structural changes which prevent sperm binding
what is the pre- embryo
preimplantation embryo- fertilisation to day 11/12
define the term embryo
phase of gastrulation, neuralation, folding and organogenesis- day 11/12 to week 8
define the term fetus
growth phase- week 9 till birth
what are the pre-implatation stages of development?
cleavage- says 1-2 morula, 16 cells- day 3 blastocyst- day 4 hatching (removal of zone pellucida for implntation)- day 5 implantation- day 5-7
what does the inner cell mass of the blastocyst become
the fetus
what do the trophoblast cells become?
the placenta
what is the blastocyst cavity called?
blastocoele
what do syncytiotrophoblast cells do?
invade maternal blood vessels forming lacunae and produce hCG
what is the function of hCG?
signals pregnancy to the corpus luteum
what is the decidual reaction?
endometrium the endometrium around the embryo becomes decidua which provides nutritional support and restricts invasion to protect the fetus from the maternal immune system
what are the layers of the bilaminar disc
epiblast and hypoblast
what does the hypoblast layer form?
hypoblast forms extrembryonic endoderm which becomes yolk sac endoderm
what does the epiblast layer form?
this differentiates into amniotic epiblast and embryonic epiblast.
embryonic epiblast differentiates into embryonic ectoderm and the primitive streak.
the primitive streak forms embryonic endoderm, embryonic mesoderm, extra embryonic mesoderm and the notochordal process
what is gastrulation?
a process of cellular migration whereby the germ layers are established
what does embryonic ectoderm form?
forms the skin, neural crest and neural plate which goes on to form the nervous system
what does embryonic mesoderm form?
forms the notochord and adult tissues such as bone, cartilage, muscle, blood, hear, kidneys, etc.
what does embryonic endoderm form?
gut tube, abdominal organs, trachea and lungs, auditory system, urinary system
what is the structure that induces neural plate formation?
the notochord
describe the processor neural tube formation
the lateral edges become elevated forming neural folds. the neural folds meet and fuse forming the neural tube
what do neural crest cells contribute to?
neural crest cells migrate and contribute to the PNS, Schwann cells, craniofacial structures, cardiovascular structures
what types does mesoderm differentiate into?
paraxial mesoderm
intermediate mesoderm
lateral plate mesoderm
what does paraxial mesoderm differentiate into and what do they form?
sclerotome- axial skeleton
myotome- muscles of back and trunk
dermatome- dermis of skin
what does lateral plate mesoderm differentiate into and what do they form?
splanchnic mesoderm- heart, mandibular muscles
somatic mesoderm- limb buds
the intraembryonic coelom forms between the two and this goes on to form body cavities
what does the splanchnopleure and somatopleure form?
splanchnopleure- gut walls
somatopleure- body walls
which embryonic folding process occurs first?
longitudinal first then transverse
what body cavities does the anterior and posterior portions intraembryonic coelom form?
anterior- pericardial cavity and pleural cavity
posterior- peritoneal cavity
what vessel carries maternal blood to the placenta?
uterine spiral arteries carry maternal blood into the placenta where it enters the lacunae and bathes the villi
what vessel carries blood from placenta back to the foetus?
the umbilical vein carries oxygenated blood from the placenta back to the foetus.
the two umbilical arteries….
carry blood from the foetus to the placenta
describe the functions of the placenta.
oxygenation of foetal blood
removal of waste from foetal blood- CO2, urea, urea, bilirubin
nutrition- glucose, aminoacides, FAs to foetus
hormone production
immune barrier
transfer of antibodies
what are neuroopores?
they are openings at either end of the neural tube
which neuropore closes first?
the anterior neuropore closes first then the posterior one
how do neural tube defects occur?
neural tube defects occur when the neural tube fails to close properly
what is spina bifida and what does it cause?
spina bifida is a neural tube defect that occurs when the posterior neuropore fails to close fully. it can happen anywhere along the spine and it means that the backbone that protects the spinal cord does not form so nerves can be damaged. it causes mild to severe physical and intellectual disabilities.
what is anencephaly and what does it cause?
anencephaly is a neural tube defect that occurs when the anterior neuropore fils to close properly. it often results in the baby being born without the front part of the brain and cerebellum. the remaining parts of the bone are often not covered by bone or skin
what is the purpose of taking folic acid and what is the recommended dose?
folic acid is taken to reduce the risk of neural tube defects. 400micrograms daily from before conception (if appropriate) and for the first 12 weeks of pregnancy.
what foods should be avoided during pregnancy and why?
soft cheese/unpasteurised milk/ pate- listeria raw eggs- salmonella raw/cured meat- toxoplasmosis liver- high vitamin A fish- mercury game- lead
what are the symptoms of ectopic pregnancy?
abdominal pain and vaginal bleeding arising between the first 4-12 weeks of pregnancy
what are risk factors for ectopic pregnancy?
some STIs, previous ectopic pregnancy, previous uterine tube surgery, PID, endometriosis
what are the types of ectopic pregnancy?
tubal- most common, associated with PID and endometriosis, mostly in ampulla
cervical- can cause severe haemorrhage
rare ectopic pregnancies- ovarian, abdominal
what are the two regions of the cervix and their micro anatomy?
endocervix- inner portion of the cervix, lined by a single layer of tall columnar mucus secreting epithelium
ectocervix- outer part of the cervix that bulges into the vagina, covered in stratified squamous epithelium (pale on histology due to presence of glycogen)
what is the composition of the cervical stroma and how does it vary?
the cervical storm is predominantly collagenous (provides strength, breaks down during cervical remodelling in preparation for labour) with varying amounts of smooth muscle. more smooth muscle in proximal cervix, decreases towards distal cervix.
what are the four layers of the vagina and their composition?
- stratified squamous epithelium mucosa
- lamina propria- rich in elastic fibres
- fibromuscular layer- inner layer of poorly organised circular smooth muscle and an outer layer of longitudinal muscle
- adventatia- fibrocollagenous tissue containing thick elastic fibres, vessels, nerves and clumps of ganglion cells
what is the transformation zone?
the area of histological change whereby the columnar epithelium of the endocervix is replaced by metaplastic stratified squamous epithelium. it predominantly occurs during puberty and the first pregnancy. the transformation zone is the most susceptible area to malignancy.
what are the histological changes associated with carcinoma of the cervix?
- cells lose their regular stratified pattern
- high nucleus to cytoplasm ratio
- variation in shape and increased mitotic activity
these changes are known as cervical intraepithelial neoplasia (CIN) and are investigated by cervical smear
what gene determines sex?
the SRY gene on the Y chromosome (present in males absent in females)
describe the development of the male reproductive tract
the SRY gene induces differentiation of the indifferent gonads into testis.
the leading cells of the testis produces testosterone which causes the mesonephric duct to differentiate into the ductus deferens and associated structures and causes spermatogoia to turn into spermatozoa. testosterone is also converted into dihydrotestosterone which causes the genital tubercle, genital swellings and urethral epithelium to differentiate into the male external genitalia.
Sertoli cells of the testis produce androgen binding factor (contributes to spermatogonia differentiation) and mullein inhibiting factor which causes the paramesonephric duct to degenerate
describe the development of the female genital tract
the absence of SRY causes the indifferent gonad to differentiate into the ovaries. the absence of testosterone means that the mesonephric duct doesn’t differentiate and degenerates. the absence of dihydrotestosterone means that the genital tubercle, genital swellings and urethral epithelium differentiate into female external genitalia. the absence of mullerian inhibiting factor means that the paramesonephric (mullerian) duct persists and forms the female genital tract
what does the urogenital sinus differentiate into in males?
prostate, urethra and bulbourethral glands
what does the urogenital sinus differentiate into in women?
paraurethral glands, greater vestibular glands, and lower genital tract
what part of the germinal epithelium degenerates to form the male gonad?
the cortex degenerates and the medulla proliferates forming the male gonad
what part of the germinal epithelium degenerates to form the female gonad?
the medulla degenerates and the cortex remains
what do they genial folds, genital tubercle and genital swellings form in males and females?
genital tubercle- glans penis (male), glans clitoris (female)
genital swellings- scrotum (male), labia majora (female)
genital folds- fuse and enclose urethra at urethral raphe (male), no fusion form labia minors (female)
what is turners syndrome?
absence of X chromosome which causes germ cells to degenerate, gonads do not differentiate and genitalia do not mature
what does an extra X chromosome in males cause?
klinfelter syndrome- small external genitalia, infertility
what are the 3 muscles of the elevator ani?
iliococcygeus, pubococcygeus, puborectalis
what are the muscles that make up the pelvic floor?
the levator ani and the (ischia)coccygeus
what are the pelvic wall muscles?
the piriformis and the obturator internus
what is the function of the puborectalis?
forms a U shaped sling around the rectum and maintains fecal continence
what is parturition?
the passage of the baby’s head through the bony pelvis
what are the cardinal movements of the foetus during delivery?
engagement
- descent
- flexion
- internal rotation
- extension
- external rotation and restitution
- anterior shoulder delivery
- posterior shoulder delivery
describe engagement of the foetal head?
head descends towards the pelvic brim in an occipitotransverse position allows the widest part of the foetal skull to fit through the widest part of the pelvic inlet
describe the cardinal movement of descent
the baby descends through the pelvic inlet towards the pelvic floor. descent occurs during to uterine contractions, amniotic fluid pressure and abdominal muscle contraction
when does flexion occur?
when the baby head comes into contact with the pelvic floor. it allows the presenting part of the head to be sub-occipito bregmatic which has a smaller diameter
describe the cardinal movement of internal rotation
the head rotates from a left/right occipito-transverse position to an anterior-posterior position. results in crowning- widest part of foetal head is through the narrowest part of the pelvis, head no longer retracts between contractions
describe the cardinal movement of extension
occiput slips beneath the subpubic arch as the head extends, nape of neck pivots against arch
describe the cardinal movement of external rotation
baby head externally rotates to face the mothers medical thigh, shoulders rotate to an anterior posterior position- this is restitution
what are fontanelles?
they are large fibrous areas located between certain sutures. the anterior and posterior fontanelles are on the top of the head, the sphenoid and mastoid on the sides.
what are the contents of the anal triangle?
anal canal, external anal sphincter, ischia-anal fosse (fat filled spaces), pudendal nerve
where does the perineal membrane attach?
ischiopubic rami
what is the perineal body?
a midline fibromuscular mass where muscles attach. it stabilises the pelvic and perineal structures
where is the deep perineal pouch?
between the pelvic floor and perineal membrane
where is the superficial perineal pouch?
between the perineal membrane and the skin
what are the contents of the female deep pouch?
urethra, urethral sphincter, vagina, deep transverse perineal muscle, perineal neurovasculature
what are the contents of the female superficial pouch?
clitoris (copora cavernosa, glans clitoris, bulb of vestibule), mons pubis, labia, muscles
what are the muscles in the superficial pouch?
bulbospongiosus- covers bulb of vestibule/penis
ischiocavernosus- covers copra cavernosa
superficial transverse perineum
what is the major neurovascular supply of the perineum?
nerve- pudendal nerve (S2-S4)
artery- internal pudendal artery (branch of ant. division of internal iliac artery)
where do the labia converge?
minora anteriorly- prepuce and frenulum (with clitoris between)
minora posteriorly- fourchette
majora posteriorly- posterior commisure
what is the nerve supply of the anterior section of the vulva?
iliolingual and genital branch of genitofemoral nerve
what is the nerve supply of the posterior section of the vulva?
pudendal nerve (perineal nerve) and posterior cutaneous nerve of the thigh
what is the blood supply of the vulva?
internal pudendal artery (branch of ant.division of internal iliac artery) and external pudendal artery (a branch of the femoral artery)
what are the content of the male deep perineal pouch?
urethra (membranous portion) external urethral sphincter bulbourethral glands deep transverse perineal muscle perineal neurovasculature
what are the contents of superficial perineal pouch?
scrotum
penis
muscles
what are the layers covering the penis from deep to superficial?
tunica albuginea visceral tunica vaginalis parietal tunica vaginalis internal spermatic fascia cremasteric fascia cremaster muscle external spermatic fascia dartos fascia dartos muscle
what are the different parts of the penis
corpus spongiosum- contains urethra
corpora cavernosa- paired structures fill with blood during reaction
what are the lobes and lobules of the breast?
a lobe is formed from one lactiferous duct and its associated structures
lobules form ate branches into terminal ductules
what changes occur during pregnancy and lactation
during pregnancy there is proliferation of the ducts, ductules and secretory alveoli
during lactation secretory alveoli become enlarged and filled with milk
where is breast cancer most likely to metastasise?
to the axillary lymph nodes as this is where most of the lymphatic drainage of the breast is to.
what are the general features of malignant breast lumps?
hard, irregular borders, fixed to underlying structures. can also have skin or nipple changes
what is fibrocystic breast disease
benign, breast lumpiness and tenderness, can be related to menstrual cycle
what are the features of fibroadenoma?
common benign breast lump
soft, well circumscribed, painless, highly mobile
what are the feature of fat necrosis?
benign inflammation of fat cells resulting in lumps
more likely in larger breasts after trauma
on examination- bruising erythema (redness), dimpling
painless
what are the features of lipoma?
benign tumour of fat cells
soft, well circumscribed, smooth and non tender. found superficially just under the skin
what are the features of a breast cyst?
develop in terminal duct
fluid filled, round, can be painful
what are the risk factors for breast cancer?
female sex, age, long interval between menarche and menopause, family history, alcohol, obesity, oral contraceptive/HRT, older age at first pregnancy or nulliparous.
what are protective factors for breast cancer?
breast feeding, pregnancy, receiving treatment for breast conditions
what are the cardinal symptoms of breast cancer?
breast lump, skin changes, nipple discharge or inversion, enlarged regional lymph nodes, change in size/shape of breast
what are the types of breast carincoma in situ
- lobular carcinoma in situ- abnormal cell growth confined to lobules of breast
- ductal carcinoma in situ- abnormal cell growth confined to the ducts of the breast. can present with breast Lum or nipple discharge. can become invasive
what is the most common type of invasive breast carcinoma?
ductal
what is pages disease of the breast?
cancer of nipple areola associated with underlying cancer. presents with an eczematous lesion on nipple/ areola
what is inflammatory breast cancer?
rapidly developing cancer which blocks the lymphatic drainage of the breast leading to redness, swelling, firmness, pain and can become hot to touch.may also have peau d’orange, skin thickening, nipple changes or palpable lump.
