Female Reproductive Tracts Flashcards
What does the female external genitalia consist of
Mons pubis
Labia major and minor
Clitoris
What covers the mons pubis from puberty
Hairy skin with substantial fatty connective tissue beneath
How is the skin of the mons pubis and labia different
Mons pubis = hairy skin with enlarged sebaceous glands and apocrine sweat glands
Labia = no hairs, sebaceous glands and heavily pigmented epidermis
Lining of vagina
Stratified squamous epithelium
Vulval end - thinly keratinised
Elsewhere - moist non-keratinised
Thickness of vaginal epithelium
Thin before puberty and after menopause
At onset of menarche and throughout reproductive life becomes thickened
What lies beneath epithelium of vagina
Lamina propria containing many small blood vessels
Fluid diffusing from these keeps the epithelium moist
What surrounds the vaginal epithelium
A fibro-muscular tube consisting of a mixture of collagen , elastic and smooth muscle fibres
At its lower end a vaginal sphincter of skeletal muscle is also present
Which glands discharge postero-laterally into the lower end of the vagina at its junction with the vulva
Mucous secreting glands of Bartholin
Cyclic changes in epithelium of vagina and cervix during menstrual cycle
The surface cells accumulate glycogen and many flake off (desquamate) following ovulation.
The desquamated cells rupture and bacteria feed on the glycogen, generating lactic acid.
This creates a low pH within the vagina that deters the entry of pathogenic organisms.
What generates a low pH within the vagina
Production of lactic acid by bacteria feeding on glycogen from desquamated cells
How can you take a sample of exfoliated Squames
With a spatula or brush and smearing it on to a glass slide
What colour are cells from the outermost layer of vagina
Pale green
What colour are cells from the inner layer of vagina
Pink
Location of cervix
Protrudes into the anterior superior wall of the vagina
Surrounded by the anterior, lateral and posterior fornices
What epithelium covers the cervix
Stratified squamous non-keratinising epithelium
What lines the cervical canal between the internal and external Ostia
Tall columnar epithelium that is thrown into deep gland-like folds
Stroma of cervix
Consists of fibrous connective tissue intermingled with smooth muscle fibres
How is the Stroma of the cervix hormonally sensitive
Softens during childbirth and canal widens to become part of birth canal
Mucus secreted by cervix during first half of menstrual cycle
Thin and watery
Mucus secreted by cervix after ovulation and during pregnancy
Viscous
Serves as a plug to prevent the entry of microorganisms into the uterine cavity
Where is the transition zone
Between the sensitive cervical lining and outer stratified squamous epithelium
What is the transition zone vulnerable to
Prone to infection and erosion
Common site for development of cancerous lesions
What lines the inside of the body and Fundus of the uterus
Epithelial endometrium
What composed the myometrium of the body and Fundus of the uterus
3 poorly defined layers of smooth muscle
How does pregnancy affect the myometrium of the uterus
Hormonally sensitive
Increase in number- hyperplasia
Become enlarged - hypertrophy
Where do large arteries and veins run in the uterus myometrium
Inner and middle layers
Large arteries and veins in the myometrium of the uterus
Supply the endometrium of uterus and give rise to spiral arteries that play a role in the process of menstruation
Endometrium of uterus
Simple columnar epithelium with tubular glands surrounded by a sub-epithelial stroma
What happens to the endometrium in the proliferative phase of the menstrual cycle
Thickness of stroma and length of glands increases during first half of menstrual cycke
What happens to the endometrium in the secretory phase of the menstrual cycle
Glands secrete
Stroma differentiates to create an environment conducive to implantation of a fertilised ovum
What is shed at menstruation
Most of the endometrium- decidua (functional layer)
Only the bases of the glands and surrounding stroma are left to establish a new endometrium in the next cycle
How long is the proliferation phase of endometrial development
10 days
What occurs during the proliferation phase of menstruation
Regrowth of new glands, stroma and blood vessels
Tubular glands appear straight and do not yet secrete endometrial mucus
Stroma is compact and contains straight extensions of endometrial arteries and veins
What is successful regrowth of the endometrium dependent on
Presence of oestrogen
Secretory endometrium structure
At time of ovulation - cells of endometrial glands display large vacuole-like accumulations of glycogen below their nuclei used to synthesise mucins that are secreted and line uterine cavity
Glands take on an irregular sacculated appearance and secretions appear in lumina
Stroma become oedematous (swollen with fluid) in places and arteries within it lengthen and take on spiral form
Function of mucins that line surface of uterine cavity
Attract and nourish the conceptus should fertilisation occur
Length of secretory phase
12 days
What happens towards the end of the secretory phase
Spiral arteries briefly close down, open again and leak blood into the stroma
What causes the decidua to detach and menses to begin
Temporary anoxia coupled with hydraulic pressure of the blood disrupts the stroma following spiral arteries closing then reopening
What is required for the successful transition from proliferative endometrium to secretory endometrium
Progesterone and oestrogen
Length of fallopian tube
10cm
Where is the fallopian tube located
Within broad ligament
Regions of uterine tube
Intramural part - embedded in wall of uterus
Short narrow isthmus
Long ampulla
Wide infundibulum closest to ovary
Epithelium of uterine tubes- how does it vary
Thrown into complex folds at wide infundibulum but reduces to a simple star shaped folding at isthmus
Fimbriae
Finger-like processes of the infundibulum that become erect at ovulation and clasp the ovary ensuring safe transfer of ovum to tube
Structure of uterine tubes
2 helical layers of smooth muscle- inner circular and outer longitudinal
Lining of uterine tubes
Simple columnar epithelium- some ciliated and some mucous secreting cells
How are the epithelial cells of the uterine tubes hormonally sensitive
Cells are taller and cilia beat more strongly at time of ovulation
Secretions are thinner and more copious
Germinal epithelium
A layer of cuboidal cells sitting on a thickened basement membrane
Where the mesovarium is continuous with the surface layer of the ovary
3 parts of the ovary
Hilum
Medulla
Cortex
Medulla of ovary
Contains stromal cells including some testosterone-secreting cells
Cortex of ovary
Contains primordial germ cells
May also contain follicles known as one or more stages of development from primary to atretic follicles
When do germ cells migrate into the ovary
10th week of uterine development
When is prophase 1 of meiosis (primary oocytes) reached
Around time of birth
How many primordial germ cells begin to differentiate each menstrual cycle
Up to 20
Dormant primordial follicles
A germ cell enclosed in a theca derived from stromal cells
Follicular development
Initially the theca consists of a single layer of squamous cells (primordial follicles) that later become cuboidal or columnar in shape. The theca then differentiates into inner granulosa cells (theca interna) that begin to secrete oestrogen and outer flattened cells (theca externa) and the follicle becomes a secondary follicle. At this stage too the germ cell develops a prominent zona pellucida that separates it from the theca.
Further growth and development of the theca, particularly the granulosa cells results eventually in the development of a mature Graafian follicle by which time the follicle has developed a fluid filled antrum and the oocyte is attached to the periphery by a stalk of granulosa cells know as the cumulus oophorus.
It should be noted that many follicles that start to differentiate fail to develop fully and perish as atritic follicles.
Once the oocyte is released from the Graafian follicle at ovulation the theca persists and continues to secrete oestrogen and progesterone as a corpus luteum even beyond the end of the menstrual cycle should fertilization and implanation occur (corpus luteum of pregnancy).
Theca interna
Inner granulosa cells that secrete oestrogen
Theca externa
Outer flattened cels
Zona pellucida
Separates the germ cell from the theca
Graafian follicle
Follicle has developed a fluid filled antrum
Cumulus oophorus
A stalk of granulosa cells that attaches the oocyte to the periphery of the Graafian follicle
What does the corpus luteum secrete
Oestrogen and progesterone
Which hormone causes thecal cells to secrete oestrogen and progesterone
Luteinising hormone
For how long does the corpus luteum secrete oestrogen and progesterone
10 days
For how long does the corpus luteum of pregnancy secrete oestrogen and progesterone
Up to 4 weeks until the developing placenta is fully established
Thecal lutein cells
Synthesise oestrogen
Small proportion of cells found in the centre of the corpus luteum
Final involution of the corpus luteum- corpus albicans
Results in formation of a pale staining fibrous mass
What hormone do most surviving thecal cells produce
Progesterone
What colour do cells stain from the deeper layers of the vaginal wall later in the menstrual cycle
Darker-staining orange
What colour do cells stain from the deeper layers of the vaginal wall in the first half of the menstrual cycle
Paler grey-staining
How does the uterus increase during pregnancy
As placenta begins to develop, burst in mitotic division within the myometrium that increases number of smooth muscle cells- short duration
Most of enlargement due to hypertrophy of muscle cells
How does the uterus regress after birth
Muscle cells lose mass and uterus returns to more or less original size
Where does fertilisation of an ovum normally occur
Ampulla of uterine tube but can occur anywhere in tube or uterus
Where do ectopic pregnancies often implant
Uterine tube
Can also occur in peritoneal cavity
What is the cycle of a follicle
Primordial
Primary
Secondary
Graafian OR reabsorbed as atretic follicles
Shape of cells in theca externa
Outer spindle shaped cells
Small stellate in shape
Pale staining
Shape of cells in theca interna
More rounded
Larger
Strongly pink staining
Name of 2 major regions of endometrium
Stratum basale - remains after menses
Decidua -shed at menses
What vestigial structure is often present in the mesovarium and what is its origin
Oophoron
Homologue of part of male genital tract
Through which part of the ovary does eruption of the Graafian follicle normally occur
Erupts through the germinal epithelium on the anti mesenteric border of the ovary
- simple cuboidal epithelium that is continuous with squamous epithelium of peritoneum
Attachments of the ovary
To broad ligament by mesovary
To uterus by utero-ovarian ligament
To pelvic wall by suspensory ligament
What covers the ovary
A single layer of modified mesothelium
Ovarian cortex
Spindle stromal cells arranged in whorls/storiform pattern
Ovarian follicles
Some luteinised cells
Ovarian medulla
Loose fibroelastic tissue with blood vessels, lymphatics and nerves
Rete ovarii-analogue of rete testis - present at the hilum
Where are primordial follicles located
Periphery of cortex
What surrounds the primordial follicles
Single layer of squamous epithelial cells - granulosa cells
What stimulates follicular development
Cyclic FSH secretion from anterior pituitary
Transition from primordial to primary follicle
Follicular epithelial cells proliferate- squamous to cuboidal or columnar appearance
Oocyte enlarges
Stromal cells become organised into connective tissue sheath
Zona pellucida forms directly around oocyte
Primary to secondary follicle
Formation of antrum (space filled with follicular fluid)
CT differentiates into theca interna and theca externa
Oocyte supported by cumulus oophorus
Structure of Graafian follicle
Ovum surrounded by thick Zona pellucida and corona radiata
Corpus luteum shape of cells
Granulosa and theca cells become polygonal, larger in size and have abundant cytoplasm contains lipid
Regression of corpus luteum
Granulosa cells decrease in size
Develop pyknotic nuclei and accumulate abnormal lipid
Cells undergo dissolution and are Phagocytosed
Progressive fibrosis by ingrowth of connective tissue
Composition of corpus albcians
Densely packed collagen with occasional follicles
Cell types in fallopian tube
Secretory
Ciliated
Peg cells
Basal
Peg cells
Effette secretory
Basal cells in fallopian tube
Lymphocytes
3 layers of uterus
Endometrium
Myometrium
Serosa
Layers of uterine endometrium
Deep basal layer- stratum basalis
Superficial functional layer- stratum compactum and stratum spongiosum
Characteristics of proliferative endometrium
Straight proliferating glands with mitotic activity
No luminal secretions
Spindled stromal cells and compact with mitotic activity
Characteristics of early secretory endometrium
Sub-nuclear glycogen vacuoles
Characteristics of mid secretory endometrium
Vacuoles above and below the nucleus
Later intraluminal secretions
Glands more rounded
Stroma - oedema
Characteristics of late secretory endometrium
Elongated and saw-toothed glands with more intraluminal secretions
Stroma- spiral arterioles, decidual change
Characteristics of menstrual endometrium
Stromal haemorrhage and granulocytes
Stromal and glandular fragmentation
Endocervix
Loose fibromuscular stroma lined by simple columnar ciliated epithelium
Thrown into crypts
Ectocervix
Dense smooth muscle stroma lined by non-keratinising stratified squamous epithelium
Site of squamocolumnar junction varies
Atrophic in postmenopausal women
Labia majora
Lined by keratinising stratified squamous epithelium
Has skin adnexae
Labia minora lining
Non keratinising stratified squamous epithelium
Bartholin’s glands
Tubuloalveolar glands
Acini lined by mucus-secreting epithelium
Minor vestibular glands
Simple tubular glands lined by mucus-secreting epithelium
Skein’s glands (periurethral glands)
Analogous to prostate
Lined by pseudostratified columnar epithelium
Hymen
Lined by non-keratinising squamous epithelium
Clitoris
Erectile tissue rich in blood vessels and nerves
