Histology of the Male and Female Reproductive Tracts Flashcards
What changes result in reduced functioning of the ovary at menopause?
Ovary stops producing gametes and becomes less reactive
Describe the location and anchoring of the ovary
Attached to posterior face of broad ligament
Anchored to uterus by ovarian ligament and to pelvic wall by suspensory ligament
Describe the structure of the ovary
Inner medulla: loose connective tissue, blood vessels
Outer cortex: primordial and maturing oocytes, highly cellular connective tissue, scattered smooth muscle cells
Describe the surface of the ovary
Irregular surface with scar tissue from previous development and release of oocytes
Simple squamous or cuboidal epithelium, continuous with mesothelium
What is the most common site of ovarian tumours?
70% of ovarian tumours are from the surface epithelium
What lies beneath the surface epithelium of the ovary?
Tunica albuginea (dense connective tissue)
How many oocyes are present in the embryo? By birth? How many undergo maturation and how many are released into the uterine tube?
5 million/ovary in the embryo
0.5 million by birth
Most degenerated over life; few thousand undergo most of maturation cycle
~500 are released
Describe the structure of the primordial oocyte
Squamous follicle cells on outside, surrounded by common basal lamina
In what phase of meiosis is the primordial oocyte arrested?
Prophase of meiosis I
Describe the structure of the primary oocyte
Surrounded by zona pellucida (within the follicle cell layer)
Follicular cells become cuboidal as the oocyte enlarges, and divide to form multi-layered granulosa cells (this supportive cell layer is called the stratum granulosum)
Surrounding stromal cells start to form theca interna and externa (surround stratum granulosum)
Describe the changes that occur in the transition between primary oocyte and secondary follicle
Stratum granulosum thickens
Fluid filled cavity called the antrum appears
Oocyte suspended on stalk of granulosa cells called the cumulus oophorus
What change occurs to the structure of the secondary follicle following its release during ovulation?
Granulosa cells around oocyte form corona radiata
What is the mature follicle called? What is its diameter?
Graffian follicle
10mm diameter
What changes to the follicle occur with the LH surge?
Completes 1st meiotic division to become the secondary oocyte
What occurs following rupture of the follicle?
The smooth muscle in the ovary contracts to aid oocyte release into the peritoneal space, where it can then enter the uterine tube
What happens to the follicle following release of the oocyte?
Formation of the corpus luteum
What changes occur during the formation of the corpus luteum?
Stromal, granulosa and thecal cells invade the cavity and differentiate into luteal cells
Cells contain lipid and are highly vascularised
What is the role of the luteal cells?
Production of progesterone and oestrogen to prepare the endometrium for implantation
What happens to the corpus luteum if fertilisation does not occur?
Lack of hormonal signal: becomes corpus albicans and involutes over 14 days
Scar remains
What is the role of the uterine tube?
Collects released oocytes
Unites sperm and egg
Provides environment for fertilisation and initial development
Describe the gross structure of the uterine tube
Expanded opening (infundibulum) with fimbriae (collects oocyte)
Ampulla
Isthmus (joins uterus)
Describe the histological structure of the uterine tube
Serosa: mesothelium with thin connective tissue layer
Smooth muscle (muscularis)
Mucosa: connective tissue with epithelium
What kind of epithelium is found in the uterine tube?
Ciliated columnar
How is the oocyte moved towards the isthmus of the uterine tube?
Peristalsis (produces waves of fluid pumping oocyte towards isthmus)
What is the role of the fluid secreted by the epithelium of the uterine tube?
Provides nutrients for oocyte
Where does fertilisation usually occur?
Ampulla of uterine tube
What happens in the isthmus of the uterine tube?
Zygote remains here for 3 days, continues to divide
How big is the uterus outside pregnancy?
~Fist-sized
Describe the structure of the uterine wall
Endometrium: mucosa
Myometrium: inner and outer longitudinal layer, highly vascular circular middle layer
Outer perimetrium: mesothelium and underlying elastic tissue
Which layers of the uterine wall respond to cyclic changes in reproductive hormones?
Endometrium and myometrium
What changes occur to the uterus during pregnancy?
Individual smooth muscle cells in the myometrium are enlarged
More smooth muscle cells are generated
Connective tissue is increased
N.B. Changes do not fully reverse after birth (thickened wall is retained)
Describe the structure of the endometrium
Mix of ciliated and secretory simple columnar epithelium
Secretory glands penetrating into lamina propria (dense connective tissue)
Supplied by helical arteries
Functional layer (sloughed off every menstrual cycle)
Basal layer (regenerates functional layer)
What changes occur with endometrial growth?
Epithelial, stromal (lamina propria) and vascular cells proliferate vigorously
Secretion (mucoid with glycogen) accumulates
Describe the structure of the endocervix
Simple columnar epithelium
Cervical glands
Describe the secretions of the endocervix
Serous and copious at ovulation
Thick and plug-like at other times