Histology of Female Repro. system Flashcards
What are the 2 functions of the ovary?
- produce gametes
- produce steroids (estrogen and progesterone)
What does the medulla of the ovary contain?
- loose connective tissue
- contorted arteries, veins and lymphatics—-continuous with HILUM of the organ
What does the cortex of the ovary contain?
- scattered follicles in highly cellular STROMA
- outer shell: dense connective tissue (TUNICA ALBUGINEA)
What enters at the HILUM of the ovary?
- helicine arteries enter from the broad ligament
- supply blood to the organ
What is the tunica albuginea covered by?
—-covered by germinal epithelium (single cuboidal layer)
When does oocytes form in the fetus?
- ~6weeks
- germ cells from the yolk sac invade the ovaries and undergo mitosis = oogonia
> undergo meiosis to form oocytes
What is oogenesis?
- development of the oocytes from oogonia
What is folliculogenesis?
- the growth of the FOLLICLE
- consistes of OOCYTE and associated support cells
How many germ cells at birth (combined)?
- 500,000
How does the occytes keep decreasing with age?
- by ATRESIA
- apoptosis -based process
When does meiosis halt in oocytes before birth? When may it further develop?
- halts at Prophase I of meiosis I
- Completes Meiosis I when Ovulation occurs
When is fertilization complete?
- in meiosis II
State the diff. stages of follicular development.
PRIMORDIAL follicle >Primary Follicle >Late Primary Follicle > Secondary Follicle > Mature GRAAFIAN follicle
What is a granulosa cell?
- They surround the oocyte
- proliferate during follicular maturation
- only source of ESTRADIOL in follicular phase of ovarian cycle
What layers are seen in the Primordial cells?
- Primary oocyte
- Pregranulosa cells
- stromal cells
…..oocyte MUST associate with the pregranulosa cells to THRIVE
What layer is specifically seen with Primary follicles?
- zona Granulosa
(cuboidal granulosa cells) - develops in the growth phase of the follicle
What specific changes occur to the primary oocyte in the primary follicle?
- –enlarges
- special ECM layer forms= ZONA PELLUCIDA
- between the oocyte and granulosa cells
What layers develop in the Late Primary follicle?
- theca interna
- outer fibroblast-like layer; Theca EXterna forms
What does theca interna do?
- secretes estrogen prescursors which will be converted to estrogen by GC
What follicular fluid- filled space forms in the secondary follicle?
- ANTRUM
- –continues to enlarge with the oocyte
- theca ext. and int. continue to proliferate
What are the largest follicles called? How big?
- Graafian Follicles
- 20mm in diameter
What occurs to the graafian follicle one day before ovulation?
- oocyte completes Meiosis I
- producing a similar in size IIary oocyte and polar body
WHat does the IIary oocyte do?
- it begins the second phase of MEIOSIS (stops at metaphase II)
When does the oocyte complete its meiosis II?
- when it has become a FULLY mature oocyte
- and ovulated and fertilized by a sperm
What does the follicle become after ovulation?
- Corpus Luteum
- —-with its theca and GC secreting estrogens and progesterones
What occurs if no implantation happens?
- corpus albicans forms (white connective tissue)
What occurs to C.Luteum if implantation occurs?
- placenta secretes HCG
- prevent degen. of C.L for a time (progesterone levels maintain)
How does the uterine tube work to ensure to entry of the ovum into the tube?
- infundibulum MOVES so its opening is ADJACENT to the site of rupture
- ovum is propelled DOWN by gentle peristalsis (currents made by the ciliated epithelium)
Where is the site of fertilization?
- usually in the ampulla
How is the uterine lining of the tube diff. at the Ampulla compared to the isthmus?
- Ampulla: MORE ciliated cells, hihgly folded, surrounded by 2 layers of SM
- Isthmus: simple archit. , mainly secretory (few ciliated cells), 3 layers of SM
Name the 3 layers of the uterine wall.
- Endometrium
- Myometrium
- Perimetrium
What is the endometrium made of?
- tubular secretory GLANDS
- embedded in connective tissue STROMA
How many layers of smooth muscle does the myometrium have?
- 3 layers of SM
- combined with COLLAGEN and elastic tissue
What is the perimetrium?
- outer, visceral covering of loose connective tissue
What is the endometrium divided into?
- Stratum Functionalis
- Stratum Basalis
Which layer undergoes degeneration and loss?
- S. FUNCTIONALIS
Which one is considered to be the RESERVE tissue and why?
- S.BASALIS
- it regenerates the S. functionalis
When does regeneration of the S. Functionalis occur and why?
- during the PROLIFERATIVE phase
- s. BASALIS grows (glands, stroma and vasculature grow)
- increasing endometrium thickness
Which hormone helps in stromal proliferation of S.functionalis ?
estrogen
How do the glands change from proliferative to secretory phase?
- glands become COILED (initially straight) in secretory phase
(secrete glycogen)
What happens in the menstruation phase for the S..Functionalis to shed?
- arterioles in the S.F constrict
- depriving the tissue of blood
> >ISCHEMIA and tissue breakdown
——>tissue breakdown, blood leakage and sloughing
How does the transition zone of the cervix come about?
- the VAGINAL surface of the cervix: Stratified Squamous Epithelium
»>mucous secreting SIMPLE COLUMNAR epithelium
What is the clinical sign. of the transition zone of the cervix?
- site of DYSPLASIA
- neoplastic changes> CERVICAL cancer
What changes occurs in the secretions of the glands in the SCE of the cervix?
SC- simple columnar epithelium
- THIN and WATERY secretions in PROLIFERATIVE phase
- THICK and VISCOUS after ovulation (to stop microorganisms to ascend)
What occurs with blockade of the glands in the SCE part of the CERVIX?
- NABOTHIAN CYST
What are the 4 layers of the Vagina?
- Non-keratinzed SSE (layer is thicker -d.t glycogen accumulation-during reproductive years)
- Lamina Propria (connect. tissue RICH in elastic fibres and thin-walled BV)
- Fibromuscular layer (inner circular, outer longitudinal)
- Adventitia
What layer is responsible for lubricating the vagina?
- cervical glands from the thin walled blood vessels of the lamina propria
How does commensal bacteria prevent pathogenic growth in the vagina?
- the commensal bact. METABOLIZES the glycogen to LACTIC acid
What is the mons pubis?
- skin containing hair follicles
overlies a subcutaneous fat pad - lies over the PUBIC SYMPHYSIS
What is the seen histologically in the Labia Majora?
- similar structure to Mons pubis
- rich in SWEAT Glands, sebaceous glands
- small bundles of SMOOTH muscle
- —no hair follicles in inner surface
How is the labia minora diff. ?
- lacks subc. fat and hair follicles
- RICH in vasculature and sebaceous glands
…the keratinzed epithelium extends into the opening of the VAGINA up to the HYMEN (transition to non-keratinzed SSE)
WHat does the clitoris contain?
- 2 tubules of erectile vascular tissue
- covered by FIBROCOLLAGENOUS sheath —-covered with skin rich with innervation and thin epidermis
