Module 12 Flashcards
Where is gonadotrophin-RH secreted from and where does it exert its action?
Hypothalamus/Anterior pituitary gland
Where is follicle stimulating hormone secreted from and where does it exert its action?
Anterior pituitary gland Ovary-follicles
Where is luteinising hormone secreted from and where does it exert its action?
Anterior pituitary gland Ovary-follicles
Where is estrogen secreted from and where does it exert its action?
Ovary: Granulosa cells Uterus: Proliferative Phase Female 2nd sexual charasteristics
Where is progesterone secreted from and where does it exert its action?
Ovary: corpus luteum Uterus: secretory phase
What happens in the ovary during Days 1-13?
FSH stimulates the follicles to mature
What happens in the ovary at Day 14?
Graafian follicle ruptures to release ovum (egg)
What happens in the ovary during Days 15-28?
Corpus luteum develops from remaining granulosa cells
Why is FSH secretion higher in the first half of the cycle than in the second?
FSH is stimulating the follicle to grow/develop/mature
What is the significance of the peak in LH secretion on Day 13?
It will cause ovulation
What happens in the uterus during Days 1-5?
menses
What happens in the uterus at Days 5-14?
Endometrium re-builds itself; proliferative phase
Which hormone is mainly responsible for the events described above?
Estrogen
What happens in the uterus during Days 14-28?
Uterus prepares to receive the fertilised egg; secretory phase.
Why do levels of estrogen and progesterone decline after 28 days?
Corpus luteum degenerates
What event does this trigger in the uterus?
Menses
What event could prevent this from happening?
Fertilisation of the egg
What are the three components of the female external genitalia?
Labia majora, labia minora, clitoris
What are the seven components of the female reproductive system?
Ovary, uterine tube (oviduct), uterus, cervix, vagina, urethra, fimbriae
Label the following diagram:
In the area known as the vestibule, which opening is more anterior, the vagina or urethra?
urethra
Name the structure that is located at the anterior margin of the vestibule
Clitoris
What kind of epithelium lines the wall of the vagin?
Non-keratinised stratified squamous
Vaginal walls release large amounts of glycogen, how does this aid the health of the vagina?
Theglycogen is metabolised by local bacteria, producing lactic acid and decreasing pH, making it toxic to foreign pathogens
What are the three segments of the uterine tube?
Ampulla, infundibulum, isthmus
What are the three layers of the uterus?
endomterium, myometrium, perimetrium
What are the associated ligaments of the frs?
broad ligament, suspensory ligament, ovarian ligament
Label the following diagram
What role do the fimbriae of the uterine tubes play in ovoluation?
Stroke developing follicle, increasing fluid movement into the fallipian tube (act like a vacuum to suck egg in)
What tupe of epithelium lines the uterine tubes?
Simple ciliated columnar
Unlike spermatozoa, the oocyte cannot propel itself, how is it able to make its way along the tube?
The beating action of the cilia of the epithelium lining the walls
The suspensory ligament attaches the ovary; what is the main function of this ligament?
Ovarian arteries, veins and nerves enter the ovary via this ligament
What is the name of the white fibrous layer of connective tissue that surrounds the outer surface of the ovary (hint: it has the same name as the white fibrous layer around the testes)?
Tunica albuginea
What structures are contained within the region of the ovarian cortex?
ovarian follicles
Label the following diagram
Name the structure that attaches the breast tissue to the underlying muscle?
Suspensory (Cooper’s) ligaments
What is the name for the secretory sacs that are located deep within the breast tissue?
Alveoli
Which anterior pituitary hormone in responsible for the initiation of milk production?
prolactin
Which posterior pituitary hormone is released when a suckling infant stimulates the breast?
oxytocin
There is an initial delay after birth before true milk production begins; until this time a product called colostrum is produced. What is the difference between colostrum and milk?
Colostrum is a yellowish fluid which is high in protein, has less lactose than milk andm almost no fat, it is rich in antibodies.
Name the type of cell division (mitosis or meiosis) by which oogonia replicate/proliferate.
mitosis
In which stage of meiosis are the primary oocytes at birth?
Halted in Meiosis 1 (it hasn’t completed the 1st meiotic division)
Approximately how many oocytes does a woman have at birth?
2 million
At which point during the ovarian cycle, is the first meiotic division completed?
End of Follicular phase, just before ovulation
What type of oocyte (primary/secondary) is ovulated from the mature follicle; what stage of meiosis is it in?
Secondary oocyte, halted during Meiosis II
When is the second meiotic division completed?
Fertilisation
What is the difference between a secondary and a mature (Graafian) follicle?
Secondary has isolated vesicles (pools) of fluid, mature pools have coalesced into one antrum
What is the zona pellucida and what does it do?
Thick glycoprotein membrane surrounding oocyte with receptors for attachment of acrosome
What hormone do the granulosa (follicular) cells secrete?
Oestrogen
Which hormones do cells of the corpus luteum produce?
Progesterone and oestrogen
What is the function of these hormones?
Oestrogen: uterine proliferation, follicle development
Progesterone: uterine secretion, pregnancy maintenance
Which of the layers of the uterine wall is considered to be the uterine lining?
endometrium
Name the components of the uterine lining
Stratum basalis and stratum functionalis, which alters depending on the day of the cycle
Which hormones influence the uterine lining to proliferate?
Oestrogen
What is the role of the spiral arteries?
Supply blood to stratum functionalis
What is the role of the tubular uterine glands?
Secrete a fluid rich in glycogen
How does the proliferative phase differ from the secretoryphase of the endometrium?
Thickening of basal and functional layers due to a hypertrophy of endometrial cells, glands become more numerous and spiral
What is the trigger for menstruation to begin?
Decline in progesterone and oestrogen levels
Which layer of the endometrium is shed during the menstrual phase?
Stratum functionalis
From which endometrial layer is the layer identified in “4” above, rebuilt?
Stratum basalis
What initially causes the events identified in “3” above?
Corpus luteum is degenerating
What else in the female reproductive cycle might the “trigger for menstruation” be responsible for (Hint: Think about what has to happen to start the next cycle)?
Declining progesterone & oestrogen levels cause the release of GnRH→ ↑FSH & LH → next batch of follicles being switched on to mature (next cycle)
Name two effects of follicle stimulating hormone (FSH).
Follicle development and oestrogen secretion from
follicle (granulosa) cells
Describe the pre-ovulatory role of oestrogen in positive
feedback.
effect on hypothalamus & anterior pituitary to cause surge in FSH & LH
Name three effects of luteinising hormone (LH).
Maturation of follicle with increased oestrogen secretion; causes ovulation and corpus luteum formation
What hormone released by the ovary exerts a negative feedback effect on the anterior pituitary gland to inhibit FSH secretion?
Inhibin
Why does the ovary release this hormone?
To signal the anterior pituitary gland that sufficient follicles have developed in this cycle.
Given that the COCP contains both oestrogen and progesterone, how would the COCP affect FSH and LH levels in the blood?
Decreases both due to negative feedback
How would the changes described above affect folliculogenesis (follicle development) and ovulation?
No LH surge = no ovulation. Decreased FSH = decreased follicle recruitment.
What structure in the ovary normally produces both progesterone and oestrogen? Is this structure present
in a patient taking the COCP?
Corpus luteum. No
At the end of a COCP packet there are usually 7 inactive pills, containing sugar. What purpose do these serve?
Withdrawal of oestrogen and progesterone leads to menses. These pills also assist the user to maintain a routine of usage.
One of the effects of the COCP is to thicken the cervical mucus. Would this assist in preventing conception?
Yes, sperm must pass through the cervical canal to enter. If this is blocked with a thick mucus they are unable to pass through.
How will the “morning after” pill affect the endometrial lining (use your knowledge of the ovarian cycle)?
Causes it to shed with a massive dose of oestrogen, which negatively feeds back lowering blood levels of FSH and LH which in turn reduces estrogen and progesterone from the corpus luteum. This mimics the rapid decline in these hormones that normally triggers menstruation
