IPP: Sexual Health Flashcards
Name the following parts of the femalw reproductive system
The female reproductive system consists primarily of the uterus, vagina, ovaries, and fallopian tubes.
Name the following parts of the male reprodutive system
What is the function of ovaries?
Ovary functions: provision of eggs capable of being fertilised and production of sex hormones.
What tissues are the ovaries made of?
The ovaries are made up of interstitial glandular tissue and primordial follicles
What are the stages of Ovarian follicle growth and development
Follicular Phase:
Step 1: Tere is a reservoir of approximately 400,000 primordial follicles built up before birth. Approximately 20 per month begin to mature giving rise to one dominant follicle.
Step 2: Oocytes are surrounded by continuous single layer of cells called granulosa cells and the zona pellucida develops between the granulosa cell layer and oocyte. The follicle increases in size as the granulosa cells increase in numbers.
Step 3: In secondary follicles (diameter 0.2mm), the oocyte increase in size. Granulosa cells grow to two or more layers and surrounded by membrane. Theca cells develop on outer layer of membrane. Theca cells and granulosa cells are production site of sex hormones, particularly oestrogens. Granulosa cells produce follicular fluid secreted into intercellular space. Fluid contains substances which further regulate follicle development and nutrients for oocyte. Granulosa cells are pushed further apart and a follicular cavity (antrum) develops. Degeneration and absorption occurs in all but one follicle - perhaps to do with maturation not coinciding with LH surge.
Step 4: In the Graafian follicle (20mm) rupture is imminent. Oocyte becomes detached and swims in follicular fluid.
Step 5: The follicle lies beneath surface of ovary, causing it to bulge. The follicle wall and ovary burst at highest point of bulge. Oocyte is washed out with granulosa cells and follicular fluid and gathered up by Fallopian tube. This is called OVULATION.
Luteal Phase:
Step 6: After the Follicular phase, then go into Luteal phase where remains of follicle collapse, blood penetrates cavity and corpus luteum develops. Granulosa and theca cells accumulate lipids and follicle becomes permeated by small blood vessels and connective tissue cells - luteinisation.
Describe the phases of the menstrual cycle
Describe the homronal feedback system that occur during the menstruation cycle
the hypothalamus releases gonadotrophin releasing hormone (GnRH) to the pituitary. GnRH acts on the anterior pituitary to release FSH (Follicle stimulating hormone) and LH (Luteinising hormone).
FSH and LH together stimulate a follicle in the ovary to develop so that the ovum (egg) within it matures. This causes the ovum to release oestrogen.
The combination of FSH, LH and oestrogen has a positive feedback effect causing the release of more oestrogen, FSH and LH.
Oestrogen causes the muscle and lining layers of the uterus to grow thicker in preparation for the possible embryo.
The surge of LH on or about day 14 causes ovulation (release of an egg from the follicle).
The remaining section of the follicle develops into the corpus luteum, which secretes the hormone progesterone for several days.
The combination of oestrogen and progesterone has a negative feedback effect on the pituitary stopping release of FSH and LH.
Describe the hormonal changes that occur during the menstrual cycle.
What does progesterone do?
First Stage of the cycle is menstruation. There is low levels of both sex hormones (oestrogen and progesterone) and increasing levels of FSH and LH stimulates follicular development.
Oestrogen levels increase as the follicle develops and the thecal and granulosa cells release oestrogen. There is a peak in oestrogen followed by surges in FSH and then LH which causes the follicle to rupture.
Progesterone is then produced by the corpus luteum. There is a rise in progesterone as the corpus luteum develops. Progesterone has the effect of maintaining the lining of the uterus and developing more blood vessels. This would be necessary for the interchange of materials with an embryo developing from a fertilised egg, if present.
Sex hormones fall if no fertilization and FSH and LH kick in again.
At the end of the cycle, the corpus luteum breaks down and therefore oestrogen and progesterone fall. This stimulates GnRH secretion from the hypothalamus.
Oestrogen and progesterone are results of these processes but are also actively involved in regulation of the follicular and luteal phases.
Describe the changes that occur to the endrometrium throughout the menstrual cycle
Desquamation Phase:
The first few days of the cycle is called the menstruation or desquamation phase. The mucosa of the endometrium is shed if there is no implantation of a fertilised egg.
Proliferative Phase:
Oestrogen of ripening follicles induce growth of the functional layers. Epithelial cells shoot out of basal layers and form narrow gland tubes with secretory cells. Spiral arterial arteries grow at the same time.
By the time ovulation takes place the functional layer is about 6-8mm.
Secretory Phase:
Increased progesterone by the corpus luteum stimulates secretory transformation of the endometrium. The endometrium secretes a glycogen containing secretion which is a source of energy for a fertilized egg. Days 19-21 there is maximum secretion in anticipation of the fertilised egg.
Production of progesterone decreases if there is no fetillisation and reduced perfusion, atrophy and degeneration of tissue components.
Describe fertility through the mensrutal cycle
What other physiological changes occur during the mensturation cycle?
- Basal body temperature
- Cervical mucus
Describe the changes in cervical mucus
Cervical mucus
Other changes occur in cervix and cervical mucous.
Oestrogen causes cervix to dilate slightly and consistency of mucous changes at ovulation
Normally cervical mucus has a dense network of threads and viscous matrix which is impermeable to spermatozoa but during ovulation there is a lower cross-linking of threads and increased volume. Also a highly nutritive environment for sperm.
Describe the changes in BBT
Basal Body Temperature
During the follicular phase of the menstrual cycle, the higher the levels of oestrogen present the lower BBTs.
After ovulation, the temperature will be raised by at least 0.2C for at least 72hr, compared to the previous 6 days.
If pregnancy does not occur, the disintegration of the corpus luteum causes a drop in BBTs that roughly coincides with the onset of the next menstruation. If pregnancy does occur, the corpus luteum continues to function (and maintain high BBTs) for the first trimester of the pregnancy. After the first trimester, the woman’s body temperature drops to her pre-ovulatory normal as the placenta takes over functions previously performed by the corpus luteum.
What are methods of contraception?
Hormonal
- Combined oral, transdermal patch, vaginal ring
- Progesterone-only oral, injectable and implant
- IUS: similar to IUD but instead of releasing copper it release progesterone into the womb
- Post-coital (emergency)
Non-hormonal (Including barrier)
- Condom (male & female)
- Diaphragm
- IUD: Small T-shaped plastic or copper device put into your uterus which release copper and prevents pregnancy (5-10 years)
- “natural methods” e.g. cervical mucus, temperature, persona
- Sterilization (male & female)
How to oral contracpetives work?
Oral contraceptives are synthetic versions of oestrogen (Estrogen) or progesterone (Progestin):
- Estrogen: Inhibits FSH and LH release from the pituitary gland. This prevents growth of the follicle and new egg release from the ovaries
- Progesterone: Inhibits LH release so reduces thickness of uterus so the egg cannot attach. It also thickens cervical mucus preventing sperm reaching the egg.
