reproduction Flashcards
ovary function
produce hormones estrogen and progesterone
site of ovum (egg cell) development and ovulation
fallopian tubes function
carry the ovum from the ovary to the uterus
usually the site of fertilization
fimbriae function
sweep the ovum into the fallopian tube following ovulation
uterus function
pear-shaped organ in which the embryo and fetus develop
involved in menstruation
cervix function
separates the vagina from the uterus
holds the fetus in place during pregnancy
dilates during birth to allow the fetus to leave the uterus
vagina function
extends from the cervix to the external environment
provides a passageway for sperm and menstrual flow
functions as the birth canal
testosterone
located in interstitial cells
stimulates spermatogenesis
promotes and regulates the development of secondary sexual characteristics
associated with sex drive levels
follicle stimulate hormone (FSH)
located in pituitary gland
stimulates the production of sperm cells in the seminiferous tubules
luteinizing hormone (LH)
located in the pituitary gland
promotes the production of testosterone by the interstitial cells
gonadotropin releasing hormone (GnRH)
located in the hypothalamus
stimulates secretion of FSH and LH
Ageing and the Female Reproductive System Female Menopause:Perimenopause
Transitional period between reproductive and non-reproductive years, lasting 2 to 8 years
5-10 years before menopause women note mild to extreme variability in frequency and quality of flow
Ovaries are still functioning, but function has started to decrease
Symptoms depend on the sensitivity of the target tissue receptors
Symptoms begin with a lengthening of the menstrual cycle which correlates with anovulatory cycles
Menstrual and(An)ovulation cycles
It is possible for a woman to become pregnant even if she is showing signs of perimenopause, because she may still be ovulating
During each menstrual cycle, the body goes through complex hormonal changes that lead up to a process known as ovulation, when a mature egg is released from the ovary. After ovulation occurs, the empty egg follicle, now called a corpus luteum, produces the hormone progesterone. Progesterone helps support a possible early pregnancy.
If conception doesn’t occur, the corpus luteum breaks down and stops producing progesterone, which is what triggers the start of a period.
During an anovulatory cycle, a woman does not ovulate and therefore does not release an egg. A woman who is not ovulating is not able to get pregnant.
Other common reasons for anovulation
Being overweight or obese
High levels of stress
Being underweight
Exercising too much
Hormonal imbalances of thyroid stimulating hormone (TSH) and prolactin
Polycystic ovary syndrome (PCOS)
Can be common during periods of hormonal transition.
A girl’s first few periods are usually anovulatory.
The first few periods after stopping birth control are often anovulatory, as is the time during perimenopause.
Many women also have an anovulatory cycle after miscarriage or after childbirth.
menopause
Point in woman’s life when she is no longer fertile and menstrual periods stop
Menopause is defined as the absence of menstrual periods for 12 months
Average age for natural menopause is 51 years, but it can occur earlier or later
Considerations for Menopause:
Women who smoke tend to start menopause earlier–on average 2 years sooner than nonsmokers
Tends to be genetically predetermined and not affected by age at menarche, childbearing or lactation, use of oral contraceptives, socioeconomic class, or race
Thinner women experience earlier
Irregular menses in women in their early 40’s
Alcohol consumption – later menopause
Menopause:Ovarian Changes
Estradiol levels remain normal to slightly elevated until about 1 year before menopause
At around 37 to 38 years women experience accelerated follicular loss until the supply is depleted
Correlates with an increase in Follicular Stimulating Hormone (FSH) and decrease in inhibin
Inhibin B is usually responsible for keeping FSH levels down
hormones
Estradiol is produced by the ovaries
Estrogen is a generic term for three similar hormones; estradiol, estrone, and estriol. Estradiol is the most potent and plentiful.
Estrogen is needed for maturation of reproductive organs, development of secondary sec characteristics, closure of long bones after pubertal growth spurt, regulation of menstrual cycle and endometrial regeneration after menstruation.
Estrogen has metabolic effects on bones, liver, blood vessels, brain and CNS, kidneys and skin. After menopause, ovarian production of estradiol and estrone is greatly decreased leading to increased susceptibility to osteoporosis
Increase in FSH stimulation accelerates follicular loss and declining inhibin production disrupts the negative feedback influence over pituitary secretion of FSH
One of two hormones (inhibin-A and inhibin-B) secreted by the gonads (by Sertoli cells in the male and the granulosa cells in the female) – inhibit the production of follicle-stimulating hormone (FSH) by the pituitary gland
In women, follicle-stimulating hormone helps to mature the ovarian follicles that release the eggs. Men’s bodies use FSH to support the growth and development of sperm.
Without the release of FSH, a woman cannot continue her reproductive cycle, as her ovaries will not release an egg.
Purposes of FSH test:
Menopause testing: If a woman’s menstrual cycle has become irregular or she has not had her period at all, a doctor may order the test. If FSH levels are high, it could indicate menopause.
Female fertility testing: If a woman is not ovulating, her FSH levels might be either high or low, depending on the cause.
Male fertility testing: In men, FSH stimulates the growth of sperm cells. If a man’s FSH levels are high, it can mean the testicles are not functioning properly.
Menopause: Uterine Changes
Proliferative growth of the endometrium
Longer exposure to estrogen and greater thickness of the endometrium, half of all women will experience dysfunctional uterine bleeding that is heavy and unpredictable
Menopause: Systemic Changes
Vasomotor flashes are characterized by rise in skin temperature, dilation of peripheral blood vessels, increased blood flow in the hands, increased skin conductance, and transient increase in heart rate followed by a temperature drop and produce perspiration over the area of flash distribution
Dizziness, nausea, headaches, or palpitations may accompany the flush
Flushes vary in frequency, intensity and duration and experienced for 1 to 15 years
Rapid changes in estrogen levels can increase emotional stress with unpredictable mood swings, weight gain, migraine headaches, and insomnia
Lower estrogen levels will decrease skin thickness and diminish skin elasticity, increasing skin dryness and wrinkling
Menopause: Breast Tissue Changes
Breast tissue becomes involuted
Fat deposits and connective tissue increase
Breasts are reduced in size and firmness
Menopause: Urogenital Tract Changes
Ovaries shrink, the uterus atrophies and the vagina shortens, narrows and loses some elasticity
Lubrication in the vagina diminishes and vaginal pH increases creating higher incidence of vaginitis
Cervix atrophies, the cervical os shrinks, vaginal epithelium atrophies, labia major and minora become less prominent
Some pubic hair is lost
Urethral tone declines throughout the pelvic area– urinary frequency or urgency, UTI’s and incontinence may occur
Regular sexual activity and orgasm may diminish some of these changes
Sexually active women have less vaginal atrophy