part 3 reproductive
- is the cycle of changes that occurs in the uterus and ovary for the purpose of sexual reproduction. It is essential for the production of eggs/ova and for the preparation of the uterus for pregnancy.
- The _________ occurs only in fertile female individual. In humans, the length of a menstrual cycle varies greatly among women (ranging from 21 to 35 days), with 28 days designated as the average length.
Menstrual cycle (ovarian-endometrial cycle)
Females begin their menstrual cycle during puberty at the onset of _______ (first menstrual period). Females continue to have many menstrual cycles throughout their lives until menopause
menarche
Each cycle can be divided into phases based on events in the _______ or in the _______
- ovary (ovarian cycle)
- uterus (endometrial/uterine cycle)
1. The ovarian cycle :
a..follicular phase,
b. ovulation, and
c. luteal phase
2. The uterine/endometrial cycle :
a. menstruation
b. proliferative phase
c. secretory phase.
The menstrual cycle is a self-regulating process during which the body undergoes many physiological and hormonal changes. It is regulated by hormones secreted from:
1. hypothalamus :
2. pituitary gland:
3. Ovaries :
1. hypothalamus :
2. pituitary gland:
3. Ovaries :
1. Gonadotropin Releasing hormone (GnRH)
2. follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
3.estrogen and progesterone
is the first part of the ovarian cycle. During this phase, the 𝙤𝙫𝙖𝙧𝙞𝙖𝙣 𝙛𝙤𝙡𝙡𝙞𝙘𝙡𝙚𝙨 𝙢𝙖𝙩𝙪𝙧𝙚 𝙖𝙣𝙙 𝙜𝙚𝙩 𝙧𝙚𝙖𝙙𝙮 𝙩𝙤 𝙧𝙚𝙡𝙚𝙖𝙨𝙚 𝙖𝙣 𝙚𝙜𝙜. This phase overlaps with the proliferative phase of the uterine cycle.
Prompted by the 𝙝𝙮𝙥𝙤𝙩𝙝𝙖𝙡𝙖𝙢𝙪𝙨, the 𝙥𝙞𝙩𝙪𝙞𝙩𝙖𝙧𝙮 𝙜𝙡𝙖𝙣𝙙 releases 𝙛𝙤𝙡𝙡𝙞𝙘𝙡𝙚 𝙨𝙩𝙞𝙢𝙪𝙡𝙖𝙩𝙞𝙣𝙜 𝙝𝙤𝙧𝙢𝙤𝙣𝙚 (𝙁𝙎𝙃). This will result to growth and development of few follicles in the ovaries. Usually, only one follicle will mature into an egg, while the others die.
Follicular phase
The dominant follicle that reaches maturity is called a ______, or _______, follicle, and it contains the ovum.
𝙩𝙚𝙧𝙩𝙞𝙖𝙧𝙮 or 𝙂𝙧𝙖𝙖𝙛𝙞𝙖𝙣
During this phase, the level of hormone 𝙚𝙨𝙩𝙧𝙤𝙜𝙚𝙣 𝙞𝙣𝙘𝙧𝙚𝙖𝙨𝙚𝙨𝙡 in parallel to the growth of the dominant follicle. Estrogen levels rise dramatically during the days before ovulation and peak about one day before ovulation. The surge in estrogen triggers a spike in yet another hormone – the luteinizing hormone, or LH. Ovulation occurs as this increase in LH causes the follicle to rupture and release an egg.
Follicular phase
- is the second phase of the ovarian cycle.
- is when a mature egg (ovum) is 𝙧𝙚𝙡𝙚𝙖𝙨𝙚𝙙 from the ovarian follicle to the nearest fallopian tube during your menstrual cycle.
The increase in 𝙡𝙪𝙩𝙚𝙞𝙣𝙞𝙯𝙞𝙣𝙜 𝙝𝙤𝙧𝙢𝙤𝙣𝙚, or LH (LH surge) triggers _________. The egg then travels into the uterus. In regular 28-day menstrual cycles, ovulation usually occurs on day 14. However, most women have different menstrual cycle lengths. In general, ovulation occurs 11 to 16 days before the next menstrual period.
Ovulation
It takes about ______ days for the egg to travel toward the uterus. If fertilization is to occur, it must happen within ____ hours of ovulation or the egg degenerates. After ovulation, the luteal phase begins.
- three to four
-24
The _______ is the final phase of the ovarian cycle and it corresponds to the secretory phase of the uterine cycle. During the ______, the pituitary hormones FSH and LH cause the remaining parts of the dominant follicle in the ovary to transform into the 𝙘𝙤𝙧𝙥𝙪𝙨 𝙡𝙪𝙩𝙚𝙪𝙢, which produce 𝙚𝙨𝙩𝙧𝙤𝙜𝙚𝙣 and large amounts of 𝙥𝙧𝙤𝙜𝙚𝙨𝙩𝙚𝙧𝙤𝙣𝙚. This process is known as 𝙡𝙪𝙩𝙚𝙞𝙣𝙞𝙯𝙖𝙩𝙞𝙤𝙣. However, The increased hormones produced by the corpus luteum suppress production of the FSH and LH that the corpus luteum needs to maintain itself. Consequently, the level of FSH and LH fall quickly over time, and the corpus luteum subsequently atrophies. When the corpus luteum involutes, and losses its secretory function and its 𝙮𝙚𝙡𝙡𝙤𝙬𝙞𝙨𝙝 lipid characterisitic, it becomes 𝙘𝙤𝙧𝙥𝙪𝙨 𝙖𝙡𝙗𝙞𝙘𝙖𝙣𝙨 (around 12 days after ovulation), which will eventually replaced by connective tissue.
Falling levels of progesterone trigger menstruation and the beginning of the next cycle.
Luteal phase
the periodic discharge of blood and mucosal tissue (endometrium) from the uterus, occurring approximately monthly from puberty to menopause in nonpregnant women. It is the first phase of the uterine cycle.
Menstruation (menses)
is the first menstrual period, usually occurring during puberty.
Menarche
Menstruation is caused by the sudden ______, especially progesterone , at the end of the menstrual cycle. This is primarily because of the involution of the corpus luteum.
reduction of the estrogen and progesterone
Regular intervals; volume is excessive or duration is longer than 7 days
Menorrhagia
Absence of periods for at least 3 cycles
Amenorrhea
Light bleeding at irregular intervals
Metrorrhagia
Heavy bleeding at irregular intervals
Menometrorrhagia
Bleeding at greater than 35-day intervals
Oligomenorrhea
Bleeding at less than 24-day intervals
Polymenorrhea
is the second phase of the uterine cycle when estrogen causes the lining of the uterus to grow, or proliferate, during this time. As the ovarian follicles mature, they secrete increasing amounts of estrogen. The estrogens initiate the formation of a new layer of endometrium in the uterus, histologically identified as the proliferative endometrium. The estrogen also stimulates crypts in the cervix to produce fertile cervical mucus, which may be noticed by women practicing fertility awareness.
Proliferative phase
is the final phase of the uterine cycle and it corresponds to the luteal phase of the ovarian cycle. During the ________-, the corpus luteum produces progesterone, which plays a vital role in making the endometrium receptive to implantation of the blastocyst and supportive of the early pregnancy, by increasing blood flow and uterine secretions and reducing the contractility of the smooth muscle in the uterus. It also has the side effect of raising the woman's basal body temperature.
Secretory phase
is defined as the permanent cessation of menstrual periods, determined retrospectively after a woman has experienced 12 months of amenorrhea (absence of menses) without any other obvious pathological or physiological cause.
It occurs at a median age of 51.4 years in normal women, and is a reflection of complete, or near complete, ovarian follicular depletion, with resulting to decrease estrogen (hypoestrogenemia) and high FSH concentrations.
Natural menopause
In the human ovary, 2 million ova are present at birth, and about 400,000 are present at the onset of puberty. Then, during the reproductive years of women, between about 13 and 46 years of age, about_______ of these follicles develop enough to expel their ova- one in each month; the remainder degenerate (become atretic). At the end of reproductive capability, at the menopause, only a few primordial follicles remain in the ovaries, and even these degenerate soon thereafter.
400
During the luteal cycle, the pituitary hormones FSH and LH cause the remaining parts of the dominant follicle in the ovary to transform into the _______, which produce 𝙚𝙨𝙩𝙧𝙤𝙜𝙚𝙣 and large amounts of 𝙥𝙧𝙤𝙜𝙚𝙨𝙩𝙚𝙧𝙤𝙣𝙚. This process is known as 𝙡𝙪𝙩𝙚𝙞𝙣𝙞𝙯𝙖𝙩𝙞𝙤𝙣. However, The increased hormones produced by the corpus luteum suppress production of the FSH and LH that the corpus luteum needs to maintain itself. Consequently, the level of FSH and LH fall quickly over time, and the corpus luteum subsequently atrophies.
𝙘𝙤𝙧𝙥𝙪𝙨 𝙡𝙪𝙩𝙚𝙪𝙢
When the corpus luteum involutes, and losses its secretory function and its 𝙮𝙚𝙡𝙡𝙤𝙬𝙞𝙨𝙝 lipid characterisitic, it becomes ________ (around 12 days after ovulation), which will eventually replaced by connective tissue.
corpus albicans