Reproduction Cycle

CHAPTER I

INTRODUCTION

A.       Background

       Reproduction is the formation of a new organism from an individual who has been there. Reproduction aims to preserve a species as a whole. So the reproductive process is not required to survival each organism such as breathing, eating, excretion and digestion, but without the reproduction of species will become extinct. Reproduction can be viewed from many different levels. At the molecular level involves the ability of a typical reproduction of nucleic acids to replace self-distinguished. At the cellular level, reproduction involves the ability of cells to replicate, and at the level of reproduction of organisms related to an individual's ability to produce offspring. Reproduction in animals grouped into two, namely the asexual reproduction and sexual reproduction.

       In the sexually mature female animal is known of the reproductive cycle. Sexual reproductive cycle is a cycle contained in the individual female sexual and non-pregnant adults, including cyclic changes in reproductive organs of a particular instance of the ovary, uterus and vagina under the control of reproductive hormones. Reproductive cycle includes esterus cycle, ovarian cycle, and menstrual cycles.

       Estrous cycle is the reproductive cycle that goes on non-primate animals sexually mature female who is not pregnant. In mice, the estrous cycle consists of several major phases are phases of diestrus, proestrus phase, the phase of estrus, and metestrus phases. Estrous cycle phases can be identified by making
vaginal smears. Observation of vaginal cytology smears can be done using a light microscope. Vaginal smear test application can be used to determine activity of a material esterogenik (Elghamry et al., 1963)

       The menstrual cycle is the reproductive cycle that goes on sexually mature female primates are characterized by the presence of menstruation. The menstrual cycle consists of 3 phases are (i) the proliferation phase, (ii) secretory phase, (iii) menstrual phase.

       In this first observation we will observe the stages that occur in the reproductive cycle. Mus musculus is the object that is used because this genus have a short estrous cycle so that we can observe the phase-phase by observing the vaginal epithelial cells.

B.     Purpose

1.      Differentiate the cells at swab vagina of Mus musculus.

2.      Determine the reproduction cycle step of female Mus musculus.

C.    Benefit

1.        The student can know about the differences of each reproduction cells in vagina which has relation in reproduction cycle.

2.        The student can know the steps of reproduction cycle in female specially in Mus musculus as an object.

3.        After finished this report, we wish this report will be refrence to the next report. So, the result from next report will be better than this report.

CHAPTER II

PREVIEW OF LITERATURE

        In the sexually mature female animal is known of the reproductive cycle. Sexual reproductive cycle is a cycle contained in the individual female sexual and non-pregnant adults, including cyclic changes in reproductive organs of a particular instance of the ovary, uterus and vagina under the control of reproductive hormones. Reproductive cycle includes, among others esterus cycle, ovarian cycle, and menstrual cycle (Adnan, 2010).

       Reproductive activity in female mammalian have ups and downs according to a regular cycle. Each organ of the reproductive system that harmoniously with the cycles of other organs in the cycle. A series of processes in reproductive activity from beginning to end and again referred to the reproductive cycle. In mammalian, the length of these cycles vary for example in mice 4-5 days, pigs about 17-20 days, and humans an average of 28 days. The cycle includes ovarian cycle, vaginal cycles, and menstrual cycle (Sugiyanto, 1996).

      During preclinical investigations into the safety of drugs and chemicals, many are found to interfere with reproductive function in the female rat. This interference is commonly expressed as a change in normal morphology of the reproductive tract or a disturbance in the duration of particular phases of the estrous cycle. Such alterations can be recognized only if the pathologist has knowledge of the continuously changing histological appearance of the various components of the reproductive tract during the cycle and can accurately and consistently ascribe an individual tract to a particular phase of the cycle. Unfortunately, although comprehensive reports illustrating the normal appearance of the tract during the rat estrous cycle have been available over many years, they are generally somewhat ambiguous about distinct criteria for defining the end of one stage and the beginning of another. This detail is absolutely essential to achieve a consistent approach to staging the cycle. For the toxicologic pathologist, this report illustrates a pragmatic and practical approach to staging the estrous cycle in the rat based on personal experience and a review of the literature from the last century (Sagepub, 2010).

       In absence of pregnancy, its phases are (1) a short time of complete prepadness for reproduction accompanied by ovulation and increased sexual desire (estrous), (2) a period during which the fruitless preparation for pregnancy undergo regession (proestrous and metestrous), and (3)a period rest (diestrous), followed by (4) a period active preparatory changes (proestrous) leading up the next estrous, when everything  is again in readiness for reproduction. The length oftime occupied bby the estrous cycle varies widely among animals. In some it occurs only once in an entire year, with the estrous being so placed season that when the young are born, conditions are favorable for their rearing. Species having only one breeding season in a year are said to be monoestrous. Other animals exhibit several breeding period in a year called polyestrous (Carlson, 1996).

       The short length of the estrous cycle of rats makes them ideal for investigation of changes occurring during the reproductive cycle. The estrous cycle lasts four days and is characterized as: proestrus, estrus, metestrus and diestrus, which may be determined according to the cell types observed in the vaginal smear. Since the collection of vaginal secretion and the use of stained material generally takes some time, the aim of the present work was to provide researchers with some helpful considerations about the determination of the rat estrous cycle phases in a fast and practical way (Scielo, 2010).

A.    Ovarium Cycle

       Cycle in ovarium include the development and growth of ovarian follicles, from primordial follicles, growing follicles and follicle Graff. Follicles that are growing divided of primary follicles, secondary follicles and tertiary follicles. Most of follicles will degenerate during the reproductive period. Follicle regression takes place before birth and lasts throughout the reproductive period. Follicular growth is mainly composed of follicular cells, primary, primary oocytes, and stroma surrounding the follicles (Sugiyanto, 1996).

B.     Estrous Cycle

       Estrus was used first by Heape (1900) as a Latin adaptation of the Greek word oistros, meaning gadfly, sting, or frenzy to describe the “special period of sexual desire of the female (Sagepub, 2010).

       Mammals other than primates do not menstruate, and their sexual cycle is called estrous cycle. It is named for the conspicuous period of “heat” or estrous at the time of ovulation, normally the only time during which the sexual interest of the female is aroused (Ganong, 1969).

       During the estrous cycle, prolactin, LH and FSH remain low and increase in the afternoon of the proestrus phase. Estradiol levels begin to increase at metestrus, reaching peak levels during proestrus and returning to baseline at estrus. Progesterone secretion also increases during metestrus and diestrus with a decrease afterwards. Then the progesterone value rises to reach its second peak towards the end of proestrus (Scielo, 2010).

       Estrous cycle is the reproductive cycle that goes on non-primate animals sexually mature female who is not pregnant. In mice, the estrous cycle consists of several major phases are phases of diestrus, proestrus phase, the phase of estrus, and metestrus phases. According to Adnan (2010), the phases are:

1.      Diestrous phase, is a phase characterized by the core of epithelial cells in very small amounts and leukocytes in very much. The duration of this phase approximately 55 hours (Billet and Wild, 1975)

2.      Proestrous phase, is a phase characterized by the core of epithelial cells are round, leukocytes no or very little. The duration of this phase approximately 18 hours (Billet and Wild, 1975)

3.      Estrous phase, the phase characterized by the epithelial cells are very much gore, and some epithelial cells with a degenerate core. The duration of this phase approximately 25 hours (Billet and Wild, 1975).

4.      Metestrous phase is the phase that is characterized by epithelial cells and leukocytes that much gore. The duration of this phase of approximately 8 hours (Billet and Wild, 1975).

       Estrous cycle phases can be identified by making vaginal smears. Observation of vaginal cytology smears can be done using a light microscope. Vaginal smear test application can be used to determine activity of a material esterogenik (Elghamry et al., 1963 (Adnan, 2010).

       The characterization of each phase is based on the proportion among three types of cells observed in the vaginal smear: epithelial cells, cornified cells and leukocytes. The collection of vaginal secretion and the use of stained material generally take 1-2 hours or more. Thus, the aim of this work was to provide the researchers some helpful considerations about the determination of the rat estrous cycle phases in a fast and practical way ( Scielo, 2010)

       When animals are in diestrous phase, then at that time the animals are not sexually active. All mammals except the primate female high level, copulation lasts only possible at certain periods within each estrous cycle. Period in which the psychological and physiological female animals are willing to accept the stud is called passion or estrous. When estrous, a female is in a different psychological state clearly than the rest of the period outside of estrus in the cycle. Males usually show no sexual interest in females beyond the period of estrous, and when the males will marry the female, the female animals will be refused. Manifestations of passion caused by female sex hormones, namely estrogen produced by ovarian follicles. Giving by exogenous estrogen in female animals can lead to lust at almost any time during the period of the estrous cycle, even in animals ovariectonized females (Adnan, 2010).

       Many animals when passion becomes very active. High activity is caused by estrogen. Mice inside the cage spontaneously ran a lot more when estrus than during diestrus (Nalbandov, 1990). Estrous cycle is closely linked to changes in reproductive organs that took place in female animals (Adnan, 2010).

C.    Menstrual Cycle

       The menstrual cycle is an ongoing cycle of reproduction on sexually mature female primates are characterized by of menstruation. In humans the menstrual usually to end at age above 45 to 50 years, this period usually called monopause period. Long menstrual cycles are usually about 28 days. The menstrual cycle usually begins between ages 12 and 15 years. This period is commonly called menarch period, and continues until reach the menopause period.

        The menstrual cycle may be divided into three major phases: (1) the menses, (2) the proliferation (follicular) phase, and (3) the secretory phase. It will be easiest follow the changes if we commence with the conditions just after a menstrual period has ended (Carlson, 1996).

       The menstrual cycle consists of 3 phases are (i) the proliferation phase, (ii) secretion phase, (iii) menstrual phase. Proliferative phase is the phase in which the endometrial glands to grow as a result ongoing cell division in repeatedly. This phase
coincided with the development of ovarian follicles and the formation of estrogen hormone produced by the follicle cells. In this phase estrogen hormone levels in blood plasma increased. At the end of this phase the performance of the gland looks straight, narrow lumen and cells began to accumulate glycogen in the area surrounding the core, spiral arteries elongated and meandering. Secretion phase or luteal phase begins after ovulation and highly depends on the formation of the corpus luteum that secretes progesterone. Progesterone works to stimulate the gland cells to secretion. Gland into the winding because the lumen widened
due to discharge material that accumulates in it. In this phase endometrial thickness reaches a maximum as a result accumulation of secretions and the occurrence of stromal edema. During phase These mitotic divisions start is declining, while elongation and the winding continuing spiral arteries and extends into the superficial endometrium.

       Menstrual phase occurs when the ovum is not fertilized, there isn’t implantation. The absence of implantation caused no formation of the placenta. The absence of the placenta caused no formation of human chorionic gonadotrophin (hCG), there is no which maintains the corpus luteum. As a result of the corpus luteum degenerate. Degeneration of the corpus luteum into the corpus albican because the production of progesterone drop dramatically until reach levels that do not maintain thickening endometrium. The result is a shrinkage and decay endometrium (Junqueiro and Carneiro, 1982). In the late phase of secretion, contraction wall of spiral arteries shut down blood flow and cause ischemia resulting death (necrosis) endometrium. At this stage, descuamation endometrium and rupture of blood vessels in the upper constriction progress and the bleeding began to arise (Junqueiro and Carneiro,
1982). Endometrium is partially loose. The number of missing in each women are not equal, even in the same woman at the time different (Adnan, 2010).

CHAPTER III

OBSERVATION METHOD

A.  Time And Place

This experiment is done at :

Day / Date                          : Tuesday, 2^nd of November 2010

Time                                   : 4.00 until 5.00 pm

Place                                   : Laboraturium Of Biology, Math And Science Faculty,

                                                  Makassar State University.

B.  Tool And Material

1.    Tools:

a.    Light microscope

b.    Objeck glass

c.    Deck glass

d.   Dropping pipette

2.    Materials:

a.    Adult female of Mus musculus which is not pregnancy.

b.    0,9% of NaCl physiological

c.    1% of Blue Methylen

d.   Mineral water

e.    Tap water

f.     Canada balm

g.    70% of alchohol

C.  Work Procedure

1.      Sterilization pipette drops used 70%  alcohol. Then entered the pipette drops into the vagina Mus musculus with a depth of about 0.5 cm, and turned with caution. then sprayed  0.9% NaCl solution into the vagina of Mus musculus used dropping pipette. sprayed and sucked repeatedly until the liquid in the pipette appears cloudy.

2.      Dropped a dropping of the liquid into the objeck glass.

3.      Added a drop 1% of blue Methylen into the objeck glass, save it about 3untill 5 minutes.

4.      Removed the dense of dye and rinse used tap water

5.      Closed the object glass used the deck glass with Canada balm around the glass.

6.      Dried it and observed on light microscope.

7.      Determined the cytology of vagina swab and the step of reproduction cycle such as;

a.       Diestrous phase

b.      Proestrous phase

c.       Estrous phase

d.      Metestrous phase

CHAPTER IV

OBSERVATION RESULT

A.  Picture Of Observation Result

1.      Diestrous phase	2.      Proestrous phase
3.      Estrous phase	4.         Metestrous phase

Notes :

1.      Leukocyte

2.      Epithelium

3.      Nucleus

4.      Keratinized epithelium

B.  Discussion

       In this observation we observed five female of Mus musculus which is not pregnancy and divided them into the 6 group of apprentices. Each group observed one object. As the result of this observation, we just found 2 phase of reproduction cycle there. That were diestrous phase and proestrous phase. The two other phase didn’t find in our observation but the assistant had explained to us about the estrous phase and metestrous phase. Here the expalation about the observation result and the theory of reproduction cycle of female Mus musculus as an object.

First Observation

       In the first observation we observed the swab vagina of Mus musculus and found the diestrous phase. On microscope we saw the core of epithelial cells in very small amounts and leukocytes in very much. It match with the statement of Billet and Wild (1975)  that diestrous phase, is a phase characterized by the core of epithelial cells in very small amounts and leukocytes in very much. The duration of this phase approximately 55 hours.

       At the start of diestrus in vagina, the vaginal epithelium is at its lowest level of approximately three to seven cells thick consisting simply of the stratum germinativum. The stratum germinativum consists of stratum basale as a single layer of columnar epithelial cells and an outer stratum spinosum as multiple layers of polyhedral cells. There is a variable infiltration by leukocytes. A reduction in the infiltration of leukocytes and a notable epithelial cell proliferation occurs toward the end of the phase with thickening of the epithelium, but with no clear stratum granulosum. The formation of a stratum granulosum is the defining characteristic for the practical staging of the end of diestrus and the beginning of proestrus.

       At the start of diestrus in uterus, the uterus is small and inactive, and the horns lack a prominent vasculature and generally show a slit-like lumen. They are lined by a low cuboidal or columnar epithelium showing occasional degenerate cells. There are few mitoses at the start of the stage and the glands are particularly inactive, but there is some increase in activity during the progression of the phase. Also, toward the end of the phase, a slight edema of the stroma adjacent to the endometrial epithelium can be seen.

       By diestrous in the ovary, the newly formed corpora lutea from the previous ovulation have attained their maximal size, and this is the best ovarian marker for diestrus, although degenerate corpora lutea will also be present. Vacuoles are commonly present, particularly in the cells in the center of these large corpora lutea, indicative of active steroidogenesis, and early fibrous tissue formation may be seen in what was previously the central, fluid-filled cavity.

Second Observation

       In the second observation we observed the swab vagina of Mus musculus and found the proestrous phase. On microscope we saw the core of epithelial cells are round, leukocytes no or very little. It match with the statement of Billet and Wild (1975)  that proestrous phase, is a phase characterized by the core of epithelial cells are round, leukocytes no or very little. The duration of this phase approximately 18 hours.

       In vagina, formation of the stratum granulosum over the stratum germinativum of the vaginal epithelium, consisting of flattened epithelial cells containing many keratohyalin granules. In uterus, the uterine endometrial lining progresses to large cells, forming a tall cuboidal to columnar epithelium. There are frequent mitoses with only limited or no epithelial cell degeneration of the glands and lining epithelium (the appearance of notable endometrial epithelial cell degeneration marks the end of proestrus/start of estrus) and little inflammatory cell infiltration, although mitotic figures disappear at the end of the stage. The endometrial vasculature becomes more prominent, and the stroma can show some edema, with the lumen generally becoming markedly dilated toward the end of the stage. And in ovaries, Ovarian corpora lutea are often degenerate, with central fibrous tissue formation, and the cells commonly contain cytoplasmic vacuoles.

Third Observation

       In the third observation we observed the swab vagina of Mus musculus and found the estrous phase. On microscope we saw the epithelial cells are very much gore, and some epithelial cells with a degenerate core. It match with the statement of Billet and Wild (1975)  that estrous phase is the phase characterized by the epithelial cells are very much gore, and some epithelial cells with a degenerate core. The duration of this phase approximately 25 hours.

       In the vagina, there is a loss of mitotic figures and a progressive shedding of the superficial mucoid and cornified layers during estrus, with a reduction in the height of the epithelium, and cell debris is present in the lumen. There is also a variable and progressive leukocyte infiltration. The end of the stage is characterized by detachment of the cornified epithelium, although some may persist, particularly adjacent to the vaginal opening. So, if there is a predominance of attached cornified epithelium, then the stage is still “estrus.” Virtually complete detachment of the cornified epithelium of the vagina marks the end of estrus and the start of metestrus. The vaginal smear shows non-nucleated cornified cells, which by late estrus have diminished when leukocytes appear.

       In the terus, changes in the endometrial epithelium define the start of estrus, with the appearance of cellular degeneration/necrosis in the glands first, followed by the lining epithelium, which becomes quite marked. It is accompanied by a loss of mitotic activity and leukocyte infiltration. Luminal dilatation may persist into late estrus, although this is generally not the case. Some endometrial epithelial mitotic activity returns by the end of estrus. In the ovaries, degenerate ovarian corpora lutea are often present at estrus, but others (the newly formed corpora lutea) are small, with cells showing a basophilic cytoplasm and occasionally a central fluid-filled cavity retained from the follicular stage. Central fibrous tissue is generally not present.

Forth Observation

       In the forth observation we observed the swab vagina of Mus musculus and found the metestrous phase. On microscope we saw the epithelial cells and leukocytes that much gore. It match with the statement of Billet and Wild (1975)  that Metestrus phase is the phase that is characterized by epithelial cells and leukocytes that much gore. The duration of this phase of approximately 8 hours.

       In vagina, the start of metestrus is marked by the mid region of the vagina showing a complete detachment of the cornified epithelium, generally with residual squames present in the lumen. As noted above, some cornified epithelium may persist, particularly adjacent to the vaginal opening. There is a continued desquamation of epithelial cells throughout the stage, with a progressive loss of the stratum granulosum and upper germinativum (stratum spinosum). There is an accompanying variable leukocyte infiltration. As noted under diestrus, the end of metestrus/start of diestrus is marked by the epithelium reaching its lowest level.

       In uterus, the uterine endometrial epithelium shows continued vacuolar degeneration, but also a marked return of mitotic activity, so both are seen together. There is also a variable leukocyte infiltration and in ovaries, the ovarian corpora lutea may still contain a fluid-filled central cavity generally devoid of fibrous tissue, and the cytoplasm of the new corpora lutea are somewhat less basophilic than at estrus but smaller than that seen at diestrus.

CHAPTER V

CONCLUSION AND SUGGESTION

A.  Conclusion

       Sexual reproductive cycle is a cycle contained in the individual female sexual and non-pregnant adults, including cyclic changes in reproductive organs of a particular instance of the ovary, uterus and vagina under the control of reproductive hormones. Reproductive cycle includes, among others esterus cycle, ovarian cycle, and menstrual cycle.

       The ovarian cycle include the development and growth of ovarian follicles, from primordial follicles, growing follicles and follicle Graff. Estrous cycle is the reproductive cycle that goes on non-primate animals sexually mature female who is not pregnant. In mice, the estrous cycle consists of several major phases are phases of diestrus, proestrus phase, the phase of estrus, and metestrus phases. The menstrual cycle is an ongoing cycle of reproduction on sexually mature female primates are characterized by of menstruation.

B.     Suggestion

1.      Before doing this experiment we have to checked out all of the tools and materials that we would used and in doing this experiment we should have enough time so we could observed with accurate observation.

2.      For the assistant should give explanation or give the apprentices some guide about what they should do in observation and making of complete report of experiment.

3.      For the apprentice should take attention for the instruction of assistant while doing experiment and be more patient to the assistant.

BIBLIOGRAPHY

Anonym_a. 2010. Determnation of Estrous Cycle Phase of Rat . www.scielo.com.   

                 Accessed on November, 4^th 2010

Anonim_b. 2010. The Female Rat Reproductive Cycle. www.sage.com. Accessed on

                 November, 4^th 2010

Ganong, William F. 1969. Review of Medical Physiology. California: Lange

                Medical Publication

Carlson, Bruce M. 1996. Patten’s Foundations of Embryology. New York: The

               McGraw-Hill Companies

Sugiyanto, J. 1996. Perkembangan Hewan. Malang: UGM

DRS.Adnan, M.Si. 2010. Buku Ajar Perrkembangan Hewan. Makassar: UNM