Tebuconazoles Lab Report

Tebuconazoles Lab Report
Testes and reproductive organ weight Oral administration of tebuconazole caused a significant (P ≤
0.01) decrease in the weight of testes, epididymis and seminal vesicles at the duration of 15 days
and highly significant (P ≤ 0.001) decrease in the weight of testes, epididymis and seminal vesicles
in 30 and 45 days at the dose of 250 mg/kg bwt/ day in the experimental rats. However,
tebuconazole showed a non significant decrease in the weight of ventral prostate at the duration of
15 days wherever a significant (P ≤ 0.01) and highly significant (P ≤ 0.001) decrease was observed
at the duration of 30 and 45 days (Table 1.1). Sperm Dynamics, Motility and Fertility The sperm
density in testes and cauda epididymis decreased highly significantly (P ≤ 0.001) after tebuconazole
administration in the all dose duration (Table 1.2) and a severe impairment of sperm motility in
cauda epididymis was also observed in the experimental rats. Control rats showed 100% positive
fertility in the mating exposure test while the rats exposed to 250 mg/kg b. wt/day dose level showed
70, 90 and 100% negative fertility in the duration of 15, 30 an 45 days respectively (Table 1.2). ...
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However, tebuconazole showed a non significant decrease in the level of serum testosterone, FSH
and LH at the duration of 15
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Thyroid Stimulating Hormone Research Paper
Thyroid stimulating hormone (TSH)
Stimulate the secretion of thyroid hormones from the thyroid gland by binding to a receptor on the
surface of the cells of the thyroid (G protein –coupled receptors).TSH is stimulated by TRH
hormone of the hypothalamus and is inhibited by Somatostatin hormone, as well as by thyroid
hormones in a negative feedback loop.
Prolactine
Is a peptide hormone which causes synthesis in milk after birth, while it assists in preparation of
breasts for milk production after birth. It is stimulated by TRH hormone of the hypothalamus and is
inhibited by dopamine and estrogens. Another function of this hormone is counteracting dopamine
which causes sexual arousal.
Growth hormone Is a peptide hormone that's stimulated by the

The Male Reproductive System
The organs of the male reproductive system are specialized for the following functions:
To produce, maintain and transport sperm (the male reproductive cells) and protective fluid (semen)
To discharge sperm within the female reproductive tract
To produce and secrete male sex hormones
The male reproductive anatomy includes internal and external structures.
What are the external reproductive structures?
Most of the male reproductive system is located outside of the man's body. The external structures
of the male reproductive system are the penis, the scrotum and the testicles.
Penis
The penis is the male organ for sexual intercourse. It has three parts: the root, which attaches to the
wall of the abdomen; the body, or ... Show more content on Helpwriting.net ...
Ejaculatory ducts – These are formed by the fusion of the vas deferens and the seminal vesicles. The
ejaculatory ducts empty into the urethra.
Urethra – The urethra is the tube that carries urine from the bladder to outside of the body. In males,
it has the additional function of expelling (ejaculating) semen when the man reaches orgasm. When
the penis is erect during sex, the flow of urine is blocked from the urethra, allowing only semen to
be ejaculated at orgasm.
Seminal vesicles – The seminal vesicles are sac–like pouches that attach to the vas deferens near the
base of the bladder. The seminal vesicles produce a sugar–rich fluid (fructose) that provides sperm
with a source of energy and helps with the sperms' motility (ability to move). The fluid of the
seminal vesicles makes up most of the volume of a man's ejaculatory fluid, or ejaculate.
Prostate gland – The prostate gland is a walnut–sized structure that is located below the urinary
bladder in front of the rectum. The prostate gland contributes additional fluid to the ejaculate.
Prostate fluids also help to nourish the sperm. The urethra, which carries the ejaculate to be expelled
during orgasm, runs through the center of the prostate gland.
Bulbourethral glands – The bulbourethral glands, or Cowper's glands, are pea–sized structures
located on the sides of the urethra just below the prostate gland. These glands produce a clear,
slippery fluid

Gametogenesis Lab Report
Gametogenesis Lab Report
1. Introduction
Gametogenesis refers to the production of haploid sex cells within an organism. The haploid sex
cells are composed of half of the genetic material of that from the germ–line of the parents. The
process of gametogenesis could not take place without two specific organs, the ovary and the testis.
These two organs, the gonads, are composed of germ cells where meiosis occurs. Meiosis is the
method that makes the germ cells haploid. In both males and females, this phenomenon can be
observed. In males, the genetic material is passed to offspring through a process known as
spermatogenesis, and in females genetic material is passed to offspring through the process of
oogenesis. However, these two processes, although similar in ... Show more content on
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Hecht, N. 1998. Molecular mechanisms of male germ cell differentiation. BioEssays 20: 555–561.
4. Ma, M., S. Yang, Z. Zhang, P. Li, Y. Gong, L. Liu, Y. Zhu, R. Tian, Y. Liu, X. Wang, F. Liu, L. He,
H. Yang, Z. Li, and Z. He. "Sertoli Cells from Non–obstructive Azoospermia and Obstructive
Azoospermia Patients Show Distinct Morphology, Raman Spectrum and Biochemical Phenotype."
Human Reproduction 28.7 (2013): 1863–873. Web.
5. Okada, Hiroyuki, Atsushi Tajima, Kazuyoshi Shichiri, Atsushi Tanaka, Kenichi Tanaka, and Ituro
Inoue. "Genome–Wide Expression of Azoospermia Testes Demonstrates a Specific Profile and
Implicates ART3 in Genetic Susceptibility." PLoS Genetics. Public Library of Science, Feb. 2008.
Web. 16 Feb. 2017.
6. Reider, C.L. (ed.). 1999. Methods in Cell Biology, Vol. 61, Mitosis and Meiosis. Academic Press,
San Diego. A wealth of valuable information on methods for studying the machinery of cell
division.
7. Schöni–Affolter, Franziska, Dr., Christine Dubuis–Grieder, Dr., and Erik Strauch, Dr. "21.1
Genetic Factors and Hormones That Determine Gender." Sertoli's Supporting Cells: Function, Mode
of Operation and Hormonal Secretion. Swiss Virtual Campus, 21 Nov. 2005. Web. 16 Feb.

The Sex Chromosome ( X And Y ) Originates From A Pair Of...
INTRODUCTION:
The Sex chromosome(X and Y) originates from a pair of autosomes (H.J. Muller, 1914) about
350million years ago in reptile–like ancestors (Charlesworth, 1991; Graves, 1995). Environmental
factor like temperature determines sex in some species e.g. crocodiles and turtles (Bull et al, 1975).
In humans, there are 22 pairs of chromosomes called the Autosomes and one pair of sex
chromosome (X–Y) which makes a total of 23pairs of chromosomes. These 23pairs (46)
chromosomes are contributed by female and male gamete. Females have 22pairs of autosomes and
one sex chromosome (X) while males have Y sex chromosome in addition to the 22pairs of
autosomes. This means that, the Y chromosome can only be inherited paternally (Lahn & Page,
1999).
The X–chromosome is about a 165mega base in size and contains about 1000 functional genes
(Ross et al, 2005) while Y chromosome is about 65mega base in size with about 178genes
(Skalestsky et al; 2003).The Mammalian Y–chromosome contains 86 genes which code for specific
proteins with peculiar functions in sex fertility (Lahn & Page, 1997). The Y chromosome is the most
evolving part of the human and chimpanzee genome. ''The Y chromosome is far superior in the
evolutionary progress than the entire human genetic code combined'' (Dr Page, 2001). The Y
chromosome is said to be the smallest chromosome in humans and contain more genes with
mutation (Heinkchen, 2005).
"The Primitive Y chromosome was found in Papaya" (Liu et al, 2004) and the Y

How Does Leydig Cells Affect The Synthesis Of Testicular...
Successful testicular function depends on the hypothalamus discharge of GNRH, which in turn
activates the release of LH and FSH to act on the testes and initiates the synthesis of testicular
steroids. Active immunization dysfunction the hypothalamic–pituitary–gonad axis, thereby
hindering the function of the Leydig and Sertoli cells and suppress the attainment of the testes
maturity and steroid synthesis [Einarsson et al., 2009] and then lower the level testosterone
hormones. The total serum testosterone concentrations are decreased, consistence with the treatment
group research results obtained in a previous study [Ramzan et al., 2013]. Another previous study
[Khan et al., 2008] showed that the serum testosterone levels are reduced in the ... Show more
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Furthermore, Huma et al., [2014] reported that protein 234 moderately lowered the testosterone
response to KISS–1 gene. Thus reduction of testosterone in the bloodstream of the treatment group
was achieved due to abnormal function of the hypothalamus–pituitary–gonadal axis, implying that
the kisspeptin recombinant oral vaccines participate in the disruption of testosterone secretion and
the overcoming of ram sexual behaviors.
The scale of the testicles is well correlated to the synthesis functionality of the sperm and further
gonadal sperm reserves [Parkinson et al., 2004]. The scrotal circumference is the best and the most
sophisticated device for estimating the mass of the reproductive organs [Lino et al., 1972; Notter et
al., 1987] and the level of testes development [Lunstra et al., 1978] inside the animal. The testicle
circumference and histological sections were assessed to determine the efficacy of the vaccine on
gonadal features. Analysis of the sub–physiological contents of testicles revealed a direct
relationship between the steroid and spermatogenic production. Our research finding shows that the
vaccine has a strong effect on the scrotal circumference of immunized ram lambs compared with the
control ram lambs (P < 0.05). Furthermore, the microscopic histological outcomes of testicles
indicate that the vaccinated ram lambs indicated lower masses of spermatogonium, spermatocytes,
and spermatids. The histological observation revealed smaller seminiferous

Cyp2e1 Week 1 Research Paper
ThUNCORRECTED PROOF
A R T I C L E I N F O
Article history:
Received 3 March 2016
Received in revised form 21 April 2016
Accepted 22 April 2016
Available online xxx
Keywords:
Furan
Rat testis
Oxidative stress
Histopathology
Caspase–3
CYP2E1
A B S T R A C T
Furan is produced in a wide variety of heat–treated foods via thermal degradation. Furan
contamination is found to be relatively high in processed baby foods, cereal products, fruits juices,
and canned vegetables. Several studies have demonstrated that furan is a potent hepatotoxin and
hepatocarcinogen in rodents. However, few studies have investigated the toxic effects of furan in the
testis. In addition, the exact mechanism(s) by which furan exerts toxicity in the testis has not been
fully ... Show more content on Helpwriting.net ...
Food Addit. Contam. Part A Chem. Anal. Control Expo.
Risk Assess. 30, 654–659.
Selmanoglu, G., Karacaoglu, E., Kilic, A., Kockaya, E.A., Akay, M.T., 2012. Toxicity of food
contaminant furan on liver and kidney of growing male rats. Environ. Toxicol.
27, 613–622.
Shayakhmetova, G.M., Bondarenko, L.B., Kovalenko, V.M., Ruschak, V.V., 2013.
CYP2E1 testis expression and alcohol–mediated changes of rat spermatogenesis indices and type I
collagen. Arch. Hig. Rada Toksikol. 64, 51–60.
Shayakhmetova, G.M., Bondarenko, L.B., Voronina, A.K., Anisimova, S.I.,
Matvienko, A.V., Kovalenko, V.M., 2015. Induction of CYP2E1 in testes of isoniazid– treated rats
as possible cause of testicular disorders. Toxicol.
Lett. 234, 59–66.
Srinivasan, K., 2014. Antioxidant potential of spices and their active constituents. Crit.
Rev. Food Sci. Nutr. 54, 352–372.

Taubert, D., Glockner, R., Muller, D., Schomig, E., 2006. The garlic ingredient diallyl sulfide
inhibits cytochrome P450 2E1 dependent bioactivation of acrylamide to glycidamide. Toxicol. Lett.
164, 1–5.
Terrell, A.N., Huynh, M., Grill, A.E., Kovi, R.C., O'Sullivan, M.G., Guttenplan, J.B.,
Ho, Y.Y., Peterson, L.A., 2014. Mutagenicity of furan in female Big Blue

Male Infertility Treatment
Infertility affects millions of married couples around the world, and at least 40 percent of infertility
is attributable to male factor infertility. The prognosis for male infertility treatment is extremely
poor, and only 15 percent of infertile men can be treated. Occupational exposure represents the
highest level of exposure to chemicals that could potentially produce adverse effects on the
reproductive system via inhalation, skin absorption, or ingestion. Thousands of chemicals exist in
the workplace; there is limited or no toxicological information available for many industrial
chemicals. Furthermore, even for compounds for which there is toxicological testing data, the data
often do not include assessment on reproductive and developmental ... Show more content on
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In order to develop and establish in vitro human spermatogenesis models, we need to build–up an
unlimited source of human spermatogonia stem cells (SSCs). Human SSCs are a unique population
of cells in postnatal mammals that undergo self–renewal. SSCs are rare in the testis, constituting
around 1 in 3 000–4 000 testicular cells. It is difficult to obtain enough SSCs to serve for the toxicity
testing from biopsy of human testis. The rapid progress in stem cell research has opened a new era
for exploring human spermatogenesis. Mouse ESCs, nonhuman primate (NHP) ESCs, and hESCs
have been differentiated into primordial germ cells (PGCs) and fetal precursors of the spermatogenic
lineage [50–61]. hiPSCs can enter meiosis and in some cases produce haploid products in vitro [55,
56, 60, 62, 63]. hESCs and hiPSCs are reported to differentiate directly into advanced male
spermatogenic lineages in vitro [56, 62, 64–66]. However, the efficiency of generation of the human
SSCs is still quite low and different among the reports. The discovery of the method to generate
human SCCs from hiPSCs in a high efficiency will open up the possibility to provide an unlimited
source of human SSCs, which can be used to construct in vitro model for reproductive toxicity
testing. Therefore, in this proposal, we will use High–Content Analysis (HCA) to optimize the
culture condition to improve the efficacy of differentiating hESCs to human SSCs, and apply these
cells to develop an integrated pathway–based high throughput (HT)/high content analysis (HCA) for
reproductive toxicity

Effects Of Kidney Failure On Erectile Dysfunction
The effects of kidney failure on erectile dysfunction
Impotence is defined as "male erectile dysfunction, that is, the inability to achieve or maintain an
erection sufficient for satisfactory sexual performance." (1)
Age, smoking and metabolic disorders are some of the major risk factors for ED. Kidney failure is a
medical condition in which the kidneys fail to adequately filter waste products from the blood (2)
and is also a risk factor for developing ED. ED's prevalence is estimated to be approximately 80%
among these patients. The etiology of ED in CKD patients is multifactorial. Abnormalities in
gonadal–pituitary system, endothelial dysfunction, disturbance in autonomic nervous system,
anemia and erythropoietin deficiency, secondary hyperparathyroidism,

Cyp19a1 Research Paper
The aromatase enzyme CYP19A1 is so named because it is responsible for catalyzing the
conversion of 19–carbon androgens to 18–carbon aromatic estrogens . The CYP19A1 is complex
bound to the SER of the cells, and is localized in the ovaries, testis, placenta, and fat–, brain–, and
bone tissues.
CYP19A1 converts AN and TS to E1 and E2b, respectively, in the granulosa cells, which are
somatic cells present in the ovaries and the placenta. Furthermore, CYP19A1 can convert TS to E2b
in the leydig, seroli, and germ cells found in the testis. This process is crucial for the initiation of
spermatogenesis and mitosis of spermatogonia . Both E2b and E1 can be further catalyzed into the
third estrogen estriol.
Estrogens are vital for the regulation of sex hormones, and are known to proliferate certain forms of
cancers. For this reason, estrogens are a recognized target for inhibition of hormone depended
diseases like breast cancer, and aromatase inhibitors (AIs) like letrozole and anastrozole are of
interest as they will lower the levels of estrogens. Both letrozole and anastrozole are currently
indicated for the treatment of post–menopausal women with breast cancer. ... Show more content on
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These includes both cellular and non–cellular methods, some described in details in protocols from
major agencies like OECD and US EPA, and others are modified in house methods. Advantages of
cellular methods, for example the H295R cell line, is that they can provide detailed information of
the substrates tested and they can express the entire steroidogenesis . This will provide a complete
picture of the regulation of hormones when influenced by a test drug. Cellular methods are however
expensive and often quite time consuming, and therefore it can be necessary to screen substrates
with a more rapid and inexpensive non–cellular method

Infertility Treatment
Stress can be broadly defined as any external and internal events that affects an organism's well
being. In attempt to maintain homeostasis, the body will respond to the psychological stress by
modifying physiological processes (Nargund, 2015). Psychological stress is a number of emotional
events that interrupts homeostasis. The disruption of homeostasis can affect many biological
systems, such as metabolism, vascular function, tissue repair, nervous system and reproductive
system. Both emotional and physical stress can have a negative impact on human reproductive
function (Cousineau, 2007; Jakobovits et al, 2002). Therefore, it is very important to know how to
cope with stress when experiencing life events that are very stressful. My presentation ... Show more
content on Helpwriting.net ...
Infertility can be curable through treatments, but going through infertility treatment can be very
challenging. There are two factors that can cause an increase on stress level of someone who's going
through infertility treatment: cost and time. These two factors can add to the stress level of couple
whose experiencing infertility. Stress or anxiety can negatively affect the treatment of infertility, and
can put the pregnancy at risk. Also any before and after psychological illness may affect fertilization
therapy. However, it is recommended to go through psychotherapeutic treatment while going
through infertility treatment. There are many researches supporting this idea and a lot of focus on
different psychotherapeutic interventions such as Cognitive–Behavioral Therapy. Another important
factor regards the social support a patient gets from the partner, family and friends and the role that
plays on reducing stress during infertility treatment. Researchers suggested that social support from
partner, family and friends play a role on reducing infertility–related stress, also and couples with
social support are more likely to go through infertility treatment successfully. However, partner
support shows the greatest association with the overall findings for both men and women
experiencing infertility (Martins, 2014; Greil at al.,

Asexual Reproduction Essay
ANIMAL REPRODUCTION & DEVELOPMENT Dr Ilma The two earthworms in this picture
are mating Each worm produces both sperm and eggs, which will fertilize – And in a few weeks,
new worms will hatch Asexual And Sexual Reproduction Both occur in the animal kingdom
Asexual reproduction is the creation of new individuals – Whose genes all come from one parent
Sexual reproduction is the creation of offspring – By the fusion of male and female gametes to form
a zygote Mechanisms of Asexual Reproduction Many invertebrates reproduce asexually by fission
– The separation of a parent into two or more individuals of approximately the same size
Mechanisms of Asexual Reproduction Budding – In which two new ... Show more content on
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Sperm form in the testes, pass through the sperm duct (vas deferens), and are stored in the seminal
vesicle. The male ejaculates sperm along with fluid from the accessory glands. (Males of some
species of insects and other arthropods have appendages called claspers that grasp the female during
copulation.) Accessory gland (b) Vagina Female honeybee. Eggs develop in the ovaries and then
pass through the oviducts and into the vagina. A pair of accessory glands (only one is shown) add
protective secretions to the eggs in the vagina. After mating, sperm are stored in the spermatheca, a
sac connected to the vagina by a short duct. Female Reproductive System The female external
reproductive structures include – The clitoris – Two sets of labia The internal organs are a pair of
gonads – And a system of

Varicoceles
3.1.1. A theory of an elevated testicular temperature
Varicoceles are thought to induce their noxious effect by elevating scrotal temperature via reflux of
warm abdominal blood through incompetent valves of the spermatic veins and there is good
evidence to support this theory.( Skandhan& Rajahariprasad , 2007).The elevated intrascrotal
temperature results in reductions of testosterone synthesis by Leydig cells and reduced Sertoli cell
secretory function. increased testicular temperature in men with varicocele may reduced sperm
quality and testicular functions ,Varicocele ligation has been demonstrated to be associated with
reductions in intrascrotal temperature in infertile men as Scrotal temperature is maintained a few
degrees below body core temperature in order to optimize the environment for normal testicular
function by the countercurrent heat exchange system but in a subfertile men with varicocele, a heat
exchange mechanism will affect and this may cause Leydig cell secretory dysfunction. Several
studies have suggested that infertile patients with varicoceles have lower serum testosterone
concentrations, leading to the hypothesis that varicoceles may alter not only spermatogenses and
even Leydig cell function, suggesting that testosterone synthesis it self may also be compromised.
(Cantatore et al. , 2010). ... Show more content on Helpwriting.net ...
A dilation of the venous plexus would then disrupt the efficiency of this system. The explanation for
why a left–sided varicocele affects the function of the contralateral testis is unclear, but any
unilateral pathology may be transmitted via the collateral drainage that exists between the testes.The
mechanism for how heat affects spermatogenesis remains speculative. There is evidence that heat
may affect androgen production which can have bad effects on the maintenance of sperm
production. (Rahman&

Epigenetic Regulation
Backgrounds
Epigenetic changes can be defined as functional, heritable changes in DNA, that do not involve a
change in the nucleotide sequence[1]. Transcriptional regulation can be controlled through
epigenetic modification and thereby can affect gene expression (44). Epigenetic modifications are
important regulators of numerous biological processes like spermatogenesis. Nowadays there is a lot
of attention to epigenetic changes as a role in identifying genetic causes of male infertility. In fact
epigenetic regulations play an important role in proper spermatogenesis and fertility preservation
(45).
Unlike somatic cell, sperm chromatin is highly organized compact structure. This specific packaging
occurs by histone to protamine transition. ... Show more content on Helpwriting.net ...
After overnight incubation and washing, the wells were treated with blocking solution. After a
second incubation and washing step, the wells were incubated with ani–H2B.W antibody. After a
third incubation and washing step, the wells were incubated with secondary anti–H2B.W antibody,
streptavidin–horseradish peroxidase (HRP). After last incubation and washing step, the wells were
incubated with the substrate tetramethylbenzidine (TMB). An acidic stopping solution was then
added and the degree of enzymatic turnover of the substrate was determined by dual wavelength
absorbance measurement at 450

Huntington Disease Research Paper
Most of the carriers of Huntington disease are usually childhood victims (Donaldson, Marsden,
Schneider, & Bhatia, 2012). From this point of view, an increase in the length of the CAG section
causes the production of an abnormal form of the Huntington protein (Donaldson, Marsden,
Schneider, & Bhatia, 2012). The lengthened defective protein is then cut into smaller and defective
fragments that bind neurons together, which in turn disrupts their required functions of the brain.
The abnormal functioning leads to eventual death of the neurons in some regions within the brain,
which in turn leads to the symptoms of Huntington disease (Marks & Neill, 2007).
Inheritance
Huntington disease is featured by an autosomal inheritance that is dominant,

The Pesticide Called Atrazine Acts as an Endocrine...
The article reviewed in this summary is
Hayes, T.B., Khoury, V., Narayan, A., Nazir, M., Park, A., Brown, T., Adame, L., Chan, E.,
Buchholz, D., Stueve, T., and Gallipeau, S. 2010. Atrazine induces complete feminization and
chemical castration in male African clawed frogs (Xenopus laevis). Proceedings of the National
Academy of Sciences 107: 4612–4617. The authors have assigned key words described throughout
this article including amphibian decline, endocrine disruption, pesticide and sex reversal. The larger
or global context for the research conducted in this article is that the pesticide Atrazine is widely
utilized across the entire world, contaminating water sources by mobilizing through rainfall,
disrupting habitats and impacting ... Show more content on Helpwriting.net ...
Spermatogenesis data was collected from five random testicular tubules as well as the largest tubule.
DNA for sex determination was obtained from the prepared toe tips of the amphibians and
aromatase samples were collected from the RNA removed from the gonads of atrazine induced
females. The authors collected data on mating choice behavior from single and paired frogs of both
male groups to ZW stock females placed in a pool together. Testosterone levels were obtained from
the same paired and single males by taking centrifuged blood samples and extracting the plasma
testosterone. Fertility data was collected by pairing controlled and atrazine exposed males with ZW
stock females and gathering eggs and embryos from these matings. The data collected spans from
hatching of the larvae until about two to three years after metamorphosis. For the morphometric
measurements, statistical analyses were performed. The dilator larynges were examined by the
proportion extended beyond the thiohyral in order to determine the significance of the length of the
extension. The presence or absence of observable nuptial pads was analyzed, to determine it as a sex
characteristic of males. Breeding glands were evaluated by considering the maximum area of the
largest gland which was then compared to the areas of other glands to observe the size differences
between the control and atrazine treated males. Stages of spermatogenesis for the testis and tubules
with and

The Endocrinology Of Male And Female Reproduction
Reproductive physiology is comprised of many tightly coordinated functions of the endocrine
system including the hypothalamus, pituitary and reproductive organs whose dynamic function
plays several critical roles in growth and development as well was reproduction. The hypothalamic–
pituitary–gonadal axis plays a critical role in the development and regulation of the reproductive
system. These tightly regulated functions within the pituitary must respond to continuously
changing signals from the central nervous system gonads and provide the quick responses. The
hypothalamic–pituitary–gonadal axis is comprised of major hormones, including gonadotropin–
releasing–hormone (GnRH), luteinizing hormone (LH) and follicular stimulating hormone (FSH)
and operate through both positive and negative feedback loops in mammals.1 When toxicants affect
any part of this axis's function, either by altering cellular activity or the signals themselves, the
physiology can impacted by immediate and downstream effects. An understanding of the
endocrinology of male and female reproduction, is required to understand how toxicological effects
can have severe consequences on reproductive physiology.
GnRH is a prominent reproductive hormone that is produced in neural cells in the hypothalamus.
GnRH is secreted into the bloodstream where it is carried downstream to the pituitary gland and
activates the Gonadotropin –Releasing hormone receptor. 2 Once these cells are activated, signal
transduction

Varicocelectomy Lab Report
Abstract Introduction: We aim to predict results of varicocelectomy on sperm density and
progressive motility using preoperative clinical, laboratory and radiological data and to propose cut–
off values for significant parameters. Methods: This prospective study was carried out between July
2011 and June 2014. We included 123 patients in our study. They were diagnosed with primary
infertility with varicocele, were scheduled for varicocelectomy, and completed their follow–up. We
excluded patients with azoospermia, total necrospermia, recurrent varicocele, and pituitary
hormonal abnormalities. Varicocele was diagnosed and graded by physical examination and colour
Doppler ultrasound. Semen analyses were completed preoperatively and 6 months postoperatively.
Microscopic subinguinal varicocelectomy ... Show more content on Helpwriting.net ...
Patient demographics, pre– and postoperative clinical data (varicocele grade and semen parameters)
were statistically analyzed. Results: The mean ± standard deviation of age, body mass index, and
subfertility duration was 28.3 ± 7.4 years, 29.1 ± 2.7 kg/m2, and 21.9 ± 7.1 months, respectively.
About 53% of our patients (n = 66) had bilateral varicocele, and unilateral disease was found in the
other 57 (46.3%) cases. Varicocele grade I was diagnosed in 42 (34.1%) patients, while the other 81
(65.9%) patients had grade II or III. Higher grades of varicocele, preoperative total testosterone
level, sperm density, and progressive motility had a statistically significant impact on the outcome of
varicocelectomy in univariate testing. Multivariate logistic analysis revealed that grade of
preoperative varicocele (95% confidence interval [CI] 5.6–6.3, p = 0.007) and sperm density (95%
CI 2.7–1.6, p = 0.0035), and progressive motility (95% CI 1.1–2.3, p = 0.0123) are independent
predictors of semen parameters improvement after varicocelectomy. Conclusion: The grade of the
varicocele, sperm density, and

Biology Ib Hl Paper
N10/4/BIOLO/HPM/ENG/TZ0/XX
88106001
Biology HigHer level PaPer 1 Tuesday 2 November 2010 (afternoon) 1 hour INSTRUCTIONS TO
CANDIDATES
Do not open this examination paper until instructed to do so. Answer all the questions. For each
question, choose the answer you consider to be the best and indicate your choice on
the answer sheet provided.
8810–6001
17 pages © International Baccalaureate Organization 2010
– 2 – 1.
[Question and image removed for copyright reasons]
2.
What is the sequence of stages during the cell cycle? A. B. C. D. G1 mitosis G1 G1     S G1
G2 G2    G2 G2 S  mitosis  cytokinesis S
 cytokinesis   mitosis
 cytokinesis S
 mitosis  ... Show more content on Helpwriting.net ...
Varieties of bacteria resistant to antibiotics reproduce faster than non–resistant varieties. Bacteria
showing resistance to antibiotics survive after antibiotics are used.
17. Which taxa do Zerynthia rumina and Zerynthia polyxena share? A. B. C. D. They share the same

class but not the same family. They share the same species but not the same class. They share the
same class but not the same genus. They share the same family but not the same species.
18. What features distinguish Platyhelminthes from Annelida? Platyhelminthes A. B. C. D.
segmented body non–segmented body bilateral symmetry no bilateral symmetry Annelida non–
segmented body segmented body no bilateral symmetry bilateral symmetry
8810–6001
Turn over
– 10 –
19. What are the names of the organs labelled I and II in the diagram below?
I
II
I A. B. C. D. pancreas small intestine gall bladder esophagus liver
II
large intestine pancreas stomach
20. Where in a cell are antigens found? A. B. C. D. In the nucleus In the cytoplasm In the plasma
membrane On the surface of the Golgi apparatus
8810–6001
– 11 –
21. Which feature maintains a high concentration gradient of gases in the ventilation system? A. B.
C. D. Thin–walled alveoli Thin–walled capillaries A moist lining of the alveoli Blood flowing in the

Seasonal Changes Within Reproductive Behavior
Jillian Greenwood
ADS 4613
10–24–2016
Seasonal changes in reproductive behavior and spermatogenesis in the stallion
Horses are polyestrous, seasonal breeders with mid–summer foaling and mating seasons in late
spring. Breeding occurs when the mare experiences photoperiod, which is the exposure to daylight
within a 24 hour period. As a result, the mare becomes receptive, and the stallion becomes more
dominate. Testosterone increases which promotes increased reproductive behavior, spermatogenesis,
and libido. Thus, photoperiod, reproductive behavior, and spermatogenesis influences fertility and
sexual behavior of the stallion.
Photoperiod is a key player in the reproductive system of the horse. Increased daily light exposure
has been shown to hasten the onset of the ovulatory season in mares (Sharp and Ginther, 1975)
increase total scrotal width and sexual behavior in the stallion (Clay and Clay, 1992). In the stallion,
LH concentrations increase at the arrival of the breeding season and begin to fall again as the winter
months approach (Irvine and Alexander, 1982; Johnson and Thompson, 1983). Stallions under
photoperiod during the winter months experience an accelerated seasonal increase in LH
concentrations and increased testosterone concentrations (Thompson, 1977). Similarly, mares
display increased LH concentrations during spring and summer months because of exposure to
constant light for 28 d during the winter (Freedman et al., 1979). This exposure increases daily LH

Essay On Immunocytochemistry
In the above figure A, there are intracellular Zn points and localisations were noticed using Fluozin–
3AM in MII eggs earlier. While after in (b), treating with 50 μM TPEN. In figure B
immunocytochemistry was performed. It shown that zinc inadequately induced by TPEN can result
in egg stimulation.
The oocyte itself also appears to play a crucial role in the activation mechanism, the exact facts of
which are yet to be properly understood. The capability to produce suitable Ca oscillations is
acquired following fruitful oocyte maturation and involves several cytoplasmic changes. Evidence
for this includes the fact that fertilized immature mouse oocytes generate fewer Ca transients of
lower amplitude than do oocytes fertilized at MII. During ... Show more content on Helpwriting.net
...
There were many disagreements in the appearance profile of PLC during the spermatogenesis as
there is not adequate proof concerning its protein translation. Another key matter is the pattern of
localization of PLCz in the sperm. Identification of PLCz position in the sperm could help ratify its
purposeful role in sperm as well as provide a standard to study the pattern of localization of PLCz in
infertile compared with the fertile men. Trials showed that in mouse, the PLC was found in the
pellet but it was confirmed to the separate sperm ends instead of heads. While experiments of human
detected that PLC was present at round spermatid stage of spermatogenesis. In IVF using boar
sperm indicates that PLC was not present which suggest that PLC was released along with the
acrosomal cap (Aarabi, et al., 2012). This study also determine the PLCζ localization over the head
of sperm, precisely the post acrosomal area in mouse and both post–acrosomal and acrosomal area
in human sperm. According to Escoffer et al., (2014) PLCζ is confined to the postacrosomal and
equatorial regions of human sperms. Zanetti and Mayorga (2009) demonstrated that the equatorial
area remains unaffected subsequent to the acrosome response, thus denying the finding of Aarabi et
al. (2012). Another study linking mouse and porcine sperm established that PLC originates in
perinuclear medium which is an oocyte penetrating region (Fujimoto, et al., 2004).
Also, according to Yoon et al., (2008)

Reproductive System
REPRODUCTIVE SYSTEM FUNCTIONS ➢ The major function of the reproductive system is to
make sure that the human species survives. ➢ It is not necessary for every human being to produce
children, but in order to continue our human species, at least some people have to have children. ➢
The four main functions of the human reproductive system are: To produce egg and sperm cells, To
transport and sustain these cells, To nurture the developing offspring, and To produce hormones.
MAJOR ORGANS ➢ In the human reproductive system, the major organs include the external
genitalia and many internal organs including gonads producing gametes and hormones. ➢ These
hormones are ... Show more content on Helpwriting.net ...
➢ In each tube is a sewing needle size passageway. At the other end of each fallopian tube is a
fringed area that looks like a funnel and wraps around the ovary. The fallopian tube does not
completely attach to the ovary. ➢ When an egg pops out of an ovary, it enters the fallopian tube and
tiny hairs in the tube's lining help push it down the narrow passageway toward the uterus. After
intercourse, sperm in the vagina passes through the cervix, the uterus, and then to the fallopian
tubes. If a sperm encounters an ovum (egg), conception occurs. 4. Ovaries ➢ The female has two
oval–shaped organs, called ovaries, that lie to the upper right and left of the uterus. ➢ The ovaries
produce, store, and release eggs into the fallopian tubes during the process called ovulation. ➢ Each
ovary measures about 1 1/2 to 2 inches in a grown woman. The ovaries are part of the endocrine
system and produce estrogen and progesterone, female sex hormones. ➢ The ovaries are among the
first organs to be formed as a female baby develops. By 20 weeks, the ovaries have about 6 to 7
million potential egg cells. From that point on however, the number begins to decrease rapidly. A
newborn infant has between 1 million to 2 million egg cells. By puberty, the number of egg cells
remaining is about 300,000. For every egg that matures and undergoes ovulation, roughly a
thousand will fail. During the course of an average

Proposal On Anabolic Steroids
Introduction
This research task will be focusing on the synthetic substance "Anabolic Steroids" .The aim of the
research task is to understand what effect the substance has on us humans and especially on the
reproductive system in our bodies. Gym and Body building is becoming more of a fashion than
anything else and can be referred to as the "modern drug" and just like when drug addicts have been
using the same drug for a long period of time and don't get the same feeling they move on to a
stronger dosage or substance and this is exactly what is happening with people today in regards to
gym and body building, people are going to the gym and lifting weights and are slowly seeing
results but these results come slowly which frustrates them so they are turning to Anabolic Steroids
to ... Show more content on Helpwriting.net ...
Anabolic steroids are consumed by individuals so that they can benefit from one of or both of the
Anabolic steroid functions .The Anabolic steroid has two functions. It serves an "Anabolic" function
which is to increase the rate of muscle growth and it serves an androgenic function which is to
catalyze the increase and growth of male sexual characteristics in both male and female consumers.
The Substance is correctly named: Anabolic–Androgenic Steroids (Anabolic Steroid Abuse , 2006)
Anabolic Androgenic steroids was defined by the FreeDictionary.com as:
"(Pharmacology) any of a group of synthetic steroid hormones (androgens) used to stimulate muscle
and bone growth for therapeutic or athletic purposes" (Anabolic androgenic steroids , 2016)
Chemical Structure of Anabolic Steroids.
Anabolic Steroids are formed by several steroid rings originating from a tetracyclic base. This a
result of the combining of one Cyclopetane (C5H10) ring and three Cyclohexane (C6H12) rings.
(Chemistry and Structure of Anabolic and Androgenic Steroids, 2016)
How Steroids Work In the

Procedures for Testicular Biopsy
Biopsy procedure Samples were blinded for the ICSI laboratory examiner. For all patients, open
surgery biopsy was applied to retrieve specimen of sperm. At the beginning of open biopsy, the skin
over the testicle was cleaned with a germ–killing (antiseptic) medicine. The area around covered
with a sterile towel. (As like what was done in onset of local anesthesia.) The testis was grasped
between the thumb and foreﬁnger of the non–dominant hand. An incision was then made over the
same area immediately. The size of the incision was about over 0.5– 1cm . An vascular area close to
midportion of medial, lateral or anterior surface of the testis was chosen, tunica albuginea incised
longitudinally with a 150 ultrasharp knife. The testicular parenchyma (approximately 50–750 mg)
was excised with sharp, curved scissors and placed in temperature–adopted Hams F10 culture
medium supplemented with 10% Plasmanate. Wet preparations transferred to the in vitro
fertilization (IVF) lab. Individual tubules were isolated by immediate initial dispersal of the
specimen with two sterile glass slides. Mincing of the tissue with a sterile scissors in the Hams F10
medium additional allowed for mechanical dispersal and preparing sequential passes of tissue
suspension (detection of fully condensed spermatids) through a 24–gauge angiocatheter. As soon as
spermatozoa were identified, no further testicular incisions are made. To prevent devascularization
of the testis from damage to the subtunical

Hormone Affects The Body
To determine which hormone is the most important for normal body functioning, we first need to
understand how each hormone affects the body.
Aldosterone– Is produced in the cortex of the adrenal glands. Aldosterone affects the body's ability
to regulate blood pressure. This hormone sends signals to organs that increase the amount of sodium
the body sends into the bloodstream or the amount of potassium released in the urine. This hormone
can increase blood volume by causing the bloodstream to reabsorb water with the sodium. Indirectly
this hormone also helps maintain the blood's pH and electrolyte levels (Huether & McCance, 2017,
p.455–458)
ADH (Antidiuretic hormone)– Is produced in the hypothalamus and is stored in the posterior
pituitary

Histone Code Hypothesis
The replacement of somatic histones with testis–specific variants in early haploid germ cells is
undoubtedly an essential step for promoting chromatin remodeling during spermiogenesis, and it is
believed to involve the histone code. The histone code hypothesis proposes that combinations of
histone modification could serve as specific signals that recruit protein domains to alter chromatin
structure to either promote or suppress gene transcription (Turner, 2002). There is evidence for the
involvement of the histone code in chromatin remodeling as stage–specific histone modifications
have been reported to occur during spermiogenesis, namely histone H4 acetylation, histone H3
methylation and phosphorylation, and histone H2A ubiquitination (Song ... Show more content on
Helpwriting.net ...
Protamines are 50 amino acid long, cysteine and arginine–rich proteins that bind tightly to the
negative DNA backbone. As with TPs, PRMs are transcribed in round spermatids and only appear in
late spermiogenesis to complete chromatin condensation. Their positive charge stabilizes the
chromatin as it abolishes electrostatic repulsion between proximal chromatin strands, forming
toroids loops (Cho et al., 2003). Further chromatin compaction occurs during epididymal transit
during which PRMs form disulfide bridges between cysteine residues to form a semi–crystalline
chromatin (Carrell et al., 2007). Two PRMs have been identified, PRM1 and PRM2, both of which
are present in human and mouse germ cells, but only PRM1 exists in the rat. There are two critical
differences dissociate the two protamines, both structurally and functionally. First, PRM2 binds
longer stretches of DNA, which renders the chromatin less compacted. Second, PRM2 coordinates
one zinc atom, which in the case of humans makes zinc deficiency an important issue (Balhorn,
2007). However, this difference does not make one PRM more essential than the other. In fact, the
PRMs must be present in equal ratio, as a change in this ratio leads to diminished semen quality and
low fertility potential in humans (Balhorn, 2007). Xenobiotics are chemicals that an organism is
exposed to that are

Klinefelter Syndrome Advantages And Disadvantages
CHROMOSOMAL ABNORMALITIES
A) NUMERICAL CHROMOSOME ABNORMALITIES
1) Klinefelter Syndrome
This syndrome was first described by Harry Klinefelter in 1942 as a clinical condition with small
testes, azoospermia, gynecomastia and an elevated serum FSH. (56) Only in 1959 was the
chromosomal basis of the disorder described. Subsequently the diagnosis of Klinefelter syndrome
has required the demonstration of the 47,XXY karyotype or one of its rarer variants. (57)
The prevalence of Klinefelter syndrome appears to be approximately 1 in 660 males, and recent data
suggest a rising incidence over the last decades. (58) It is the most frequent form of primary
testicular dysfunction affecting spermatogenesis as well as hormone production and is found in ...
(66) The rate of diploidy of sperm as well as disomy for gonosomes and autosomes seems to be
increased in patients with Klinefelter syndrome, however, the majority of sperm appear to be
normal. (67) Preliminary data suggest that in about 20 – 50 percent of patients with Klinefelter
syndrome it may be possible to retrieve sperm by TESE. (68) Several pregnancies have been
achieved with testicular sperm used for ICSI. The embryos show normal or aneuploid karyotypes
which can be identified by preimplantation or prenatal diagnosis. Interestingly, the birth of normal
children conceived by assisted reproductive techniques seems to be rule, suggesting that the few
sperm which can be found in about 50% of patients with Klinefelter syndrome possibly derive from
the clonal expansion of spermatogonia with unremarkable karyotype problems.

Ductus Deferens Research Paper
Ductus deferens
The ductus deferens (otherwise known as the vas deferens) is a structure found in the male
reproductive system. There are two ductus deferens and they are identical in their structure and
function. The primary function of the ductus deferens is to store and transport sperm to the
ejaculatory duct, connecting the epididymis, merging into the urethra pushing it forward and
allowing the sperm to exit the body. The ductus deferens are designed for this function,
characterised by thick muscular walls, which perform peristalsis. The inside wall consists of a moist
folded layer of mucous membrane, which is further surrounded by three layers of circular and
longitudinal muscle fibres. At the end of the ductus deferens are the ampulla, ... Show more content
on Helpwriting.net ...
The skin of the scrotum becomes wrinkled due to the underlying dartos muscle. The testes must be
kept at temperature that is lower than 3oC, so that spermatogenesis can occur. The scrotum uses a
muscle (the cremaster muscle) to achieve this. When the cremaster muscle shrinks, the testes move
closer to the scrotum, and this increases the temperature of them. They can also be cooled down by
dilating and moving away from the testes, dropping them in temperature. The testes receive their
blood flow from the anterior and posterior scrotal artery. The venous blood flows through the
testicular veins and then into the vena cava. Another function of the testes is to protect the testes
from injury, hence why one testis hangs lower than the other, to avoid compression in the event of
impact.
Testes (Male gonads)
The testes are two ovular organs found in the male reproductive system. They are held in place by a
spermatic cord, which is a collection of vessels, nerves and ducts that run from more than one part
of the testes. The testes function to create the hormone testosterone; a primary male sex hormone
which generates the production of sperm. The seminiferous tubules which are located in the testes
are responsible for the production of sperm cells, and the sperm made in this process line the tubules
until they reach maturity and are released into the lumen of the seminiferous tubule.
Seminal

Essay On Immunocastration In Milk
In addition, consistent with the low density of spermatogonia, spermatids and seminiferous tubules
observed in testicles, the mRNA expressions of LH–β and FSH–β in the pituitary gland were both
significantly decreased after immunocastration in the treated rams. The result is in agreement with
the findings of [Wei et al., 2011] in rabbit and [Fang et al., 2010] in boar that GNRHR mRNA
expression in the pituitary was significantly decreased in immunocastrated animals. Furthermore,
[Sakurai et al., 1992] reported that there was a reduction of GNRHR mRNA in the pituitary and
protein concentration after passive immunocastration of male sheep. Another group showed that the
amount of GNRHR was significantly lower in the sheep that were immunized ... Show more content
on Helpwriting.net ...
In general, oral immunization with active kisspeptin DNA vaccine plays a significant role in
suppressing GNRH secretion in the hypothalamus, GNRHR in the pituitary, and negative regulation
of the secretion of steroid hormones. Leydig cells have essential roles in the maintenance of
steroidogenesis and spermatogenesis in the testes. The failures of both processes are attributed to
Leydig cell dysfunction. In the current research, expression of testicular LH receptor and FSH
receptor mRNAs was significantly lower in the treated ram lambs (P < 0.05), implying that testicular
responsiveness to LH stimulation was impaired. Indeed, active immunization against GNRH in
boars significantly reduced testicular LH receptor and testosterone concentrations following
treatment with exogenous LH [Wei et al. 2011; Wei et al., 2012]. Moreover, expression of testicular
LHR mRNA was significantly decreased, which further confirmed that the functions of Leydig
within testes were severely impaired. In addition, it is well known that FSH plays a role in
spermatogenesis. However, the expression levels of FSHR mRNA in the testes of treated rams and
control rams were not siginificantly different, demonstrating oral kisspeptin DNA immunization has
no influence on

Why Do Gamete Cells Come Into Play
Do you ever wonder how babies are made? Well, that's where gamete cells come into play. Gamete
cells are haploid cells, or reproductive cells. These cells possess one pair of chromosomes from the
parent. During meiosis, haploid cells are divided and the chromosomes fuse together producing
genetically new instructions. Gamete cells play a crucial role in the development of a baby.
Meiosis is the process in which the gamete cells turn from haploid to diploid. Meiosis involves eight
stages: Prophase 1, Metaphase 1, Anaphase 1, Telophase 1, Prophase 2, Metaphase 2, Anaphase 2,
and Telophase 2. Prophase 1 is when chromosomes cross over. The chromosomes exchange genetic
information making new and distinct traits. Metaphase 1 is when the crossed–over

What Is Male Infertility?
Infertility is a global problem affecting about 8–12% of couples worldwide. Male infertility
accounts for about 50 % of such cases (Inhorn, 2003). Several factors contribute to its etiology such
as hormonal imbalance, physical and psychological stress, environmental and genetic factors
leading to compromised semen parameters (McGrady, 1984; Irvine, 1998). Pathophysiology of male
infertility is associated with various abnormalities occurring at the cellular & molecular level.
Secondary conditions such as diabetes mellitus and obesity have also been linked to male infertility
(Sexton & Jarow,1997; Pasquali et al., 2007; Best & Bhattacharya, 2015). Oligospermia or low
sperm count and poor sperm quality have been reported as the major causes of

Arctic Ground Squirrel Research Paper
Unlike temperate dwelling ground squirrels, arctic ground squirrels undergo a long hibernation
seasons (six to eight months) and a relatively short active season. When ground squirrels begin their
active season when environmental conditions are still harsh (Buck and Barnes 1999). Although
conditions are harsh, male and female ground squirrels still undergo reproduction and produce
offspring. Male and female ground squirrels differ in the timing of seasonally recurring life cycle
events (Buck and Barnes 1999; Sheriff et al. 2011). Male ground squirrels end heterothermy earlier
than females and remain sequestered in their hibernacula to undergo spermatogenesis while they
consume a food cache. Males then emerge, engage in male–male combat to gain

Differences Between Eastern And Western Gray Squirrels
The eastern and western gray squirrels are two different species of squirrels that inhabit the Grand
Canyon in Arizona. Both squirrels can appear in a variety of colors, which include black, gray,
brown, cream and red and prior co inhabited the same location before being isolated in different
regions. The eastern gray squirrel normally inhabits the northeastern side of the Grand Canyon while
the western gray squirrel lives in three separate locations along the western side of the Grand
Canyon. Squirrel species on opposite sides of the Grand Canyon provide an example of: a.
Anagenesis. b. Sexual selection. c. Allopatric speciation. d. Sympatric speciation. e. All the above
Exaggerated secondary sexual characteristics can occur as a result of

Types Of Reproduction And Asexual Reproduction
Introduction:
We explored the reproductive system. It is important because without it all living things would
become extinct.
The two different types of reproduction are sexual and asexual reproduction. Types of asexual
reproduction include binary fission, budding, and fragmentation. Budding is when another organism
grows out of the parent cell, and separates once it's fully developed. Fragmentation is when an
organism splits into more pieces which each form into their own organism. Binary fission is when
the parent cell copies its genetic material and then splits into two. The advantages of asexual
reproduction are that it produces a lot of offspring, takes little energy, and is speedy. The
disadvantage is that the offspring are clones. Types of sexual reproduction include external and
internal fertilization. External fertilization means that the eggs are fertilized outside of the two
parent organisms, while internal fertilization happens inside of the two parent organisms. The
advantages of sexual reproduction is that the offspring vary genetically. The disadvantages are that
there are fewer offspring, it takes longer, it requires more energy, and a partner must be found.
Gametogenesis is the production of gametes. There are two kinds of gametogenesis, oogenesis and
spermatogenesis. Oogenesis happens in the ovaries, and makes eggs. It only happens during fetal
development, and produces two polar bodies and one ovum. Spermatogenesis happens in the testes,
and occurs

Case Study Of Foetal Leydig Cells
The foetal Leydig Cell population arises shortly after testicular differentiation around 7 weeks in a
human after gestation by the Human Chorionic Gonadotropin (hcG), this is known as the first wave
(45). These cells function, mainly to produce androgens which are essential for masculinization of
the foetus as well as in the descent of the testes in the scrotum, these androgens subsequently act as
paracrine factors within the seminiferous tubules, testosterone, is only first detected around 6–7
weeks of gestation and peaks around 13–14 weeks (45). In cases where Leydig cells fail to develop
or fail to produce androgens, pseudohermaphrodism occurs (46). The androgen produced ensures
the Wolffian duct is maintained and there is ... Show more content on Helpwriting.net ...
Postnatal differentiation of human Leydig cells involves a variety of cellular cascades resulting in
mature Leydig cells. When the 'second wave' occurs after 2–3 months of birth there is a gradual
increase in testosterone levels, the neonatal cell population during this time frame is a mix of mature
well–developed Leydig cells and smaller ones (52). These cells possess well–developed
steroidogenic machinery expressing both the LH receptor and key steroidogenic enzymes such as
3βHSD, P450scc, P450c17 required for androgen synthesis (53). The neonatal androgen surge is
believed to play a role in imprinting various cell types in the prostate, hypothalamus, genetalia and
kidney, in such a way they respond appropriately to androgen stimulation during adulthood (54).
The Leydig cells then regress and testis remain dormant until puberty (55). Following a prolonged
childhood period of steroidogenic quiescence, the hypothalamus generates a pulse of GnRH around
the 12th year (56). The onset GnRH typically occurs at night and is due in part to the gradual decline
in nocturnal melatonin secretion from the pineal gland (56). This GnRH triggers release of the
pituitary gonadotropin LH that ultimately stimulates the Leydig cells to grow in number and size,
whilst also maturing and differentiating to

Endosulfan Literature Review
Impact of Endosulfan on Male Reproductive functions – a review
ABSTRACT
Endosulfan is an organochlorine insecticide and acaracide used to control a broad range of insect
and arthropod pests on a wide variety of crops in many agrosystems. It can cause acute and chronic
toxicity. Endosulfan is a neurotoxin, haematoxin, genotoxin and nephrotoxin. Toxicity of this
insecticide on reproductive organs is confirmed. So this article reviews experimental and
epidemiological studies of reproductive toxicity of endosulfan in males. The Literature search was
carried on PubMed for the years 1994 –2014. Twelve experimental studies and two human studies
on Male Reproductive Toxicity induced by endosulfan were identified. Based on the findings, it
suggest that endosulfan can affect the male reproductive system and also that these effects are likely
to be larger if exposure occurs during the developmental phase. Further investigation of endosulfan
as reproductive toxicant is warranted.
Keywords: Endosulfan, Organochlorine insecticide, Male reproductive system
INTRODUCTION
Chemicals ... Show more content on Helpwriting.net ...
Lower SMR scores appear to reflect lower serum testosterone levels for age. In there study, they
were not able to confirm disturbed spermatogenesis observed in animal studies.
In a cross–sectional study on humans showed an Inverse associations between Organochlorine (OC)
pesticide concentrations (endosulfsan) and testosterone in men, suggest that these OC compounds
may have triggered anti–androgenic effects in men and estrogenic effects in women in this
population20.
Mechanism of

Essay about Discuss the Male Reproductive System
Discuss the Male Reproductive System
The reproductive system is questionably the body system that is the most important influence on life
as we know it. It is the w ay in which we procreate and ensure our existence as a species. However,
the penis is only one part of the male reproductive system, which constitutes of a series responsible
for generating, storing, and transporting the genetic material contained in the sperm cells. The main
organs include: testicles (or testes), the epididymides, the vas deferens, the ejaculatory duct, the
urethra, and the penis. Others are the scrotum, urogenital opening, and the prostate gland.
The penis is a male organ, responsible for transporting urine and semen outside the body. It is a ...
Testes are kept in the scrotum sac and are two oval shaped glands, about 8,5cm long and 2.5cm
wide. A midline septum divides the scrotum into two halves and each testical is covered in two
tunics; the Tunica vaginalis from the peritoneum and the Tunica albuginea which is a deeper tunic
and a fibrous capsule. The septa from this layer then divides the testes into 250 – 300 wedge shaped
compartments or lobules. It is in these lobules that seminiferous tubules are found, where sperm is
made. Each lobule contains about 1 – 4 seminiferous tubules. The network into which seminiferous
tubules empty is called the Rete testis. After which, the epididymis receives sperm from the rete
testis network.
The scrotum is a loose sac of skin and superficial fascia outside the abdominopelvic cavity, fascia,
and smooth muscle that encloses and supports the testes outside the body at an optimum temperature
for the production of sperm, about 3 degrees below body temperature. When the temperature is too
low, the spermatic cord (This cord is surrounded by skeletal muscle and suspends the testes) tightens
thus pulling the testes closer to the body. When the temperature is too hot, the cord relaxes resulting
in the testes moving further away from the body. The muscles responsible for this are Cremaster
muscles, which extend from the internal obliques and elevate the testes. Most men might have
noticed that when this happens, the scrotum skin wrinkles. This is due to the smooth muscle in the

Female Phenotypes
There are many cases of natural gender transformation in human populations that have been
reported, particularly in the Caribbean islands of North America, however the National Institutes of
Health (NIH) have reported some cases in Turkey, Egypt and Papua New Guinea. Some males with
female phenotypes at birth begin to develop physical male characteristics when they hit adolescence.
This is commonly known as Guevedoces, which is translated to mean "penis at age twelve," or
machihembras meaning "first a woman, then a man" (1). These individuals are born with an XY
genotype with both of their sex chromosomes intact. It is the Y chromosome that releases
testosterone up to eight weeks into development to identify the sex of the fetus. The release ... Show
more content on Helpwriting.net ...
Testosterone signals to developing germ cells and then can be translated directly to changes in gene
expression, known as the traditional pathway. Another way is testosterone can activate kinases to
maintain spermatogenesis which is known as the nontraditional pathway. In the absence of
testosterone, spermatogenesis does not proceed beyond the meiosis stage. The traditional
testosterone signaling pathway starts off with the testosterone diffusing through the plasma
membrane to bind with the androgen receptors (AR). The receptor then undergoes an alteration in
conformation which activates receptor proteins in the cytosol. AR is then able to translocate to the
nucleus where it binds to androgen response elements. It is after this that the androgen response
elements and the receptors can alter the expression of genes to change cellular function. The non–
classical kinase activation pathway is when testosterone interacts with the androgen receptor then
activate Proto–oncogene tyrosine–protein kinase, Src, which is a non receptor tyrosine kinase
protein (3). This activation of Src causes the activation of the EGF receptor via intracellular
pathway. The EGF receptor then activated the MAP kinase cascade through Ras resulting in
activation of RAF and MEK then later ERK (3). Once these are activated, they turn on the genes
that control male sex characteristics These steps are critical to maintain spermatogenesis and male

Dual Control Model
From all the models that explain about human sexuality, I think the most useful model would
Bancroft's dual control model. The dual control model explains of what Masters and Johnson's left
out in their research about human sexuality. In Masters and Johnson's research about human
sexuality said that people are physiological arousal through a process of only excitation stimulus. In
the Dual Control Model, Bancroft explains of how we as humans need to balance of two process in
human sexuality called excitation and inhibition. Bancroft believes that it was very important to now
only understand excitation process, but to also focus on the inhibition process as well.
He believed that sexuality was adaptive across many species of a balance between the excitation and
inhibition. Excitation is explained as something that is powerful in sexuality that can be a
distraction, but with distractions that are so powerful can lead to disadvantages. Bancroft believe
that these process are due to an evolutionary sense, because inhibition process allows us to stop us
from the powerful sex and survive any ... Show more content on Helpwriting.net ...
The inhibition process is important due to physiology of the reproductive system in men's
spermatogenesis. Spermatogenesis is the process of developing sperm, this process usually take 24
hours for a man to develop 30 million sperms. So if a man is having sex everyday due to low
inhibition process, it is less likely for him to be able to impregnate is partner. Bancroft also was able
to do more research about both process, which came about that these process are more of balance
between the two. Meaning that sometimes having too much of excitation or inhibition, and having
little of both can creates problems. Bancroft found that people with an imbalance of excitation and
inhibition can actually experience sexual disorders or problem such as erectile

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