Humans human sperm midpiece. Medical search. Frequent questions

The mitochondrial sheath (MS), an important organelle in the midpiece of spermatozoa, is crucial to sperm motility. (nih.gov)
However, the over production of oxygen free radicals in sperm membrane decreases the antioxidant defense activity thereby leading to low sperm motility and viability, DNA fragmentation and protein denaturation. (scialert.net)
In spermatozoa, several key functions are regulated by cytoplasmic Ca2+ concentration such as sperm capacitation, chemotaxis, hyperactive motility, and acrosome reaction. (123dok.net)
In mammals, adenosine 3', 5'-cyclic monophosphate (cAMP) is known to play highly important roles in sperm motility and acrosomal exocytosis. (plos.org)
It is involved in flagellar movements and motility, and in cellular events that occur in the sperm head, that will lead to successful interaction with the egg and to fertilization [ 1 , 2 ]. (plos.org)

Intracytoplasmic sperm injection was used to treat the patients. (nih.gov)
Moreover, two patients were treated with intracytoplasmic sperm injection and achieved good outcomes. (nih.gov)
Isolated teratozoospermia does not affect in vitro fertilization outcome and is not an indication for intracytoplasmic sperm injection. (myhealth.gov.my)

The size of the sperm midpiece is determined in part by the volume of mitochondria in the sperm. (wikipedia.org)
Sperm midpiece size is tied to sperm competition in that individuals with a larger midpiece will have more mitochondria, and will thus have more highly motile sperm than those with a lower volume of mitochondria. (wikipedia.org)
The midpiece: that contains mitochondria which are responsible for energy production needed for sperms movement. (online-sciences.com)
MDT combines sperm and egg from the biological parents with healthy mitochondria from a female donor's egg. (ivf.net)
The midpiece harbors the small "powerhouses" (mitochondria) that produce the energy, which fuels the rapid tail movements needed for propulsion. (healthandscience.eu)

The morphological assessment of human spermatozoa which includes the evaluation of the percentage of morphologically normal sperm and the determination of the incidence of various morphological abnormalities has always been part if semen analysis in couples consulting for infertility. (myhealth.gov.my)
Sperm morphology was assessed in the initial semen analysis using the Kruger-Tygerberg Strict Criteria as outlined by the World Health Organization. (myhealth.gov.my)
The male reproductive system consists of a pair of testes that produce sperm (or spermatozoa ), ducts that transport the sperm to the penis and glands that add secretions to the sperm to make semen (see diagram 13.2). (wikibooks.org)
When a man ejaculates his semen into the vagina of a woman, somewhere between 60 and 450 million sperm cells are dispatched. (healthandscience.eu)

Sperm competition is a form of post-copulatory sexual selection whereby male ejaculates simultaneously physically compete to fertilize a single ovum. (wikipedia.org)
The ovum forms a vitelline membrane that prevents the further entry of any other sperm. (tutordale.com)
The tail: thin and long and it is responsible for the movement of the sperm till reaches the ovum . (online-sciences.com)
The sperms rush the ovum at the beginning of the fallopian tube . (online-sciences.com)
Fertilization occurs by the fusion of the nucleus of sperm (which contains 23 chromosomes ) with the nucleus of the ovum (which contains 23 chromosomes ) to form the zygote (fertilized ovum), which contains a nucleus with 46 chromosomes (23 pairs of chromosomes ). (online-sciences.com)
The ovum surrounds itself with a coat after the penetration of sperm inside it to prevent the penetration of any other sperm . (online-sciences.com)
In biological terms sexual reproduction involves the union of gametes - the sperm and the ovum - produced by two parents. (wikibooks.org)

Since, ROS is essential for the normal sperm physiology, rationale use of antioxidants is advocated. (scialert.net)
The study indicates that the protein encoded by this gene is required for normal sperm production. (sciencedaily.com)
However, the focus of this article is going to be on the assessment of image analysis to indicate the normal sperm morphology of an ejaculate. (myhealth.gov.my)
Assessing approximately 200 spermatozoa and the value of normal sperm is calculated in percentage. (myhealth.gov.my)

The patients' spermatozoa displayed multiple midpiece defects, including absent MS and central pair, scattered or forked axoneme and incomplete plasma membrane. (nih.gov)
Spermatozoa from Armc12 -/- mice showed parallel defects in the midpiece. (nih.gov)
Mature spermatozoa are characterized by an head, midpiece and a long tail for locomotion. (innovations-report.com)
October - Mature spermatozoa are characterized by an head, midpiece and a long tail for locomotion. (innovations-report.com)
The mature and ejaculated spermatozoa are carried to the female tract in seminal plasma, which supports key sperm functions such as interactions with the various environments of the tubular genital tract, with the oocyte and with the female immune system and potentially helps modulate sperm rejection or tolerance [ 2 ]. (biomedcentral.com)

In this process, the typical elongated sperm cells are formed from round germ cells. (innovations-report.com)

Binding of the sperm to this inner glycoprotein membrane induces the release of hydrolytic enzymes from the acrosome. (tutordale.com)

Oxygen free radicals are naturally produced by mitochondrial and sperm plasma membrane and have beneficial and detrimental effects that cannot be overlooked. (scialert.net)

This mediates the fusion of the sperm membrane with the plasma membrane of the egg, facilitating the fertilization of the two haploid nuclei. (tutordale.com)
Egg membranes are also believed to play a role in maintaining species specificity during fertilization, preventing the egg membranes from being accessed by sperm of a different species. (tutordale.com)
In flowering plants, the sperm cell and egg cell meet and fertilization takes place in the flower. (tutordale.com)
The sperm-specific ion channel CatSper is the principal calcium channel in sperm mediating the calcium influx into the sperm flagellum and acting as an essential modulator of downstream mechanisms involved in fertilization. (123dok.net)
At the same time, we found evidence for recent positive directional selection acting on several human testis-enriched genes ( MORC1 , SLC9B1 , ROPN1L , DMRT1 , PLCZ1 , RNF17 , FAM71D and WBP2NL ) that play important roles in human spermatogenesis and fertilization. (biomedcentral.com)
The minisymposium, organized by Victor D. Vacquier, included the following presentations: "An Hypothesis to Explain the Evolution of Species-Specific Fertilization" by Victor D. Vacquier, "Molecular Biology of the Zona Pellucida: Genetic Mutations and Fertility" by Jurrein Dean, and "Sperm-Egg Membrane Interactions During Fertilizations" by Janice P. Evans. (bioone.org)

Sperm cells are highly sensitive to reactive oxygen species (ROS), which are produced during cellular oxidation. (mdpi.com)

More studies of fertility outcomes in large populations are required to refine the application of CASA to measuring sperm morphology. (myhealth.gov.my)
Using less stringent statistical criteria (uncorrected p -values), also the gene SPATA16 , which has a pivotal role in male fertility and for which episodes of adaptive evolution have been suggested, also displays a putative signal of diversifying selection in the human branch. (biomedcentral.com)
A new, Greek study of 225 men, who frequented a fertility clinic in Athens, showed that those who consumed a predominantly Mediterranean diet had more active sperm cells compared with those who ate a less healthy diet. (healthandscience.eu)

It plays a key role during sperm capacitation [ 3 - 6 ] and the acrosomal exocytosis [ 7 - 10 ], where it affects different intracellular signalling pathways. (plos.org)

In normal cell biology, ROS levels increase with a decreasing antioxidant response, resulting in oxidative stress which threatens sperm biology. (mdpi.com)
Oxidative stress has numerous effects, including increased apoptosis, reduced motion parameters, and reduced sperm integrity. (mdpi.com)
In other words, sperm cells are not able to repair their own DNA damage and are therefore highly vulnerable to oxidative stress caused by free radicals. (healthandscience.eu)
Therefore, it is vital to protect the sperm cells and their DNA against free radicals and oxidative stress, and our only shield against these threats are antioxidants such as vitamin A, vitamin C, vitamin E, selenium, and zinc. (healthandscience.eu)
Did you know that sperm cells are extremely vulnerable towards oxidative stress caused by free radicals, and that stress, poisoning, tobacco smoke, and radiation increase the free radical load? (healthandscience.eu)

Mammalian sperm cells present highly specific lipidic composition, high content of polyunsaturated fatty acids, plasmalogenes and sphingomyelins. (scialert.net)
Discovery of a gene in multiple mammalian species could pave the way for a highly effective, reversible and non-hormonal male contraceptive for humans and animals. (sciencedaily.com)
This review aims to provide insights into the structure, localization, and function of the mammalian CatSper channel, primarily human and mice. (123dok.net)

It is through their transit in the epididymis that sperms cells complete important maturation steps crucial for fulfilling their functions. (123dok.net)
Possible cause of male infertility: Gina Esther Merges and Prof. Hubert Schorle study genes involved in sperm maturation. (innovations-report.com)
Since it is exclusively made in humans and mice during the maturation of male sperm, it has been postulated that the protein is important for this phase of development," notes corresponding author Prof. Hubert Schorle from the Institute of Pathology at UKB, who is also a member of the Transdisciplinary Research Area (TRA) "Life & Health" at the University of Bonn. (innovations-report.com)

In humans, it leads to widely heterogenous morphological pattern, with many cellular abnormalities which may be associated with sperm dysfunction. (myhealth.gov.my)
2001). Sperm Morphological defects Related to Environment, Lifestyle and Medical History of 1001 male Partners of Pregnant Women from Four European Cities. (myhealth.gov.my)

Sperm-egg interactions occur at multiple levels on the egg surface, first with the egg's extracellular matrix and then with the egg's plasma membrane. (bioone.org)

As in somatic cells, sperm intracellular cAMP concentration is regulated by the opposite action of two enzymes: the adenylyl cyclases (AC), which synthesize cAMP from ATP, and the phosphodiesterases (PDE), which break the phosphodiester bond of cAMP to form 5'-adenosine monophosphate (AMP). (plos.org)

Both sperm and egg are only haploid cells. (tutordale.com)

The morphology of sperm cells is the end result of a highly complex process of cellular modifications occurring during spermiogenesis. (myhealth.gov.my)

Recent human transcriptomic analyses revealed a very large number of testis-enriched genes, many of which are involved in spermatogenesis. (biomedcentral.com)
This comprehensive transcriptomic data lead us to the question whether positive selection was a decisive force influencing the evolution and variability of testis-enriched genes in humans. (biomedcentral.com)
Episodic diversifying selection, possibly driven by sperm competition, was not an important force driving the evolution of testis-enriched genes in the human lineage. (biomedcentral.com)
New research shows that epigenetic factors (factors that affect the environment of the sperm cell) determine sperm health and are therefore crucial for activating the genes of the sperm cell so the fetus can develop. (healthandscience.eu)

The key male reproductive organ in humans is the testes. (biomedcentral.com)
They have two main functions: the efficient production of sperm (spermatogenesis) over a male's reproductive life span and the synthesis of hormones necessary to develop male sex characteristics. (biomedcentral.com)
The reproductive organs of mammals produce the gametes (sperm and egg cells), help them fertilize and then support the developing embryo. (wikibooks.org)

When they knocked out the gene in mice, it created infertility only in the males, impacting their sperm count, movement and shape. (sciencedaily.com)
In the WSU study, the male mice lacking this gene produced 28% less sperm that moved 2.8 times slower than in normal mice - and about 98% of their sperm had abnormal heads and mid-pieces. (sciencedaily.com)
This explains why the sperm of male mice with a mutated Actl7b gene is not able to develop the characteristic shape. (innovations-report.com)

The volume of sperm in ejaculates scales proportionately with testis size and, consistent with the intermediate weight of human males' testes, ejaculate volume is also intermediate between primates with high and low levels of sperm competition. (wikipedia.org)
The testes of the adult human male produce about 2 billion sperms per day. (online-sciences.com)
In many animals (including humans) the testes descend into the scrotal sacs at birth but in some animals they do not descend until sexual maturity and in others they only descend temporarily during the breeding season. (wikibooks.org)

Our findings prove for the first time that defects in ARMC12 cause asthenozoospermia and multiple midpiece defects in humans. (nih.gov)

Sperm cells are smaller than other cell types and have a tail that moves. (healthandscience.eu)

Disrupting this protein wouldn't require any hormonal interference, a key hurdle in male contraception since testosterone plays other roles beyond sperm production in men including building bone mass and muscle strength as well as red blood cell production. (sciencedaily.com)

This unusual structure of sperm membrane is responsible for its flexibility and the functional ability of sperm cells. (scialert.net)
The egg in humans contains two major protective layers the corona radiata containing follicular cells, and the zona pellucida. (tutordale.com)
While sperm cells are made in the pollen, egg cells are made in the ovule, the structure that becomes the seed. (tutordale.com)
After being released in the lumen of the seminif- erous tubules, sperm cells have to accomplish several challenging tasks before reaching and fertilizing the egg. (123dok.net)
We found that the splicing factors hnRNPA1/A2, PTBP1/2, and U1-snRNP inhibit ZAPS production and demonstrated the feasibility to modulate the ZAPL/S balance by splice-switching antisense oligonucleotides in human cells. (bvsalud.org)
Male sperm cells are constantly produced in large quantities in the testicles during so-called spermatogenesis. (innovations-report.com)
Without ACTL7B, development is blocked, the cells often remain in a roundish shape, usually do not form the elongated, typical sperm shape and die to a large extent ," says first author Gina Esther Merges, a doctoral student in Professor Schorle's laboratory. (innovations-report.com)
Using this criterion, any subnormally (or borderline forms) classified sperm cells are going to be indicated as abnormal. (myhealth.gov.my)
The more healthy sperm cells a man is able to produce, and the faster they are able to swim, the greater are the chances that one of them reaches its target - the egg - and fertilizes it. (healthandscience.eu)
This is most likely because this type of diet is rich in vitamins, minerals, and essential fatty acids that protect and nourish the sperm cells. (healthandscience.eu)
The content of nutrients in the diet affects the immature sperm cells in the testicles as well as those that are fully matured, which require a lot of energy and protection of their genetic payload. (healthandscience.eu)
All cells in the human body have a nucleus that contains our genetic coding (DNA), which is our cellular blueprint. (healthandscience.eu)
What is more, sperm cells only contain very little cytoplasm that normally produces enzymes, which help repair cellular DNA. (healthandscience.eu)
This makes the sperm cells vulnerable to something called DNA fragmentation, which not only impairs the sperm's ability to swim but may also mean that the first sperm cell to reach the egg is not necessarily the most suited one. (healthandscience.eu)
All human cells contain selenium . (healthandscience.eu)
Sperm cells are particularly dependent on selenium, as this nutrient is a vital part of (seleno)proteins in the filament, which delivers the forward propulsion. (healthandscience.eu)

Sperm competition occurs between sperm from two or more rival males when they make an attempt to fertilize a female within a sufficiently short period of time. (wikipedia.org)
When this gene is inactivated or inhibited in males, they make sperm that cannot fertilize an egg, and that's a prime target for male contraceptive development. (sciencedaily.com)
In other words, while the sperm cell is technically able to fertilize the egg, the egg may not develop properly because of the fragmented sperm cell DNA. (healthandscience.eu)

The male gamete , sperm, is a smaller, mobile cell that meets up with the much larger and less mobile female gamete , egg or ova. (tutordale.com)

Physiological evidence, including testis size relative to body weight and the volume of sperm in ejaculations, suggests that humans have experienced a low-to-intermediate level of selection pressure for sperm competition in their evolutionary history. (wikipedia.org)
In humans, testis size relative to body weight is intermediate between monogamous primates (such as gorillas) and promiscuous primates (such as chimpanzees), indicating an evolutionary history of moderate selection pressures for sperm competition. (wikipedia.org)
Among humans, as with relative testis size and ejaculate volume, the size of the sperm midpiece is small compared to other primates, and is most similar in size to that of primates with low levels of sperm competition, supporting the theory that humans have had an evolutionary history of intermediate levels of sperm competition. (wikipedia.org)
ARMC12 is mainly expressed in the midpiece of elongated and late spermatids in the human testis. (nih.gov)

EDITOR'S PREFACE: The first paper in this issue of Biology of Reproduction is a minireview entitled "Getting Sperm and Egg Together: Things Conserved and Things Diverged," by Janice P. Evans. (bioone.org)

Several features of the anatomy of the human penis are proposed to serve as adaptations to sperm competition, including the length of the penis and the shape of the penile head. (wikipedia.org)
By weight, the relative penis size of human males is similar to that of chimpanzees, although the overall length of the human penis is the largest among primates. (wikipedia.org)

We used two methodological approaches to detect different levels of positive selection, namely episodic positive diversifying selection (i.e., past selection) in the human lineage within primate phylogeny, potentially driven by sperm competition, and recent positive directional selection in contemporary human populations, which would indicate adaptation to different environments. (biomedcentral.com)

In situations where the risk of sperm competition is higher, males will allocate more energy to producing higher ejaculate volumes. (wikipedia.org)

Sexual reproduction is most commonly seen in humans, most animals, and some plants. (tutordale.com)
The initial focus, however, is on giving humans more control over their own reproduction. (sciencedaily.com)
Human Reproduction. (myhealth.gov.my)

Researchers have suggested that males produce more and higher quality sperm after spending time apart from their partners, implying that males are responding to an increased risk of sperm competition, although this view has been challenged in recent years. (wikipedia.org)

The differing rates of sperm competition among other primates indicates that sperm competition is highest in primates with multi-male breeding systems, and lowest in primates with single-male breeding systems. (wikipedia.org)
This condition, the most common diagnosis for human male infertility, shows a decrease in the amount of sperm produced, slowed mobility and distorted shape so that the sperm are unable to fuse with an egg. (sciencedaily.com)
During mating, the male secretes billions of sperms , which move from the vagina towards the uterus then to the fallopian tube . (online-sciences.com)
The female lays the eggs and then the male deposits his sperm on or at least near them. (wikibooks.org)
In reptiles and birds, eggs are fertilized inside the body when the male deposits the sperm inside the egg duct of the female. (wikibooks.org)

Human spermatogenesis requires about 70 days for a complete cycle. (biomedcentral.com)

However, spermatozoa's lipids are the main substrates for peroxidation, which may provoke severe functional disorder of sperm. (scialert.net)
In the human lineage (after correction for multiple testing) we found that only the gene TULP2 , for which no functional data are yet available, is subject to episodic positive diversifying selection. (biomedcentral.com)
and 3) characterization of functional domains in different sperm ligands (fertilin-α and fertilin-β in the mouse and lysin in the abalone) that recognize cognate binding sites on the egg surface. (bioone.org)

You don't want to wipe out the ability to ever make sperm - just stop the sperm that are being made from being made correctly," he said. (sciencedaily.com)

Nevertheless, there is a large body of research that explores the physiological adaptations males do have for sperm competition. (wikipedia.org)
Human males, like other animals, exhibit prudent sperm allocation, a physiological response to the high cost of sperm production as it relates to the actual or perceived risk of sperm competition at each insemination. (wikipedia.org)
This suggests that, at least within males, there is evidence of allocation of higher quality sperm production for copulatory purposes. (wikipedia.org)
It is also possible that males may be producing larger volumes of sperm in response to actions from their partners, or it may be that males who produce larger volumes of sperm may be more likely to spend more time away from their partners. (wikipedia.org)

Developing a way to curb population growth and stop unwanted pregnancies is really important for the future of the human race," said Oatley. (sciencedaily.com)
Cyclic AMP (adenosine 3', 5'-cyclic monophosphate) is an important player in sperm function. (plos.org)

Sperm cell membranes are high in polyunsaturated fatty acids and are sensitive to oxygen free radical induced damage mediated by lipid peroxidation. (scialert.net)
Studies show that in around 50% of the cases where a couple is infertile, the man's sperm cell DNA is not properly protected. (healthandscience.eu)

Evidence suggests that diet plays a vital role in sperm quality. (healthandscience.eu)

In mammals the sperm are placed in the body of the female and the eggs are fertilized internally. (wikibooks.org)

Compared to other animals, and primates in particular, humans show low-to-intermediate levels of sperm competition, suggesting that humans have a history of little selection pressure for sperm competition. (wikipedia.org)
Sperm intracellular cAMP levels depend on the activity of adenylyl cyclases, mostly SACY, though transmembrane-containing adenylyl cyclases are also present, and on the activity of cyclic nucleotide phosphodiesterases (PDE) whose role is to degrade cAMP into 5'-AMP. (plos.org)

However, the role of ARMC12 in human asthenozoospermia remains unknown. (nih.gov)

Studies have found that the volume of sperm does vary between ejaculates, and that sperm produced during copulatory ejaculations are of a higher quality (younger, more motile, etc.) than those sperm produced during masturbatory ejaculates or nocturnal emissions. (wikipedia.org)
Although there can be many underlying causes, poor sperm quality is an increasing problem. (healthandscience.eu)
The study supports earlier findings, where scientists have observed that men who eat a lot of whole-grain, fruit, vegetables, legumes, and fish have better sperm quality. (healthandscience.eu)
Did you know that poor sperm quality increases the risk of miscarriage? (healthandscience.eu)
Men with poor sperm quality should attempt to eat a healthy and balanced diet, whether it is Mediterranean-style or not. (healthandscience.eu)

Anatomy5

Organisms3

Diseases1

Analytical, Diagnostic and Therapeutic Techniques and Equipment2

Phenomena and Processes6

Disciplines and Occupations1

Information Science3

Motility5

Intracytoplasmic sperm inj3

Mitochondria5

Semen4

Ovum7

Normal sperm4

Spermatozoa5

Elongated sperm cells1

Acrosome1

Mitochondrial1

Fertilization6

Reactive oxygen1

Fertility3

Capacitation1

Oxidative stress5

Mammalian3

Maturation3

Morphological2

Plasma membrane1

Concentration1

Haploid cells1

Morphology1

Genes4

Reproductive3

Mice3

Testes3

Defects1

Tail1

Protein1

Cells16

Fertilize3

Gamete1

Testis4

Biology1

Penis2

Primate1

Ejaculate1

Reproduction3

Researchers1

Male5

Spermatogenesis1

Functional3

Correctly1

Males4

Important2

Cell2

Suggests1

Eggs1

Levels2

Role1

Quality5