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But it takes just one to fertilize, and in fact after one has made contact with the egg, the others do not make any contact with it, there is a kind of shield that prevents others from reaching the egg.. just one does the job.Quote:
Originally Posted by aaj2008
That is why we needed this thread, J_9 is an expert, and Alty should be one-
I did not say the egg itself... I said the outer layer...Quote:
Originally Posted by snowalps
The outer layer of the egg is the egg.
Then it's the egg..Quote:
Originally Posted by aaj2008
An egg cell is 150 microns in size, and is colourless and semi-transparent. It is the shape of a sphere and its outer part is surrounded by a soft yet tough membrane. Within the structure of the egg there are extra nutrients like fat, sugar and proteins. This reserve of nutrients will ensure that the egg cell is nourished on its journey and, if fertilization occurs, will take care of its needs until it reaches the uterus...
Here you go (from Wikipedia) --
Penetration
Fertilization starts with a man and a woman initiating sexual intercourse. The man inserts the penis into the womans vagina, penetrating her vaginally. When the man experiences orgasm, semen containing millions of sperm are ejaculated from the penis and deposited in the vagina. Propelled through the female reproductive tract by flagellation, some of these sperm may reach the cell membrane of the oocyte, and a single sperm may penetrate the membrane. To reach the oocyte, the sperm must pass through the corona radiata and the zona pellucida; two layers covering and protecting the oocyte from fertilization by more than one sperm.
Corona radiata
The sperm passes through the corona radiata, a layer of follicle cells on the outside of the secondary oocyte.
Acrosome reaction
The acrosome reaction must occur to mobilise enzymes within the head of the spermatozoon to degrade the zona pellucida.
Zona pellucida
The sperm then reaches the zona pellucida, which is an extra-cellular matrix of glyco-proteins. A special complementary molecule on the surface of the sperm head then binds to a ZP3 glyco-protein in the zona pellucida. This binding triggers the acrosome to burst, releasing enzymes that help the sperm get through the zona pellucida.
Some sperm cells consume their acrosome prematurely on the surface of the egg cell, facilitating for surrounding, having on average 50% genome similarity, to penetrate the egg cell.[1] It may be regarded as a mechanism of kin selection.
Cortical reaction
When the sperm penetrates the zona pellucida, the cortical reaction occurs: cortical granules inside the secondary oocyte fuses with the plasma membrane of the cell, causing enzymes inside these granules to be expelled by exocytosis to the zona pellucida. This in turn causes the glyco-proteins in the zona pellucida to cross-link with each other, making the whole matrix hard and impermeable to sperm. This prevents fertilization of an egg by more than one sperm.
Thank you wondergirl, I hate going back and forth :)
Is it true that mastubation is healthy for the males body?
Quote:
Originally Posted by aaj2008
Yes, many are trying to be the first in as they surround the egg, but once that soft, yet tough membrane is penetrated by just one, a reaction takes place that causes that membrane to harder to all other sperm trying to get in.
In actuality there are very few (given the number that started the journey) who even get to the egg. Many are misshapen, are too weak, or have no sense of direction (and certainly won't just follow the others because that would be conceding that they don't know where they are going in the first place). Given that, along with several other steps along the way... secretion of necessay enzymes, penetration, acceptance by the egg, available proteins, etc. having any of those functions fail, will cause the egg not to be fertilized. When you think about all that has to be in place for it to happen, from both the male and the female side, it is no wonder it can take quite a bit of time for conception to occur.
Even more simple... Think of it as a pie eating contest... all the members are trying to be first to finish as quickly as possible and win the prize. They aren't helping each other, just focusing on the job at hand, and they will vary in what they bring to the table and how they tackle the job. There can be only one winner who finishes first. Once that one finishes, the others stop the race... :)
Yes... I know this... I'm not retarded.. they said it takes one sperm to get someone pregnant... so you agree with me... one sperm entering the vaginal canal has a low chance of getting someone pregnantQuote:
Originally Posted by DoulaLC
Yes, this is true actually. It helps keep the prostate healthy.Quote:
Originally Posted by Mrcuddlesworth
No one called you retarded, so please keep those comments out of this thread.Quote:
Originally Posted by aaj2008
One sperm is not going to enter the vaginal canal it's impossible for a man to release just one sperm.
I think the emotional side of sex ed is important too so here are my questions:
If I have sex with my boyfriend will that make him love me/ stop him leaving me?
If I haven't had sex by the age X will I be a loser/alone forever/uncool etc?
All my friends are having sex and I'm not, does this mean there is something wrong with me?
It always makes me sad for the kids who ask these questions.
I agree with you in part... You said "it takes millions of sperm to penetrate the egg" and that they make a hole for that one sperm. Perhaps it is somewhat a case of semantics, but yes, while millions of sperm will be ejaculated, only a few hundred (at best) reach the egg. They are not working together to make an entrance for one lucky sperm, the ones that are able to even get close enough to attach to the egg (just one of the many hurdles to overcome) are all trying to be that first one in.Quote:
Originally Posted by aaj2008
Others have said "it takes just one"... referring to the one that gets through to the egg (which is true), not that just one will be present in the ejaculate (which no one has stated).
Quote:
Originally Posted by templelane
Depends on a person's perspective, but IMO:
1) Having sex may or may not strengthen someone's feelings towards the other person. If often depends on what the feelings are to begin with. It certainly won't stop someone from leaving... even though girls (in particular) are often told that. One thing young girls, and even older women, should consider is that if their partner truly cares about them, there will be no pressure to have sex. No "If you loved me you would"... "I'll stay with you if you get pregnant". No guy is worth hanging onto if it means you have to compromise your values, or what you believe to be right for you, in order for him to want to be with you. In a healthy relationship, you don't try to persuade someone to go against what they are comfortable with.
2) This goes for both girls and boys... as both often get mixed messages about what they "should" be doing, usually under the assumption that everyone else already is. Guys sometimes feel they are expected to at least try to get their girlfriend to have sex with them and girls sometimes feel if they don't "give in" their boyfriend will find someone else who will. Unfortunately, guys will get the better end of the deal in regard to reputations... they are often seen more as a "real man" with a number of conquests under their belt... whereas girls are more often seen as being easy if they have a number of partners. The pressure to fit in and not stand out is tremendous... which is unfortunate. In time, when these kids are older... much of the time, the girls in particular, wish they hadn't slept around as much or given in to keep a boyfriend and would do things differently if they could go back. Guys will often still say they prefer a wife who has not slept around... the adage that some girls are for sleeping with and just having a good time, while others are the type you would want to actually marry, raise children with, and spend your life together.
3) Many times, not ALL of the friends really are having sex... and even if they were, it wouldn't mean there is anything wrong with someone who wasn't. In some cases, it could even be that that person knows themselves better, is more mature, is not going to take any chances, and is able to stand up for what they believe is right for them and their future. Just as with a boyfriend or girlfriend, your friends should support you in what your decision regarding when to have sex is. Even friends, in their own insecurity, will sometimes make comments simply because they have a sense of guilt or regret about their own actions and it is much easier if others they know are also in the same boat. Many probably wish they could go back and do things differently, especially if they were the ones who believed the lines used to get them to have sex in the first place.
Now, saying all of that... I know full well that many young people will find it difficult to overcome those feelings of thinking they don't fit in if they aren't having sex, of wanting to have someone like or love them, of needing to hang onto a boyfriend or girlfriend for fear they will be alone, or simply feel that they really are in a loving and committed relationship... those are the kids in particular who need the education of ways to keep themselves as safe as possible if they are deciding to have sex.
Doula, it is so good to have you here!! Glad you found the thread.
I know this is a little goofy since I am a sophomore in Nursing school and I still don't know this... but hey all we have learned so far is about the body. Nothing about birth control.
HOW exactly does birth control help to prevent pregnancy? I'm under the impression that it is made up of hormones.. estrogen and progesterone to help prevent ovulation? Is that the only thing it does?
If the pill is made to prevent ovulation - how do some people get pregnant while taking it? No ovulation = no egg to get fertilized = no baby.
Thanks :)
AnxiousRN, There are many different birth control pills out there. Some contain estrogen and progestin, others contain only progestin.
The pill is meant to stop the ovaries from releasing eggs, it's also supposed to make the mucus in the cervix get thicker, making it harder for the sperm to enter. Also, the lining of the uterus gets thinner making it hard for a fertilized egg to attach to the wall.
Notice that nowhere in that description did I say, "It will do this and that." I said "it's supposed to do these things". No birth control is 100% effective.
Also remember, the pill is only effective if taken daily, around the same time each day. In other words, there's lots of room for human error.
The pill and a condom is a good combination, but still not 100% effective in some cases.
Having said that, using birth control is still better than not using anything, you will lower the odds of pregnancy with birth control, but you won't completely take away the possibility of becoming pregnant.
Hi I just want to ask...
If we had sex and he inject the sperm inside the vagina...
Is the sperm going to fall off if the girl have pee after the sex
... just curious:)
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