I’ve seen videos showing the scale of a human egg and it’s visible to the naked eye- it’s definitely not as small as i thought it would be. So how are girls born with millions of eggs already? Im thinking that large of an amount would take up a considerable amount of space. And how do girls lose eggs from birth if they dont have their first period til adolescence? Since im assuming eggs are mainly lost through periods, excluding trauma or ovarian disorders.
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Eggs are constantly deteriorating. The vast, vast majority of eggs never ovulate, they just degrade and die. Periods are the body disposing of an egg after it was primed for conception. Unused eggs die far more often and without all the uncomfortable cramps and stuff
Eggs are constantly deteriorating. The vast, vast majority of eggs never ovulate, they just degrade and die. Periods are the body disposing of an egg after it was primed for conception. Unused eggs die far more often and without all the uncomfortable cramps and stuff
Human girls have about 6 million eggs during fetal development, but most of them die and are reabsorbed before birth, when only about 1 million are left. Most of these eggs also die and are reabsorbed before puberty. By that time, there’s about 300,000 eggs left, and the bulk of those are never released during ovulation.
Human egg cells are about 1/10 of a mm in diameter, meaning about 1,000 of them would fit in a one millimeter cube. Stacking 1,000 such cubes together would make a cube 1 centimeter on each side, and that cube would contain about 1 million egg cells. Spread that over two ovaries and there’s plenty of room for a million egg cells even in a baby.
During a woman’s life, her oocytes go through different stages of development (primary and secondary oocyte stages) and get stuck in different moments of meiosis. By the time a girl is born she already has all of the oocytes she will ever have because her gem cells eventually all specialize and lose the ability to self-renew, these oocyte are stuck in meiosis 1 and we call them primary oocytes.
When a girl starts menstruating clusters of oocytes start being recruited every month for ovulation, the oocytes start maturing and start growing along with a bunch of cells that surround them; they grow because they need to accumulate enough nutrients to support a growing embryo after fertilization, plus mitochondria to power all of that growth. Even though a small cluster of hundreds of follicles start maturing at the early stages of the female menstrual cycle, in normal conditions only one becomes the largest and the rest stop developing and die. Only one big oocyte being ovulated per month.
That’s how most oocytes are lost during a girl’s lifetime
Human girls have about 6 million eggs during fetal development, but most of them die and are reabsorbed before birth, when only about 1 million are left. Most of these eggs also die and are reabsorbed before puberty. By that time, there’s about 300,000 eggs left, and the bulk of those are never released during ovulation.
Human egg cells are about 1/10 of a mm in diameter, meaning about 1,000 of them would fit in a one millimeter cube. Stacking 1,000 such cubes together would make a cube 1 centimeter on each side, and that cube would contain about 1 million egg cells. Spread that over two ovaries and there’s plenty of room for a million egg cells even in a baby.
Basically the same way they are born with all the fingers they have.
I’m guessing you’re more asking why they aren’t continually produced like sperm?
It would be very hard to confine such growth to produce just one or two every X days..
I’d also think that such a limited relaae system would only work if you had just one master cell they grew from there would be a much higher chance of that cell mutating and going bad thus ending the cycle.
And of course, mass production isn’t going to work as you would risk the massive problems with so many.. men don’t produce a few sperm, they produce millions.. not a good option for the number of children to try and carry.
In addition to the answers already here, I want to add that when you’re thinking about egg cells as large you may be thinking about egg cells after they leave the ovary. Eggs ‘in storage’ are a bit smaller than eggs getting squeezed down a fallopian tube that can be fertilized. Part of the life cycle of an egg is that before it is released from the ovary it spends a few days maturing in a fluid sac on the outside of the ovary. Part of the process is maturing is just growing. All this to say: the eggs in storage are not quite as big as you might be thinking.
During a woman’s life, her oocytes go through different stages of development (primary and secondary oocyte stages) and get stuck in different moments of meiosis. By the time a girl is born she already has all of the oocytes she will ever have because her gem cells eventually all specialize and lose the ability to self-renew, these oocyte are stuck in meiosis 1 and we call them primary oocytes.
When a girl starts menstruating clusters of oocytes start being recruited every month for ovulation, the oocytes start maturing and start growing along with a bunch of cells that surround them; they grow because they need to accumulate enough nutrients to support a growing embryo after fertilization, plus mitochondria to power all of that growth. Even though a small cluster of hundreds of follicles start maturing at the early stages of the female menstrual cycle, in normal conditions only one becomes the largest and the rest stop developing and die. Only one big oocyte being ovulated per month.
That’s how most oocytes are lost during a girl’s lifetime
Basically the same way they are born with all the fingers they have.
I’m guessing you’re more asking why they aren’t continually produced like sperm?
It would be very hard to confine such growth to produce just one or two every X days..
I’d also think that such a limited relaae system would only work if you had just one master cell they grew from there would be a much higher chance of that cell mutating and going bad thus ending the cycle.
And of course, mass production isn’t going to work as you would risk the massive problems with so many.. men don’t produce a few sperm, they produce millions.. not a good option for the number of children to try and carry.
In addition to the answers already here, I want to add that when you’re thinking about egg cells as large you may be thinking about egg cells after they leave the ovary. Eggs ‘in storage’ are a bit smaller than eggs getting squeezed down a fallopian tube that can be fertilized. Part of the life cycle of an egg is that before it is released from the ovary it spends a few days maturing in a fluid sac on the outside of the ovary. Part of the process is maturing is just growing. All this to say: the eggs in storage are not quite as big as you might be thinking.
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