egg cell and sperm
For a conception an egg cell and many sperm are needed. When the cells
find each other, they fuse after a while and the chromosomes come
together. Then the zygote (= fertilized egg) is formed and can begin to
divide. Phenomenology gives us the characteristics of the ovum and
sperm. There are no cells in humans that are so different and yet
belong so much together.
ovum and sperm
Size and shape
The egg cell (or ovum, or oocyte) is the largest human cell. She
measures 0.15 to 0.2 mm and is just visible to the naked eye. She is
also the roundest cell, she is almost perfectly round (Fig. 4). She
therefore has the largest volume in relation to her surface. The cell
consists of a large amount of cytoplasm (= cell fluid) in
which the nucleus is dissolved (and therefore invisible) until
just before conception.
Sperm cells are the smallest human cells. They are no more than a
nucleus with a small amount of cytoplasm, some mitochondria (the energy
suppliers of the cell) and a long tail. They have hardly any content
and are the straightest cells.
Egg cell and sperm are each others opposite. Large versus small, round
versus straight, cytoplasm versus nucleus. The differences are great,
at the same time they belong together if we perceive the ovum as a
sphere and the straight sperm as the corresponding radius.
The cytoplasm of a normal body-cell is in movement, the nucleus is not.
The two gametes (= germ cells) show different features. The egg cell
consists primarily of cytoplasm, she is internally
mobile. The nucleus is outspread, the chromosomes are unwound
(not folded up). The cell is internally active and mobile. The
sperm cells have hardly any cytoplasm and are concentrated in their
DNA. They have a crystalline structure. These cells are internally
structured and rigid.
In contrast, the ovum is externally not active. After her release, she
passively moved by the fluid-flow in the oviduct (uterine tube), while
the sperm cells are
active, using their tails to swim against the stream of fluid in the
oviduct. They are externally active and mobile.
The ovum is internally mobile and externally passive, this is a
polarity. The sperm shows the opposite: internally passive and
externally mobile. Egg cell and sperm have a polarity and are opposite
each other, we see a double polarity.
An egg cell is a metabolically active cell; substances are absorbed and
released. E.g. nutrients are absorbed, substances that affect the
uterus and substances that attract the sperm are released. An egg cell
lives only 12 to 24 hours in her own
environment and cannot be preserved. The egg cell can easily be
destroyed. She is an active cell and open to the environment.
Sperm cells do not absorb or release substances. There is no
with the environment. They live about 3 to 5 days in the womb and can
be preserved and frozen at temperatures below 60 °C. They are
not easy to destroy. They are closed off from the environment and
The open and vulnerable state of the egg cell is polar to the closed
robust state of the sperm cells.
For a conception one ovum and millions of sperm are required. The one
ovum is worth as much as all those millions of sperm. A man with less
than 20-40 million sperm in an ejaculation is barren. Such great
numbers are necessary because most sperm do not reach the ovum. Also,
for a conception more than one spermatozoon is necessary. See the page
The ovum is alone and the sperm are with millions. One sperm cell is
nothing, one ovum determines everything. One is polar to millions. One
comprises everything, it is all there is, whereas the millions of sperm
cells are infinitive, have no importance on their own.
The egg cell develops in one of the two ovaries in the warm
abdominal cavity, the
sperm develop in the testicles just outside the body in a relatively
The ovum develops in warm- and sperm in relative
Egg cells are produced well before birth in a huge number of
so called primordial egg cells (primordial oocytes). From the beginning
on, there is a continuous process of dying, so that at birth 2 million
(!) are left. That process of dying goes on after birth. At the onset
of puberty there remain
about 40,000 ova. Then every four weeks a number of them begin a
process of maturation. Of these, only one (sometimes two or three) ovum
the rest dies. In total about 400 ova mature (13 per year for 30
years). At menopause, no primordial egg cells are left.
In men, a very different process is going on. The first sperm cells are
formed only from puberty on, before that they are not produced. Then
goes on and on and never stops, hundreds per second, millions each day.
Sperm cells are constantly being newly formed.
Egg cells are old cells that became mature. Primordial oocytes are in a
process of dying. Sperm cells are newly formed and are young. The
maturation process of ova is an expiring process, it stops. The
formation of the sperm is a vital process, it never stops.
From a primordial oocyte only one mature egg cell develops.
During meiosis the rest of
the mass of the nucleus is excreted as polar bodies. The cell
grows during maturation, the amount of cytoplasm increases.
the ovum moves from the centre of the ovary to the edge (Fig. 5).
From a primordial spermcell four sperm cells develop. The cytoplasm
is eliminated, the cell is getting smaller. When some cytoplasm stays
behind, the sperm cell cannot swim well and cannot reach the egg cell.
Sperm cells are produced at the edge of the testis and stored inside.
At egg cell maturation the focus is on one cell, that expands
in volume. Sperm cells show concentration of material and
expansion of the number. Egg cells move from the inside to the outside,
sperm cells from the outside to the inside.
In appearance and processes egg cell and sperm are mutually
antagonistic, each others opposite. Large versus small, internally -
active, old versus young, concentration versus expansion,
etc. During maturation of these gametes two cells are formed
which differ maximally and seem to go to
extremes in their individuality. The development and maturation show
increasing divergence, a process of polarization.
When they are mature, ovum and sperm can come together and
resolve the polarity in a conception, so that a new human being can
be born, that has all the cell shapes that lie between the two
extremes. If not,
there is no viability, and then they die.
||the ovary, inside
||testes, outside the
|formed from - until
||before birth -
||puberty - death
development of the ovum
Ova are created as primordial oocytes in million copies as early as
in the embryonic stage and their number is gradually reduced. They
lie separated from each other in follicles and are surrounded
by a layer of nutritive, so called follicular cells. In the
primordial follicles (= initial vesicles) they lead a passive
In Fig. 5 the development of the egg cell can be
seen clockwise from the left (primordial follicles).
- The development begins with the thickening of the
surrounding layer of nutritive cells, this is called the primary
follicle (= first vesicle).
- This stage leads to the secondary follicle, because
in the layer of nutritive cells an antrum (= cave) arises. The ovum
grows and gets larger. The follicle
produces oestrogen, a hormone that stimulates the wall of the uterus to
- The antrum grows larger. Around the ovum a layer is
formed, called the zona pellucida (= translucent layer). Around it are
the nutritive cells in the
corona radiata (= radiating wreath). The growth of the ovum continues.
The wall of the uterus continues to thicken.
- Then the ovum is shot away into the abdominal cavity.
There is a moment when the ovum floats freely in the abdominal cavity.
Then she will be collected by the fimbriae of the
oviduct. The interception is an active process, the oviduct moves to
the ovum. The remaining cavity in the ovary is called the corpus luteum
yellow small body) that makes progesterone, which also plays a role in
the thickening of the uterine wall, so that the fertilized ovum can
implant. When a
fertilization does not occur, then the thickened wall comes loose and
development of sperm
From a germ, four equal sperm cells are formed by division.
Around the nucleus a hard cap is formed, the acrosome (acros =
top, soma = body). Then the cytoplasm is ejected and the cell gets
move to the beginning of the tail, that becomes thicker and longer. The
cells are stored for about 60 days, after which they are resorbed. If a
small cloud of cytoplasm remains with the nucleus, the
sperm is badly damaged and will have trouble moving forward.
Van der Wal, J., 2003. Dynamic morphology and embryology. In:
Bie, van der G & M. Huber, Foundations of anthroposophical
medicine. Floris books, Edinburgh.
Bie, G van der, 2001. Embryology. Louis Bolk
It is not strictly true that they are the largest and smallest cells.
In the spinal cord there are larger cells, in the small brains smaller
cells. This does not affect the principle. The difference between ovum
and sperm remains enormous.
Spermatozoon (A) and ovum (C). B shows the sperm at the same scale
as the ovum
Since several years an ovum can be frozen by vitrification, a process
whereby water is removed and replaced by a concentrated liquid, leaving
no freezing crystals, which can damage the chromosomes.
Differences between an egg cell and sperm
Konig (1986) gives a similarity between the development of the ovum and
the evolution of the earth, as it is described by Rudolf Steiner in
1. The egg is surrounded for many years by tissue of the ovary. He
compares this to the Warmth Stage of the earth, or the Saturn Stage.
2. The nutritive cells thicken, and the ovum increasingly stands on her
own. He compares this to the Air or Sun Stage of the earth.
3. In the layer of nutritive cells the fluid-filled antrum is created.
This is compared to the Water or Moon Stage of the earth.
4. The release of the ovum is compared with the (current) solid stage
of the earth. The cell is completely on herself and will either develop
Oogenesis, the development of the egg cell in the ovary (from the
Spermatogenesis, the development of sperm