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I'm Dr. Banumathy,
Anatomist from
Tamil Nadu, India.
The topic for discussion today
is "Introduction to
Human Embryology".
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The development of human
beings before birth of
the child is called
prenatal development.
The development after birth
is postnatal development.
The study of the
developmental anatomy in
the prenatal period
is embryology.
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Human development commences
from a single cell zygote.
The zygote is
formed by the union
of two highly specialized cells.
The male gametes are
the sperms and the female
gametes are the ova.
The sperms are produced in
the testes and the ova
are formed in the ovary.
The development of
the gonads depends on
the gonadotrophic hormones
of the pituitary gland.
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The gonads, testis in
males and ovary in
females develop from
the genital ridge
of the intermediate mesoderm.
However, the primordial
sex cells are
derived from the
endoderm of the hindgut.
These cells migrate to
the developing gonads.
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The male gonads are testis.
They are paired organs
situated in the
skin pouch scrotum.
Each testis is oval in
shape and is covered
by a capsule tunica
albugenia testis.
Numerous fibrous bands divide
the testis into lobules.
In each lobule are
present three or four
white string-like structures
called the seminiferous tubules.
Spermatogenesis takes place
in the seminiferous tubules.
The sperms are transported to
the exterior through
the epididymis,
vas deferens, ejaculatory duct,
urethra and external
urethral orifice.
