Do humans have Gill slits in embryonic stage? If they have Gill slits what does it become in adults?
Do humans have Gill slits in embryonic stage? If they have Gill slits what does it become in adults?
As an embryo begins to develop its three dimensional structure and its body organs start to form the tissue between the head and torso starts to grow around and as it does this it forms a series of ridges and hollows. For a brief time (28 days to 44 days) the grooves between the ridges have a superficial resemblance to slits when viewed from the outside.
However, as the Web of Life textbook admitted, they do not form holes that penetrate from the inside to the outside as gills in a fish do. Neither do they ever develop any of the structure of a fish gill. The correct name for the series of ridges and grooves is “pharyngeal arches and clefts” and they develop into parts of the face and the throat region, including the jaws, chewing muscles and larynx (voicebox). The only groove that remains as an indentation is the one closest to the head end of the embryo. It forms the external earhole. The others are incorporated into the structures of the face and neck.
What we call *gill slits* are, in fact, Pharyngeal "pouches". It appears to superficially resemble fish gills, nut does not in fact have anything to do with any form of respiration!
Rather than having anything to do with vestigial apparatus for breathing or respiration, the pharyngeal "pouches" develop into parts of the face, neck, and important glands! "
In man and other mammals, these arches and pouches develop into part of the face, muscles of mastication and facial expression, bones of the middle ear, and endocrine glands.
MEANWHILE, the embryo's lungs develop quite independantly of these gill slits.
As an embryo begins to develop its three dimensional structure and its body organs start to form the tissue between the head and torso starts to grow around and as it does this it forms a series of ridges and hollows. For a brief time (28 days to 44 days) the grooves between the ridges have a superficial resemblance to slits when viewed from the outside.
However, as the Web of Life textbook admitted, they do not form holes that penetrate from the inside to the outside as gills in a fish do. Neither do they ever develop any of the structure of a fish gill. The correct name for the series of ridges and grooves is “pharyngeal arches and clefts” and they develop into parts of the face and the throat region, including the jaws, chewing muscles and larynx (voicebox). The only groove that remains as an indentation is the one closest to the head end of the embryo. It forms the external earhole. The others are incorporated into the structures of the face and neck.
What we call *gill slits* are, in fact, Pharyngeal "pouches". It appears to superficially resemble fish gills, nut does not in fact have anything to do with any form of respiration!
Rather than having anything to do with vestigial apparatus for breathing or respiration, the pharyngeal "pouches" develop into parts of the face, neck, and important glands! "
In man and other mammals, these arches and pouches develop into part of the face, muscles of mastication and facial expression, bones of the middle ear, and endocrine glands.
MEANWHILE, the embryo's lungs develop quite independantly of these gill slits.
