17.
A C T I O N S
O F
V I T A M I N S
A
A N D
C
673
8. Bone and cartilage
Although cartilage and bone were the first tissues to be exposed to
the action of excess of vitamin A in organ culture, an account of this
work has been kept to the last, because much more is known about the
action of the vitamin at the cellular level in this material.
Fig. 14. Explant of oesophagus from a 13-day embryonic chick grown in normal medium for
6 days. The darkly stained sheet of cuboidal ciliated cells is being sloughed from the underlying stratified epithelium. x625. (Aydelotte, 1963a.)
FIG. 15. Similar explant cultivated for 6 days on medium containing 7-5 i.u. vitamin A/ml.
The epithelium consists of tall, columnar, ciliated cells with a few mucous elements. Parts of
mucous glands below the epithelium, can be seen at either side of the photograph, x 625.
(Aydelotte, 1963a.)
A C T I O N S
O F
V I T A M I N S
A
A N D
C
673
8. Bone and cartilage
Although cartilage and bone were the first tissues to be exposed to
the action of excess of vitamin A in organ culture, an account of this
work has been kept to the last, because much more is known about the
action of the vitamin at the cellular level in this material.
Fig. 14. Explant of oesophagus from a 13-day embryonic chick grown in normal medium for
6 days. The darkly stained sheet of cuboidal ciliated cells is being sloughed from the underlying stratified epithelium. x625. (Aydelotte, 1963a.)
FIG. 15. Similar explant cultivated for 6 days on medium containing 7-5 i.u. vitamin A/ml.
The epithelium consists of tall, columnar, ciliated cells with a few mucous elements. Parts of
mucous glands below the epithelium, can be seen at either side of the photograph, x 625.
(Aydelotte, 1963a.)