Question

The layer of cells that secretes enamel of tooth is
A) Dentoblast
B) Osteoblast
C) Ameloblast
D) Odontoblast

Answer 1

Hint: These cells are derived from oral epithelium tissue and are of ectodermal origin.

Complete answer:
Ameloblasts are cells that are present only during tooth development and deposit tooth enamel.

Ameloblast cells are columnar, hexagonal cells that are approximately 4 mm in diameter, 40 mm in length. Ameloblasts cells secrete the enamel proteins enamelin and amelogenin. These proteins will later mineralize to form enamel. Ameloblast cells control ionic and organic compositions of enamel. Studies are indicative that a circadian clock (24-hour) is probably involved in the regulation of enamel production on a daily cycle by the ameloblasts. These cells maintain favorable conditions for biomineralization by adjusting their secretory and absorptive activities to maintain favorable conditions for biomineralization. The ameloblast cells differentiate from preameloblasts (origin from inner enamel epithelium). This differentiation is a result of signaling from the ectomesenchymal cells of the dental papilla. Initially, the preameloblasts differentiate into presecretory ameloblasts resulting in secretory ameloblasts that lay down the tooth enamel. The first stage of amelogenesis involves the differentiation of ameloblasts from preameloblasts in a process known as the pre-secretory (or inductive) phase.

So, the correct answer is ‘Ameloblast’.

Note: - Tooth enamel is the hard outermost layer of the tooth forming the surface of the crown.
- Ameloblasts are like osteoblasts in the production of bone tissue.
- Dental enamel can not regenerate.
- After the first layer of dentin (predentin) has been laid by odontoblasts, the ameloblasts become fully functional.