DH110 M4 Knowledge check Ch. 7 (All three attempts)

Enamel is composed of ______ hydroxyapatite.

96%

The surface of the enamel rod is called the rod

sheath

T/F: Enamel rods extend perpendicular to the dentoenamel junction.

True

A developmental defect at the dentinoenamel junction of enamel that looks like small branches and are filled with enamelin is called (a/an)

enamel tuft.

Which of the following best defines the neonatal line?

An accentuated incremental line.

The organic component of enamel is called

enamelin.

T/F: Hunter-Schreger bands reduce the chance of splitting of the enamel along the rod length.

True

An enamel ______ houses a small extension of a living odontoblast.

spindle

T/F: Lamellae are cracks in the surface of enamel and are visible to the naked eye.

True

Which of the following best defines perikymata?

Growth lines visible as ridges on the surface of enamel.

T/F: Ameloblasts migrate away from the dentinoenamel junction as they produce enamel rods.

True

Which part of the enamel rod is most sensitive to demineralization?

Core

All of the following are true with Enamel lamellae except. Which one is the exception?

Enamel lamellae are only microscopic cracks in the surface of enamel.

Which of the following best defines incremental lines?

Lines that result from the rhythmic recurrent deposition of enamel

Ameloblasts produce _______ as they migrate.

enamel rods

T/F: Incremental lines result from the rhythmic, recurrent deposition of enamel.

True

T/F: Each enamel rod is formed by a single ameloblast.

False

T/F: Light and dark enamel rod groups are known as striae of Retzius.

False

T/F: In the Hunter-Schreger phenomenon, adjacent rod groups interdigitate with parallel and perpendicular rods.

True

T/F: Enamel is an impermeable tissue.

False

Two ameloblasts are needed to form which part of the enamel rod

neck.

T/F: Enamel rods extend from the dentinoenamel junction to the enamel outer surface.

True

Perikymata are found in which location?

Cervical third of the crown's facial aspect