Oral Histology: General Embryology Chap:2

Front 1

Rostral

Back 1

Term meaning towards the beak
or head end

Front 2

Cephalic or cranial

Back 2

A term meaning toward the head
end

Front 3

Caudal

Back 3

A term meaning near or toward
the tail

Front 4

Dorsal

Back 4

A term meaning near or toward
the back.

Front 5

Ventral

Back 5

A term meaning near the front

Front 6

Sagittal

Back 6

A term meaning the vertical
plane which cuts the embryo in
left and right parts (previously
parasagittal).

Front 7

Medial

Back 7

A sectioning plane in the middle
of the medial plane (previously
midsagittal or sagittal section).

Front 8

Coronal

Back 8

A section in the vertical or frontal
plane parallel to the main axis of
the embryo which cuts the
embryo in dorsal and ventral
parts.

Front 9

Transverse

Back 9

A section perpendicular to the
Cephalocaudal axis dividing the
embryo into caudal and cephalic
portions, cross section.

Front 10

Growth

Back 10

Growth is an increase in size or
number of cells in the whole or
any part of the organism

Front 11

Morphogenesis

Back 11

This is a change in shape or
location of a cell or tissue

Front 12

Critical period

Back 12

Times during which an organ system is being developed.

*Exposure to teratogens during the critical period can cause
developmental defects.

Front 13

Morphogenic Movements

Back 13

This is a change in location of
cells during development, e.g.
gastrulation, neurulation, neural
crest migration, etc.

Front 14

Patterning

Back 14

The establishment of a
programmed subset of cells in
proper relation to each other and
to surrounding tissues., e.g.
shaping of bones and muscles on limbs, positioning of specific
tooth types within the jaws,
patterning of hair, etc

Front 15

Cytodifferentiation

Back 15

A complex process by which a
cell or cell line attains and
expresses a stable phenotype.
This usually occurs over the
course of several generations
with cells expressing
intermediate phenotypes.

Front 16

Morphodifferentiation

Back 16

A change in shape of a
developing organ due to
morphogenic movements or
differential growth

Front 17

Tissue (epithelial-mesenchymal)
interaction

Back 17

Interactions between tissues
which are necessary for
subsequent development of one
or all of the tissues involved e.g., the interaction of oral epithelium and dental mesenchyme is necessary for the formation of teeth: the interaction between the notochord and ectoderm is
needed for the formation of the
neural plate.

Front 18

Differentiation

Back 18

The process of achieving a stable different phenotype. It results in a loss of potentiality but cells gain new properties.

Front 19

Induction

Back 19

This is the action or physical
presence of a tissue or molecule
which causes differentiation

Front 20

Primary induction

Back 20

Early events occurring during the
blastula and gastrula stages that
lead to the formation of axial
tissues (neural plate, paraxial
mesoderm, notochord).

Front 21

Competence

Back 21

On receiving an environmental
cue, it is the ability of a cell to
differentiate along a certain line.

Front 22

Down syndrome

Back 22

Trisomy 21
*facial clefts
*shortened palate
*protruding and fissured tongue
*delayed eruption in teeth