Craniofacial Developmental Disorders

Question 1

what is the definition of induction?

Answer 1

The process by which one tissue or cell influences another to differentiate/develop

(the process by which an undifferenciated cell is instructed by specific organisers to produce a morphogenic effect)

Question 2

what is the definition of proliferation?

Answer 2

controlled cellular growth and accumulation of by products

Question 3

what is the definition of differentiation

Answer 3

change in identical embryonic cells to become distinct structurally and functionally

Question 4

what is the definition of morphogenisis?

Answer 4

development of specific tissue structure or differing form due to embryonic cell migration or proliferation and inductive interactions

Question 5

what is the definition of maturation?

Answer 5

attainment of adult function and size due to proliferation, differentiation and morphogenesis

Question 6

what weeks does the embryonic period of prenatal development take place?

Answer 6

beginning of the 2nd - the end of the 8th

Question 7

what does the embryonic pattern arise from?

Answer 7

Arises from the spatial and temporal regulation of induction, cell proliferation, differentiation, morphogenesis and maturation

These processes cause the structure of the implanted blastocyst to become, with further development, an embryo

Question 8

what is cytodifferentiation?

Answer 8

the development of different cell types

Question 9

what is histodifferentiation?

Answer 9

the development of different histologic tissue types within a structure

Question 10

what is morphodifferentiation?

Answer 10

the development of the differing morphology, which makes up its structure or shape, for each organ or system

Question 11

what process increases the complexity of the structure and function of cells, during the embryonic period?

Answer 11

morphongenesis, the process of development of specific tissue structures or shape

Question 12

At what week does a blastocyst take on distinct human characteristics and is now a recognisable embryo?

Answer 12

the 8th week of prenatal development (the end of the embryonic period)

Question 13

what happens during the second week of prenatal development?

Answer 13

the blastocyst is implanted into the uterine wall
blastocyst grows by increased proliferation of the embryonic cells, with differentiation occurring resulting in changes in cellular morphogenesis

The increased number of embryonic cells creates the embryonic cell layers (germ layers) within the blastocyst

Question 14

what are the 3 germ layers?

Answer 14

the mesoderm, endoderm and ectoderm

Question 15

in the second week what is developed from the blastocyst?

Answer 15

a bilaminar embryonic disc - epiblast and hypoblast (2 layers)

Question 16

in the third week, with the layers present the bilaminar disc has thickened into what?

Answer 16

a trilaminar embryonic disc

the epiblast layer is now considered the ectoderm and creation of the new embryonic cell layers (mesoderm and endoderm)

Question 17

what happens during the 4th week of prenatal development (within the embryonic period)

Answer 17

the trilaminar embryonic disc undergos folding

This (for the first time) establishes the axis, which places forming tissues types into their proper positions for further embryonic development as well as producing somewhat a tubular embryo

Question 18

what are dynamic interactions?

Answer 18

interactions that happen quickly

Question 19

what are reciprocal interactions?

Answer 19

one is in control of another

Question 20

what are sequentially interactions?

Answer 20

the timing of events

Question 21

what are the 2 general types of phenomena that tissue interactions are associated with?

Answer 21

instructive and permissive

Question 22

what is the instructive phenomena of tissue interactions?

Answer 22

the ability of one tissue to determine specific patterns of morphogenesis and differentiation that will develop in associated tissue

Question 23

what is the permissive (or facilitative) phenomena of tissue interactions?

Answer 23

the ability of an interacting tissue to provide certain conditions that is necessary for its committed partner tissue to progress to full expression of its pre-determined phenotype

Question 24

what are the future structures of the ectoderm?

Answer 24

epidermis; sensory epithelium of the eyes, ears, nose, nervous system, and neural crest cells; mammary and cutaneous glands

Question 25

what are the future structures of the mesoderm?

Answer 25

Dermis, muscle, bone, lymphatics, blood cells and bone marrow, cartilage, reproductive and excretory organs

Question 26

what are the future structures of the endoderm?

Answer 26

organs of the GI and respiratory systems (linings), liver and pancreatic cells

Question 27

what is the origin of the ectoderm?

Answer 27

the epiblast layer

Question 28

what is the origin of the mesoderm?

Answer 28

migrating cells from the epiblast layer

Question 29

what is the origin of the endoderm?

Answer 29

migrating cells from the epiblast layer

Question 30

what is the process that establishes the three distinct embryonic cell layers?

Answer 30

gastrulation

Question 31

what does teratogenic mean?

Answer 31

able to disturb the growth and development of an embryo or fetus

Question 32

what drugs are known teratogens involved in congenital malformations?

Answer 32

ethanol, tetracycline, phenytoin sodium, lithium, methotrexate, aminopterin, diethylstilbestrol, warfarin, thalidomide, isotretinoin (retinoic acid), androgens, progesterone

Question 33

what chemicals are known teratogens involved in congenital malformations?

Answer 33

methylmercury and polychlorinated biphenyls

Question 34

what ainfections are known teratogens involved in congenital malformations?

Answer 34

rebulla virus, syphilis spirochete, herpes simplex virus, human immunodeficiency virus (HIV)