Craniofacial Development Flashcards
What is developmental biology?
What is the origin of human tissue?
Induction?
Cell differentiation?
- study of the processes by which organs grow and develop, genetic control of cell growth, differentiation and morphogenesis, which is the process that gives rise to tissues, organd and anatomy, but also regeneration and ageing
Origin of human tissue: epithelial mesenchymal interactions
Induction: the process in which an undifferentiated cell is instructed by specific organisers to produce a morphogenic effect
Cell differentiation: chemical substances such as growth factors and morphogens induce cells to initiate specific cellular processes including DNA synthesis in a specific temporal and spatial manner
What happens during prenatal development to embryonic period?
Define:
- induction
- proliferation
Between 2-8 weeks we go from a disc of cells to an embryo through states of induction, proliferaton, differentiation, morphogenesis and maturation
Induction: action of one group of cells on another that leads to the establishment of the developmental pathway in the responding tissue
Proliferation: controlled cellular growth and accumulation of by products
Define:
- differentiation
- morphogenesis
- maturation
Differentiation: change in identical embryonic cells to become distinct structurally and functionally
Morphogenesis: development of specific tissue structure or differing form due to embryonic cell migration or proliferation and inductive interactions
Maturation: attainment of adult function and size due to proliferation, differentiation and morphogenesis
What is cytodifferentiation?
Histodifferentiation?
Morphodifferentiation?
When do we have a recognisable embryo?
Cytodifferentiation: development of different cell types
Histodifferentiation: development of different histologic tissue types within a structure
Morphodifferentiation: development of differing morphology, which makes up a structure or shape, for each organ or system
An embryo is recognisable by the eighth week of prenatal development, which is the end of the embryonic period
What happens during the second week of development?
What are the embryonic cell layers?
The implanted blastocyst grows by increased proliferation of the embryonic cells, with differentiation occuring resulting in changes in cellular morphogenesis
- the increased number of embryonic cells creates the germ layers within the blastocyst
- ectoderm
- mesoderm
- endoderm
- neural crest cells - drive tooth development
What occurs in the 4th week of development?
4th week: disc undergoes embryonic folding establishing the axis which places forming tissue types into their proper positions for further development as well producong a tubular embryo
What are the two general types of tissue interactions?
Instructive: the ability of one tissue to determine specific patterns of morphogenesis and differentiation that will develop in an associated tissue
Permissive: the ability of an interacting tissue to provide certain conditions that is necessary for its commited partner tissue to progress to full expression of its pre-determined phenotype
