Pharyngeal Arches Flashcards
What are the 4 fundamental aspects of developmental biology?
Proliferation - cell growth
Pattern formation - cells grow in the right place at the right time
Morphogenesis - shape
Differentiation - different types of cells
What is a dynamic interaction?
Happens quickly
What is a reciprocal interaction?
One type of cell/tissue is in control of another
What is a sequential interaction?
Timing of events
Tissue interactions appear to be associated with at least 2 general types of phenomena Tissue interactions appear to be associated with at least 2 general types of phenomena, what are these?
Instructive
Permissive (facilitative)
What is the instructive phenomena associated with tissue interactions?
the ability of one tissue to determine specific patterns of morphogenesis and differentiation that will develop in an associated tissue
What is the permissive phenomena associated with tissue interactions?
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
What is the tissue interaction governing cell differentiation and morphogenesis throughout embryonic development?
Secondary inductions
What is an organ rudiment?
an organ or part incompletely developed in size or structure
What is the organiser of differentiation to form specific structures in early embryology?
signalling centre
What are the 3 true primary germ layers form outer to inner?
Ectoderm
Mesoderm
Endoderm
What is the not true primary germ layer?
neural crest/ecto-mesenchyme
what process brings about the primaru germ layers?
gastrulation
What does the endoderm go on to form?
Many of the bodys inner linings
most of the GI tract, the lungs, liver, pancreas etc
What does the ectoderm go on to form?
The bodys outer linings, including the epidermis, the skin (outer most layer) and hair
What does the mesoderm go on to form?
The dermis of the skin, the heart, muscles, bones, bone marrow (therefore the blood) etc
what week does the development of the pharyngeal arches start?
week 4/5
What arch do they mandible and maxilla develop from?
pharyngeal arch 1
What cartilage is found in pharyngeal arch 1?
Meckel’s cartilage
What cartilage is found in pharyngeal arch 2?
Reichert’s cartilage
How is meckel’s and reichert’s cartilage described?
as transient - it is almost completely disappeared/developed into other structures by week 20
What is the stomadeum?
The precursor to the oral cavity
what can be described as “a highly migratory cell population with the ability to acquire a broad spectrum of cell fates”
the neural crest
What seperates the pharyngeal arches on the endodermal (internal) surface?
pouches
What seperates the pharyngeal arches on the ectodermal (external) surface?
pharyngeal cleft