Term
|
Definition
| Morphogenesis is the creation of form during development. |
|
|
Term
| How is morphogenesis accomplished? |
|
Definition
This is accomplished at the cellular level whereby changes in cells
lead to the formation of functional tissues and organs of the body. |
|
|
Term
| What are the two main types of cells embryos have? |
|
Definition
The epithelial cells form sheets or tubes through their tight
interconnections.
The other cell type is referred to as mesenchymal cells. |
|
|
Term
| List 6 cellular processes that produce morphogenesis. |
|
Definition
1) direction and number of cell divisions
2) cell shape changes
3) Cell movement/motility
4) Cell growth
5) Cell death
6) Cell membrane or extracellular matrix changes |
|
|
Term
| Do mesenchymal and epithelial cells accomplish morphogenesis the same way? |
|
Definition
|
|
Term
| How do the two cell types accomplish morphogenesis through cell division? |
|
Definition
| Somatic cells undergo mitosis to produce more cells in all directions to produce hyperplasia as seen in mesenchymal cells or can occur in rows such as seen for epithelial cells in gastrulation. |
|
|
Term
| How do the two cell types accomplish morphogenesis through cell shape changes? |
|
Definition
Cell shape changes can also occur as shown for
condensation of mesenchymal cells in cartilage or in neurulation in epithelial cells. |
|
|
Term
| How do the two cell types accomplish morphogenesis through cell movement? |
|
Definition
Cell movement involves the movement of cells at particular times and places such as in heart mesenchyme or intercalation or migration of epithelial cells in gastrulation and the chick endoderm.
Epithelial cells may also disperse as seen in
Mullerian duct degeneration. |
|
|
Term
| How do the two cell types accomplish morphogenesis through cell growth? |
|
Definition
Cell growth of mesenchymal cells also involves
hypertrophy as in the example of fat cells or for epithelial cells in neurulation. |
|
|
Term
| How do the two cell types accomplish morphogenesis through cell death? |
|
Definition
Interdigital mesenchyma is an example of the fifth
process involving cell death of mesenchymal cells and delamination of the chick hypoblast is also a form of cell death. |
|
|
Term
| How do the two cell types accomplish morphogenesis through cell membrane or extracellular matrix changes? |
|
Definition
The last process, matrix secretion and degradation
occurs in cartilage mesenchyme or, for the case of epithelial cells, synthesis or removal of the extracellular layer in organ formation. |
|
|
Term
| Morphogenesis also involves communication between cells which occurs in two major ways, list them. |
|
Definition
1) diffusible substances such as hormones, growth factors, or morphogens
2) surface contact between cells |
|
|
Term
| Of the two types of communication in morphogenesis which is more important? |
|
Definition
|
|
Term
| What are the two common patterns of embryogenesis involved in morphogenesis? |
|
Definition
| Gastrulation and organogenesis |
|
|
Term
|
Definition
the movement of cells from the blastula
surface to the interior of the embryo |
|
|
Term
|
Definition
|
|
Term
| What is cell intercalation? (Common epithelial morphogenetic movements) |
|
Definition
| a group of cells modify their relative position by transiently shortening some of their cell-cell junctions. |
|
|
Term
| What is invagination? (Common epithelial morphogenetic movements) |
|
Definition
some cells constrict
their apical surface, often modifying their length along their apico-basal axis, whereas neighboring cells remain unchanged. |
|
|
Term
| What is rotation? (Common epithelial morphogenetic movements) |
|
Definition
| a group of cells rotate relative to other cells |
|
|
Term
| What is sheet extension? (Common epithelial morphogenetic movements) |
|
Definition
| a cohesive sheet of cells extends toward a common direction. |
|
|
Term
| What is tube formation? (Common epithelial morphogenetic movements) |
|
Definition
| a sheet of cells constrict apically, allowing external cells within the sheet to seal and form a lumen. |
|
|
Term
| What is tube constriction and elongation? (Common epithelial morphogenetic movements) |
|
Definition
cells
forming a tube modify their shape by reducing their overall circumference, while maintaining their relative position. |
|
|
Term
| _____ constriction drives invagination. |
|
Definition
|
|
Term
| How do primary mesenchyme cells migrate along the extracellular matrix? |
|
Definition
| Primary mesenchyme cells migrate along the extracellular matrix using filopodia to detect chemical cues |
|
|
Term
| Molecular changes at the cell surface mediate what? |
|
Definition
| Molecular changes at the cell surface mediate the selective recognition of cells and the formation of tissues and organs. |
|
|
