Physiology 3140A Lecture Notes - Lecture 3: Basal Lamina, Stratum Basale, Epithelium
2 May 2018
School
Department
Course
Professor
3140 – Lecture 3
Cell-Matrix Interactions
September 13 2017
Embryonic (and adult) cells are broadly classed
Epithelial cells
- In skin; line body cavities (e.g., the digestive tract)
- Polarized:
o Apical surface faces out
o Basal surface rests on the basement membrane (extracellular matrix that supports cells)
o Connected with adjacent cells by specialized attachments including:
• Tight junctions
• Desmosomes
• Gap junctions
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- Have junctions in the cell
- All the cells are attached to each other
o Cell to cell junctions – holding one cell to the other
- Epidermis/skin = 5-7 cells thick
o Have multiple layers of the epithelium cells
o Begin to get smaller and more rounded
- All the cells are polarized
o Apical surface: faces out
o Basal surface: faces the basement membrane/ basal lamina
• Extracellular matrix that supports the cells
- One layer thick: gut apical surface is facing the actual lumen of the gut
Mesenchymal cells
- Poorly differentiated
- Have the potential to develop into many different tissue types, including epithelial cells
o Why fibroblasts are mesenchymal like and not mesenchymal can not force them to
become something else without genetic manipulation
- Not attached to adjacent cells
o Do not have cell-cell contact
- Do not have apical-basolateral polarity because they don’t have cell-cell attachment
- Have leading edge and lagging (or trailing) end
o Especially if they are migrating
o Ex. Fibroblasts – they migrate
• If you have wound, fibroblasts are one of first cells that migrate to the area
- Are in contact with extracellular matrix (via focal adhesions)
o Focal adhesion: attaches cell to the matrix like a suction cup
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
In skin; line body cavities (e. g. , the digestive tract) Polarized: apical surface faces out, basal surface rests on the basement membrane (extracellular matrix that supports cells, connected with adjacent cells by specialized attachments including: All the cells are attached to each other: cell to cell junctions holding one cell to the other, have multiple layers of the epithelium cells, begin to get smaller and more rounded. All the cells are polarized: apical surface: faces out, basal surface: faces the basement membrane/ basal lamina, extracellular matrix that supports the cells. One layer thick: gut apical surface is facing the actual lumen of the gut. Have the potential to develop into many different tissue types, including epithelial cells: why fibroblasts are mesenchymal like and not mesenchymal can not force them to become something else without genetic manipulation. Not attached to adjacent cells: do not have cell-cell contact. Do not have apical-basolateral polarity because they don"t have cell-cell attachment.
