Lecture 3 - Integrating Cells

Question 1

Which polymers are rich in the connective tissue?

Answer 1

Collagen

Question 2

How are cells attached in CT compared to the epithelial tissue?

Answer 2

In Connective Tissue, cells are rarely directly attached as they are sparsely distributed

In Epithelial Layer, cells are attached by a bunch of cell-cell adhesions, via lateral sides or basal to the basement membrane.

Question 3

How are epithelial cells attached to one another?

Answer 3

Via attachment proteins eg. Desmosomes, Gap Junctions, Tight Junctions and Adhesion Junctions

Question 4

How are cells attached to the basement membrane?

Answer 4

Via Hemi-Desmosomes, Focal Adhesions which both require Integrins

Question 5

What are integrins? Best example of where they are found?

Answer 5

Proteins which bind the cytoskeleton of cells to the extracellular matrix outside cells (ECM)
Found in skin

Question 6

2 roles of integrins?

Answer 6

Communicate by transducing signals in and out of cells

Attach cells to surfaces

Question 7

How do cells mature in the Connective Tissue layers? Where do they begin?

Answer 7

Start as a primary Mesenchymal Stem Cell
Has ability to interconvert between several types of cells (Adipose, Muscle, Bone, Cartilage, Haematopoic and Connective Tissue)
Can re-convert back into initial cells (not mesenchymal)

Question 8

What lines ALL cavities and free surfaces of body?

Answer 8

Epithelial cell sheets

Question 9

What is the purpose of specialised junctions between epithelial cells?

Answer 9

Connect epithelial cells together

Form tissue barriers that inhibit movement of water, solutes, cells etc. from one part of the body to another