Epithelial Specializations

Question 1

Function of Zonula Occludins/Tight Junctions

Answer 1

Prevent selective flow of solutes

Epithelial Polarity

Question 2

Adhesion of Zonula Occludins/Tight Junctions

Answer 2

Adhesion between claudin/occudin and actin cytoskeleton via ZO1, ZO2, ZO4.

Question 3

Function of Zonula Adherins

Answer 3

Link cells to form 1 functional unit

Question 4

Adhesion of Zonula Adherins

Answer 4

Adhesion between catenins/ vinculins/ actinins and actin/myosin via E cadherins

Question 5

Function of Desmosomes

Answer 5

Adhesion between cells

Stress bearing

Question 6

Adhesion of Desmosomes

Answer 6

Cadherins (desmoglians and desmocolin) are linked via plakoglobin/desmoplakin to intermediate filaments

Question 7

Function of Gap Junctions

Answer 7

Provide electrical conductance
Allow passage of ions
Impermeable to nucleic acids, proteins, polysaccharides

Question 8

Gap Junctions Structure

Answer 8

Plaque made of connexons

Question 9

Function of Hemidesmosomes

Answer 9

Connect epithelia to basement membrane

Question 10

Adhestion of Hemidesomosomes

Answer 10

Integrin associated with Collagen Type 17 is linked to cell via plectin/BP230 and IF.

Integrin associated with Collagen Type 17 is linked to CT via laminin

Question 11

Function of Basement Membrane

Answer 11

Attaches epithelia to CT

Made up of basal lamina + reticular lamina

Question 12

Basal Lamina

Answer 12

Attached to epithelia via integrin

Made up of Type 4 collagen, laminin, nidogen, perlecan

Question 13

Reticular Lamina

Answer 13

Type 3 Collagen

Question 14

How are basal and reticular lamina secured together?

Answer 14

Type 7 collagen

Question 15

Epidermolysis Bullosa

Answer 15

cleavage between basal/reticular lamina

Question 16

Pemphigus

Answer 16

autoimmune against desmoglians

Question 17

Impetigo

Answer 17

Staph that attacks desmoglians