Area marked by the arrow in the given figure contain all the following, except:
A. Zona occludens
B. Fascia adherens
C. Macula adherens
D. Gap junction
Ans: A. Zona occludens
(Ref. Gray’s 40/e p140; Ganong 25/e p41, 24/e p43)
- Given diagram is showing intercalated discs of cardiac muscle containing all types of cellular junctions except occluding tight junction (Zona occludens).
- Junctional complex between neighbouring cells in cardiac muscle cells.
- Interdigitating transverse parts of intercalated disc form a fascia adherens, with numerous desmosomes.
- Gap junctions are found in longitudinal parts of disc.
- Type of junction that tie cells together & endow tissues with strength and stability.
- Also referred as “tight junctions”.
- Characteristically surround apical margins of cells in epithelia (intestinal mucosa, renal tubular walls & choroid plexus).
- Desmosome & zonula adherens help to hold cells together.
- Hemidesmosome & focal adhesions attach cells to their basal laminas.