Cellular junctions present in cardiac muscle are all except
High-Yield Explanation
Ans. (a) Zonula occludens(Ref: Ganong's Review of medical physiology 25th ed/p. 112)Cardiac muscle cells are connected by,Fascia adherens - it is the structural analog of zonula adherens#Gap junctions#Macula adherens"Zonula occludens is the other name for tight junction. It is absent in cardiac muscle"Gap Junctions* Gap junctions permits substances to pass between the cells without entering the extracellular fluid (ECF)* Gap junctions are composed entirely of an integral membrane protein called connexons* Each connexon is made up of six protein subunits called connexins* Gap junctions are abundant in cardiac muscles which are called as intercalated discs. It is because of this,cardiac muscle functions as single unit called as functional syncytium* Gap junctions are also seen in single unit smooth muscles seen in visceral organs* Mutations in connexin leads to many human diseases namely,Connexin (C x) subtype mutationDiseaseCx32X-linked Charcot-Marie- Tooth diseaseCx26, Cx30, and Cx31Congenital sensorineural hearing lossCx30Clouston syndromeCx40Idiopathic atrial fbrillationCx46 and Cx50Cataract