Although your answer is correct for 1, the main function of intercalated discs in the cardiac muscle is to make sure that each cell in atrial myocardium and the ventricular myocardium contract together as a syncytium. All the other ones look right . Also, you forgot to put the | right after the [hide] when you began answering the question and that is why your answers weren't hidden.
Quick question: can epinephrine and norepinephrine both be vasoconstrictors and vasodilators in blood vessels? Or is one strictly a vasoconstrictor and the other a vasodilator, and depending upon the quantity of each, vasoconstriction or vasodilation occurs? Your wording kinda confused me