Nucleic acids Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are made up of nucleic acids found in the nuclei of living cells.They are the vehicles of genetic inheritance. Nucleic acids are condensation polymers of nucleotides.ucleic acids Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are made up of nucleic acids found in the nuclei of living cells.
After the ventricles complete their contraction phase, they relax and the SA node initiates another impulse to start another cardiac cycle. The Heart: Conduction System The heart pumps blood through the body This is accomplished by contraction and relaxation of the cardiac muscle tissue in the myocardium layer.
SA node: The SA node (SA stands for sinoatrial) is one of the major elements in the cardiac conduction system, the system that controls the heart rate.