This review discusses the latest developments in the hemodynamics of mitral stenosis. English-language journal articles, reviews, and textbooks from the clinical, physiology, and engineering literature related to mitral valve stenosis were identified and reviewed. The main conclusions are: (1) the hemodynamics of mitral stenosis are determined by the complex anatomical and pathophysiologic features of the valve apparatus, (2) the properties of the left ventricle, atrium, and pulmonary vasculature also have a major impact on the hemodynamic significance and the clinical syndrome of mitral stenosis, (3) the valve and the cardiac chambers have a functional reserve that become exhausted as the stenosis worsens and/or the compensatory mechanisms of the chambers fail, and (4) a careful approach to data acquisition and analysis will lead to an accurate assessment of the hemodynamics of mitral stenosis before and after therapeutic interventions.
Explanation:please say a thanks because i wrote it by my own hands from note book
RNA polymerase is always present in the cell, but sometimes present in viruses.
tRNA is always present in the cell but never present in viruses.
Ribosomes are always present in a cell but never present in viruses.
Genes are always present in the cell, but always present in viruses.
Explanation:
Viruses are acellular microorganisms that do not have a biochemical or gene expression of their own. They hijack the host's gene expression system.
RNA polymerase is the enzymes that forms RNA primers during DNA replication and the mRNA transcript of template DNA during transcription. Therefore, RNA polymerase is always required in cells.
Most viruses lack RNA polymerase except some RNA viruses such as polio viruses that contain an RNA dependent RNA polymerase, an enzyme that synthesizes mRNA from an RNA template.
Viruses lack tRNA and ribosomes as they are not capable of translation on their own.
Unlike the gene expression machinery, all organisms including viruses have a genome. Viruses can have both DNA and RNA genomes.
