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General principles on caring for older adults
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
Age-associated changes in the anatomy and physiology of the cardiovascular system are described in Chapters 1 and 2. Decreased elasticity and increased stiffness of the arterial system leads to isolated systolic hypertension. Stiffness and delayed relaxation of the left ventricle predispose to diastolic heart failure. Reduced responsiveness to beta-adrenergic stimulation and circulating catecholamines limits the maximum heart rate response and peak cardiac output, contributing to decreased exercise tolerance. Fibrosis of the cardiac skeleton and conduction system, and decrease in the sinus node pacemaker cells increase the risk of atrial fibrillation and other arrhythmias. Calcification of fibrous valve rings increases the prevalence of calcific aortic and mitral stenosis. Decreased sensitivity of carotid baroreceptors predisposes to orthostatic hypotension, syncope, falls, and adverse effects of cardiovascular drug therapy (e.g., diuretics, beta-blockers).
The Cardiovascular System
Published in Pritam S. Sahota, James A. Popp, Jerry F. Hardisty, Chirukandath Gopinath, Page R. Bouchard, Toxicologic Pathology, 2018
Calvert Louden, David Brott, Chidozie J. Amuzie, Bindu Bennet, Ronnie Chamanza
In mammals, birds, and reptiles, the four-chambered heart consists of right and left atria and right and left ventricles, and the atria and ventricles are separated by the atrioventricular (AV) valves. The cardiac muscle and valves are supported at the base of the heart by the cardiac skeleton (Robinson et al. 1983). The cardiac skeleton consists of four fibrous rings, the fibrous triangle and the fibrous or membranous part of the ventricular septum. The fibrous triangle fills the space between the AV openings and the base of the aorta. Depending on the species, it is composed of dense fibrous connective tissue (pigs and cats), fibrocartilage (dogs), hyaline cartilage (horse), and bone (os cordis) in ruminants and the fibrous rings can become metaplastic in older animals and form bone.
Cardiovascular system
Published in Aida Lai, Essential Concepts in Anatomy and Pathology for Undergraduate Revision, 2018
Cardiac skeleton– Four rings surrounding AV orifices, aortic orifice and opening of pulmonary trunk– Maintain patency of openings and separate A muscles and V muscles
Aortic valve: anatomy and structure and the role of vasculature in the degenerative process
Published in Acta Cardiologica, 2021
Vasiliki Katsi, Nikolaos Magkas, Alexios Antonopoulos, Georgios Trantalis, Konstantinos Toutouzas, Dimitrios Tousoulis
Owing to the semilunar fashion that the leaflets are attached to the wall of the aortic root, three triangles are formed, the interleaflet triangles, each one found between the attachments of two adjacent leaflets and between two adjacent sinuses of Valsalva [3,5] (Figure 2). The interleaflet triangle between the right and left coronary leaflet faces the pulmonary valve and its base is on the septal component of the right ventricle outflow tract [7]. The interleaflet triangle between the left and the non-coronary leaflet along with the larger part of the non-coronary leaflet and a part of the left coronary leaflet are in fibrous continuity with the anterior leaflet of the mitral valve via the aortic-mitral curtain. The two edges of the aortic-mitral curtain are thickened and form the right and left fibrous trigones that anchor the aortic-mitral unit to the roof of the LV [5] (Figures 1(A) and 2). The triangle between the right and non-coronary sinus faces the right atrium [11] and is confluent with the membranous septum; the membranous septum and the right fibrous trigone constitute the central fibrous body of the heart, which is the strongest part of the cardiac skeleton [5,10] (Figures 1(A) and 2).
C-Phycocyanin prevents acute myocardial infarction-induced oxidative stress, inflammation and cardiac damage
Published in Pharmaceutical Biology, 2022
Vanessa Blas-Valdivia, Daniela Nikita Moran-Dorantes, Placido Rojas-Franco, Margarita Franco-Colin, Neda Mirhosseini, Reza Davarnejad, Ahmad Halajisani, Omid Tavakoli, Edgar Cano-Europa
Figure 5 shows the effect of C-phycocyanin on AMI-induced heart damage. The photomicrographs of sham groups show evident integrity of the longitudinal myocardial cell membrane near to epicardium. The myocardium contains cross-striated muscle cells (cardiomyocytes) with one centrally placed nucleus. The cardiomyocytes are arranged in spirals or longitudinally attached to the cardiac skeleton, which may make connective tissue. The AMI photomicrographs show that this pathology promotes interstitial oedema with massive necrosis of cardiac muscle fibres with different vacuolar change grades and inflammatory infiltrated zones; although, the C-phycocyanin treatment reduces the oedema, necrosis and inflammatory process.