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Morphologic features and pathology of the elderly heart
Published in Wilbert S. Aronow, Jerome L. Fleg, Michael W. Rich, Tresch and Aronow’s Cardiovascular Disease in the Elderly, 2019
Atsuko Seki, Gregory A. Fishbein, Michael C. Fishbein
Thickening of the tunica intima is seen in practically all arteries of the human body and has been described in association with aging (Figure 2.3). Originally, the intima consists of only a thin layer of endothelial cells lining the vascular lumen, with minimal subendothelial connective tissue. With aging, smooth muscle cells migrate from the tunica media and accumulate in the intima. The cells undergo a switch from a differentiated contractile to a synthetic phenotype (20). Cytoskeletal markers are reduced and cell morphology becomes more rounded, owing to an increase in rough endoplasmic reticulum and other cytoplasmic organelles. Proliferative behavior in response to growth factors increases. Slowly, over time, this proliferation results in intimal thickening. Larger arteries, such as the aorta, are the most affected. Both peripherally and in the coronary vasculature, this phenomenon plays a significant role in the development of cardiovascular diseases such as hypertension and atherosclerosis.
SBA Answers and Explanations
Published in Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury, SBAs for the MRCS Part A, 2018
Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury
Atherosclerosis is a focal disease of the tunica intima of large and medium-sized arteries and consists of the gradual accumulation of focal raised patches (plaques) on the arterial lining in response to arterial wall injury. Its complications are the main cause of death in urbanized societies.
Hyperglycemia Impairs Blood Vessel Function
Published in Robert Fried, Richard M. Carlton, Type 2 Diabetes, 2018
Robert Fried, Richard M. Carlton
As previously noted, arteries are made up of three major wall layers encircled by muscle rings. From the outside in, the tunica adventitia is made entirely of collagen; the middle layer, the tunica media, has an extra layer of smooth muscle that allows the vessel to increase or decrease in size; the tunica intima is the inner cell layer.
Targeting VCAM-1: a therapeutic opportunity for vascular damage
Published in Expert Opinion on Therapeutic Targets, 2023
Mayarling F Troncoso, Magda C Díaz-Vesga, Fernanda Sanhueza-Olivares, Jaime A Riquelme, Marioly Müller, Luis Garrido, Luigi Gabrielli, Mario Chiong, Ramon Corbalan, Pablo F Castro, Sergio Lavandero
The cardiovascular system includes the heart and blood vessels that pump and deliver blood throughout the body. Blood vessels are structured in three layers: the tunica intima, media, and adventitia. The tunica intima, or inner layer, comprises endothelial cells (EC) in contact with the blood. The tunica media or medial layer is formed mainly by vascular smooth muscle cells (VSMC) and the extracellular matrix, such as collagen and elastin, that regulates vascular tone and the integrity of vessels. In capillaries, the medial layer does not contain VSMC, but pericytes form a thin wall that facilitates the transport of blood components [3]. The adventitia layer, or outer layer, comprises fibroblasts, nerves, and small arteries (Vasa vasorum) that deliver nutrients to this layer [4].
Berberine alleviates monosodium glutamate induced postnatal metabolic disorders associated vascular endothelial dysfunction in newborn rats: possible role of matrix metalloproteinase-1
Published in Archives of Physiology and Biochemistry, 2022
Abeer A. Abo Zeid, Ibrahim Rowida Raafat, Abeer G. Ahmed
Light microscopic examination of H&E stained aortic sections of control rats, revealed three layers from inward outward. The 1st layer was the tunica intima with its regular lining endothelial cells. The next layer appeared was the tunica media that showed smooth muscle cells with their nuclei appeared dark blue arranged in concentric layers alternating with collagen and elastic fibres. The third layer was the tunica adventitia which consisted of loose connective tissue containing elastic and collagen fibres (Figure 2(A)). Mallory’s trichrome stained sections showed regular distribution of connective tissue in the intima and in the media (Figure 2(B)).Sudan III stained sections of control showed only one orange brown fat cell in the media (Figure 2(C)). Also, Van Geison stained sections of control showed regularly arranged brown elastic fibres all through the media (Figure 2(D)).
On the importance of tunica intima in the aging aorta: a three-layered in silico model for computing wall stresses in abdominal aortic aneurysms
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Mario de Lucio, Marcos Fernández García, Jacobo Díaz García, Luis Esteban Romera Rodríguez, Francisco Álvarez Marcos
With regard to numerical models, the first three-layered models assumed an isotropic linear elastic response for all the layers, like Gao et al. (2006, 2008) for three-layered aneurysmal and non-aneurysmal aortic archs, where the Young’s modulus of the medial layer was assumed to be three times larger than that of the intimal and adventitial layer. Gao et al. also peformed FSI analyses on two dimensional (2 D) axisymmetric geometric models of stented three-layered aneurysms (Gao et al. 2013). Simsek and Kwon (2015) and Gholipour et al. (2018) evaluated the rupture potential of three-layered idealized aneurysmal and non-aneurysmal geometries assuming different hyperelastic isotropic material properties for each layer. Recent studies analyzed the inclusion of residual stresses in three-layered aneurysms, like Pierce et al. (2015) for a patient-specific geometry. Other researchers like Strbac et al. (2017) even studied how to improve the finite element codes for computing faster, and more accurate solutions in three-layered patient-specific geometries. Nonetheless, the structural role played by tunica intima during the development of atherosclerosis, and its through-the-thickness stress distribution has not been clarified yet.