Fascia and the Circulatory System
David Lesondak, Angeli Maun Akey in Fascia, Function, and Medical Applications, 2020
Far from being inert, as previously assumed, current research suggests that the adventitia has a dynamic effect on the tunica media and endothelium, including the size of the lumen. Immune cells and progenitor cells reside in the adventitia, providing protection and repair for the vessels and possibly also the surrounding tissues.6 Stenmark et al. describes the adventitia as a “biologic processing center” that may be the first to react to vessel injury.7 Surrounding tissues also affect arteries through the adventitia. The cells of the adventitia respond to mechanical tension transmitted through the fibrous matrix around the vessels. Connective tissue fibers connect to nitric oxide receptors in arterioles and send signals that create vessel dilation in response to muscular contraction.8
Predicting the Biomechanics of the Aorta Using Ultrasound
Ayman El-Baz, Jasjit S. Suri in Cardiovascular Imaging and Image Analysis, 2018
The aortic wall is composed of three layers: the intima, media, and adventitia. These layers serve different biochemical and biomechanical functions. These functions dictate the size and structure of each layer. The intima is essentially a monolayer of endothelial cells adherent to a basement membrane [13], which serves as a barrier between the circulating blood and the thrombogenic media [14]. In the ascending aorta, intimal thickening is minimal but does present in atherosclerotic lesions. The biological structure of the media is critically important to the mechanical function of the aortic wall and progression of aneurysms, which will be discussed further in the following. Lastly, the adventitia is composed of thick bundles of collagen fibrils, vasa vasorum, and loose connective tissues. It provides the aorta with stiffness and support at higher levels of mechanical stress [15].
Renal Pathophysiology
Manit Arya, Taimur T. Shah, Jas S. Kalsi, Herman S. Fernando, Iqbal S. Shergill, Asif Muneer, Hashim U. Ahmed in MCQs for the FRCS(Urol) and Postgraduate Urology Examinations, 2020
Regarding retroperitoneal fibrosis (RPF), which of the following is FALSE?One possible pathogenesis could be the development of vasculitis in the adventitial vessels of the aorta and periaortic small vessels.Inflammatory bowel disease (IBD) is reported to be a cause of RPF.The classic radiologic findings include medial deviation of extrinsically compressed ureters with hydronephrosis.CT typically reveals a well demarcated retroperitoneal mass, isodense to muscle on unenhanced studies.Tamoxifen, a steroidal anti-oestrogen, has also been used for primary treatment at a dose of 20 mg per day with a reported response rate of 80%.
Nuclear receptor subfamily 1 group D member 1 suppresses the proliferation, migration of adventitial fibroblasts, and vascular intimal hyperplasia via mammalian target of rapamycin complex 1/β-catenin pathway
Published in Clinical and Experimental Hypertension, 2023
Ke Peng, Mingliang Wang, Jun Wang, Qiang Wang, De Li, Xiongshan Sun, Yongjian Yang, Dachun Yang
Intimal hyperplasia is a crucial process for ISR (5). Adventitia, an important part of the vascular wall, serves as an active participant in the vascular diseases (30). Recent research showed that AFs, the main component of vascular adventitia, were involved in intimal hyperplasia and vascular remodeling (30,31). Nevertheless, the underlying mechanisms are largely unknown. Our current study demonstrates that NR1D1 suppresses the proliferation and migration of AFs. NR1D1-mediated regulation of AFs depends on the downregulation of β-catenin and mTORC1. Inhibition of β-catenin by NR1D1 relies on the decreased activity of mTORC1. Importantly, NR1D1 also suppresses the early-stage proliferation of AFs within adventitia and subsequent intimal hyperplasia. Therefore, our data highlight a crucial role of NR1D1 in the treatment of intimal hyperplasia-associated vascular diseases.
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].
MicroRNAs as possible biomarkers for screening of aortic aneurysms: a systematic review and validation study
Published in Biomarkers, 2018
Areti Moushi, Kyriaki Michailidou, Marinos Soteriou, Marios Cariolou, Evy Bashiardes
An aortic aneurysm is defined as a local dilation of the aorta to greater than 1.5 times its normal diameter. There are two types of aortic aneurysm; thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA). TAA includes the ascending aorta, the aortic arch and the descending aorta, whereas AAA includes the aorta within the abdominal cavity. The histological structure of the aortic wall is comprised of three layers. The Intima is composed of a single layer of endothelial cells supported by connective tissue. The endothelium is involved in producing and responding to inflammation mediators (Saito et al.2013). The media is composed of elastic lamellae and smooth muscle cells (abundant in abdominal aorta), multiple types of collagen, and proteoglycans (Humphrey and Taylor 2008). The adventitia is composed of connective tissue rich in type I collagen fibres, elastin and fibroblasts (Humphrey and Taylor 2008), and includes the vasa vasorum and nervi vasorum. Numerous proteins were identified to be differentially expressed in aneurysmal aortic tissue when compared with normal aorta, affecting different mechanisms. Τhis included the expression of proteins of vascular smooth muscle cell, actin, elastin and desmin as well as extracellular matrix and fibrolysis mechanisms (Borges et al.2010, Eberlová et al.2013).
Related Knowledge Centers
- Gastrointestinal Tract
- Mesothelium
- Peritoneum
- Serous Membrane
- Tunica Externa
- Vein
- Connective Tissue
- Artery
- Loose Connective Tissue
- Retroperitoneal Space