Lung Matters
Namrita Lall in Medicinal Plants for Cosmetics, Health and Diseases, 2022
The lungs are the major organs of the respiratory system, with this pulmonary circulation aiding in gaseous exchange. Each of the lungs is paired and separated into lobes, with the left lung consisting of two lobes and the right lung consisting of three lobes. Blood circulation to the lungs plays a vital role, as blood is required to transport oxygen from the lungs to other tissues throughout the body. Deoxygenated blood from the body is delivered to the lungs via the pulmonary artery to the capillaries that form respiratory membranes with the alveoli, where oxygen is replenished. The pulmonary veins then return newly oxygenated blood to the heart for further transport throughout the body. Parasympathetic and sympathetic nervous systems throughout the lungs coordinate both bronchodilation and bronchoconstriction of the airways. The pleural membrane that is composed of visceral and parietal pleural layers encloses the lungs. These two layers have a space between them known as the pleural cavity. The pleural membrane has mesothelial cells which create pleural fluid, serving as a lubricant to reduce friction during breathing and as an adhesive to adhere the lungs to the thoracic wall, thereby facilitating the movement of the lungs during ventilation (Baile, 1996).
Electrophysiology
A. Bakiya, K. Kamalanand, R. L. J. De Britto in Mechano-Electric Correlations in the Human Physiological System, 2021
The cardiopulmonary system consists of blood vessels that carry nutrients and oxygen to the tissues and removes carbon dioxide from the tissues in the human body (Humphrey & McCulloch, 2003; Alberts et al., 1994). Blood is transported from the heart through the arteries and the veins transport blood back to the heart. The heart consists of two chambers on the top (right ventricle and left ventricle) and two chambers on the bottom (right atrium and left atrium). The atrioventricular valves separates the atria from the ventricles. Tricuspid valve separates the right atrium from the right ventricle, mitral valve separates the left atrium from the left ventricle, pulmonary valve situates between right ventricle and pulmonary artery, which carries blood to the lung and aortic valve situated between the left ventricle and the aorta which carries blood to the body (Bronzino, 2000). Figure 3.9 shows the schematic diagram of heart circulation and there are two components of blood circulation in the system, namely, pulmonary and systemic circulation (Humphrey, 2002; Opie, 1998; Milnor, 1990). In pulmonary circulation, pulmonary artery transports blood from heart to the lungs. The blood picks up oxygen and releases carbon dioxide at the lungs. The blood returns to the heart through the pulmonary vein. In the systemic circulation, aorta carries oxygenated blood from the heart to the other parts of the body through capillaries. The vena cava transports deoxygenated blood from other parts of the body to the heart.
Cardiovascular System
David Sturgeon in Introduction to Anatomy and Physiology for Healthcare Students, 2018
We have already observed that the heart is a muscular pump that propels blood through the circulatory system in order to deliver the various substances it carries to where they are needed. For example, the heart ensures that tissues receive a constant supply of oxygen and glucose for cellular metabolism and that deoxygenated blood (containing carbon dioxide) is returned to the lungs to undergo gaseous exchange. From a functional point of view, therefore, the heart is quite easy to understand. However, the way it maintains an uninterrupted (and appropriate) flow of blood through the circulatory system, and adapts to a constantly changing internal and external environment, is more complicated. In terms of the gross (visible to the naked eye) anatomy of the heart, it is about the size of its ‘owners’ fist and is situated between the two lungs roughly in the centre of the thoracic cavity (Figure 7.5). This central compartment is known as the mediastinum and also contains a number of large blood vessels, the oesophagus, trachea, thoracic duct, thymus gland and the phrenic and cardiac nerves. The inferior (lower) aspect of the heart is known as the apex because it forms a point that is directed toward the left hip. It rests upon the diaphragm at about the level of the fifth intercostal space (the gap between the fifth and sixth ribs). The superior (upper) aspect of the heart is somewhat confusingly known as the base (since it is flat) and is situated behind the sternum at the level of the third costal (rib) cartilage.
Research Progress in Bioinspired Drug Delivery Systems
Published in Expert Opinion on Drug Delivery, 2020
Qirong Tong, Na Qiu, Jianbo Ji, Lei Ye, Guangxi Zhai
The micron size and instability of the cell-based carriers largely limit their ability to diffuse outside blood vessels and be directly in contact with tumor cells. Erythrocytes fail to achieve active targeting without undergoing modifications with targeting ligands on the surface, limiting application for cancer treatment. However, WBCs possess many recognition receptors on the cell membrane which could overcome the disadvantages of RBCs. Additionally, as a component of blood, they demonstrate prolonged blood circulation. Therefore, it can be stated that WBC-based BDDSs can avoid elimination by MPS and overcome the vascular barrier, as well as achieve sufficient tissue targeting for efficacious drug delivery. Furthermore, many research groups harnessed the immunological properties of WBCs to construct DDSs for immune therapy [22,23]. There are two types of important WBCs: macrophages and lymphocytes.
Novel formulations of metal-organic frameworks for controlled drug delivery
Published in Expert Opinion on Drug Delivery, 2022
Congying Rao, Donghui Liao, Ying Pan, Yuyu Zhong, Wenfeng Zhang, Qin Ouyang, Alireza Nezamzadeh-Ejhieh, Jianqiang Liu
More accurate optimization on the size, morphology, surface characteristics, etc. To ensure the extension of the blood circulation, stability under physiological conditions, control cargo release, enhance cell absorption, and in vivo system targeted administration. Although the MOF surface has made significant progress in engineering, many types of MOFs are still limited in the aqueous solution and buffer solution, which hinders drug-controlled release. In terms of MOF, the synthesis of MOF is mainly under the heat conditions of high boiling point. It is carried out in polar solvents, such as dimethylformamide (DMF) and diethylformamide (DEF) [194]. Due to the increased environmental issues and growing demand for sustainable products and processes, introducing/developing more green methods (for reducing waste generation, organic solvent-free techniques, producing fewer hazard by-products) is a critical issue [195–197].
Modelling and simulation of fluid flow through stenosis and aneurysm blood vessel: a computational hemodynamic analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
J. V. Ramana Reddy, Hojin Ha, S. Sundar
Blood vessels play an important role in the circulatory system; These are in the form of tubes that carry blood between the heart and all parts of the body. The blood vessel size varies enormously; in the case of arteries, it varies from 1 mm to 8 µm while 1 mm to 20 µm for veins. An artery carries oxidized blood away from the heart, whereas a vein is the blood vessel that collects and transports blood toward the heart. The general appearance of the arteries is rounded lumen, while veins are irregular and often collapse. As compared to arteries, veins are thin-walled vessels with a large and irregular lumen. The diseases of arteries, veins, and lymph vessels alert to blood flow disorders that affect circulation, thus resulting in disturbance in organ function. An aneurysm is a pathological condition. It weakens the blood vessel wall due to the bulging area in that area, resulting in an abnormal widening or ballooning more significant than 50% of the standard diameter. The arteries are mostly exposed to an aneurysm rather than a vein among the several blood vessels.