The circulatory system

2020 ◽  
Vol 14 (11) ◽  
pp. 548-553
Author(s):  
Ian Peate

The circulatory system transports blood around the body. The blood carries a number of other substances needed by the body to function effectively; the cardiovascular system keeps life pumping through the body. This article offers an overview of this essential body system. It is vital to understanding the various functions of the cardiovascular system, along with its various pathways of veins, arteries and capillaries when providing people with safe and effective care. A glossary of terms has been included. A short quiz at the end of the article has been provided to encourage recall and learning.

2021 ◽  
Vol 27 (2) ◽  
pp. 47-52
Author(s):  
H.V. Lukyantseva ◽  
O.M. Bakunovsky ◽  
S.S. Malyuga ◽  
T.M. Oliinyk ◽  
N.R. Manchenko ◽  
...  

The cardiovascular system is one of the most important functional systems of the body, which determine the level of physical performance of the body. Insufficient study of the response of the circulatory system to the combination of strength training with endurance exercises requires more detailed comparative studies of the impact of dynamic and static loads on the indicators of central hemodynamics. Accordingly, the aim of our study was to study the characteristics of the reaction of the cardiovascular system in the period of early recovery after dosed exercise of a dynamic and static nature. The study examined the response of the central hemodynamics of young men in the period of early recovery after dynamic loading (Martine functional test) and static loading (holding on the stand dynamometer DS-200 force with a power of 50% of maximum standing force). The change in circulatory system parameters was recorded using a tetrapolar thoracic impedance rheoplethysmogram on a computerized diagnostic complex “Cardio +”. It is established that the dynamic load in the period of early recovery does not cause a significant positive chronotropic effect, leads to a decrease in vascular resistance of blood flow, to an increase in pulse blood pressure. The increase in cardiac output is mainly due to the increase in stroke volume, which indicates a fairly high functional reserves of the heart. It is revealed that under conditions of static loading the reaction of central hemodynamics and the course of early recovery are radically different from the changes of indicators under dynamic loading. In persons with a normodynamic type of reaction to dynamic load, there are no significant changes in the minute volume of blood at a similar volume of active muscle mass static load. Meeting the metabolic needs of working skeletal muscles and compensating for the oxygen debt is realized by increasing the total peripheral vascular resistance and increasing systolic blood pressure in the postpartum period. The physiological meaning of this phenomenon is to maintain a sufficient level of venous return of blood to ensure the pumping function of the heart.


Author(s):  
VA Belyayeva

Background: One of the main negative factors of the educational environment is the increased stress impact on the cardiovascular system of students preparing for examinations. The cumulative effect of a long-term, systematic exposure to stressors may be accompanied by impaired mental and somatic health of students. The extent of response to stress is individual; it is usually determined by cardiovascular health and a complex of psychophysiological characteristics of the body. Objective: To study the main parameters of central hemodynamics in medical students depending on the body mass index and adaptive potential in the pre-examination study period Materials and methods: In spring–summer 2019, 170 medical students (young men and women aged 20.4 ± 0.3 years) with different adaptive potential of the circulatory system were surveyed during a pre-exam study period to establish their anthropometric indicators, blood pressure and heart rate and to further estimate the body mass index and the main central hemodynamics parameters. Results: The average heart rate of students during the pre-exam study period was 85.4 ± 12.21 beats per minute. The level of metabolic and energy processes in the myocardium was characterized as moderate with a tendency to insufficient functional capacity of the cardiovascular system (CI = 90.4 ± 1.22). Significant differences were revealed in a number of parameters un-der study depending on gender, body mass index (F = 3.99; p = 0.00890) and the adaptive potential of the circulatory system (F = 23.08; p = 0.00000). Conclusions: In the pre-examination study period, both the heart rate and the Kerdo index among the students were elevated, which indicates the predominance of sympathetic autonomic stress. The students with tense adaptation mechanisms demonstrated higher values of certain hemodynamic parameters. The pulse pressure and the Robinson index were higher in overweight students compared to their peers with a normal body mass index. None of the students with class 1 obesity had a satisfactory level of adaptation of the circulatory system. The analysis of central hemodynamic parameters enables the assessment of tolerance of the cardiovascular system of students to the burden of learning.


Author(s):  
O.V. Zhbankova ◽  
◽  
O.I. Yushkova ◽  
A.V. Kapustina

Abstract. Introduction. Professional selection of workers in extreme occupations associated with increased danger and responsibility is an important task of labor physiology. The study of psychomotor skills under conditions of acute stress, the assessment of the physiological reactions of the cardiovascular system will determine the professional suitability of candidates for various specialties (technical or intellectual-analytical). Purpose of work. The study of diagnostic methodological approaches to assessing the professional suitability of persons in hazardous professions in psychophysiological professional selection. Materials and methods. Psychophysiological studies included the study of psychomotor skills, psychological testing according to the MMIL and 16 FLO tests, physiological studies of hemodynamic features in candidates with different resistance to stress (calculation of stroke blood volume - SV, MC blood minute volume and peripheral resistance of PS), professional analysis of the labor activity of workers to identify the requirements that hazardous professions place on the body of workers, Research results. In candidates for engineering and technical specialties, the tension of the circulatory system reflected high values of the average dynamic pressure (105.73 ± 1.45 mm Hg), changes in the optimal hyperkinetic type of blood circulation to hypokinetic: 66.7% of those examined with low resistance to stress. In candidates for communicative specialties, a sufficient level of physical activity contributed to the stability of the indicators of the cardiovascular system. Conclusions. Informative indicators have been established for assessing the professional suitability of candidates to perform official tasks in extreme conditions: changes in handwriting signs, peculiarities of psychological status (anxiety, conformism), hemodynamic characteristics


Author(s):  
Michelle Green ◽  
Kirsten Huby

This chapter will outline the anatomy and physiology of the cardiovascular system and the changes that occur during childhood as this body system matures. Signs and symptoms of cardiovascular failure and nursing assessment and monitoring of the child will also be discussed. This knowledge will enable the nurse to recognize cardiovascular failure as early as possible and commence appropriate interventions. A range of interventions and clinical skills required for cardiovascular support are also explained, utilizing evidence-based guidelines. All aspects of care will be discussed using a family centred and child-friendly approach. The Nursing and Midwifery Council (NMC) introduced the use of essential skills clusters (ESC) to help pre-registration nursing students meet the standards of proficiency required for registration (NMC, 2007b). They are written from the perspective of what the public can expect of a newly qualified nurse and are designed to improve safe and effective practice. The information contained within this chapter covers aspects of most of the skills clusters. In particular, the underpinning principles from: care, compassion, and communication (1); organizational aspects of care (9, 10); infection prevention and control (22, 25, and 26); and nutrition and fluid management (29, 32) which are integrated throughout the discussion. At the end of this chapter you will: ● Understand the anatomy and physiology of the cardiovascular system and the changes that occur during childhood as this body system matures. ● Learn to recognize signs and symptoms of cardiovascular failure. ● Be familiar with nursing assessment and cardiovascular monitoring of the child. ● Understand how the nurse recognizes cardiovascular failure as early as possible and commences appropriate interventions. ● Begin to develop an understanding of the range of interventions and clinical skills required for cardiovascular support. The cardiovascular system is vital for supplying the tissues of the body with blood. This blood supply enables the needs of individual cells for oxygen and nutrients and removal of waste products to be met (metabolic demands). The body is also able to achieve these functions under a variety of circumstances: at rest or sleeping; during exertion through exercise; and during the extra demands placed on the body as a result of illness.


Author(s):  
Martin E. Atkinson

The circulatory system has two interrelated, but distinct parts, the cardiovascular system which circulates blood around the body and the lymphatic system which returns excess fluid from the tissues to the cardiovascular system. The function of the cardiovascular system is to oxygenate blood in the lungs and distribute the oxygenated blood to the tissues of the body. At the same time, carbon dioxide that accumulates as a result of metabolism of oxygen within the tissues is removed from the tissues and transported to the lungs where it is released from the blood and exhaled. The cardiovascular system comprises the heart, a muscular pump, and blood vessels. Arteries convey blood to thin-walled capillaries where gaseous exchange takes place and veins return blood to the heart. The cardiovascular system is often described as two parallel systems; the pulmonary circulation moves blood through the lungs and the systemic circulation circulates blood through the body. Trace the circulation of blood through the two systems in Figure 4.1 by following the arrows from the side of the heart coloured red. It follows a figure-of-eight (8) pattern with the two systems interlinked at the heart, the upper loop representing the pulmonary circulation and the lower loop the systemic circulation. The heart is a muscular pump driving blood at considerable pressure through arteries that get progressively smaller in both circulations until capillaries are reached. Arteries are sometimes dismissed as mere plumbing, but they play a vital role in regulating the blood flow through organs and tissues. Capillary walls are only one cell thick, allowing for the efficient diffusion of gases and small nutrient molecules to and from tissues. Waste gases and metabolites are also returned to the circulatory system through capillaries and these unite to form veins carrying blood under comparatively low pressure back to the heart. The heart comprises two muscular pumps arranged in parallel and beating in unison. As you can see in Figure 4.1, these two pumps are designated as the right and left sides of the heart. Each pump consists of two chambers, a thin-walled atrium that receives blood from one or other circulation and a thick-walled ventricle that ejects blood into the circulations.


Author(s):  
Anna V. Zayitceva ◽  
Khistina T. Oniani

Introduction. Increased nervous and emotional loads in doctors of children's medical organizations are caused by frequent stressful effects, shift work mode. The study of the features of the formation of the functional state of the body of surgeons will make it possible to scientifically justify measures to prevent overstrain to preserve the health of employees. The aim of study is to research the functional state of the body of doctors of children's medical organizations with a shift work schedule to justify and develop measures for physiological and hygienic optimization of work. Materials and methods. Complex physiological and hygienic studies included occupational analysis of labor activity, physiological studies of the state of the Central nervous system (CNS) and the cardiovascular system with the study of the features of response to functional loads (ECG recording on a 12-channel electrocardiograph and continuously using Holter monitoring). Results. The study of the features and degree of adequacy of the cardiovascular system's response to dosed physical activity revealed the tension of the regulatory mechanisms of the circulatory system with a pronounced increase in heart activity in surgeons during night hours. Conclusions. Stable indicators of CNS functions (concentration of attention, etc.) were established during various shifts, due to the requirements of the work itself, adverse changes in the cardiovascular system, more pronounced during the night shift, deterioration of ECG changes to functional load, which indicates a decrease in the functional capabilities of the myocardium.


Author(s):  
Алексей Дмитриевич Акишин ◽  
Иван Павлович Семчук ◽  
Александр Петрович Николаев

Постоянно растущий интерес к разработке новых неинвазивных и безманжетных методов измерения параметров сердечной деятельности, использование которых давало бы возможность непрерывного и удаленного контроля сердечно-сосудистой системы, обуславливает актуальность данной работы. В многочисленных публикациях продолжаются обсуждения преимуществ и недостатков различных методов ранней диагностики сердечно-сосудистых заболеваний. Однако артефакты движения являются сильной помехой, мешающей точной оценке показателей функционирования сердечно-сосудистой системы. Одним из перспективных методов контроля является метод оценки физиологических параметров с использованием фотоплетизмографии. Данная статья посвящена разработке устройства для фотоплетизмографических исследований и алгоритмических методов обработки регистрируемых сигналов для обеспечения мониторинга сердечного ритма с заданной точностью. В работе используются технологии цифровой адаптивной фильтрации полученных сигналов для мониторинга сердечного ритма в условиях внешних механических и электрических помеховых воздействий, ухудшающих точностные характеристики системы, а также разработана архитектура системы и изготовлен макет устройства, который позволил провести измерения для определения оптимального алгоритма цифровой обработки сигналов. При использовании устройства применялись методы адаптивной фильтрации на основе фильтров Винера, фильтров на основе метода наименьших квадратов и Калмановской фильтрации. Разработанное устройство для фотоплетизмографических исследований обеспечило возможность мониторинга сердечного ритма с заданной точностью, контроля текущего состояния организма и может быть использовано в качестве средства диагностики заболеваний сердца The constantly growing interest in the development of new non-invasive and cuff-free methods for measuring the parameters of cardiac activity, the use of which would give the possibility of continuous and remote monitoring of the cardiovascular system, determines the relevance of this work. Numerous publications continue to discuss the advantages and disadvantages of various methods of early diagnosis of cardiovascular disease. However, motion artifacts are a strong hindrance to the accurate assessment of the performance of the cardiovascular system. One of the promising control methods is the method for assessing physiological parameters using photoplethysmography. This article is devoted to the development of a device for photoplethysmographic studies and algorithmic methods for processing recorded signals to ensure monitoring of the heart rate with a given accuracy. The work uses technologies of digital adaptive filtering of the received signals to monitor the heart rate in conditions of external mechanical and electrical interference, which worsen the accuracy characteristics of the system, as well as the architecture of the system and a prototype of the device, which made it possible to carry out measurements to determine the optimal algorithm for digital signal processing. When using the device, the methods of adaptive filtering based on Wiener filters, filters based on the least squares method and Kalman filtering were used. The developed device for photoplethysmographic studies provided the ability to monitor the heart rate with a given accuracy, control the current state of the body and can be used as a means of diagnosing heart diseases


2021 ◽  
Vol 22 (15) ◽  
pp. 7931
Author(s):  
Ning Liu ◽  
Shiqiang Sun ◽  
Pengjie Wang ◽  
Yanan Sun ◽  
Qingjuan Hu ◽  
...  

Serotonin, also known as 5-hydroxytryptamine (5-HT), is a metabolite of tryptophan and is reported to modulate the development and neurogenesis of the enteric nervous system, gut motility, secretion, inflammation, sensation, and epithelial development. Approximately 95% of 5-HT in the body is synthesized and secreted by enterochromaffin (EC) cells, the most common type of neuroendocrine cells in the gastrointestinal (GI) tract, through sensing signals from the intestinal lumen and the circulatory system. Gut microbiota, nutrients, and hormones are the main factors that play a vital role in regulating 5-HT secretion by EC cells. Apart from being an important neurotransmitter and a paracrine signaling molecule in the gut, gut-derived 5-HT was also shown to exert other biological functions (in autism and depression) far beyond the gut. Moreover, studies conducted on the regulation of 5-HT in the immune system demonstrated that 5-HT exerts anti-inflammatory and proinflammatory effects on the gut by binding to different receptors under intestinal inflammatory conditions. Understanding the regulatory mechanisms through which 5-HT participates in cell metabolism and physiology can provide potential therapeutic strategies for treating intestinal diseases. Herein, we review recent evidence to recapitulate the mechanisms of synthesis, secretion, regulation, and biofunction of 5-HT to improve the nutrition and health of humans.


1968 ◽  
Vol 46 (3) ◽  
pp. 321-327 ◽  
Author(s):  
M. A. Alikhan

Tbe circulatory system, lying in the mid-dorsal line of the body, consists of an oval heart, the opthalmic artery, and a dorsal abdominal artery.The digestive system comprises a wide, large alimentary tube and two pairs of digestive glands. An oesophagus, a proventriculus, midgut, and a short proctodacum or hindgut form the digestive tube. The digestive glands are very well developed and are beaded in form; each pair lies on either side of the alimentary canal.The reproductive organs are well developed in both sexes: in the male they consist of paired testes and their vas deferentia, and in the female paired bilobed ovaries and oviducts.A cerebral or supraoesophageal ganglion, a suboesophageal ganglion, and seven thoracic ganglia form the nervous system. The supraoesophageal ganglion is united with the suboesophageal ganglion by means of the circumoesophageal commissures, whereas the thoracic ganglia and suboesophageal ganglia are linked with each other by paired connectives.The gills and the tracheae are the organs of respiration. The gills are borne of the bases of the pleopods and are enclosed in the branchial chamber. The tracheae are located on the lateral lobes of the first two pleopods only.


Author(s):  
Enoch Lam

Leukemia is a cancer of the blood, where the body produces an overabundance of immature white blood cells. It is the most common childhood cancer and possibly originates from chemical exposure during fetal development. Understanding the molecular mechanism and causes of childhood leukemia will help the development of therapeutic and preventative strategies to reduce and treat occurrences of this cancer. Benzene is a non-polar aromatic ring that has been confirmed to cause leukemia in adults. Benzene metabolites can generate free radicals that could potentially be involved in the development of childhood leukemia through in utero exposures. It is found in tobacco smoke, gasoline, industrial solvents and many other substances. Pregnant mothers can be chronically exposed to these substances through daily activities. In order to help determine the mechanism of benzene toxicity, a study was performed to determine the presence of free radicals in the livers of fetal mice at gestation day 14. Fetal liver cell cultures were exposed to varying concentrations of benzene and additional cell cultures were exposed to various concentrations of a benzene metabolite mixture, composed of hydroquinone and benzoquinone. RNA was extracted from these cells and converted into complementary DNA. cDNA was then used in quantitative polymerase chain reactions to analyze a set of genes that are regulated by an antioxidant pathway. This pathway can be activated in response to oxidative stress, and a change in gene expression would indicate the presence of benzene or benzene metabolite toxicity in the liver at gestation day 14.


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