Diagnostic Devices
Laurence J. Street in Introduction to Biomedical Engineering Technology, 2022
This chapter examines the circulatory system including the relevant characteristics of blood, the physiology and measurement of blood pressure, blood oxygen, blood gases and other components, and blood flow. To discuss the nervous system, including the details of nerve signals, the mechanisms of anesthetics and how they are monitored, the physiology and measurement of EEG signals, and the use of muscle and nerve stimulators. Blood pressure is a vital sign that can give important information to medical staff and is thus one of the most commonly measured physical parameters. The circulatory system is under the influence of gravity, so pressure tends to be lower in the highest parts of the body. Due to the cyclic pumping of the heart, blood pressure varies correspondingly, with its highest value at the point of maximal cardiac output, falling to a low value between contractions. Blood vessels have a degree of elasticity as well as mechanical resistance to flow.
Respiratory and Cardiovascular Responses
Alan G. Heath in Water Pollution and Fish Physiology, 2018
The circulatory system provides the means of transport for essentially everything in an animal's body. Because control of the rate of blood flow and its distribution in a fish is based primarily on homeostasis of respiratory gases, the cardiovascular responses to pollution are included in this chapter with the respiratory system. The typical teleost fish respiratory system consists of the buccal and paired opercular cavities and the gills suspended between them. A cough occurs at a random position during a respiratory cycle and is characterized as a rapid expansion and contraction of the buccal and opercular cavities. These movements produce a two-to fivefold increase in the reversal phase of the differential pressure across the gills. The function of the circulatory system is intimately related to the process of respiratory gas exchange and the control mechanisms for this system are largely based on the detection of changes in blood oxygen.
The patient with acute cardiovascular problems
Peate Ian, Dutton Helen in Acute Nursing Care, 2020
This chapter gives a clear understanding of the normal anatomy and applied physiology of the cardiac and circulatory systems and explains how altered physiology can lead to acute deterioration. An improved understanding of these principles will enhance nursing assessment and recognition of acute problems and enable an appropriate response to medical emergencies caused by cardiac and circulatory disorders. The structure and function of blood, mechanisms of clotting and the ABO and rhesus systems are outlined. The arterial and venous system, and the peripheral circulation and an understanding of common problems of the circulatory system are provided. How the nurse assesses the cardiovascular system and the identification of common problems and medical emergencies related to the cardiovascular system is provided along with information regarding how these are identified and managed. The role of haemodynamic monitoring in the assessment and management of therapies that optimise cardiac output and the functioning of the cardiovascular system is detailed.
Representations of the human circulatory system
Published in Journal of Biological Education, 2009
Asunción López-Manjón, Yolanda Postigo Angón
There is no agreement about the robustness of intuitive representations of the circulatory system and their susceptibility to change by instruction. In this paper, we analyse to what extent students with varying degrees of biology instruction and different ages (High School Health Science and Social Science students and first and final year University Psychology students) have been able to change their intuitive beliefs into scientific representations of the workings of the human circulatory system. We analysed two aspects of the representation of the circulatory system: models of the circulatory system (the relationship between the heart and lungs in the blood pathway) and the circulatory system pattern (the blood pathway between organs). In relation to the models of the circulatory system, we found differences among the different groups of students according to the amount of biological instruction they had. The majority of participants (High School Social Science students and both University Psychology student groups) had an incomplete model, which did not include the lungs while the High School Health Science students group had a scientific representation. As for the circulatory system pattern, we did not find differences among groups. However, we cannot conclude that the representations of the two aspects of the circulatory system (model and pattern) are independent. The data in this study show that compulsory human physiology instruction did not enhance the acquisition of a scientific representation of the human circulatory system.
Changes in the central and peripheral circulatory system in response to the cold: own studies using impedance plethysmography and Doppler ultrasound
Published in International Journal of Occupational Safety and Ergonomics, 2016
Elżbieta Łastowiecka-Moras, Eliza Kozyra-Pydyś
The aim of the study was to determine the cardiovascular response to continuous (4 °C for 60 min) and intermittent (10 min at 4 °C and 10 min at room temperature alternately) exposure to the cold in 30 healthy young men. The subjects were equipped with a set of identical clothing (insulation 2.1 clo) and during the stay in the chamber and outside performed the same activities, i.e., walking on a treadmill at a speed of 0.5 km/h. The tests included assessing the central circulatory system using the Holter system and assessing the peripheral circulatory system using impedance plethysmography and Doppler ultrasound. The analysis of the parameters that describe the central and peripheral circulation poses a difficulty in determining which variant of exposure constitutes a greater load on the circulatory system. It should be noted that even the conditions used in the study may cause adverse effects in the cardiovascular system.
Does it Make a Difference? Investigating the Assessment Accuracy of Teacher Tutors and Student Tutors
Published in The Journal of Experimental Education, 2013
Stephanie Herppich, Jörg Wittwer, Matthias Nückles, Alexander Renkl
Tutors often have difficulty with accurately assessing a tutee's understanding. However, little is known about whether the professional expertise of tutors influences their assessment accuracy. In this study, the authors examined the accuracy with which 21 teacher tutors and 25 student tutors assessed a tutee's understanding of the human circulatory system in the course of tutoring. The authors found that the teacher tutors were more accurate than were the student tutors in assessing whether a tutee had a low or high level of knowledge about concepts relevant to the human circulatory system. In addition, in comparison with the student teachers, the teacher tutors more accurately assessed the number of concepts that a tutee would know. However, the teacher tutors and the student tutors did poorly in assessing a tutee's mental model of the human circulatory system even though the teacher tutors were more aware of their assessment difficulties than were the student tutors.
Related Knowledge Centers
- Blood
- Amino Acid
- Lymph
- Hormone
- Oxygen
- Electrolyte