A Mathematical Study of Non-Newtonian Micropolar Fluid in Arterial Blood Flow Through Composite Stenosis

2014 ◽  
Vol 8 (4) ◽  
pp. 1567-1573 ◽  
Author(s):  
R. Ellahi ◽  
S. U. Rahman ◽  
M. Mudassar Gulzar ◽  
S. Nadeem ◽  
K. Vafai
Keyword(s):  
Blood Flow ◽  
Micropolar Fluid ◽  
Arterial Blood Flow ◽  
Mathematical Study ◽  
Arterial Blood ◽  
Flow Through

The selective closure of feline carotid arteriovenous anastomoses (AVAs) by GR43175

Cephalalgia ◽  
1989 ◽  
Vol 9 (9_suppl) ◽  
pp. 41-46
Author(s):  
Marion J Perren ◽  
Wasyl Feniuk ◽  
Patrick Pa Humphrey
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Peripheral Resistance ◽  
Haemodynamic Effects ◽  
Arterial Blood Flow ◽  
Arteriovenous Anastomoses ◽  
Arterial Blood ◽  
Flow Through ◽  
Carotid Arterial ◽  
Dose Dependent

The haemodynamic effects of the selective 5-HT1-like agonist GR43175 have been compared with that of ergotamine in anaesthetized cats. Both GR43175 (30–1000 μg/kg intravenously) and ergotamine (0.3–30 μg/kg intravenously) caused a dose-dependent reduction in the proportion of cardiac output passing through arteriovenous anastomoses (AVAs). However, unlike GR43175, the effect of ergotamine (30 μg/kg intravenously) was associated with marked increases in diastolic blood pressure and total peripheral resistance. In further studies, the effect of GR43175 on the distribution of blood flow within the carotid bed has been examined. GR43175 caused a reduction in total carotid arterial blood flow which was entirely due to a reduction in flow through carotid AVAs. These results demonstrate that GR43175, unlike ergotamine, has a highly selective vasoconstrictor action on AVAs within the cranial circulation of anaesthetized cats. Such a mechanism may be important in its antimigraine activity.

scholarly journals Changes in bronchial and pulmonary arterial blood flow with progressive tension pneumothorax

1996 ◽  
Vol 81 (4) ◽  
pp. 1664-1669 ◽  
Author(s):  
Paula Carvalho ◽  
Jacob Hildebrandt ◽  
Nirmal B. Charan
Keyword(s):  
Blood Flow ◽  
Gas Exchange ◽  
Tension Pneumothorax ◽  
Blood Gases ◽  
Left Pulmonary Artery ◽  
Arterial Blood Flow ◽  
Mechanically Ventilated ◽  
Arterial Blood ◽  
Flow Through ◽  
Pulmonary Arterial

Carvalho, Paula, Jacob Hildebrandt, and Nirmal B. Charan.Changes in bronchial and pulmonary arterial blood flow with progressive tension pneumothorax. J. Appl. Physiol. 81(4): 1664–1669, 1996.—We studied the effects of unilateral tension pneumothorax and its release on bronchial and pulmonary arterial blood flow and gas exchange in 10 adult anesthetized and mechanically ventilated sheep with chronically implanted ultrasonic flow probes. Right pleural pressure (Ppl) was increased in two steps from −5 to 10 and 25 cmH2O and then decreased to 10 and −5 cmH2O. Each level of Ppl was maintained for 5 min. Bronchial blood flow, right and left pulmonary arterial flows, cardiac output (Q˙t), hemodynamic measurements, and arterial blood gases were obtained at the end of each period. Pneumothorax resulted in a 66% decrease inQ˙t, bronchial blood flow decreased by 84%, and right pulmonary arterial flow decreased by 80% at Ppl of 25 cmH2O ( P < 0.001). At peak Ppl, the majority ofQ˙t was due to blood flow through the left pulmonary artery. With resolution of pneumothorax, hemodynamic parameters normalized, although abnormalities in gas exchange persisted for 60–90 min after recovery and were associated with a decrease in total respiratory compliance.

Cord Hemangioma Complicated by Umbilical Vein Rupture; What We Missed on Color Doppler

2018 ◽  
Vol 1 ◽  
pp. 10
Author(s):  
Matin Goldooz ◽  
Mike Draper ◽  
Jessica Comstock ◽  
Anne Kennedy
Keyword(s):  
Blood Flow ◽  
Umbilical Cord ◽  
Doppler Ultrasound ◽  
Umbilical Artery ◽  
Umbilical Vein ◽  
Color Doppler ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Cystic Component ◽  
Flow Through

Umbilical cord hemangiomas are rare tumors of the umbilical cord. Doppler ultrasound has been shown to be useful in the diagnosis of cord hemangioma and evaluation of arterial blood flow through the mass. In this study, we present a 28-year-old pregnant woman with an umbilical cord mass with solid and cystic components. She was followed with weekly umbilical artery (UA) Doppler ultrasound, but the fact that the umbilical vein (UV) ran in the wall of the mass was not noted prospectively. At the time of placental delivery, the cystic component of the mass ruptured tearing the UV causing significant bleeding. The case illustrates the importance of using Doppler ultrasound to both look for UA compromise and to map the UV location through the entirety of the cord.

scholarly journals PULMONARY ARTERIAL BLOOD FLOW THROUGH AN ACUTELY ATELECTATIC LUNG

1961 ◽  
Vol 42 (5) ◽  
pp. 599-606 ◽  
Author(s):  
Rudolph C. Camishion ◽  
Yoshinori Ota ◽  
Vincent D. Cuddy ◽  
John H. Gibbon
Keyword(s):  
Blood Flow ◽  
Arterial Blood Flow ◽  
Arterial Blood ◽  
Flow Through ◽  
Pulmonary Arterial

scholarly journals Alteration of Relative Rates of Biodegradation and Regeneration of Cervical Spine Cartilage through the Restoration of Arterial Blood Flow Access to Rhomboid Fossa: A Hypothesis

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4248
Author(s):  
Kirill V. Zhukov ◽  
Alexandre A. Vetcher ◽  
Bagrat A. Gasparuan ◽  
Alexander Y. Shishonin
Keyword(s):  
Blood Flow ◽  
Cervical Spine ◽  
The Body ◽  
Arterial Blood Flow ◽  
Dissipative Flow ◽  
Arterial Blood ◽  
Flow Through ◽  
Rhomboid Fossa ◽  
Rates Of Decay ◽  
Multiple Chronic Diseases

We found the logical way to prove the existence of the mechanism that maintains the rates of biodegradation and regeneration of cervical spine cartilage. We demonstrate, that after we restore access to arterial blood flow through cervical vertebral arteries to rhomboid fossa it causes the prevalence of regeneration over biodegradation. This is in the frames of consideration of the human body as a dissipative structure. Then the recovery of the body should be considered as a reduction of the relative rates of decay below the regeneration ones. Then the recovery of cervical spine cartilage through redirecting of inner dissipative flow depends on the information about oxygen availability that is provided from oxygen detectors in the rhomboid fossa to the cerebellum. Our proposed approach explains already collected data, which satisfies all the scientific requirements. This allows us to draw conclusions that permit reconsidering the way of dealing with multiple chronic diseases.

scholarly journals Mathematical modeling of non-Newtonian fluid in arterial blood flow through various stenoses

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Pinyo Owasit ◽  
Somchai Sriyab
Keyword(s):  
Blood Flow ◽  
Newtonian Fluid ◽  
Symmetric Function ◽  
Arterial Blood Flow ◽  
Governing Equations ◽  
Arterial Blood ◽  
Cardiovascular Patients ◽  
Velocity Flow ◽  
Flow Through ◽  
Asymmetric Function

AbstractSince the stenosis geometry of some cardiovascular patients cannot be described by a vertically symmetric function throughout the stenosis, so it motivates us to study the blood flow through a vertically asymmetric stenosis. In addition, we compare the flow quantities in bothvertically symmetric and asymmetric stenoses. The vertically symmetric stenosis is explained by a vertically symmetric function such as an exponential function in bell shape and a cosine function in cosine shape. The vertically asymmetric stenosis is interpreted by a vertically asymmetric function such as the combination of two different stenosis shapes. Blood is treated as a non-Newtonian fluid which is represented in the power-law model. The finite difference scheme is used to solve governing equations for obtaining the flow quantities such as axial velocity, radial velocity, flow rate, resistance to flow, and skin friction. We investigated the way that the stenosis height, stenosis length, and non-Newtonian behavior affect the flow quantities through three various stenoses. The flow quantities in the bell shape and cosine shape of stenosis show significantly different behavior. Moreover, we found that the flow quantities in the single shape (bell shape or cosine shape) have the same behavior as the flow quantities in the combined shape in the first half part, but have a slightly different behavior in the last half part.

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