Relation between histological age-changes in the carotid body and atherosclerosis in the carotid arteries

1987 ◽  
Vol 101 (12) ◽  
pp. 1271-1275 ◽  
Author(s):  
Patrick Lowe ◽  
Donald Heath ◽  
Paul Smith
Keyword(s):  
Blood Flow ◽  
Carotid Body ◽  
Carotid Arteries ◽  
Carotid Sinus ◽  
Carotid Bifurcation ◽  
Age Changes ◽  
Histological Changes ◽  
Atherosclerotic Lesions ◽  
Flow Through ◽  
Human Carotid

Abstract Histological changes in the human carotid body associated with increasing age are accompanied by occlusive atherosclerotic lesions in the arteries of the carotid bifurcation, and are probably ischaemic in origin. The carotid sinus, however, is unusually susceptible to the development of atheroma and its occlusion appears to have little influence in compromising blood flow through the glomic arteries.

Age-Dependent Morphological Changes of the Human Carotid Bifurcation

1999 ◽  
Author(s):  
Baruch B. Lieber ◽  
Ajay K. Wakhloo ◽  
Andreas R. Luft ◽  
Afshin A. Divani
Keyword(s):  
Blood Flow ◽  
Blood Supply ◽  
Carotid Sinus ◽  
Subsequent Development ◽  
Carotid Bifurcation ◽  
Support Pressure ◽  
Morphological Development ◽  
Sinus Wall ◽  
The Brain ◽  
Human Carotid

Abstract The development, significance and function of the human carotid sinus is not yet well understood. The arterial wall within the carotid sinus is well enervated and it contains baroreceptive neural terminals. One hypothesis that was put forward is that the dilation, which may involve all vessels of the carotid bifurcation, exists to support pressure sensing1. Another hypothesis that is supported only by phenomenological observations assume that the function of the sinus is to protect the brain by slowing blood flow and reducing pulsatility2. Yet another hypothesis interprets the sinus as an ontogenetic or phylogenic residual3. More recently, carotid hemodynamics has been investigated using in vitro and computational models. Flow patterns in the carotid sinus were found to be complex and as such have been implicated in the hetrogenesis and subsequent development of atherosclerosis at this site. However, the development of this unique sinus morphology, the role of hemodynamics in such development, and the physiological implications created by this unique morphology have not been investigated. Understanding the hemodynamic and developmental forces that play a role in remodeling of the carotid bifurcation and development of the sinus is of both fundamental and clinical interest and can lead to better prognostication and therapy of carotid disease. Therefore, we initiated a study of the morphological development of the human carotid bulb using different age groups under the hypothesis that sinus morphology reflects an adaptive change in response to alterations in cerebral blood supply during the developmental years of the brain. This adaptation attempts to reduce hydraulic losses in the carotid bifurcation through reduced flow disturbances and maintain high level of blood supply to the brain than consumes about 15% of cardiac output under basal conditions. In addition, it may protect the sinus wall from high shear stress and/or the brain from highly pulsatile blood flow conditions. Initially, we analyzed the angle and sinus morphology of the carotid bifurcation in pediatric and adult patients using biplane digital subtraction angiograms to characterize changes that occur as the brain matures.

Analysis of inhibitory effect of dopamine on carotid body chemoreceptors in cats

1976 ◽  
Vol 230 (6) ◽  
pp. 1494-1498 ◽  
Author(s):  
SR Sampson ◽  
MJ Aminoff ◽  
RA Jaffe ◽  
EH Vidruk
Keyword(s):  
Blood Flow ◽  
Carotid Body ◽  
Carotid Sinus ◽  
Direct Action ◽  
Inhibitory Effect ◽  
Gas Mixture ◽  
Carotid Sinus Nerve ◽  
Perfusion Pump ◽  
Flow Through ◽  
Carotid Body Chemoreceptors

The inhibitory effect of dopamine on carotid body chemoreceptors was studied in anesthetized cats to determine whether it was dependent on changes in blood flow in the vicinity of the receptors. The blood supply to the carotid body was isolated, and flow was controlled with a perfusion pump. Single- or few-fiber recordings were made from the peripheral end of the cut carotid sinus nerve in seven cats. The rate of discharge of 68 chemoreceptor strands increased when flow through the carotid body was stopped. This response was reduced or abolished by dopamine in animals ventilated with either room air (15 strands) or a gas mixture of 95% O2 and 5% CO2 (53 strands). These results suggest that dopamine exerts its inhibitory effect primarily through a direct action on the chemoreceptors rather than by a vasomotor effect in the carotid body.

Morphological Age-Depended Development of the Human Carotid Bifurcation

2000 ◽  
Author(s):  
Jaehoon Seong ◽  
Ajay K. Wakhloo ◽  
Baruch B. Lieber
Keyword(s):  
Blood Flow ◽  
Blood Supply ◽  
Developmental Stages ◽  
Carotid Sinus ◽  
Subsequent Development ◽  
Carotid Bifurcation ◽  
Morphological Development ◽  
Carotid Bulb ◽  
The Brain ◽  
Human Carotid

Abstract The development, significance and function of the human carotid sinus are not clearly understood. The arterial wall of carotid sinus is densely enervated and it contains baroreceptive neural terminals. It has been hypothesized that the dilation, which may involve all vessels of the carotid bifurcation, serves to support pressure sensing. Another hypothesis based on phenomenological observations presumes that the function of the sinus is to slow the blood flow and reduce the pulsatility in order to protect the brain (1). Yet another postulate states that the sinus is an ontogenetic or phylogenic residual. More recently, in vitro and computational models have been used to investigate carotid hemodynamics. Complex flow patterns have been found in the carotid sinus. These patterns have been implicated in the carotid bulb heterogeneity and subsequent development of atherosclerosis at this site. However, long term development of this unique sinus morphology has not been investigated. It is of both fundamental and clinical interest to form an understanding of the hemodynamics and developmental forces that play a role in remodeling of the carotid bifurcation and maturation of the sinus. This understanding can lead to better prognostication and therapy of carotid disease. Therefore, a study of the morphological development of the human carotid bulb was initiated. Carotid bulbs from various human developmental stages were evaluated to test the hypothesis that morphology of the sinus reflects an acclimated change in response to alterations in cerebral blood supply with aging. This acclimation attempts to diminish hydraulic losses in the carotid bifurcation through reduced flow disturbances. Under basal conditions, a high level of blood supply to the brain is maintained that consumes about 15% of cardiac output. Furthermore, it may protect the brain from highly pulsatile blood flow conditions and/or the sinus wall from high shear stress. Initially, we analyzed the sinus morphology and the angle of the carotid bifurcation in four human developmental stages, namely newborn, pediatric, adolescent and adult patients (Groups I, II, III, and IV, respectively). The analysis was performed using biplane digital subtraction angiograms to characterize changes that occur as the brain matures.

scholarly journals Effects of Hematocrit on Blood Flow Through A Stenosed Human Carotid Artery

2020 ◽  
pp. 2106-2114
Author(s):  
Sefiu Onitilo ◽  
Mustapha Usman ◽  
Deborah Daniel
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Carotid Arteries ◽  
Governing Equations ◽  
Flow Through ◽  
Wall Shear ◽  
Human Carotid

In this paper, the effects of hematocrit of red blood cells on blood flow through a stenosed human carotid artery was considered by taking blood as a Newtonian fluid. The governing equations on blood flow were derived. The mathematical content involved in the equations are the variables of interest such as number of stenosis , percentage of hematocrit  of red blood cells in the blood, flow rate, wall shear stress, and viscosity of the blood. Guided by medical data collected on the constraint of blood flow in stenosed human carotid arteries, the governing equations were used to check the effects of pressure gradient, wall shear stress, velocity, and volumetric flow rate of blood in the human carotid arteries. Also, the one-dimensional equation for the steady and axially symmetric flow of blood through an artery was transformed using Einstein’s coefficient of viscosity and hematocrit of red blood cells with the help of the boundary conditions. The effects of hematocrit on the blood flow characteristics are shown graphically and discussed briefly. It was discovered that the resistance increases as the level of hematocrit increases. Also, the wall shear stress decreases with the increase in the hematocrit level of the red blood cells. 

scholarly journals Effect of Endogenous Estrogen on Blood Flow Through Carotid Arteries

Stroke ◽  
2001 ◽  
Vol 32 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Jaroslaw Krejza ◽  
Zenon Mariak ◽  
Magdalena Huba ◽  
Slawomir Wolczynski ◽  
Janusz Lewko
Keyword(s):  
Blood Flow ◽  
Carotid Arteries ◽  
Endogenous Estrogen ◽  
Flow Through

Histological Changes Associated with Ageing of the Human Carotid Body

1987 ◽  
pp. 262-270 ◽  
Author(s):  
Gerard Hurst ◽  
Donald Heath ◽  
Paul Smith
Keyword(s):  
Carotid Body ◽  
Histological Changes ◽  
Human Carotid

scholarly journals Reconstruction of blood flow patterns in a human carotid bifurcation: A combined CFD and MRI study

2000 ◽  
Vol 11 (3) ◽  
pp. 299-311 ◽  
Author(s):  
Quan Long ◽  
X. Yun Xu ◽  
Ben Ariff ◽  
Simon A. Thom ◽  
Alun D. Hughes ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Bifurcation ◽  
Flow Patterns ◽  
Mri Study ◽  
Blood Flow Patterns ◽  
Human Carotid

Carotid body control of bronchial circulation in sheep

1988 ◽  
Vol 65 (3) ◽  
pp. 1152-1156 ◽  
Author(s):  
M. Alsberge ◽  
M. Magno ◽  
M. Lipschutz
Keyword(s):  
Blood Flow ◽  
Carotid Body ◽  
Bronchial Artery ◽  
Aortic Pressure ◽  
Vascular Response ◽  
Pressure Transducers ◽  
Flow Through ◽  
The Common ◽  
Electromagnetic Flow Meter ◽  
Alpha Chloralose

The bronchial vascular response to chemoreceptor stimulation was studied in sheep anesthetized with alpha-chloralose, paralyzed with pancuronium, and artificially ventilated with room air. Blood flow through the common bronchial artery was measured with an electromagnetic flow-meter. Pressures were measured in the left atrium and aorta using appropriately placed catheters connected to pressure transducers. The carotid body was vascularly isolated and perfused at aortic pressure with blood of varied PO2 and PCO2. The viability of our preparation was assessed by the occurrence of a bradycardia in response to carotid body stimulation, and only data from animals demonstrating a bradycardia were analyzed. During hypoxic perfusion of the carotid body, heart rate decreased 6% (P less than 0.05). Bronchial blood flow increased by 46% and bronchial vascular resistance decreased by 23%, both of which were significant changes (P less than 0.05). During control experiments in which the carotid body was perfused with normoxic blood, there were no significant (P greater than 0.05) changes in any of the parameters. These data suggest that carotid body stimulation results in a reflex bronchial vasodilation.

Thermoregulatory influences on common carotid blood flow in the dog

1982 ◽  
Vol 52 (5) ◽  
pp. 1138-1146 ◽  
Author(s):  
M. A. Baker ◽  
M. J. Hawkins ◽  
R. D. Rader
Keyword(s):  
Blood Flow ◽  
Carotid Arteries ◽  
Strongly Correlated ◽  
Heavy Exercise ◽  
Hypothalamic Temperature ◽  
Carotid Blood Flow ◽  
Ambient Temperatures ◽  
Flow Through ◽  
The Common ◽  
Common Carotid Arteries

Common carotid blood flow (CCBF) and respiratory water loss (RWL) were measured in dogs resting at ambient temperatures between 25 and 50 degrees C, during hypothalamic heating, and during light and heavy exercise at ambient temperatures of 25 and 35 degrees C. In resting dogs, CCBF varied with the level of RWL. Elevations in CCBF and RWL occurred within seconds of each other during bursts of panting. Mean unilateral CCBF increased from 6.2 ml . min-1 . kg-1 at 25 degrees C to 16.8 ml . min-1 . kg-1 at 45 degrees C, in parallel with increasing RWL. Hypothalamic heating elicited simultaneous elevations in CCBF and RWL, and the level of CCBF was strongly correlated with the hypothalamic temperature. Both CCBF and RWL increased rapidly at the onset of exercise and continued to rise during a 15-min run. Highest rates of blood flow and evaporation occurred during heavy exercise at 35 degrees C. It is concluded that the rate of blood flow through the common carotid arteries in the dog is related to the thermoregulatory needs of the animal, and most of the increased flow occurring during heat stress is destined for evaporative surfaces of the nose, mouth, and tongue.

Application of a locally conservative Galerkin (LCG) method for modelling blood flow through a patient-specific carotid bifurcation

2010 ◽  
Vol 64 (10-12) ◽  
pp. 1274-1295 ◽  
Author(s):  
R. L. T. Bevan ◽  
P. Nithiarasu ◽  
R. Van Loon ◽  
I. Sazonov ◽  
H. Luckraz ◽  
...  
Keyword(s):  
Blood Flow ◽  
Carotid Bifurcation ◽  
Patient Specific ◽  
Flow Through ◽  
Locally Conservative
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