Video Experimental Relacionado
Updated: Jul 29, 2026

09:33
A Methodological Approach to Non-invasive Assessments of Vascular Function and Morphology
Published on: February 7, 2015
Viscosidad sanguínea y respuesta local al frío en el fenómeno de Raynaud primario
Lancet (London, England)
|November 12, 1977
Resumen
La viscosidad de la sangre y el plasma no parecen ser factores importantes en el fenómeno de Raynaud primario. La reducción de la viscosidad plasmática a través de la venesección no afectó la provocación de los síntomas en pacientes con enfermedad de Raynaud.
Área de la Ciencia:
- Reumatología Reumatología.
- Hematología Hematología.
Sus antecedentes:
- La enfermedad de Raynaud es una condición que afecta a la circulación sanguínea.
- La viscosidad de la sangre completa y del plasma a veces se consideran factores contribuyentes potenciales.
Objetivo del estudio:
- Para investigar el papel de la viscosidad de la sangre en el fenómeno primario de Raynaud.
- Para determinar si existen diferencias de viscosidad entre pacientes y controles.
Principales métodos:
- Comparación de la viscosidad de la sangre entera y del plasma en diez mujeres con fenómeno de Raynaud primario y diez controles.
- Se evaluó el efecto de la venesección (reducción de la viscosidad plasmática) en la provocación de síntomas en cinco pacientes.
Principales resultados:
- No se encontró ninguna diferencia significativa en la viscosidad entre los pacientes y los controles.
- La veneción no alteró la provocación del fenómeno de Raynaud.
Conclusiones:
- Es poco probable que el aumento de la viscosidad de la sangre sea un factor causal significativo en el fenómeno de Raynaud primario.
- La viscosidad puede desempeñar un papel en las formas secundarias de la enfermedad, pero no primaria.
Más Videos Relacionados
Videos de Conceptos Relacionados
Vascular Spasm
The vascular phase, also known as vasospasm, is the initial stage of hemostasis, crucial for preventing excessive bleeding when a blood vessel is injured. After a vessel is cut, nerves in the damaged area trigger pain and other sensory impulses. Simultaneously, the smooth muscles in the vessel wall contract, resulting in a vascular spasm. This contraction reduces the vessel's diameter at the injury site, slowing or stopping blood loss through the vessel wall. Vascular spasms typically last for...
Veins as Blood Reservoirs
Veins, while chiefly responsible for circulating blood back to the heart, also function as storage vessels for blood. They house approximately 64 percent of the body's total blood volume, a feat made possible by their high capacitance—the inherent ability to expand and accommodate large volumes of blood, even under low pressure. The large diameter and thin walls of veins augment their distensibility, significantly more so than arteries, due to their classification as capacitance vessels. When...
Vascular Resistance
Vascular resistance is a critical concept in understanding blood flow dynamics in the circulatory system. It refers to the resistance that blood encounters as it flows through the blood vessels. This resistance is a key factor in determining blood pressure and cardiac workload.
The primary determinants of vascular resistance are vessel diameter, blood viscosity, and vessel length. Among these, vessel diameter plays the most significant role due to the fourth power relationship described by...
The primary determinants of vascular resistance are vessel diameter, blood viscosity, and vessel length. Among these, vessel diameter plays the most significant role due to the fourth power relationship described by...
Autoregulation of Blood Flow
Autoregulation mechanisms are characterized by their inherent capacity for self-regulation without necessitating specific nervous stimulation or endocrine control. These mechanisms facilitate the adjustment of blood flow and, therefore, perfusion specific to each tissue region. This self-regulation encompasses chemical signals and myogenic controls.
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.
Chemical Signaling in Autoregulation
Chemical signaling operates at the precapillary sphincter level, inciting either contraction or relaxation.
Assessment of the Cardiovascular System III: Palpation
Palpation involves feeling the body to evaluate texture, size, consistency, and tenderness for assessing cardiovascular health. The following steps are organized in a head-to-toe order:
Jugular Venous Pressure (JVP) Measurement
Position the patient at a thirty- to forty-five-degree angle or in a semi-fowler's position. Look for the highest point of pulsation in the internal jugular vein and measure the vertical distance to the angle of Loius or sternal angle. A normal JVP is 3-4 cm above the...
Jugular Venous Pressure (JVP) Measurement
Position the patient at a thirty- to forty-five-degree angle or in a semi-fowler's position. Look for the highest point of pulsation in the internal jugular vein and measure the vertical distance to the angle of Loius or sternal angle. A normal JVP is 3-4 cm above the...
Acute Inflammation III: Local and Systemic Effects
Acute inflammation produces a coordinated set of local and systemic changes that limit injury, eliminate pathogens, and initiate repair. These responses arise within minutes of infection, trauma, or chemical insult and are driven by vascular alterations and leukocyte-derived mediators. When the stimulus resolves, the reaction typically abates within days.Local EffectsAt the site of injury, arteriolar vasodilation increases blood flow, resulting in redness and warmth. Simultaneously, increased...

