central venous pressure

Examples of central venous pressure in the following topics:

• Pressure in the Body

  • One such critical bodily system which relies on pressure for functionality is the circulatory system, which is an example of a closed fluid system under pressure.
  • The mean arterial pressure (MAP) is the average pressure over a cardiac cycle and is determined by , where CO is the cardiac outputs, SVR is the systemic vascular resistance, and CVP is the central venous pressure (CVP).
  • In practice, the mean arterial pressure (MAP) can be approximated from easily obtainable blood pressure measurements in , where Psys is the measured systolic pressure and Pdias is the measured diastolic pressure.
  • The mean arterial pressure (MAP) is the average pressure over a cardiac cycle and is determined this equation, where CO is the cardiac outputs, SVR is the systemic vascular resistance, and CVP is the central venous pressure (CVP).
  • In practice, the mean arterial pressure (MAP) can be approximated from easily obtainable blood pressure measurements.

• Venous Blood Pressure

  • Venous pressure is the vascular pressure in a vein or the atria of the heart.
  • Variants of venous pressure include:
  • Central venous pressure, a good approximation of right atrial pressure, which is a major determinant of right ventricular end diastolic volume.
  • Jugular venous pressure (JVP), the indirectly observed pressure over the venous system.
  • Portal venous pressure or the blood pressure in the portal vein.

• Pulmonary Edema

  • The chronic development of pulmonary edema may be associated with symptoms and signs of "fluid overload," this is a non specific term to describe the manifestations of left ventricular failure on the rest of the body and includes peripheral edema (swelling of the legs, in general, of the "pitting" variety, wherein the skin is slow to return to normal when pressed upon), raised jugular venous pressure and hepatomegaly, where the liver is enlarged and may be tender or even pulsatile.
  • In the case of cardiogenic pulmonary edema, urgent echocardiography may strengthen the diagnosis by demonstrating impaired left ventricular function, high central venous pressures, and high pulmonary artery pressures.

• Artery Function

  • Arteries are blood vessels that carry blood away from the heart under pressure.
  • Arterial pressure varies between the peak pressure during heart contraction, called the systolic pressure, and the minimum or diastolic pressure between contractions, when the heart expands and refills.
  • This pressure variation within the artery produces the observable pulse that reflects heart activity.
  • The pressure in the arterial system decreases steadily, highest in the aorta and lowest in the venous system, as blood approaches the heart after delivery of oxygen to tissues in the systemic circulation.
  • Distinguish the function of the arterial system from that of venous system

• Lymphatic Vessel Structure

  • The activity of smooth muscles allows lymph vessels to slowly pump lymph fluid through the body without a central pump or heart.
  • As the pressure falls, the open valve then closes so that the lymph fluid cannot flow backwards.
  • Without valves, the lymphatic system would be unable to function without a central pump.
  • Smooth muscle contractions only cause small changes in pressure and volume within the lumen of the lymph vessels, so the fluid would just move backwards when the pressure dropped.
  • Blood vessels also have valves, but only in low pressure venous circulation.

• Cerebrospinal Fluid and Its Circulation

  • Cerebrospinal fluid is a clear fluid that acts as a cushion for the brain and maintains overall central nervous system homeostasis.
  • CSF is reabsorbed into venous sinus blood via arachnoid granulations.
  • This continuous flow into the venous system dilutes the concentration of larger, lipid-insoluble molecules penetrating the brain and CSF.
  • When CSF pressure is elevated, cerebral blood flow may be constricted.
  • The venous system is also important in this equation.

• Introduction to Blood Pressure

  • Blood pressure is the pressure that blood exerts on the wall of the blood vessels.
  • Systolic pressure is thus the pressure that your heart emits when blood is forced out of the heart and diastolic pressure is the pressure exerted when the heart is relaxed.
  • During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure.
  • A normal blood pressure should be around 120/80, with the systolic pressure expressed first.
  • Gravity affects blood pressure via hydrostatic forces (for example, during standing) Valves in veins, breathing, and pumping from contraction of skeletal muscles also influence venous blood pressure.

• Ventricles

  • This system is continuous with the central canal of the spinal cord.
  • From there, it passes into the central canal of the spinal cord and into the cisterns of the subarachnoid space via three small foramina: the central foramen of Magendie and the two lateral foramina of Luschka.
  • The fluid then flows around the superior sagittal sinus to be reabsorbed via the arachnoid villi into the venous system.
  • This means they can be easily blocked, causing high pressure in the lateral ventricles.
  • The fourth ventricle narrows at the obex, where the fourth ventricle narrows to become the central canal in the caudal medulla.

• Distribution of Lymphatic Vessels

  • Conversely, lymph nodes are not found in the areas of the upper central nervous system, where tissue drains into cerebrospinal fluid instead of lymph, though there are some lymph vessels in the meninges.
  • This fluid is mainly water from plasma that leaks into the intersitial space in the tissues due to pressure forces exerted by capillaries (hydrostatic pressure) or through osmotic forces from proteins (osmotic pressure).
  • When the pressure for interstitial fluid in the interstitial space becomes large enough it leaks into lymph capillaries, which are the site for lymph fluid collection.
  • Lymph vessels become larger, with better developed smooth muscle and valves to keep lymph moving forward despite the low pressure and adventia to support the lymph vessels.
  • Lymph nodes found closer to the heart filter lymph fluid before it is returned to venous circulation through one of the two lymph ducts.

• Types of Shock

  • The typical signs of shock are low blood pressure, a rapid heartbeat, and signs of poor end-organ perfusion or decompensation (such as low urine output, confusion, or loss of consciousness).
  • In some people with circulatory shock, blood pressure remains stable.
  • While the general signs for all types of shock are low blood pressure, decreased urine output, and confusion, these may not always be present.
  • This typically occurs due to a reduction in venous return, but may also be caused by blockage of the aorta.
  • Neurogenic shock arises due to damage to the central nervous system, which impairs cardiac function by reducing heart rate and loosening the blood vessel tone, resulting in severe hypotension.