Search results
Results from the WOW.Com Content Network
The circle of Willis (also called Willis' circle, loop of Willis, cerebral arterial circle, and Willis polygon) is a circulatory anastomosis that supplies blood to the brain and surrounding structures in reptiles, birds and mammals, including humans. [1] It is named after Thomas Willis (1621–1675), an English physician. [2]
You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made.
An average adult contains five to six quarts (roughly 4.7 to 5.7 liters) of blood, accounting for approximately 7% of their total body weight. [9] Blood consists of plasma, red blood cells, white blood cells, and platelets. The digestive system also works with the circulatory system to provide the nutrients the system needs to keep the heart ...
Often expressed in cm/s. This value is inversely related to the total cross-sectional area of the blood vessel and also differs per cross-section, because in normal condition the blood flow has laminar characteristics. For this reason, the blood flow velocity is the fastest in the middle of the vessel and slowest at the vessel wall.
The pathway consists of a para-arterial influx mechanism for CSF driven primarily by arterial pulsation, [2] which "massages" the low-pressure CSF into the denser brain parenchyma, and the CSF flow is regulated during sleep by changes in parenchyma resistance due to expansion and contraction of the extracellular space.
[1] [2] Some of the blood entering the right atrium does not pass directly to the left atrium through the foramen ovale, but enters the right ventricle. This blood consists of oxygenated placental blood and deoxygenated blood returning from the fetal circulation. [2] This blood is pumped into the pulmonary artery. At the pulmonary artery, it is ...
Normal blood pressure when at rest is within the range of 100–140 millimeters mercury (mmHg) systolic and 60–90 mmHg diastolic. [69] High blood pressure is present if the resting blood pressure is persistently at or above 140/90 mmHg for most adults. [67] Different numbers apply to children. [70]
[1] [2] The peripheral arteries supply oxygenated blood to the body, and the peripheral veins lead deoxygenated blood from the capillaries in the extremities back to the heart. [ 3 ] Peripheral veins are the most common intravenous access method in both hospitals and paramedic services for a peripheral intravenous (IV) line for intravenous ...