Reference source/supplementary reading for lecture Your Brain on Collision Sports

  • Body World Pics
  • Brain Poster Session: Experimental Cerebral Ischemia – Blood Flow and Metabolism
  • Microvascular Flow Physics



Capillaries measure 5-10 μm in diameter and enable the interchange of water, oxygen, carbon dioxide, and many other nutrient and waste chemical substances between blood and surrounding tissues.[3] True capillaries branch mainly from metarterioles and provide exchange between cells and the circulation. The internal diameter of 8 μm forces the red blood cells to partially fold into bullet-like shapes and to go into single file in order for them to pass through. Continuous capillaries have a sealed endothelium and only allow small molecules, like water and ions to diffuse. There are those with numerous transport vesicles and tight junctions and those with few vesicles and tight junctions. Fenestrated capillaries have pores in the endothelial cells (60-80 nm in diameter) that are spanned by a diaphragm of radially oriented fibrils and allow small molecules[1] and limited amounts of protein to diffuse. Sinusoidal or discontinuous capillaries are special fenestrated capillaries that have larger openings (30-40 μm in diameter) in the endothelium to allow [[red blood cell]s and serum proteins to enter. 



In 2007, Bhatia and L. Mahadevan, a Harvard professor of applied mathematics who studies natural and biological phenomena, started working together to understand how sickle cells move through capillaries. In the current study, the researchers recreated the conditions that can produce a vaso-occlusive crisis: They directed blood through a microchannel and lowered its oxygen concentration, which triggers sickle cells to jam and block blood flow.

Read more: Sickle Cell Disease Examination Via Blood Flow Measurement | Medindia