Cord blood oxygen

Koller MR, Bender JG, Miller WM Papoutsakis ET (1992b) Reduced oxygen tension increases hematopoiesis in longterm culture of human stem and progenitor cells from cord blood and bone marrow. Experimental Hematology 20 264-270. 

Koller, M. R., J. G. Bender, E. T. Papoutsakis, and W. M. MiUer. 1992. Effects of synergistic cytokine combinations, low oxygen, and irradiated stroma on the expansion of human cord blood progenitors. Blood 80(2) 403-11. 

Many different types of sensory receptors are located throughout the body. These receptors monitor the status of the internal environment or that of the surroundings. Sensory receptors are sensitive to specific types of stimuli and measure the value of a physiological variable. For example, arterial baroreceptors measure blood pressure and chemoreceptors measure the oxygen and carbon dioxide content of the blood. The information detected by these sensors then travels by way of afferent neuronal pathways to the central nervous system (CNS). The CNS is the integrative portion of the nervous system and consists of the (1) brain and the (2) spinal cord. 

Medication Transportation System. If the brain, the spinal cord, and the nerves make up the body s communication system, then the heart, blood vessels, and blood are the body s transportation system. Blood carries oxygen and nutrients to the organs and then returns the wastes for disposal. Medications use this same internal highway system to travel throughout the body. 

Severe, acute reduetion in oxygenation, for example by complete arrest of uterine flow or complete umbiheal cord occlusion, is not associated with a decrease in eerebrovascular resistance, as is seen in more mild insults. This suggests that the ability of the fetus to adapt to hypoxia has been overwhelmed. The rate at which the fetal arterial O2 content falls may be a determinant of the response elicited whether it be a rapid onset of ECoG isoelectricity (32,120), reduced regional cerebral blood flows (17), a failure of cardiovascular adaptive responses (139), an increase in eerebral lactate production (140), or a 50% reduction in cerebral metabolic rate... 

Peeters L, Sheldon R, Jones M, Makowski E, Meschia G. Blood flow to fetal organs as a function of arterial oxygen content. Am J Obstet Gynecol 1979 135(5) 637-646. Johnson G, Palahniuk R, Tweed W, Jones M, Wade J. Regional cerebral blood flow changes during severe fetal asphyxia produced by slow partial umbilical cord compression. Am J Obstet Gynecol 1979 135(l) 48-52. 

Fig. P-66. The growing fetus depends on its mother for nutrients and removal of wastes. The mother s heart pumps blood through the uterine arteries into the placenta nutrients and oxygen diffuse through the placental membranes into the fetal bloodstream by way of the umbilical cord and wastes pass in the reverse direction to the maternal bloodstream through the uterine veins.

It was recently proposed that kinin is responsible for the circulatory changes at birth which result in conversion of the foetal to the new-born circulation. Presumably, the decreased temperature of the umbilical cord, the increased partial tension of oxygen in the blood and the increased concentration of circulating granulocytes all activate the kininogenase and thus induce kinin release. Kinin then constricts the umbilical artery and vein and the ductus arteriosus and dilates the pulmonary vasculature. All these effects of kinin have been confirmed experimentally in the lamb. 

---