Kidney ultrasound. Also called: renal ultrasound. A kidney ultrasound is used to determine the size, shape and location of the kidneys without cutting the skin. A kidney ultrasound makes it possible to see the kidneys from outside the body by using ultrasonic waves.
An early recognized function of astrocytes is the control of K + levels in the brain. Neuronal activity leads to an increase in K + concentration from a resting level of about 3 mM to a maximum of 10 - 12 mM under physiological conditions and to even higher values under pathological conditions.strocytes may also limit the number of synapses since astrocyte membranes can ensheath the neuronal processes and thus compete with synapses. Astroglial cells can also be involved in the elimination of synapses in the CNS, the process which underlies the final tuning and plasticity of the neuronal inputs.
Astrocytes (Astro from Greek astron = star and cyte from Greek kyttaron = cell), also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. The proportion of astrocytes in the brain is not well defined.Depending on the counting technique used, studies have found that the astrocyte proportion varies by region and ranges from 20% to 40% of all glia. Structural: They are involved in the physical structuring of the brain. 2  Astrocytes get their name because they are star-shaped. 3  They are the most abundant glial cells in the brain that are closely associated with neuronal synapses.