With increasing age, the kidney atrophy shifts the renal parenchyma pyelon index to 1:2:1. Renal Ultrasound Anatomy The kidney is a bean-shaped organ, which has usually a smooth convex lateral organ boundary.
Bipolar disorder may result from a chemical imbalance within the brain. The brain's functions are controlled by chemicals called neurotransmitters. An imbalance in the levels of one of these neurotransmitters, such as norepinephrine, may cause bipolar disorder. When levels of this chemical are too high, mania occurs.
Bipolar Disorder. Causes of Bipolar Disorder. Both genetic elements and environmental factors can create vulnerability to the disorder, so the causes vary from person to person. While the disorder can run in families, no one has definitively identified specific genes that create risk for developing the condition.