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.
Causes. The exact cause of bipolar disorder is unknown, but several factors may be involved, such as: 1  Biological differences. 2  People with bipolar disorder appear to have physical changes in their brains. 3  The significance of these changes is still uncertain but may eventually help pinpoint causes.4  Neurotransmitters.he exact cause of bipolar disorder is unknown, but several factors may be involved, such as: 1  Biological differences. 2  Neurotransmitters. 3  Inherited traits. 4  Symptoms. 5  Risk factors.