Embryo 54 Day Old Heart and Nervous System
Computer Generated Image from Micro-MRI, actual size of embryo = 26.0 mm - This image provides a left-sided view from the left side of the embryo during its eighth week of development. The age is calculated from the day of fertilization. The image has been manipulated so that the skin appears translucent. The primary focus of this image is the central nervous system. The two main organs that comprise this system are the brain and spinal cord which are highlighted in orange. The three main components of the brain can be observed. The largest portion in the front of the head is called the forebrain, the narrow middle segment is called the midbrain, and the hindbrain is the portion that connects the midbrain with the spinal cord. The nerve endings surrounding the spinal cord are indicated in white. Proportionately, the brain and central nervous system make up far less of the baby's body mass. The embryonic brain has yet to develop the iconic folds and wrinkles we recognize in adult brains. The heart is highlighted in bright red.