Different Cells are Replaced at Different Rates

Different types of cells have different lifespans, e.g.:  we shed our skin cells about every 35 days red blood cells live about 120 days, platelets 6 days and white cells less than a day most of the adult skeleton is replaced about every 10 years the average age of a fat cell seems to be about 10 years a 25-year-old heart replaces about 1% of all its cardiomyocytes (heart muscle cells ) over the course of a year, while a 75-year-old heart replaces about half a percent ...

 The Development of the Human Brain

Two types of cells are important here. The first type, glial cells, make up 90 percent of the brain cells inside your child’s head. They give the brain its structure and help the neurons correctly process information. It’s a good name; glial is a Greek word for glue. The second type of cell is the familiar neuron. Though they do a lot of your child’s thinking, neurons make up only about 10 percent of the total number of brain cells. That’s probably where we get the myth that you us...