What happens at puberty?
Why are some babies disabled at birth?
How does the baby breathe in the uterus?
What determines whether a baby is a boy or a girl?
What happens to the fertilized egg cell?
How does fertilization occur?
How are babies born?
Why must we sleep?
What is a stroke?
A stroke is a serious medical condition occurring as a result of an interruption in the supply of oxygen to the brain. The most frequent reason for a stroke is the blockage or bursting of a blood vessel in the brain. In both cases, the blood circulation and, hence, the supply of oxygen to the brain is interrupted. The result is damaged brain tissue. Stroke patients may lose all information that was stored in the damaged area and may have to relearn simple things like walking, swallowing, or writing. Sometimes, the brain can build new connections between the brain cells and repair the damage.
What is memory?
How do nerve cells transmit signals?
Signal transmission through nerve cells is quite complicated. Like all the other cells, nerve cells also have a cell body with a nucleus. There are fine extended branches known as dendrites and a long ‘tail’ called the axon on the body of the nerve cells. Axons in the brain are smaller than 1 mm, whereas in the spinal cord they can be as long as 1 m. A chemical substance is released through an electrical impulse into the synapses present at the end of the axon. This chemical substance, known as the neurotransmitter, is transferred to the dendrite of another nerve cell and the signals are transmitted.
What is the structure of our brain?