MEDICAL PHYSIOLOGY

Detailed explanation-1: -A small amount of brain tissue from a person cannot be distinguished from a small amount of brain tissue from a monkey. The human brain produces its own natural opiates that elevate mood and ease pain. The brain accounts for a larger percentage of body weight in humans than in any other species.

Detailed explanation-2: -The information systems of humans and other animals operate so similarly that you could not distinguish between small samples of brain tissue from a human and a monkey. This allows researchers to study other animals to discover how our own systems work.

Detailed explanation-3: -The human brain is about three times as big as the brain of our closest living relative, the chimpanzee. Moreover, a part of the brain called the cerebral cortex – which plays a key role in memory, attention, awareness and thought – contains twice as many cells in humans as the same region in chimpanzees.

Detailed explanation-4: -Brain tissue is composed of neuronal, glial and endothelial cells, and although there must be biological rules that determine the numbers of cells of each subtype and the volumes (or masses) occupied by them, little is known about such rules, if they indeed exist.