Biology - Human Brain

Introduction

• The brain of a human being is the central organ of the nervous system.

• The human brain consists of three parts namely the cerebrum, the brainstem and the cerebellum.

• The brain of a human being plays significant role, as it controls most of the activities of the human body.

• The brain is located inside the head, and protected by the skull bones.

• The brain consists of more than 86 billion neurons and almost equal number of other cells as well.

• Brain activity is made possible because of the interconnections of all the neurons that are linked together.

• The study of brain functions is known as neuroscience.

• An adult human brain weighs about 1.2 to 1.4 kg (i.e. average weight); which is about 2% of the total body weight.

Parts of Human Brain

• A human brain is primarily classified as the −

  • Forebrain

  • Midbrain

  • Hindbrain

• Forebrain is largely made up of cerebrum, thalamus, hypothalamus and pineal gland.

• Midbrain is largely made up of a portion of the brainstem.

• Hindbrain largely made up of the remaining brainstem, cerebellum and pons.

• Further, the (brain) hemisphere is conventionally classified into four lobes namely −

  • Frontal lobe

  • Parietal lobe

  • Temporal lobe

  • Occipital lobe

• The naming is done according to the skull bones that overlie them.

Cerebrum

• Divided into nearly symmetrical left and right hemispheres by a deep groove, the cerebrum is the largest part of the human brain.

• Cerebrum normally controls higher brain functions including language, logic, reasoning, and creativity.

Functions of Human Brain

• Major functions of human brain are −

  • Perceive or sense the signal coming from the (external) environment

  • Giving sense of feelings and emotion

  • Regulating and controlling the human behaviors

  • Regulating and controlling the physical action

  • Regulating the memory function

  • Process of thinking (and other cognitive process)