Biology - Human Brain


  • 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.

Human Brain
  • 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.

Parts of Brain


  • 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)