Table - 1 : Let us study the functions of the various parts of the brain


Fore brain

Olfactory lobes :

These clubshaped widely spread bodies are visible from the ventral surface only.

Functions :

These are concerned with sense of smell

Cerebrum :

It consists of two lobes called cerebral hemispheres. The surface of the
cerebrum has many folds, they appear as elevations (Gyri) and depressions (Sulci). Sulci
are very prominent and divide each hemisphere into four lobes.
  1. ask your teacher the name of those lobes.

  2. observe the fig. 10 which part connects the two hemispheres ?

    3. Functions :

    i) Seat of mental abilities, controls thinking, memory, reasoning, perception, emotions and speech.
    ii) Interprets sensations and responds to cold, heat, pain and pressure

    Diencephalon :

    This rhomboidal shaped lobe visible from inferior surface of brain. It lies
    between cerebrum and mid brain. It is divided into thalamus and hypothalamus (Master
    control centre of endocrine system). Where as Pituatory gland is called Master gland.

    Functions :

    i) Relay centre for sensory impulses, such as pain, temperature and light.
    ii) Reflex centre for muscular activities.
    iii) Centre for certain emotions such as anger.
    iv) Centre for water balance, blood pressure, body temperature, sleep and hunger.
    v) The hypothalamus controls the pituitary gland, which functions as the
    master gland

    Mid-brain :

    This is a small thick stalked portion. This connects forebrain with cerebellum and pons of hind brain.
    1. observe optic lobes of mid brain in the brain model in your laboratory.
    2. observe the fig. 10 which part connects the two hemispheres ?

    Functions :

    It relays motor impulses from the cerebral cortex to the spinal cord and relays
    sensory impulses from the spinal cord to the thalamus, reflexes for sight and hearing.

    Hind brain :

    This is the last part of the brain consists of cerebellum, medulla oblongata.

    Cerebellum :

    It is located below the cerebrum and above medulla oblongata. It consists
    of two large cerebellar hemispheres.

    Functions :

    i) Maintains posture, equilibrium and muscle tone.
    ii) Coordinates voluntary movements initiated by cerebrum.

    Medulla oblongata :

    It is almost triangular shaped. Medulla oblongata extends from pons
    to spinal cord. Ask your teacher grey and white matters of medulla oblongata

    Functions :

    i) Contains centre for cardiac, respiratory and vasomotor activities.
    (Vasomotor refers to actions upon a blood vessel which alter its diameter)
    ii) Coordinates reflexes like swallowing, coughing, sneezing and vomiting.
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