STRUCTURE AND FUNCTION OF HUMAN BRAIN

                             HUMAN BRAIN

Brain is the most vital organ which is made up of nervous tissue. It lies in cranial cavity and weigh about 1400 gm. It is covered externally by meanings which is made up of 3 layers piamater ( inner), archnoid layer (middle) and a duramater ( outer).

     

    The brain is divided into 3 parts.

1. Prosencephalon ( fore brain )
2. Mesencephalon ( mid brain )
3. Rhombencephalon ( hind brain )

1. Prosencephalon consists of anterior telencephalon and posterior diencephalon. The telencephalon includes cerebral hemisphere or cerebrum and olfactory lobes.

        Cerebrum:- 

                  The cerebrum is folded forming sulci and gyri to accommodate more neurons. It is made up of  inner white matter & outer grey matter. A median fissure divides the brain into two cerebral hemisphere which are joined by a curved thick band of nerve fibres called corpus callosum. Each half divided into 5 lob

• Frontal lobe - It has motor area, speech area and pre motor area.
• Parietal lobe - It includes pain and temperature area, speech area and taste area.
• Tempral lobe - It includes auditory area and visual area.
• Occipital lobe - It concerned with vision and sensory function.
• Insula or Island of Reil - It integrates the activity of other part of cerebrum.            

The floor of the cerebrum is called corpora striatum. The lateral ventricles ( 1st and 2nd cavities in cerebral hemisphere ) open into 3rd ventricle or diocoel ( cavity of diencephalon) by a foramen of Monro. In humans, diencephalon is externally covered by cerebrum.

       

        Cerebral hemisphere are centres of memory, speech, hearing, vision, voluntary action, involuntary muscle movement etc.

        The main parts of diencephalon are 

• Dorsal epithalamus contain pineal body which secretes melatonin
• Lateral thalamus perceives sensation of heat, cold and pain 
• Hypothalamus or floor of the diencephalon contains hypophysis or pituitary glands and mammillary body lies behind the hypophysis. Two optic nerves cross to form optic chiasma in the front of pituitary gland. Hypothalamus is thermoregulatory centre of the brain. It also control hunger, thirst, fear, anger, emotion, sleep and also produced neurohormones which control the secretion of pituitary gland. It also regulate water balance and the carbohydrates and fat mrtabolism.

2. Mesencephalon consists of  4 optic lobes or corpora quadrigemina and crura cerebri.

       It is vision reflex centres. The posteriors pair is called inferior colliculi. It is auditory reflex centre.

3. Rhombencephalon consists of cerebellum, pons varolli and medulla oblongata. Cerebellum is provided with tree like Arbor vitae. Pons varoli is a transverse band of nerve fibres which connect two cerebellar hemisphere. Pons varolli is the controlling centre of respiration. Cerebellum maintains body posture. Medulla oblongata is the cardiac centre, vasomotor, respiratory centre, gastric centre and reflex centre.

GOOGLE'S NEW WFH PLAN TILL 2021

Google extends Work From Home facility to its employees till June 30 next year

Due to the current corona virus epidemic, the world largest search engine company Googles  has taken a big decision in the interest of its employees. Google will allow most of its employees to work from home until 30 June 2021. Google gave this information on Monday. 

In an e-mail sent to his employees, Google CEO Sundar Pichai said, "To facilitate the employees in determining their upcoming plans, we are extending our global voluntary work from home option till 30 June 2021.

           The Wall Street Journal, the first to provide information about Google's move, said that this would now make the option of Work From Home for about 200,000 Google employees and contractors around June 30, 2021. It was earlier scheduled to end in December 2020.

           Following Google's move, other tech companies and large employers may also extend the work from home option deadline, as returning to employees' offices may increase the risk of infection.

          However various tech companies have said that they are expected to gradually open their offices in the coming months. At the same time, Twitter has said that it will allow all its employees to work from home indefinitely.

Significantly, India is a major market of Google and has a presence in Hyderabad and Bangalore. Pichai recently launched a Rs 75,000 crore investment plan in India, under which it plans to digitize the Indian economy over the next seven years.

Facebook and Twitter are also at work from home

Facebook and Twitter Incorporated have also allowed most of their employees to work from home indefinitely after coronovirus and lockdown. But no other company has taken the decision that Google has taken for such a long time yet. The company is publicly committed to maintaining its remote work policies in 2021.Which is the first technology company to work publicly in an effort to give employees more clarity to work from home.