Exercises
Answer the following: (a) Which part of the human brain is the most developed? (b) Which part of our central neural system acts as a master clock?
(a) The most developed part of the human brain is the Cerebrum.
The cerebrum forms the major part of the human brain and is the site for higher mental functions. Its cerebral cortex (grey matter) is highly folded (convoluted) and contains motor areas, sensory areas, and large association areas responsible for complex functions like memory, intelligence, communication, intersensory associations, and conscious thought. The human cerebrum is proportionally the largest and most elaborately developed among all animals.
(b) The Hypothalamus acts as the master clock (biological clock) of our central neural system.
The hypothalamus contains a group of neurosecretory cells that control circadian (24-hour) rhythms of the body. It regulates the body's biological clock by controlling sleep-wake cycles, body temperature fluctuations, hormone release patterns, and other time-dependent physiological processes. The suprachiasmatic nucleus (SCN) within the hypothalamus is the primary circadian pacemaker.
Answer: (a) Cerebrum — the largest, most complex part; site of consciousness, memory, intelligence, and voluntary control. (b) Hypothalamus — contains the master circadian clock (suprachiasmatic nucleus) that controls 24-hour biological rhythms.