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A Handbook of Biology
Cerebrum: Largest part. It has 2 cerebral hemispheres held together by a
tract of nerve fibres (Corpus callosum).
Outer part of cerebrum is called cerebral cortex. It has convulsions &
depressions and is formed of gray matter.
Inner part of cerebrum is formed of white matter.
Cerebral cortex consists of Motor area: Controls voluntary movements of
muscles.
Sensory (Somaesthetic) area: Controls the functioning of sense organs.
Association area: It is neither clearly sensory nor motor in function.
Responsible for intersensory associations, memory and communication.
Diencephalon : It consist of thalamus & hypothalamus
Thalamus: It is the structure around which the cerebrum wraps. It is
a coordinating centre (relay station) for sensory and motor impulses.
Hypothalamus: It Regulates temperature, thirst, hunger and emotions.
(NEET 2019).
Secretes hypothalamic hormones.
Controls pituitary gland.
Controls sleep, wakefulness, blood pressure, heart rate.
The inner parts of cerebral hemispheres and a group of associated deep
structures like amygdala, hippocampus, hypothalamus, etc. together
constitute limbic system (Limbic lobe). It regulates sexual behavior,
motivations, emotions (excitement, pleasure, rage, fear, etc).
B. MÏDBRÅÏÑ (MËSËÑÇËPHÅLØÑ)
It is located between thalamus/hypothalamus and Pons .
A canal (cerebral aqueduct) passes through the midbrain.
Mid brain consists of 4 round lobes called Corpora quadrigemina . Their
anterior pair is the centre of visual reflexes and the posterior pair is a
centre of auditory reflex.