CEREBELLUM::
It is the biggest part of the hind brain and is situated behind the pons and medulla oblongata The median portion of the cerebellum is separated from the pons and medulla by the fourth ventricle it weighs about 150 gm in an adult Cerebellum in general has two hemispheres (right and left cerebellar hemispheres ) joined by a narrow median strip the vermis From the functional point of view cerebellum has been divided into two parts :
(1) Floccular -nodular lobe
(2) Corpus cerebelli
Fig CEREBELLUM
1.The Floccular nodular part consists of flocculi their peduncles and nodule This part is connected with helps in regulation of posture and equilibrium
2.The Corpus Cerebelli has anterior lobe and posterior lobe This part receives tactile proprioceptive auditory and visual impulses through the spinal cord and cerebrum This part is involved in the regulation of posture muscle tone synergic movements and overall integration and co-ordination of muscular movements
In general the cerebellum is not involved with sensation or consciousness and its removal does not cause any impairment of them but it plays an important role in the reflex regulation of tone posture and integration and co-ordination of skeletal muscle contractions (i.e.motor movements) It acts as a link between the cerebral cortex and peripheral motor activities
Lesions of cerebellum will cause defect of posture and voluntary movements There may be hypotonia (decrease in muscle tone ) vertigo (a feeling of rotating environment ) tremors (involuntary skeletal muscle movements ) asthesia (weakness of movements ) ataxia (inco-ordinated movements ) etc
0 Comments