19. Long answer question IV

 

Spinal cord extends from the medulla oblongata for about 22 to 32 cm42 to 45 cm long. It acts as means of communication between spinal nerves and brainoesophagus and brain. It carries impulses to and from the brain to the controls most of the reflex actions. The same three protective membranes found in the brain surround the spinal cord. The spinal cord is a  cylindricalpear shaped structure that runs through the vertebral column’s neural canal. The meninges also cover it. It extends from the medulla oblongata's lower end to the first lumbar vertebrafirst sacral vertebra. Filum terminaleCorpora quadrigemina is a thin fibrous thread-like structure that extends down the posterior-most region of the spinal cord. The spinal cord contains the central canal.

 

The central canal is a pericardial fluidcerebrospinal fluid filled channel located within the spinal cord. The two types of neural tissue that make up the spinal cord are internalexternal grey matter and internalexternal white matter. 

 

 The cauda equinaCorpora quadrigemina, or horse’s tail, is a collection of spinal nerves located below the second lumbar vertebra in the vertebral column. The conus medullaris Crura cerebri is the end portion of the spinal cord, from which a fine filament termed filum terminale emerges, anchoring the spinal cord within the vertebral column.