Question

1. What is the cauda equina, filum terminale, conus medularis, cervical and lumbar enlargements?

Answer 1

Ans- Cauda equina- The collection of nerves at the end of the spinal cord is called cauda equina. It is so called due to resembling to the tail of horse. It consists of 2-5th lumbar nerves, 1-5th sacral nerve pairs and coccygeal nerve.

Filum terminale- It is one of the modification of pia mater which is a delicate strand of fibrous tissue. It proceeds downwards from conus medullaris and connects conus medullaris and coccyx and stabilises spinal cord.

Conus medullaris- Also called conus terminalis , it is the tapered lower end of the spinal cord. It is the most distal bulbous part and it's tapering end continues as filum terminale. Distal to this end is cauda equina. Conus medullaris occurs near L1 and L2.

Cervical enlargements- It extends from fifth cervical to first thoracic vertebra and corresponds with the major nerves which supply the upper limbs. It corresponds to brachial plexus nerve which innervates upper limbs. It results from the enlargement of gray mater that contains machinery to operate limbs. Thus it is due to increase input and output to upper limbs.

Lumbar enlargement- It is the widened area of spinal cord which supplies the lower limbs. It is from level T11 to L2. It corrosponds to lumbosacral plexus nerves which innervates lower limbs.