NOTE ON SPINAL CORD

 SPINAL CORD

★THE SPINAL CORD IS IN FACT A TUBULAR BUNDLE OF NERVES. 

STARTS FROM;

★IT STARTS FROM BRAIN STEM AND EXTENDS TO LOWER BACK. SPINAL CORD IS THE

   CONTINUATION OF MEDULLA OBLONGATA. MEDULLA OBLONGATA NARROWS DOWN

   INTO AN OVAL SHAPED HOLLOW CYLINDER, THE SPINAL CORD, RUNNING THROUGH 

   THE VERTEBRAL COLUMN.

CONSIST OF;

★IT CONSIST OF A VERY LARGE NUMBER OF NEURONS. THE CELL-FIBRES AND BODIES 

   OF WHICH ARE ARRANGED IN A DEFINITE PATTERN.

COVERED BY;

★LIKE BRAIN, SPINAL CORD IS ALSO COVERED BY  MENINGES. THE VERTEBRAL

   COLUMN SURROUNDS AND PROTECTS SPINAL CORD.

SIZE OF SPINAL CORD;

★SPINAL CORD IS ROUGHLY 40cm LONG AND ABOUT AS WIDE AS YOUR THUMB FOR

   MOST OF ITS LENGTH.

REGIONS OF SPINAL CORD;

OUTER REGION;

★THE OUTER REGION OF SPINAL CORD IS MADE OF WHITE MATTER .

★CONTAINING MYELINATED AXONS.

CENTRAL REGION;

★THE CENTRAL REGION IS BUTTERFLY SHAPED THAT SURROUNDS THE CENTRAL

   CANAL.

★IT IS MADE UP OF GREY MATTER AND CONTAINING NEURON CELL BODIES.

SPINAL NERVES;

★31 PAIRS OF SPINAL NERVES ARISE ALONG SPINAL CORD. THESE ARE "MIXED"

   NERVES BECAUSE EACH CONTAINS AXONS OF BOTH SENSORY AND MOTOR 

   NEURONS.

ROOTS OF SPINAL NERVES;

★AT THE POINT WHERE SPINAL NERVE ARISES FROM SPINAL CORD, THERE ARE TWO

   ROOTS OF SPINAL NERVE. BOTH ROOTS UNITE AND FORM ONE MIXED SPINAL NERVE.

DORSAL ROOT;

★THE DORSAL ROOT CONTAINS SENSORY AXONS AND A GANGLION WHERE CELL

   BODIES ARE LOCATED.

VENTRAL ROOT;

★THE VENTRAL ROOT CONTAINS AXONS OF MOTOR NEURONS.

TWO MAIN FUNCTIONS OF SPINAL CORD;

SPINAL CORD PERFORMS TWO MAIN FUNCTIONS.

★IT SERVES AS A LINK BETWEEN BODY PARTS AND BRAIN. SPINAL CORD 

   TRANSMIT NERVE IMPULSES FROM BODY PARTS TO BRAIN AND FROM

   BRAIN TO BODY PARTS.

★SPINAL CORD ALSO ACT AS A COORDINATOR, RESPONSIBLE FOR SOME 

   SIMPLE REFLEXES.

SPINAL CORD AND SPINAL NERVES