THE ARTICLE ON SPINAL CORD



Introduction

The medulla spinalis may be a elongated, tubular, nearly cylindrical a part of the central system nervosum made from nerve tissue which occupies the upper 2/3 of whole spinal canal,that means, extends from medulla within the brainstem or upper border of atlas to the Lumber region of the spinal column . The average length is 45 cm and weight is about 30 gms of adult candidate.

The physiology of medulla spinalis primarily within the transmission of nerve signal from the motor area to the body, and from the afferent fibers of the sensory neurons to the sensory cortex. It is helping to coordinate reflexes and contains reflex arcs which will independently control reflexes. it's also the situation of groups of spinal interneurons that structure the neural circuit referred to as central pattern generators.. These circuits are liable for controlling motor instructions for rhythmic movements like walking.

STRUCTURE OF medulla spinalis

  • The medulla of spinal cord consists of grey and white nervous matter, in both of which there's a supporting framework of neuroglia.
  • Medulla spinalis are protected by three layers of tissue or membranes called Meninges that surround the canal. The meninges made from by three layers, from outside to in word 1] dura 2] Arachnoid mater 3] meninx.
  • Dura mater is that the outer layer and it forms a troublesome protective coating between the dura and surrounding bone of the vertebrae may be a space called epidural space.
  • The Arachnoid mater is that the middle protective layer of meninges, the space between arachnoid mater and meninx is named subacrcnoid mater and it contains our spinal fluid [CSF].
  • Inner layer is meninx tightly connected with medulla spinalis.
  • The Gray mater: It is situated centrally and has the shape of a fluted column which runs through its whole length. It is looks like letter 'H'. It is again divided into two part 1] Anterior horn cell 2] Posterior horn cell.
  • The anterior horn cell is directed forwards and somewhat laterally.. Posterior horn cell is directed backwards and somewhat laterally. The extension of gray matter extend into the lateral white column, where they form a network termed the FORMATIO RETICULARIS.
  • Anatomically Gray matter consists of neuroglia, nerve cells and nerve fibers. In the whole neuroglia is arranged within the sort of a sponge like network, but within the gelatinous substance round the central canal and on the apices of the posterior horn it's considerably condensed. The nature of nerve cells are multipolar and vary greatly in size and shape but they'll be classified in three main groups consistent with their position. they're the cells of the anterior horn, the cells of the lateral horn and therefore the cells of the posterior horn.
  • THE WHITE MATTER-- The substantia alba is found outside of the gray matter and consists almost totally of MYELINATED MOTER and SENSORY axons. The Columns of substantia alba carry information either up or down the medulla spinalis and consists chiefly of medullated nerve-fibers. The nerve fibers are arranged in three white columns, they're anterior, lateral and posterior.
  • Medulla spinalis proper ends during a region called the CONUS MEDULLARIS, while the meninx continues as an extension called the FILUM TERMINALE, which anchors the medulla spinalis to the coccyx. Now  cauda equina forms because the medulla spinalis stops growing long at about age four, albeit the spinal column continues to elongate until adulthood. This extends to sacral spinal nerves originating within the upper lumbar region.

Anatomically there are 31 pairs medulla spinalis nerve segments during a human spinal cord:

1] 8 cervical segments forming 8 pairs of CERVICAL NERVES (C1 spinal nerves exit the vertebral column between the foramen and therefore the C1 vertebra; C2 nerves exit in between the posterior part of the C1 vertebra and the lamina of C2; C3–C8 spinal nerves undergo the IVF above their corresponding cervical vertebrae, with the exception of the C8 pair which exit between the C7 and T1 vertebrae)

2] Twelve thoracic segments forming 12 pairs of THORACIC NERVES

3] Fifth lumbar segments forming 5 pairs of LUMBER NERVES

4] 5 sacral segments forming 5 pairs of SACRAL NERVES

5] 1 coccygeal segment



DEVELOPMENT OF THE medulla spinalis

Medulla spinalis is developed from a part of ectoderm during gestational period.

Cavity of ectoderm within the region of the medulla spinalis becomes narrowed down of a dorsiventral slit by the expansion of its lateral walls. At the 5th week of development a longitudinal groove termed as sulcus limitans appears on the inner surface of the lateral wall. There are four stages of the medulla spinalis that arises from the ectoderm.

Beural tube begins to develop, the notochord begins to secrete an element referred to as sonic hedgehog and as a result the ground plate then also begins to secrete, this probably induce the basal plate to develop motor neurons, During maturation of the ectoderm , its lateral walls thicken and form a longitudinal groove called sulcus limitans. The overlying ectoderm secretes bone morphogenetic protein. It induces the roof plate to start to secrete morphogenetic protein which can induce the alar plate to develop sensory neurons. Alar plate and the basal plate are separated by the sulcus limitans, the ground plate also secretes netrins. Plexus choroideus tissue and therefore the central canal of the caudal medulla spinalis is crammed with spinal fluid . Now massive efferent tracts grow down from the brain into the lateral and anterior parts of the medulla spinalis , intervening between the surface and therefore the derivatives of the alar and basal laminae. Further thickening of those areas is produced by the passage into them of important ascending tracts, whose constituent fibers arise from the cells derived from the alar laminae.


BLOOD SUPPLY OF medulla spinalis

Anatomically medulla spinalis is supplied by anterior spinal artery and therefore the right and left posterior spinal arteries.



INVESTIGATION

  • For the disease of medulla spinalis these investigations are remarkable
  • CSF fluid aspiration
  • CT Scan of medulla spinalis
  • MRI of medulla spinalis



HOMEOPATHIC MEDICINES ON medulla spinalis DISEASE

ACTEA RECIMOSA 30,200 as per patient's condition for older patient

CAUSTICUM 200 trauma and deviation

GELSEMIUM 200 any deviation

HYPERICUM 200 for injury

KALI PHOS 6X for injury

THUJA OCC 30 for tumour on medulla spinalis


NB: this text is for student and physician..

 

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