Topography and morphology of the spinal cord
On completion of this study unit you will be able to:
- Describe the location and anatomical relations of the spinal cord.
- Identify the parts and enlargements of the spinal cord.
- Name the sulci and landmarks along the surfaces of the spinal cord.
- Describe the meninges which surround the spinal cord.
The spinal cord is a component of the central nervous system (CNS) that arises as a continuation of the medulla oblongata of the brainstem. It is a cylindrical structure enclosed within the vertebral canal, occupying 2/3 of the vertebral column length.
The spinal cord extends from the foramen magnum to the L1/L2 vertebra, where it terminates as the medullary cone. A thin thread, formed as an extension of the meninges, the filum terminale, extends from the tip of the medullary cone all the way to the 1st coccygeal vertebra (Co1) and functions to anchor the spinal cord in place.
The spinal cord, similar to the brain, is invested in three meningeal coverings. From superficial to deep, these are the dura mater, arachnoid mater, and pia mater. Separating the dura mater from the periosteum of the vertebral canal is the fat-filled epidural space. Between the arachnoid and pia mater is the subarachnoid space, filled with cerebrospinal fluid. The subarachnoid space caudal to the medullary cone is known as the lumbar cistern. Due to the absence of spinal cord in this region, the cerebrospinal fluid filled lumbar cistern is the site for lumbar puncture.
The spinal cord functions as a conduit for information between the brain and the periphery. It also serves to generate reflexes which ensure the smooth running of daily activities.
Watch the video below to find out more about the external morphology of the spinal cord.
Explore the topography of the spinal cord from a superior view with the video below.
Take a quiz
Put your knowledge on the gross anatomy of the spinal cord to the test with the quiz below.
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Take a closer look at the external morphology of the spinal cord using the atlas galleries below.
|Location||Within the vertebral canal of the vertebral column
Beginning: Medulla oblongata of brainstem at foramen magnum
Termination: Medullary cone at vertebral level L1/L2
|Parts||Cervical, thoracic, lumbar, sacral, coccygeal
Cervical enlargement → supplies upper limbs
Lumbosacral enlargement → supplies lower limbs
Anterolateral → Anterior median fissure, anterolateral sulcus
Posterolateral → Posterior median sulcus, posterior intermediate sulcus (cervical and upper thoracic levels), posterolateral sulcus
|Meninges||Superficial to deep: Dura mater, arachnoid mater, pia mater|
|Function||Conducts impulses from the brain to the body and generates reflexes|
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