Medulla Spinal Anatomy and Functions

Medulla Spinal

• Definition: The medulla spinal, or spinal cord, is a cylindrical structure that extends from the base of the brain to the lower back, encased within the vertebral column.

• Structure:

  • Composed of gray matter (nerve cell bodies) and white matter (myelinated axons).
  • Divided into segments corresponding to the vertebral levels: cervical, thoracic, lumbar, sacral, and coccygeal.
  • Each segment gives rise to a pair of spinal nerves.

• Functions:

  • Conduction Pathway: Transmits signals between the brain and the peripheral nervous system.
  • Reflexes: Mediates reflex actions independently of the brain (spinal reflexes).

• Gray Matter:

  • Arranged in an H or butterfly shape.
  • Contains dorsal (sensory) and ventral (motor) horns.

• White Matter:

  • Organized into tracts: ascending (sensory) and descending (motor) pathways.
  • Major tracts include the corticospinal, spinothalamic, and dorsal columns.

• Protection:

  • Surrounded by three layers of membranes called meninges (dura mater, arachnoid mater, pia mater).
  • Cerebrospinal fluid (CSF) circulates in the subarachnoid space for cushioning.

• Clinical Relevance:

  • Injuries: Can lead to loss of sensation, motor function, or reflexes below the injury site.
  • Diseases: Conditions like multiple sclerosis or amyotrophic lateral sclerosis (ALS) affect spinal cord function.

• Development:

  • Forms during embryonic development from the neural tube.
  • Continues to grow, but typically stops elongating around the age of 4.

• Blood Supply:

  • Supplied by anterior and posterior spinal arteries, with additional contributions from segmental arteries.

• Associated Disorders:

  • Spinal stenosis, herniated discs, and spinal cord tumors can impact function and lead to neurological symptoms.

These notes summarize the key concepts related to the medulla spinal, facilitating understanding of its structure, function, and clinical significance.

Definition and Structure

• Medulla spinal, also known as the spinal cord, extends from the brain base to the lower back and is protected by the vertebral column.
• Consists of gray matter (nerve cell bodies) and white matter (myelinated axons).
• Divided into five segments corresponding to vertebral levels: cervical, thoracic, lumbar, sacral, and coccygeal.
• Each segment produces a pair of spinal nerves.

Functions

• Conduction Pathway: Facilitates communication between the brain and peripheral nervous system.
• Reflex Actions: Capable of mediating reflexes without brain involvement, known as spinal reflexes.

Gray Matter

• Organized in an H or butterfly shape, contains:
  • Dorsal horns responsible for sensory information.
  • Ventral horns involved in motor function.

White Matter

• Structured into tracts that serve specific functions:
  • Ascending Tracts: Carry sensory information to the brain.
  • Descending Tracts: Transmit motor commands from the brain.
• Major tracts include the corticospinal, spinothalamic, and dorsal columns.

Protection

• Surrounded by three protective membranes (meninges):
  • Dura mater, arachnoid mater, and pia mater.
• Cerebrospinal fluid (CSF) flows in the subarachnoid space, acting as a cushion for the spinal cord.

Clinical Relevance

• Injuries: Can result in loss of sensation, motor function, or reflexes beneath the injury site.
• Diseases: Conditions such as multiple sclerosis and amyotrophic lateral sclerosis (ALS) significantly impact spinal cord function and health.

Development

• Develops embryonically from the neural tube.
• Growth typically ceases around age four, although the structure continues to mature.

Blood Supply

• Receives blood from anterior and posterior spinal arteries, with contributions from segmental arteries.

Associated Disorders

• Disorders like spinal stenosis, herniated discs, and spinal cord tumors can disrupt normal function and lead to neurological symptoms.

Explore the structure and functions of the medulla spinal, or spinal cord, in this quiz. Understand its composition of gray and white matter, the segments corresponding to vertebral levels, and its role in conduction pathways and reflexes. Test your knowledge on spinal nerves and major tracts.