Regions of the Spinal Cord to Know for Honors Anatomy and Physiology

The spinal cord is divided into distinct regions, each with unique functions and structures. Understanding these regions—cervical, thoracic, lumbar, sacral, and coccygeal—helps us grasp how they support movement, sensation, and overall body function in anatomy and physiology.

1. Cervical region

   • Comprises the first seven vertebrae (C1-C7) in the neck.
   • Responsible for supporting the head and facilitating neck movement.
   • Contains nerves that control upper limb function and diaphragm (breathing).
   • Includes the cervical enlargement, which supplies nerves to the arms.

2. Thoracic region

   • Consists of twelve vertebrae (T1-T12) located in the upper and mid-back.
   • Provides attachment points for the ribs, contributing to the thoracic cage.
   • Contains nerves that innervate the trunk and abdominal muscles.
   • Plays a role in maintaining posture and stability of the upper body.

3. Lumbar region

   • Made up of five vertebrae (L1-L5) in the lower back.
   • Supports the weight of the upper body and allows for flexibility and movement.
   • Contains the lumbar enlargement, which supplies nerves to the lower limbs.
   • Important for activities such as lifting and bending.

4. Sacral region

   • Comprises five fused vertebrae (S1-S5) forming the sacrum.
   • Connects the spine to the pelvis and supports pelvic organs.
   • Contains nerves that innervate the lower limbs and pelvic region.
   • Plays a key role in walking and maintaining balance.

5. Coccygeal region

   • Consists of four fused vertebrae forming the coccyx (tailbone).
   • Serves as an attachment site for ligaments and muscles of the pelvic floor.
   • Provides support when sitting and contributes to pelvic stability.
   • Represents the vestigial remnant of a tail in human evolution.

6. Gray matter

   • Composed of neuronal cell bodies, dendrites, and unmyelinated axons.
   • Located centrally in the spinal cord, forming an "H" or butterfly shape.
   • Responsible for processing and integrating sensory and motor information.
   • Divided into dorsal (sensory) and ventral (motor) horns.

7. White matter

   • Composed of myelinated axons that form ascending and descending tracts.
   • Surrounds the gray matter in the spinal cord, facilitating communication.
   • Contains pathways for sensory information to travel to the brain and motor commands to travel to the body.
   • Organized into columns (funiculi) that carry specific types of information.

8. Central canal

   • A small, fluid-filled channel running through the center of the spinal cord.
   • Contains cerebrospinal fluid (CSF), which cushions and nourishes the spinal cord.
   • Plays a role in the circulation of CSF within the central nervous system.
   • May be involved in the development of certain neurological conditions if obstructed.

9. Dorsal horn

   • The posterior part of the gray matter in the spinal cord.
   • Primarily involved in processing sensory information from the body.
   • Contains interneurons that relay signals to the brain and motor neurons.
   • Plays a critical role in reflex actions and pain perception.

10. Ventral horn

    • The anterior part of the gray matter in the spinal cord.
    • Contains motor neurons that send signals to skeletal muscles.
    • Responsible for voluntary and reflexive movements.
    • Plays a key role in motor control and coordination.