The spinal nerves are the body’s major nerves within the peripheral nervous system (PNS). They link the spinal cord to the rest of the body, allowing messages to travel back and forth.

These nerves carry three types of signals: motor (movement), sensory (feeling), and autonomic (involuntary processes).

There are 31 pairs of spinal nerves, grouped by their location in the spine:

8 pairs of cervical nerves (C1-C8).

12 pairs of thoracic nerves (T1-T12).

5 pairs of lumbar nerves (L1-L5).

5 pairs of sacral nerves (S1-S5).

1 pair of coccygeal nerves (CO1).

Each pair connects to a specific section of the body, helping to control and sense that area.

spinal column — Spinal nerves are peripheral nerves that emerge from the spinal cord and carry motor, sensory, and autonomic signals between the spinal cord and the rest of the body. There are 31 pairs of spinal nerves: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal, named according to their corresponding vertebral levels.

How Spinal Nerves Work

Spinal nerves emerge from the spinal cord and split off to reach every corner of your body. They act like highways, carrying information to and from your brain.

Think of your spinal nerves like a two-way street:

On one side, sensory nerves are like delivery drivers bringing information (such as pain, touch, or temperature) from your skin and organs to your brain.
On the other side, motor nerves are like outgoing trucks carrying instructions from your brain to your muscles, telling them how to move.

Anatomy of Spinal Nerves

Each spinal nerve is formed from two roots:

The dorsal root brings sensory information into the spinal cord.
The ventral root sends motor commands out to the body.

These roots join together near the spine to form a spinal nerve. Some groups of nerves merge to form a large plexus of nerves, whereas some divide into smaller branches without forming a plexus.

Spinal nerves exit the spine through small openings between vertebrae called intervertebral foramina.

Key terms

💡 Dorsal Root: The back part of the spinal nerve where sensory information enters the spinal cord.

💡 Ventral Root: The front part of the spinal nerve where motor commands leave the spinal cord and travel to muscles.

💡 Plexus: A bundle of nerves that branch out and control specific body areas—like an electrical junction box that sends power to different rooms.

💡 Intervertebral Foramen: A small opening between two spine bones where nerves exit the spinal cord and travel to the body.

Function: Sensory and Motor Roles

Spinal nerves are mixed nerves, meaning they perform both sensory and motor functions:

Sensory: They carry signals from the skin, muscles, and organs to the spinal cord.
Motor: They deliver commands from the spinal cord to muscles, causing movement.

These signals allow you to do everything from lifting your arm to sensing heat or pain.

Spinal Nerve Groups

Cervical Nerves (C1–C8)

Located at the top of the spine, these nerves control the neck, shoulders, arms, and diaphragm:

C1–C3: Head and neck movement
C4: Upper shoulders and diaphragm (breathing)
C5: Deltoid and biceps (upper arms)
C6: Wrist extension and partial biceps
C7: Triceps and wrist extension
C8: Hand and finger flexion (grip)

C1–C5 form the cervical plexus, while C5–T1 contribute to the brachial plexus, which controls the arms and upper back.

Thoracic Nerves (T1–T12)

These nerves branch into the chest and abdominal muscles:

T1–T2: Upper chest, arms, and hands
T3–T5: Chest wall and breathing
T6–T8: Chest to abdomen
T9–T12: Abdomen and lower back

Lumbar Nerves (L1–L5)

Located in the lower back, these nerves control the legs and lower body:

L1: Groin and genitals
L2–L4: Front thighs, hips, knees
L5: Outer lower legs and feet

L1–L4 form the lumbar plexus, which supports movement and sensation in the abdomen and legs.

Sacral Nerves (S1–S5)

These nerves manage the pelvis and back of the legs:

S1: Hips and groin
S2: Back of thighs
S3: Buttocks
S4–S5: Perineal area (genital and pelvic floor)

L4–S4 combine to form the sacral plexus, which includes the sciatic nerve (the body’s largest nerve).

Coccygeal Nerve (CO1)

This single nerve affects sensation around the tailbone and coccyx region.

Spinal Nerve Damage

Damage to spinal nerves can disrupt communication between the brain and body.

Imagine your spinal nerves as the electrical wiring in your house:

When everything is working, signals flow smoothly—lights turn on, appliances run, and everything functions as expected. But if the wires are pinched, frayed, or broken, the signals get disrupted.

In your body, this shows up as pain, tingling, weakness, or numbness when spinal nerves are damaged.

Symptoms of Spinal Nerve Damage

Pain (mild to severe)
Numbness or tingling in limbs
Muscle weakness
Loss of reflexes
Back or neck problems

💡 Reflexes: Automatic, rapid responses to certain stimuli—like when your knee jerks after being tapped.

Common Conditions That Affect Spinal Nerves

Compressive Neuropathy

Occurs when spinal nerves are compressed or pinched. This can be temporary or permanent, and often causes sharp pain or numbness.

Herniated Disc

Also called a “slipped disc,” this happens when a disc between vertebrae bulges out and presses on a nerve. It often causes pain, numbness, or weakness.

Trauma

Injuries like falls or accidents can stretch, bruise, or tear spinal nerves. Neck injuries may affect the cervical plexus, while lower back injuries can impact the lumbar plexus.