Spinal Lab

Spinal Cord The Spinal Cord

Extends from C1 to L2; carries nerve signals between the brain and body.

Conus Medullaris The Spinal Cord

Cone-shaped end of the spinal cord.

Cauda Equina The Spinal Cord

Bundle of spinal nerves that fan out below the conus medullaris.

Filum Terminale The Spinal Cord

Fibrous strand that anchors the spinal cord to the coccyx.

Vertebrae Spinal Cord Coverings

Bones that protect the spinal cord.

Epidural Fat Spinal Cord Coverings

Fat located between the vertebrae and dura mater.

Meninges Spinal Cord Coverings

Three protective membranes surrounding the brain and spinal cord.

Dura Mater Meninges Spinal Cord Coverings

Outermost, tough fibrous meningeal layer.

Arachnoid Mater Meninges Spinal Cord Coverings

Middle, web-like meningeal layer.

Subarachnoid Space Meninges Spinal Cord Coverings

Space containing cerebrospinal fluid (CSF).

Pia Mater Meninges Spinal Cord Coverings

Thin inner meningeal layer that directly covers the spinal cord.

Gray Matter Spinal Cord Cross-section

Inner H-shaped region containing neuron cell bodies.

Dorsal Horn Gray Matter Spinal Cord Cross-section

Posterior gray horn that receives sensory information.

Ventral Horn Gray Matter Spinal Cord Cross-section

Anterior gray horn containing motor neurons.

Lateral Horn Gray Matter Spinal Cord Cross-section

Side gray horn containing autonomic neurons.

White Matter

Outer region containing myelinated axons.

Posterior Funiculus White Matter

Posterior white column.

Anterior Funiculus White Matter

Anterior white column.

Lateral Funiculus White Matter

Lateral white column.

Central Canal Grooves and Spaces

Small canal containing cerebrospinal fluid (CSF).

Posterior Median Sulcus Grooves and Spaces

Shallow groove on the posterior spinal cord.

Anterior Median Fissure Grooves and Spaces

Deep groove on the anterior spinal cord.

Spinal Nerve Spinal Nerve and Roots

Mixed nerve containing both sensory and motor fibers.

Dorsal Sensory Root Spinal Nerve and Roots

Root carrying sensory impulses into the spinal cord.

Dorsal Root Ganglion Spinal Nerve and Roots

Cluster of sensory neuron cell bodies.

Ventral Motor Root Spinal Nerve and Roots

Root carrying motor impulses out of the spinal cord.

Axon Nerve

Nerve fiber that carries impulses away from the neuron.

Myelin Nerve

Fatty covering that speeds nerve impulse conduction. Wraps around myelin.

Endoneurium Nerve

Connective tissue surrounding a single axon.

Fascicle Nerve

Bundle of axons.

Perineurium Nerve

Connective tissue surrounding a fascicle.

Nerve Nerve

Bundle of fascicles.

Epineurium Nerve

Connective tissue surrounding an entire nerve.

Spinal Nerves

31 pairs of spinal nerves.

Cervical Spinal Nerves

8 pairs (C1-C8).

Thoracic Spinal Nerves

12 pairs (T1-T12).

Lumbar Spinal Nerves

5 pairs (L1-L5).

Sacral Spinal Nerves

5 pairs (S1-S5).

Coccygeal Nerve Spinal Nerves

1 pair (Co1).

Dorsal Ramus Rami

Branch supplying the back.

Ventral Ramus Rami

Branch supplying the front and limbs.

Rami

Two splits after spinal nerve leaves vertebrae

Plexuses

Branching of nerves after rami) (flat man)

Cervical Plexus

Nerve network from C1-C4.

a. Branching nerves in neck off of C1 - C4

b. Includes Phrenic nerve to diaphragm muscle

Phrenic Nerve

Branch of the cervical plexus that controls the diaphragm.

Brachial Plexus

Nerve network from C5-T1 supplying the arm.

a. Branching nerves to arm off of C5 - T1

Thoracic Region Plexuses

No plexus; contains mainly intercostal nerves.

a. Mainly intercostal nerves come off spinal nerves T2 - T12

Intercostal Nerves

Nerves between the ribs from T2-T12. Thoracic area (no plexus)

Lumbar Plexuses

Nerve network from L1-L5 supplying the abdomen and leg.

a. Branching nerves to abdomen and leg off of L1 - L5

Sacral Plexus

Nerve network from S1-S5 supplying the buttocks, hips, and leg.

a. Branching nerves to buttocks, hips, and leg off of S1 - S5

b. Includes Sciatic nerve down entire leg to foot = longest nerve in body

Sciatic Nerve

Longest nerve in the body; travels from the sacral plexus down the leg to the foot. Sacral Plexus

Spinal Reflex Arc

Pathway of a spinal reflex.

Sensory Receptor Spinal Reflex Arc

Detects a stimulus and starts the nerve impulse. Starts nerve message

Sensory Afferent Neuron Spinal Reflex Arc

Carries sensory information into the spinal cord from the sense

Interneuron Spinal Reflex Arc

Neuron within the spinal cord that processes information.

Motor Efferent Neuron Spinal Reflex Arc

Carries motor impulses from the spinal cord to a muscle.

Effector Muscle Spinal Reflex Arc

Muscle that performs the response.

Patellar Tendon Reflex Testing Reflexes

Knee-jerk reflex testing L2-L4 spinal nerves.

Achilles Tendon Reflex Testing Reflexes

Ankle-jerk reflex testing S1-S2 spinal nerves.

Babinski Reflex Testing Reflexes

Reflex testing the plantar response of the foot.