Chapter 14: Spinal Cord & Spinal Nerves

Name One Function of the “Spinal Cord” INVOLVED THROUGH the “Spinal Nerves”.

Through “Spinal Nerves”: involved in sensory and motor INNERVATION of the ENTIRE body & head.

Name One Function of the “Spinal Cord” describing what it PROVIDES.

Provides a two-way conduction pathway FOR signals BETWEEN the body & brain.

Name One Function of the “Spinal Cord” describing what it ACT AS.

Acts as a MAJOR CENTER for reflexes.

Where does the “Spinal Cord” BEGINS?

At the “Foramen Magnum of the Skull” and EXTENDS to “Vertebra L1” or “Vertebra L2”.

In par of the “Spinal Cord”, DEFINE “Conus Medullaris”.

The TAPERED END of the “Spinal Cord”

In par of the “Spinal Cord”, what does the “Conus Medullaris” CONTINUE AS?

The “Filum Terminale”.

In par of the “Spinal Cord”, DEFINE “Filum Terminale”.

A LONG FILAMENT from the TAPERED ENDS of the “Conus Medullaris”.

In par of the “Spinal Cord”, following the “Filum Terminale”, it then BECOMES AS what?

The “Coccygeal Ligament”.

In par of the “Spinal Cord”, the “Coccygeal Ligament”, ATTACHES TO what?

The “Coccyx”.

How is the “Spinal Cord” ANCHORED?

The “Conus Medullaris” CONTINUES AS the “Filum Terminale” (which BECOMES the “Coccygeal ligament”) and ATTACHES TO the “Coccyx”, anchoring the “Spinal Cord” in place.

The “Spinal Cord” is anchored to PREVENT what?

UPWARD movement.

In par of the “Spinal Cord”, DEFINE “Cauda Equina”.

A COLLECTION of “Nerve Roots” at the “Inferior End of the Vertebral Column”.

In par of the “Spinal Cord”, which NERVE ROOTS of “Cauda Equina” must do BEFORE?

The “Lumbar Nerve Root” & “Sacral Nerve Root” MUST DESCEND before REACHING their corresponding “Intervertebral” or “Sacral Foramina”.

In par of the “Spinal Cord”, what CONTAINS the “Cervical” & “Lumbar Enlargements”?

These areas contain MORE nerves for limb INNERVATION.

In par of the “Spinal Cord”, what CONTAINS the “Posterior Median Sulcus” & “Anterior Median Fissure”?

Longitudinal grooves on the “Spinal Cord” SURFACE.

In par of the “Spinal Cord”, identify the 3 Functions of “Meninges”.

1. Protection

2. PHYSICAL Stability

3. Shock ABSORPTION

In par of the “Spinal Cord”, DEFINE the“Denticulate Ligament” of the “Meninges”.

EXTENSIONS of the “Pia Mater” that CONNECT IT to the “Spinal Arachnoid Mater”.

In par of the “Spinal Cord”, the “Denticulate Ligament” of the “Meninges” PREVENTS what?

Side-to-side movement of the “Spinal Cord”.

In par of the “Spinal Cord”, the “Epidural Space” of the “Meninges” CONTAINS 2 of what?

Adipose tissue and blood vessels.

In par of the “Spinal Cord”, the “Epidural Space” of the “Meninges” is a DELIVERS what?

Anesthetics.

In par of the “Spinal Cord” & “Meninges”, a “Spinal Tap” (Lumbar Puncture) is inserted into WHERE to OBTAIN what?

A needle INSERTED INTO the “Subarachnoid Space” to OBTAIN “Cerebrospinal Fluid”.

In par of the “Spinal Cord” & “Meninges”, an “Epidural” is injected into WHERE.

The anesthetic is INJECTED INTO the “Epidural Space” (ABOVE the “Dura Mater”).

In par of the “Spinal Cord” & “Meninges”, WHY is the “Epidural” injected into the “Epidural Space”?

It is where fat and blood vessels help ABSORB the medication.

In par of the “Spinal Cord” & “Meninges”, if NOT IN the “Cranium”, where does the “Epidural” ONLY EXISTS?

Only ALONG the “Spinal Column”.

In par of the “Spinal Cord”, the “Gray Matter” is a (4) COMPOSED of what?

1. Neuron Cell Bodies

2. Short Unmyelinated Axons

3. Dendrites

4. Neuroglia

In par of the “Spinal Cord”, the “Gray Matter” is SHAPED-LIKE what?

The letter H.

In par of the “Spinal Cord”, name the 8 Features of “Gray Matter”.

1. Gray Commissure

2. Central Canal

3. (2) dorsal Horns

4. (2) Ventral Horns

5. (2) Small Lateral Horns

In par of the “Spinal Cord”, the 2 “Small Lateral Horns” of the “Gray Matter” is (2) ONLY PRESENT in the what?

“Thoracic” & “Lumbar” regions.

In par of the “Spinal Cord”, the 2 “Small Lateral Horns” of the “Gray Matter” CONTAINS what?

Autonomic (sympathetic) neurons.

In par of the “Spinal Cord”, the “White Matter” (2) CONTAINS what?

Myelinated and Unmyelinated axons.

In par of the “Spinal Cord”, name the 3 Organized Columns of “White Matter”.

1. Ventral Column

2. Lateral Column

3. Dorsal Column

In par of the “Spinal Cord”, what is FOUND in the 3 Organzied Columns of “White Matter”?

Tracts.

In par of the “Spinal Cord”, the “Tracts” ORGANZIE what in the “White Matter”?

“Tracts” within the 3 Organzied Columns ORGANIZE SIMILAR types of axons FROM specific parts of the body.

notes

Draw a cross section of a spinal cord & how messages are transmitted:

How can you tell ventral or dorsal sides of spinal cord?
1)
2)
3)

In par of the “Nervous Conduction” of the “Spinal Cord”, NAME the 3 “Fiber” Types.

1. Ascending Fibers

2. Descending Fibers

3. Commissural Fibers

In par of the “Nervous Conduction” of the “Spinal Cord”, DEFINE the “Ascending Fibers”.

CARRIES sensory information to the brain.

In par of the “Nervous Conduction” of the “Spinal Cord”, DEFINE the “Descending Fibers”.

MOTOR from brain to spinal cord, TARGETING muscles or glands.

In par of the“Nervous Conduction” of the “Spinal Cord”, DEFINE the “Commissural Fibers”.

CARRY signals across “Spinal Cord”.

In par of the“Nervous Conduction” of the “Spinal Cord”, NAME the 3 “Column” Types.

1. Dorsal Column

2. Ventral Column

3. Lateral Columns

In par of the “Nervous Conduction” of the “Spinal Cord”, is there a DIVISION between the 3 “Column” Types?

NO obvious division between them; they are CONTINUOUS with each other.

In par of the “Nervous Conduction” of the “Spinal Cord”, what is in EACH 3 “Column” Types?

INDIVIDUAL (sensory or motor) tracts.

In par of the “Nervous Conduction” of the “Spinal Cord”, ALL NEURONS in the same “Tract” within the “Columns” (4) HAVE what?

The SAME myelination, speed, diameter & relay information in the SAME DIRECTION.

In par of the “Nervous Conduction” of the “Spinal Cord”, name an EXAMPLE of “Tracts” within the “Columns”.

The “Lateral Spinothalamic Tract” which CARRIES pain and temperature sensory information to brain.

In par of the “Nervous Conduction” of the “Spinal Cord”, the “Dorsal Root” CONTAINS ONLY what?

ONLY sensory nerve fibers.

In par of the “Nervous Conduction” of the “Spinal Cord” and the “Dorsal Root” where do IMPULSES ENTER?

Impulses enter the “Dorsal Root”.

In par of the “Nervous Conduction” of the “Spinal Cord” and the “Dorsal Root” where do ONLY INTERNEURONS EXTEND to?

Interneurons ONLY extend to the “Gray Dorsal Horn”.

In par of the “Nervous Conduction” of the “Spinal Cord”, each the “Dorsal Root” HAS what?

SWELLING—called the “Dorsal Root Ganglion”.

In par of the “Nervous Conduction” of the “Spinal Cord”, what is LOCATED in the “Dorsal Root Ganglion”?

Cell Bodies of Sensory Neurons.

In par of the “Nervous Conduction” of the “Spinal Cord”, the “Ventral Root” CONTAINS ONLY what?

Motor neurons.

In par of the “Nervous Conduction” of the “Spinal Cord”, the “Ventral Root” impulses LEAVES the what?

Anterior root.

In par of the “Nervous Conduction” of the “Spinal Cord”, the “Ventral Root” implulses SUPPLIES the what?

Skeletal muscle.

In par of the “Nervous Conduction” of the “Spinal Cord”, WHERE are the cell bodies of the “Ventral Root”?

Gray matter.

In par of the “Nervous Conduction” of the “Spinal Cord”, because the cell bodies of the “Ventral Root” are in the gray matter, WHERE is the ganglion?

The ganglion is NOT PRESENT with the cell bodies in the gray matter.

In par of the “Spinal Cord” IDENTIFY the 2 “Reflex Arcs”.

1. Monosynaptic Arc

2. Polysynaptic Reflex Arcs

In par of the “Spinal Cord” DEFINE the “Monosynaptic Arc”.

FASTEST arc.

In par of the “Spinal Cord”, DESCRIBE how the sensory neurons WORK WITH the“Monosynaptic Arc”.

Sensory neurons WITH receptor SENSE stimulus & bring message to spinal cord.

In par of the “Spinal Cord”, who does the sensory neurons of the “Monosynaptic Arc” SYNAPSE WITH and WHY?

Motor neurons that SEND a message to an effector.

In par of the “Spinal Cord”, what is an action EXAMPLE of the “Monosynaptic Arc”?

Knee jerk.

In par of the “Spinal Cord” DEFINE the “Polysynaptic Reflex Arc”.

SLOWER arch.

In par of the “Spinal Cord” WHO and HOW does the “Polysynaptic Reflex Arc” DETECT?

Sensory neuron WITH receptors DETECTS the stimulus.

In par of the “Spinal Cord” WHERE does the signal of the “Polysynaptic Reflex Arc” PASSES TO?

The interneurons in the spinal cord—this is called, “Integration”.

In par of the “Spinal Cord” HOW MANY interneurons of the “Polysynaptic Reflex Arc” OCCUR in integration?

From one to hundreds of interneurons.

In par of the “Spinal Cord” what does the motor neuron of the “Polysynaptic Reflex Arc” SENDS?

A RESPONSE to the effector (muscle or gland).

In par of the “Spinal Cord” what is an action EXAMPLE of the motor neuron of the “Polysynaptic Reflex Arc”?

Pull foot away from pain, but also ACTIVATES other muscles so you DON’T FALL.

The “Spinal Nerves” CONTAINS which 2 Structures?

1. Nerve Plexus

2. Dermatomes

The “Spinal Nerve” CONTAINS what?

MIXED of both motor fibers and sensory fibers.

As the “Spinal Nerve” APPORACHES the Spinal Cord, what happens?

Both the motor fibers & sensory fibers SEPARATE, forming “roots”: the “Ventral Root” and the “Dorsal Root”.

In par of the “Spinal Nerve” what ONLY CONTAINS the“Ventral Root”?

ONLY motor fibers.

In par of the “Spinal Nerve” what ONLY CONTAINS the“Dorsal Root”?

ONLY sensory fibers.

How is the “Spinal Nerve” (3) ARRANGED?

1. Endoneurium

2. Perineurium

3. Epineurium

In par of the “Spinal Nerve” what does the“Endoneurium” COVERS?

Nerve fiber (axon).

In par of the “Spinal Nerve” what does the“Perineurium” ARRANGES?

Nerve fibers INTO fascicles.

In par of the “Spinal Nerve” what does the“Epineurium” COVERS?

The ENTIRE peripheral nerve.

In par of the “Spinal Nerve” DEFINE the“Drosal Ramus” and “Ventral Ramus”.

The BRANCHING of the spinal nerve.

In par of the “Spinal Nerve” what does the“Drosal Ramus” and “Ventral Ramus” DELIEVERS to?

Delivers both sensory & motor fibers TO the dorsal compartments AND ventral compartments of the body.

In par of the “Spinal Nerve” what does the“Ramus Communicans” LEADS to?

The sympathetic trunk ganglia.

In par of the “Spinal Nerve” what does the“Ramus Communicans” ALLOWS what to DO?

Allows sympathetic fibers (Autonomic Nervous System) to TRAVEL TO the sympathetic ganglion.

How MANY PAIRS of “Spinal Nerves” are in the body?

31 pairs.

The 31 Pairs of “Spinal Nerves” are all ATTACHED TO what?

The spinal cord.

Each “Spinal Nerves” CONTAINS how many “Nerve Fibers”?

THOSUANDS of nerve fibers.

In par of the “Spinal Nerves” the “Cervical Nerves” CONTAINS how many PAIRS?

8 PAIRS of cervical nerves.

In par of the “Spinal Nerves” how are the “Cervical Nerves” PLACED?

1. One nerve is ABOVE C1

2. One nerve is BELOW C7

3. Six nerves IN-BETWEEN.

In par of the “Spinal Nerves” the “Thoracic Nerves” CONTAINS how many PAIRS?

12 PAIRS of thoracic nerves.

In par of the “Spinal Nerves” the “Lumbar Nerves” CONTAINS how many PAIRS?

5 PAIRS of lumbar nerves.

In par of the “Spinal Nerves” the “Sacral Nerves” CONTAINS how many PAIRS?

5 PAIRS of sacral nerves.

In par of the “Spinal Nerves” the “Coccygral Nerve” CONTAINS how many PAIRS?

1 PAIR of coccygeal nerve.

How does the “Spinal Nerves” LEAVES the vertebrae?

Via intervertebral foramen AND sacral foramen.

In par of the “Spinal Nerves” DEFINE the“Nerve Plexus”.

A “braid” of a network of nerves.

In par of the “Spinal Nerves” and the“Nerve Plexus”, the “Ventral Rami” is ALL spinal nerves—EXCEPT what?

T2–T12.

In par of the “Spinal Nerves” and the“Nerve Plexus”, where does the “Ventral Rami” BRANCH and JOINS to?

The ventral rami branch & join EACH OTHER lateral to the vertebral column.

In par of the “Spinal Nerves” and the“Nerve Plexus”, the “Ventral Rami” branch and joins to CONTAIN what?

So each branch of the plexus CONTAINS fibers from several different spinal nerves.

In par of the “Spinal Nerves” and the“Nerve Plexus”, the “Ventral Rami” branch and joins beacuse the TRAVEL is what?

Fibers from each spinal nerve travel to the body's limbs in several DIFFERENT ways.

In par of the “Spinal Nerves” and the“Nerve Plexus”, what HAPPENS when one spinal nerve is DAMAGED?

Damage to ONE spinal nerve CANNOT completely paralyze a particular muscle.

Name the 5 “Nerve Plexus” of the “Spinal Nerves”.

1. Cervical Plexus

2. Brachial Plexus

3. Lumbar Plexus

4. Sacral Plexus

5. Coccygeal Nerve

In par of the “Nerve Plexus”, NAME the “Cervical Plexus” 2 Nerves.

1. Spinal Nerve

2. Phrenic Nerve

In par of the “Cervical Plexus” the “Spinal Nerves”, INERVATES what?

Spinal nerves FROM the cervical plexus innervates the head, neck, and diaphragm.

In par of the “Cervical Plexus” the “Spinal Nerves” PROVIDES SENSATION to (5) who?

1. Neck

2. Ear

3. Cheek

4. Shoulder

5. Clavicular Region

In par of the “Cervical Plexus” the “Spinal Nerves” PROVIDES what TYPE OF INNERVATION to who?

Provides motor innervation to neck muscles.

In par of the “Cervical Plexus” the “Spinal Nerves” PROVIDES motor innervation to (4) what neck muscles?

1. Infrahyoid Muscles

2. Scalenes

3. Trapezius

4. Levator Scapulae

In par of the “Cervical Plexus” the “Phrenic Nerves” CONTAINS which fibers?

Fibers from C3–C5.