Card Set Information
Foramen Magnum L1 – L2
-Spinal Cord growth stops at 4years old
-Vertebral column grows until full height reached
- About 18 inches long
-End of cord = conus medullaris
1.Cauda Equina (“horse’s tail”)
-Spinal nerves are pulled with growing vertebrae.
-Exit sacral foramina.
2. Filum Terminale
tethers conusmedullaris to the sacral vertebrae, via coccygealligament.a.
-Prevents superior movement.
3. Laterally, denticulate ligament
-Composed of Pia Mater attached to Arachnoid
-Prevents lateral movement
1. Done between L3 & L4, or L4 & L5.
2. Reduce chance of spinal cord injury because it is BELOW tip of cord.
3. Sample of CSF taken from Sub-arachnoid space
1. Catheter inserted intoepidural space.
2. Left in place with continuous infused analgesic.
3. Long-term pain relief
carries SENSORY impulses up towards brain,
and MOTOR impulses down from the brain (TRACTS).
Can act as an integration center!
1. Sensory input received
2. Signal travels down a sensory neuron
3. Info integrated by interneuron (NOT BRAIN)
4. Motor signal sent out by motor neuron
5. Motor signal travels to EFFECTOR and appropriate reaction occurs
1. Central in the spinal cord.
2. Contains Mostly cell bodies & unmyelinatedinterneurons.
3. Central Canal (CSF) surrounded by gray commissure.a. Neuron crossover site.
3. Arranged in 3 Horns
a. Posterior (Dorsal) Horn
b. Anterior (Ventral) Horn
c. Lateral Horn
Arranged in 3 Horns
a. Posterior (Dorsal) Horn
- Somatic & VisceralSensory fibers
b. Lateral Horn
- Visceral motor
c. Anterior (Ventral) Horn
- Somatic motor cell bodies
- axons of interneurons
1. Peripheral in the spinal cord.
2. Contains Myelinated & unmyelinated axon.
3. Arranged in 3 Columns (Funiculi)
a. Lateral Column
b. Anterior Column
c. Posterior Column
4. Each column contains “Tracts”:
a. Axons that share
b. Tracts may travel in 3 directions…
1. Branch from spinal cord.
2. 31 pairs.
3. Carries BOTH sensory & motor neurons
4. Formed through fusion of ventral & dorsal ROOTS.
5. Innervates (connect with) muscles, skin, and glands of neck & body
6. Nerve splits to form:
a. Dorsal Ramus
1) Innervating back!
2) T1-L2, only
b. Ventral Ramus
1) Innervating sides & front!
2) Includes all plexuses!
Lumbar vs. Sacral Plexus
• Lumbar leads anterior
• Sacral leads posterior
Nerve Plexuses (4)
a. Nerve Network.
b. All from ventral rami.
c. Thoracic nerves don’t form plexus
a. The area of the body that is monitored by a specific sensory nerve.
b. Map of Somatic Sensory Innervation.
c. Doctors use this to determine damage to nerves.
a. Detect mechanical or physical change.
b. Touch, vibration, pressure, stretch.
• detect position of body in space.
Detects heat or cold within range.
a. Detects chemical change.
b. Molecules dissolved in fluid
.c. Taste, smell, etc
Detect photons (light).
Detects tissue damage and pain.