Spinal Cord-Nervous system part 2 Flashcards
Where does the spinal cord start and end?
-Continues from the medulla oblongata (foramen magnum) to the conus medullaris (at the disc betweeen L1 and L2)
Where does the cervical enlargement start and end?
From C4-T1
Where does the lumbar enlargment start and end?
From T9-T12
What does the filum terminale arise from?
Arises from the conus medullaris
What is the function of the Filum terminale?
Anchors the spinal cord to the coccyx
True or false?
The spinal cord contans the major reflex center.
True
What are the 4 different plexuses of the spinal cord?
- Cervical plexus
- Brachial plexus
- Lumbar plexus
- Sacral plexus
What is the function of the white matter?
High speed travel
What is the function of the gray matter?
Descion making
Label 1-3
1=Spinal cord
2=Conus medullaris (tip of spinal cord)
3=CSF
True or false?
The spinal cord is completly surrounded by the vertebra?
True
What are the 3 forms of protection that the spinal cord has?
- The vertebra
- Meninges
- Intervertebral discs
What is the function of CSF?
Acts as a shock absorber
What is the function of the intervertebral discs?
Allows for compression
True or false?
The spinal meninges are continuous with the crainial menininges.
True
Where do the meninges extend to?
The level of S2
What are the three layers of the meninges from deep to superficial?
- Pia mater
- Arachnoid mater
- Dura mater
What are the three spaces between the meninges?
- Epidural space
- Subdural space
- Subarachnoid space
Where is the epidural space located?
Between the dura mater and the vertebra
Where is the subarachnoid space located?
Between the arachnoid and the pia maters
What does the subarachnoid space contain?
It contains CSF
If somone was in need of a sample test for menningitus, where would you draw the sample from? Why?
-From betweeen the spinous processees of L3/L4
-We do this so that we have no chance of hitting the spinal cord
What are the 2 types of meningitus?
- Bacterial
- Viral
Why dont we take a sample from L4/L5?
Because at that level, there is a lot more tissue
How many pairs of spinal nerves are there?
31 pairs
Where do spinal nerves exit?
The intervertebral foramina
How many spinal nerves are there in the;
1. Cervical level
2. Thoracic level
3. Lumbar level
4. Sacral level
5. Coccygeal
- C=8
- T=12
- L=5
- Sacral=5
- Coccygeal=1
True of false?
All spinal cord segments are aligned with thier respective vertebra.
False
At what vertebral level does the spinal cord end at?
L1/L2
Which spinal nerves exit to their respective vertebral foramina?
The roots of lumbar, sacral and coccygeal nerves
Which way does the root of the lumbar, sacral and coccygeal nerves descend?
On an angle
What is the cauda equina?
The spinal nerves located at the end of the spinal cord
What are the spinal nerves formed by?
2 roots from the spinal cord
1. Posterior (dorsal) root
2. Anterior (ventral) root
What system does the posterior (doral) root control?
Sensory
What system does the anterior (ventral) root control?
Motor
True or false?
All spinal nerves are mixed.
True
What does the dorsal root contain?
Contains only axons of sensory neurons
What does the dorsal root ganglion contain?
Cell bodies of sensory neurons
Label 1-5
- Spinous process of verebra
- Subarachnoid space
- Dura and arachnoid mater
- Pia mater
- Epidural space
What two fissures are located in the white matter?
- Anterior median fissure
- Posterior median fissure
Label 1-10
What are the 3 horns located in the grey matter?
- Posterior (dorsal) horn
- Lateral horn
- Anterior (ventral) horn
What is the commissure?
The cross bar of “H”
Where does the central canal extend?
The entire length of the spinal cord
What is the central canal filled with?
CSF
What does the posterior (dorsal) horn contain?
- Incoming sensory neurons
- Cell bodies and unmyelinated axons of interneurons
What does the anterior (ventral) horn contain?
- Somatic motor nuclei
- Nerve impulses for contraction of skeletal muscles
Where is the lateral horn located?
In T and L segments of the spine
What does the lateral horn contain?
- Autonomic and enteric motor nuclei
- Clusters of cell bodies of motor neurons that regulate the heart, glands, smooth muscle
How is the white matter divided?
By columns
What are the 3 columbs of the white matter?
- Posterior (dorsal) column
- Lateral column
- Anterior (ventral) column
What do each of the columns located in the white matter contain?
Tracts (bundles of axons in the CNS)
True or false?
Sensory tracts are ascending.
True
True or false?
Motor tracts are ascending.
False; descending
True or false?
The lateral and anterior columns are ascending and descending.
True
Label 1-10
What do spinal nerves branch into aftr passing through the intervertebral foramina?
They branch into rami
True or false?
The branches of the spinal nerves go directly to the area they supply.
FALSE; they do not go directly to the area that they supply; EXEPT for the intercoastal nerves T2-T12
What do branches of the spinal nerves form?
They form networks called a plexus
What are the 5 plexus’ of the body?
- Cervical
- Brachial
- Lumbar
- Sacral
- Coccygeal
Where does the cervical plexus start and end?
From C1-C5
What part of the body recieves nerves from the cervical plexus?
The head, neck, superior part of chest and shoulders
Where do the phrenic nerves arise from?
The cervical plexus at the levels of C3, C4 and C5
What is the function of the phrenic nerves?
They supply the motor neurons to the diaphragm
What are the names of the muscels affected by the cervical plexus?
- Sternocliedomastoid
- Erector spinae
- Levator scapulae
What is the brachial plexus formed by?
The anterior rami of C5-C8 and T1
What are the major nerves supplied by the brachial plexus?
- Musculocutaneuous
- Axillary
- Radial
- Median
- Ulnar
- Long thoracic
Where does the lumbar plexus arise from?
The roots from L1 to L4
What part of the body does the lumbar plexus supply nerves to?
- Anterolateral abdominal wall
- External genitals
- Anterior part of lower limbs
What are the major nerves supplied by the lumbar plexus?
- Femoral
- Obturator
- Saphenous
Where does the sacral plexus arise from?
The roots of L4-S4
What parts of the body does the sacral plexus supply nerves to?
- Buttocks
- Perineum (genitals)
- Posterior part of lower limbs
What is the major nerve supplied by the sacral plexus?
The siatic nerve
What does the sciatic nerve travel through, and what does it branch into?
-Travels through the greater sciatic notch
-Branches into tibial and common fibular nerves at the knee
What is sensory stimuli from diaphragm often interpreted as?
Often interpreted as pain over shoulder and lower neck
What nerve is responsible for the wrist drop?
The radial nerve
What nerve is responsible for winging of the scapula?
The long thoracic nerve
What are dermatomes?
-Areas of skin suppled by sensory neurons from a single spinal nerve
-Useful to determine neurologic levels
What are the 3 different types of reflexes that the spinal cord is responsible for?
- Patellar reflex
- Pupillary light reflex
- Babinski sign
What is the method of injury for this patient?
Spinal cord compressed due to extreme hyperflexion
What projection is this and how would you best represent this?
It is an AP oblique 45 degree with a 15 degree cephlad angle
What projection is this and how would you best represent this?
True lateral thoracic spine
What projection is this and how would you best represent this?
True lateral lumbar spine
What projection is this and how would you best represent this?
AP axial 15 degree cephlad angle of the sacrum
