Lecture 7: Spinal Cord and Spinal Nerves Flashcards
The cranial/spinal nerve branches, as well as the ganglia, belong to which part of the nervous system?
PNS
Are Multipolar neurons motor or sensory neurons?
Are Pseudounipolar neurons motor or sensory neurons?
Multipolar = motor
Pseudounipolar = sensory
What are the cell bodies in the CNS known as? How do they connect to one another?
nuclei; via tracts
What are the cell bodies in the PNS known as? How do they they connect to one another?
Ganglia; via nerves
True or False: Glial cells are non-excitable
True
What are glial cells in the CNS are known as?
What are the glial cells in the ganglia known as?
Astrocytes
Satellite cells
_____ are the myelinating cells of the central nervous system (CNS)
Where are Schwann Cells located?
Oligodendrites
PNS
Role of microglia?
Immune defense
Which cells are important for CSF production?
Ependymal cells
Each axon is covered by what type of tissue?
Connective tissue
Axons are bundled into ____
fascicles
A nerve contains many
fascicles, bundled together with
____ tissue & ____ vessels
adipose; blood
What type of neurons are found in dorsal root ganglia?
Somatic sensory neurons (pseudounipolar)
What type of ganglia is located in the autonomic?
Sympathetic ganglia
Parasympathetic ganglia
The spinal cord is an extension of the _____
medulla oblongata
Where does the spinal cord start and end at?
foramen magnum/C1 to between L1-L2
What are the two prominent enlargements
separated by the thoracic region?
Cervical and Lumbar enlargements
______is the tapered end of the spinal cord
Conus medullaris
In an average adult, the spinal cord ends at __or__.
In an embryo, the spinal cord ends at ___
L1/L2
C1-ish
Which structure is filled with CSF?
A. Filum Terminale
B. Conus medullaris
C. Lumbar Cistern
C. Lumbar Cistern
____ is an enlargement of subarachnoid space between L2-S2 vertebrate AND site of lumbar punctures
Lumbar Cistern
True or False: Nerves of cauda equina ’float’ in CSF
True
Lumbar puncture is done between which two vertebrate?
L3 and L4
Which artery is found within the Anterior Longitudinal Fissure?
Anterior Spinal Artery
Which arteries are found in the Posterolateral Sulci?
Posterior spinal arteries
The Posterior Median Fissure contains which vein?
Posterior Spinal Vein
True or False: In the spinal cord, the core is composed of grey matter that is surrounded by white matter
True
Gray matter is ____ while white matter is myelinated ____ and ____
neuronal cell bodies; axons/glial cells
Label these sulci and grooves:
Word Bank
-Anterior Median Fissure
-Central Canal
-Posterior Median Sulcus
-Posterolateral Sulci
True or False: The Central Canal contains CSF in infants but is closed in adults
True
Label these white matter structures:
Word Bank
- Anterior Funiculi
-Anterior Commisure
-Posterior Funiculus
-Left Lateral Funiculus
Label these gray matter structures:
Word Bank
- Dorsal Horn
- Lateral Horn
- Ventral Horn
- Gray Commisure
What levels of the spinal cord are the lateral horns present at?
T1-L2 and S2-S4
True or False: The vertebral column contains a vertebral canal and provides structural support & physical protection
True
What three contents does the vertebral canal contain?
1) Adipose Tissue
2) Vasculature
3) Meninges (fibrous layers)
Label the three meninges:
Which meninges is continuous with the
cranial dura?
Dura Mater
____ is the theoretical space between dura &
vertebral wall; can be exploited to target
anesthesia to specific spinal nerves
Epidural Space
True or False: The Epidural Space contains adipose tissue & the
internal vertebral plexuses
True
True or False: You puncture the dura mater during a lumbar puncture but not during epidural anesthesia
True
The Arachnoid mater connects the outer dura with the inner pia mater via the ______
arachnoid trabeculae
The ____ space lies between the arachnoid and pia mater
Subarachnoid Space
What is the subarachnoid space filled with?
CSF
____: a potential space that lies between the dura and arachnoid
Subdural Space
Which meninges is the innermost layer that encases
the spinal cord?
Pia mater
_____ are the modified teeth-like folds of pia project outwards, between where
the spinal nerve roots arise
Denticulate Ligaments
_____is a narrow thread of pia extending from the base of the conus medularis to
anchor the inferior end of the spinal cord to the first segment of the coccyx
filum terminaleis
What two structures act as harnesses that anchor the spinal cord in place?
filum terminale; denticulate
ligaments
True or False: There are 31 pairs of spinal nerves,
all of which contain both motor & sensory fibers
True
What are the two roles of spinal nerves?
1) Deliver sensory information to the
spinal cord
2) Sends motor signals to effector organs
Label this spinal nerve:
What type of neurons are present in the dorsal root ganglia?
A. Motor neurons
B. Sensory neurons
Sensory neurons
Where are pseudounipolar cells located?
Dorsal Root Ganglia
Afferent fibers exit a ganglion via _____ and synapse in the ___ of the spinal cord
dorsal rootlets; dorsal horn
The ventral horns contain the cell bodies of _______ neurons
somatic motor neurons
The efferent neurons exit the spinal cord as ___ and unite to form the ____
ventral rootlets; ventral root
The pre-ganglionic visceromotor fibers exit via the ______
ventral rootlets
Label this visceromotor fiber
Pre-ganglionic fibers from the lateral horn join the spinal nerve via the ____
A. chain ganglia
B. visceromotor fibers
C. ventral root
C. ventral root
Rami communicans travel via ___ rami communicans to chain ganglia (T1-L2)
white
Rami communicans synapse with ______ neurons
post-ganglionic visceromotor neurons
Postganglionic fibers pass via ____ rami communicans back to the spinal nerve
A. white
B. grey
B. grey
Postganglionic fibers pass via ____ rami communicans back to the spinal nerve
A. white
B. grey
B. grey
Spinal nerves divide into two branches: the ____ rami and the ____ rami
Dorsal Rami and the Ventral Rami
____ Rami distribute signals to and from the deep muscles and skin of the back
____ Rami branch and interconnects to form plexuses
Dorsal Rami
Ventral Rami
True or False: Ventral rami in the thoracic region form intercostal and thoracoabdominal nerves
True
What are the four nerve plexuses?
1) Cervical Plexus
2) Brachial Plexus
3) Lumbar Plexus
4) Sacral Plexus
The Cervical Plexus corresponds to the C_-C_ anterior rami
C1-C5
Which nerve plexus innervates:
-Posterior head
-Some neck muscles
-Diaphragm
Cervical Plexus
C5-T1 is associated with which nerve plexus?
Brachial Plexus
Which nerve plexus innervates the shoulder, axilla, and upper limb?
Brachial Plexus
Which nerve plexus innervates abdomen, pelvic region, and anterior/medial thigh?
Lumbar Plexus
Which nerve plexus is associated with L1-4?
Lumbar Plexus
Which plexus corresponds to L4-S4 and innervates pelvic, gluteal, thigh, and leg/foot region?
Sacral Plexus
Which rami do NOT form a plexus?
Thoracic ventral rami
(T1-T12)
T1 divdes into two branches: the largest branch to the ____ and the smallest branch to the _____
large branch = brachial plexus
small branch = 1st intercostal nerve
____ forms 2nd to 6th intercostal nerves
____forms thoracoabdominal nerves
_____ forms the subcostal nerve
A. T7-T11
B. T2-T6
C. T12
D. T11
T2-T6: forms 2nd to 6th intercostal nerves
T7-T11: forms thoracoabdominal nerves
T12 forms the subcostal nerve
___ spinal nerve pairs from ___ spinal cord segments
31
Where do spinal nerves emerge from?
Vertebral column - between the vertebrate
Which spinal nerves exit above named vertebrate?
Which spinal nerves emerge below named vertebrate
Cervical spinal nerves
All other spinal nerves
Label the sacral spinal nerves
Word Box
- Dorsal Ramus
- Posterior sacral foramen
- Anterior sacral foramen
- Ventral Ramus
True or False: Nerves T1 co-emerge inferior to pedicles of their respective vertebrate
True
The area of skin a single spinal nerve innervates is a ______
The muscle a single spinal nerve innervates is a ____
dermatome
myotome
True or False: Dermatomes can be assessed by testing skin sensation and numbness may indicate spinal nerve damage
True
True or False: Myotomes can be assessed by testing the action of muscles and weakness in a muscle group may indicate damage to a specific nerve
True
____ is the longitudinal band of pia in the anterior median fissure; acts as a sheath for anterior spinal artery
Linea splendens
____connects the nuclei of the CNS and contains mostly myelinated axons and glial cells
Nerve tracts
Anterior white commissure is deep to ____
anterior median fissure
Ventral Horns contain cell bodies from what type of neurons?
Motor neurons
___ horns contain proximal axons of sensory neurons and cell bodies from interneurons
Dorsal Horns
The lateral horns contain cell bodies from ______ neurons
Sympathetic
____ is a remnant of the neural tube and passes centrally along the length of the spinal cord within the gray commissure
Central canal
Spinal nerve root projections from __onward
L2
_____:~3 mm deep anterior groove running along the length of the spinal cord, lined by the linea splendens
Anterior median fissure
____: Longitudinal grooves on posterolateral surface, which contains right and left posterior spinal arteries
Posterolateral sulci
Posterior spinal arteries anastomose with
the anterior spinal artery forming a vascular
plexus around the spinal cord called the _____
vasocorona
_____: Longitudinal groove along posterior surface, which contains posterior spinal vein
Posterior median sulcus