spinal cord Flashcards
What are the 3 membranes that surround the brain and spinal cord?
Dura mater
Arachnoid mater
Pia mater
What fills the compartment formed by the meninges and act as a cushion and means of exchanging substances between the brain and the rest of the body?
Cerebrospinal fluid (CSF)
Blood brain barrier is specialized endothelial cells that regulate ___ contents
CSF
Meninges are continuous from ___ to ___
Brain, spinal cord
Tough, outermost meninges layer bound to the surface of the skull, bound loosely to vertebral canal, and innervated
Dura mater
Middle meninges layer
Arachnoid mater
Thin, inner most meninges layer that envelopes the entire brain/spinal cord (vascularized)
Pia mater
What space is between the dura mater and the periosteum/lig of the vertebral canal that contains CT, fat, venous plexuses?
Epidural space
What is the narrow space between the arachnoid and dura mater?
Subdural space
What is the space between the arachnoid and pia mater that contains CSF and large blood vessels of CNS?
Subarachnoid space
Where is cerebrospinal fluid produced?
Choroid plexuses
What are denticulate lig? Where are they found?
Anchoring lig formed by pia mater
Lat on spinal cord with processes extending from the pia to dura mater
The spinal cord occupies upper 2/3 of vertebral canal from ___ to L2. It’s continuous w ___ at upper end and ___ at lower end
Foramen magnum
Brainstem
Cauda equina
Parts of the spinal cord
Conus medullaris
Filum terminale
Cauda equina
Nerve roots come together and form?
Spinal nerve @ given spinal level
Enlargements at spinal cord occur @?
Cervical: origin of spinal nerves (brachial plexus)
Lumbar: origin of spinal nerves (lumbar and sacral plexus)
Grey matter
Inner core of spinal cord made up of unmyelinated cell bodies and synapses between neurons
Grey matter horns
Dorsal: sensory info (into spinal cord)
Ventral: motor info (leave spinal cord)
Lat:autonomic sympathetic nerves (leave via ventral horns)
White matter
Around grey matter, made of myelinated neurons, form tracts nerve fibers running up and down spinal cord
Each spinal nerve has 3 func component
Somatic component (motor and sensory)
Visceral component (autonomic sympathetic NS)
___ pairs spinal nerves
31
8 C, 12 T, 5 L, 5 S, 1 Coccygeal
Spinal nerves consist of
Dorsal root: sensory
Ventral root: motor
T/F: C1&2 spinal roots are horizontal and form spinal nerves at same level as their intervertebral foramen?
T
C3-8 spinal roots slope
Obliquely down never exceeding height of 1 vertebrae
Thoracic spinal roots slope
Obliquely down and in lower region, descend length of at least 2 vertebrae
Lumbar, sacral and coccygeal spinal roots descend
Almost vertically (exit via intervertebral foramen or sacral foramina more than 2 segments from where originate)
What structures of the intervertebral foramen affect the spinal nerves?
Vertebral body and intervertebral discs ant
Zygapophysial joints and ligamentum flavum post
Pedicles above and below
What exits intervertebral foramen?
Spinal nerves
Blood vessels (segmental medullary arteries)
Sinuvertebral (recurrent meningeal) nerves
Sinuvertebral (recurrent meningeal) nerves supplies
Post longitudinal lig and intervertebral discs @ lvl
Blood vessels of vertebral canal
Dura mater and dural sleeve
ANS (autonomic NS) func
Responsible for stability and maintenance of body’s internal environment (homeostasis)
Structures supplied by ANS have ___ innervation functioning at subconscious lvl
Involuntary
ANS contains motor and sensory nerve fibers which go to which types of musc?
Smooth, cardiac musc
Exocrine glands
Parasympathetic arm of the ANS (craniosacral sys)
PSNS
Responsible for conserving energy and routine maintenance of bodily activities (rest and digest)
PSNS neurons exit CNS w
Cranial and sacral spinal nerves
Sympathetic arm of the ANS (thoracolumbar sys)
SNS
Prepare body for emergencies (fight or flight)
PSNS: pre-ganglionic fibers are ___, post-ganglionic fibers are ___
Long
Short
Where do pre- and post-ganglionic fibers synapse in SNS?
Sympathetic chain ganglia in thoracic and lumbar regions
OR
Abdominal and cervical ganglia
T/F: sympathetic chain ganglia lie on the medial sides of bodies of the thoracic and lumbar vertebrae
F: lat side
Pre-ganglionic fibers run between
CNS and ganglion
Post-ganglionic fibers run between
Ganglion and target tissue innervated
Neurons usually travel via
White rami communicans (pre-ganglionic fibers) to sympathetic ganglia near thoracic or lumbar vertebral body to synapse w post-ganglionic neuron
Post-ganglionic neuron travels via
Gray rami communicans
(Secrete norepi)
Symp neurons outside intervertebral foramen, pre-ganglionic fibers can do 1 of 4 things
1 enter symp chain ganglia (enter and exit same lvl)
2 enter symp chain ganglia travel up/down lvls then
exit
3 enter symp chain ganglia w/o synapsing and cont
traveling (thoracic to abdominal cavity)
4 SNS innervation to adrenal gland
Main ganglia in abdominal cavity?
Celiac, sup, inf mesenteric ganglia
(Where symp mesenteric pre- and post-ganglionic
neurons synapse)
There are only ___-ganglionic symp neruons in 4th pathway (adrenal gland)
Pre
What acts as “post-ganglionic neuron” in 4th pathway?
Epi
What arteries provide main blood supply to cerebral arterial circle (circle of Willis) at base of brain
Internal carotid and vertebral arteries
Vertebral arteries give off 3 main longitudinal arteries that run down the spinal cord
Ant spinal artery (union of branches off of vertebral arteries)
2 post spinal arteries (each = branch off of each vertebral arteries)
Spinal arteries give off
Radicular arteries and segmental medullary arteries
Radicular arteries run along along ___to enter spinal cord and vascularize just nerve roots by coming off of segmental medullary arteries
Spinal nerve root
Segmental medullary arteries come off of ___&___ and anastomose w ___&___
Ant and post spinal arteries
Post intercostal and lumbar arteries
T/F: 3 ant and post spinal beings run longitudinally w arteries
T
T/&F medullary and radicular veins are paired with arteries
T
