Neuroanatomy of the Spine (Quiz 2) Flashcards
What are the 9 contents of the vertebral canal?
1) PLL
2) periosteum of vertebrae
3) meninges
4) dural sac
5) CSF
6) epidural space/fat
7) spinal cord
8) vessels (arteries and veins)
9) nerve rootlets and roots
The spinal cord extends from the foramen magnum to….
L1/L2 (osseous)
The spinal cord extends from the _________________ to ___________________
medulla oblongata, conus medullaris (soft tissue)
note: conus medullaris is cone shaped at the end of the spinal cord
At the end of the spinal cord/conus medullaris is a collection of nerve roots called…
cauda equina (looks like horses tail)
The spinal cord is tethered to the coccyx by a structure called the __________________. It anchors the cord to the meninges and coccyx. It contains nervous tissue and connective tissue. It is covered by ______ mater. The most dorsal portion is called the coccygeal ligament
filum terminale, pia
The spinal cord is wrapped in connective tissue called meninges. What are the meninges from superficial to deep?
test q
-dura mater
-arachnoid mater
-pia mater
What does the spinal dural sac help protect?
spinal cord (its a thick leathery material)
What is the spinal dural sac formed by?
test q
dura and arachnoid mater
The spinal dural sac runs the length of the vertebral canal. What is it anchored by?
-superiorly at the foramen magnum
-inferiorly at the coccyx by the filum terminale
The spinal dural sac is called ________________ as it extends laterally through the IVF and wraps around nerve roots blending in with the epineurium for protection
dural root sheath
The arachnoid mater forms trabeculae that span the _________________ connecting the arachnoid and pia mater, which stabilizes the spinal cord
subarachnoid space
What is the subarachnoid space filled with?
CSF
What is the difference between the central canal and the subarachnoid space in terms of CSF?
test q
central canal holds CSF within the spinal cord
subarachnoid space holds CSF that surrounds the cord
The lumbar cistern is where the dural sac comes together and holds what?
cauda equina + CSF
The lumbar cistern is an enlargement of what space in the dural sac?
subarachnoid space
Lumbar cistern contains….
-CSF
-filum terminale
-nerve roots
-cauda equina
The lumbar cistern extends from the ___________________ to ____________________
conus medullaris, 2nd sacral vertebra
Where is the location of a lumbar puncture?
lumbar cistern
What is the thin innermost layer of the meninges?
pia mater
What does the pia mater cover?
-spinal cord
-nerve roots
-vessels
-filum terminale
What ligaments are formed by the pia mater and what is its function?
pia mater forms denticulate ligaments to secure the dural sac
Where is the epidural space located?
between the vertebral periosteum and dura mater
What does the epidural space contain?
veins and fat
The epidural space runs the length of the vertebral canal. What are its boundaries?
-superiorly= foramen magnum
-inferiorly= sacral hiatus
-laterally= IVFs
The spinal cord has 2 enlargements that give rise to plexuses that innervate the limbs. What are they and what segments are involved in each one?
1) cervical enlargement (C4-T1)
2) lumbar (lumbosacral) enlargement (T11-S1)
What is responsible for spinal cord enlargements?
the amount of ventral horn grey matter
Ventral horn contains what neurons?
somatic motor neurons that are responsible for limb movement (the spinal cord enlargements are at the levels of limbs for limb movement)
What cell bodies and axons are found in dorsal horns?
-interneuron cell bodies
-sensory axons
Ventral horns are mostly somatic motor neuron cell bodies. Where do ventral horns exit and what do they do?
-exit spinal cord via ventral rootlets to roots
-send signals to skeletal muscle for limb movement
Where are lateral horns found?
at thoracic and superior lumbar cord segment levels only
Lateral horns are mostly _________________ nervous system motor neuron cell bodies
sympathetic
Where do lateral horns exit and what do they do?
-exit spinal cord with somatic motor neurons via ventral roots
-send signals to visceral organs, eyes, glands, skin, genitalia, and the bladder
What does the gray commissure connect? What does it surround?
-connects horns
-surrounds central canal, CSF flows through canal
Most of the cords white matter is composed of _____________ tracts
myelinated
Ascending sensory pathways involves 3 neurons. What are they?
1) 1st order neurons
2) 2nd order neurons
3) 3rd order neurons
1st order neurons from ascending sensory pathways form __________ receptors to brain stem or spinal cord
somatic
2nd order neurons from ascending sensory pathways start in brainstem or spinal cord and go to ______________ (except olfactory). The axons decussate
thalamus
3rd order neurons from ascending sensory pathways start in the thalamus and go to….
primary somatosensory area
The dorsal white column has ______________ tracts
ascending
What does the dorsal white column carry?
sensory impulses from periphery to brain
Where does the dorsal white column decussate?
at medulla oblongata
The dorsal white column is made up of 2 tracts. What are they and their functions?
1) fasciculus gracilis (discriminative touch and vibration, source of stimulus can be precisely located on body)
2) fasciculis cuneatus (joint proprioception)
The spinocerebellar tracts has __________ tracts
ascending
What is the function of spinocerebellar tracts?
-carry sensory proprioceptive fibers from skeletal muscles or tendons to the cerebellum
-subconscious
-allows cerebellum to coordinate skeletal muscle movement
Which tract did we learn is the only one that DOES NOT decussate?
spinocerebellar tracts
Spinothalamic tracts has ____________ tracts
ascending
What is the function of spinothalamic tracts?
-mainly transmits impulses for pain and temp., but also course touch and excessive pressure
-acute pain can be precisely located (ex: pin prick test)
-chronic or visceral pain is difficult to precisely locate
Where do spinothalamic tracts decussate?
in spinal cord
Do descending motor pathways deal with voluntary or involuntary movement?
voluntary
What 2 neurons are involved in descending motor pathways?
UMNs and LMNs
Where do UMNs originate and what do they do?
-originate in or just under the cortex
-convey efferent (motor) impulses from the brain to spinal cord
Where do LMNs originate and what do they do?
-originate in the ventral horn of the spinal cord
-they convey efferent motor impulses from the cord to skeletal muscle, glands, and viscera
Pyramidal/ corticospinal tracts have ___________ tracts
descending
Pyramidal/corticospinal tracts have a direct pathway. UMNs descend without synapsing from the cortex to the spinal cord. What impulses do they send and to where?
send efferent motor impulses to skeletal muscles
Extrapyramidal tracts have indirect motor pathways that are complex and multi-synaptic. What 4 tracts are involved within extrapyramidal tracts?
1) rubrospinal tracts
2) reticulospinal tracts
3) vestibulospinal tracts
4) tectospinal tracts
What are rubrospinal tracts?
-a part of extrapyramidal tracts
-derived from red nucleus
-controls flexor muscles (allows you to make a fist)
What are reticulospinal tracts?
-a part of extrapyramidal tracts
-in charge of excitation and inhibition of antigravity muscles to controlling equilibrium
-in charge of proprioception (usually with the use of extensor muscles)
What are vestibulospinal tracts?
-a part of extrapyramidal tracts
-in charge of visual and hearing sensations
-excitation and inhibition of antigravity muscles to controlling equilibrium
What are tectospinal tracts?
-a part of extrapyramidal tracts
-mediate head movements in response to visual stimuli (move head when you hear or see something)
