Spinal Cord Flashcards
Which portions of the rexed laminae contain cell bodies involved in pain sensation?
1, 2, 5, 6


- The dorsal spinocerebellar and cuneocerebellar tracts convey […] information.
- They pass through the […] peduncle in order to gain access to the cerebellum.
- Do these tracts cross?
- Describe briefly their course of travel.
- Unconscious proprioception
- Inferior cerebellar
- Don’t cross
- Spinocerebellar: input from lower body and trunk DRG cells with unconscious proprioception info synapse on cell bodies in clarke’s nucleus –> leaves gray matter laterally and enters dorsal spinocerebellar tract –> continues dorsally until inferior cerebellar peduncle –> continues into cerebellum
- Cuneocerebellar: input from upper body DRG cells with unconscious proprioception info –> ascend via cuneate fasiculus to cuneate nucleus –> synapse on cell body that travels to cerebellum via inferior cerebellar peduncle

If looking at a cross-section of the spinal cord, how would you know whether that section was lumbar?
- Round
- More grey matter than white matter
The spinal medullary arteries supply blood to the […]
Directly to the cord, supplementing the ASA and spinal arterial plexus
In the parasympathetic NS, […] is the neurotransmitter released from both the preganglionic and postganglionic neurons.
Acetylcholine


The […] enter at the posterolateral sulcus.
Posterior root fibers (sensory) –> frequently called the posterior root entry zone
For the Dorsal Column / Medial Lemniscus tract:
- What information that is transmitted?
- What is the entry site on the spinal cord?
- What area of the spinal cord do the fibers traverse (e.g., lateral, anterior, dorsal, etc)
- First, second, and third synapses?
- Site of crossing, if any?
- Type of fiber(s)?
- Fine touch, pressure, conscious proprioception
- Dorsal roots/dorsal horn
- Dorsal column
- First synapse in dorsal nuclei (gracilis or cuneatus) of medulla; second synapse in VPL of thalamus
- Sensory decussation (internal arcuate) of medulla
- Sensory


Where is the lesion?
What would cause this to occur?
Injury to anterior SC, ASA stroke
From T1 to L1/L2, the interomedial nucleus (aka lateral horn) contains cell bodies that convey what information?
Preganglionic sympathetic neurons
From levels C8 to L3, clarke’s nucleus contains cell bodies that convey what information?
Unconscious proprioception


What do the neurons in rexed lamina 5 do?
Process sensory afferent stimuli from cutaneous, muscle, and joint mechanical pain receptors as well as visceral pain receptors
The posterior spinal artery supplies which part of the spinal cord?
The posterior columns and posterior horn
Describe the circulation of CSF and the structures involved in the process.



Tectospinal tract
- Function
- Connects what 2 structures
- Where does it cross
- Coordination of head and eye movement
- Superior colliculus and spinal cord
- Superior colliculus (midbrain) to innervate contralateral muscles
If looking at a cross-section of the spinal cord, how would you know whether that section was sacral?
- Round
- MUCH more grey matter than white
Arachnoid Mater
- Composed of what?
- What is just below the arachnoid mater?
- Connection to dura?
- Connection to pia?
- elastic and fibrous tissue
- Subarachnoid space filled with CSF
- Not connected to dura but held against its inner surface by CSF pressure
- Arachnoid trabecular (delicate strands of connective tissue) span subarachnoid space and connect arachnoid and pia mater
What is brown - sequard syndrome?
A hemisection of the spinal cord.
- There will be loss of fine touch and motor below and on the same side as the lesion –> dorsal columns and lateral corticospinal cross in medulla, lesion in SC will affect same side as lesion
- There will be contralateral loss of pain and temp –> anterolateral system crosses in SC few levels up or down. If there is a left lesion, then pain and temp from the right will be lost below the lesion.

Reticulospinal tract
- Function
- Crosses?
- Automatic posture and gait related movements
- Doesn’t - ipsilateral
In which rexed lamina are motor interneurons found?
8
In genreal, the alpha and gamma motor neurons that innervate skeletal muscle are found in which rexed laminae?
8, 9
At each level, terminal branches of the spinal medullary arteries join to form an arterial network called the […]
Arterial vasocorona

If looking at a cross-section of the spinal cord, how would you know whether that section was thoracic?
- Round
- More white matter (stains darker in stains of cord)
- Lateral horns present
- Clarke’s nuclei
Describe the venous drainage of the spinal cord.

Which rexed laminae are involved in the anterolateral descending pathway?
1, 2, 5
The […] supplies blood to the dorsal and ventral roots and the dorsal root ganglion.
Spinal radicular arteries
Where is the lesion?
What could cause this to occur?

Injury to upper cervical SC, stroke (PSA)

What are the cell bodies in rexed lamina 7 involved in?
Preganglionic autonomic neuron cell bodies and neuron cell bodies of Clarke’s nucleus
How can you distinguish the spinal cord between thoracic levels?
- Thoracic cord is round
- Posterior and anterior horns are small
- Progressive decrease in white matter from T1 - T12
The anterior spinal artery supplies what part of the spinal cord?
The anterior 2/3 of the cord


Cell bodies for the visceral reflexes are contained in which rexed lamina?
7
What is this condition called?
What are the symptoms?

Syringomyelia - syrinx (cyst) in cervical central spinal cord
AKA arnold-chiari malformation
Symptoms - incontinence, impotence, loss of pain and temp in cape like distribution



What is found in rexed lamina 10?
- Grey matter surrounding central canal
- Neural glia (immune cells)
The cell bodies in the spinal cord invovled in the flexion reflex are found in which rexed lamina?
6
The sympathetic NS arises from spinal levels […]
T1 - L3
For the lateral spinothalamic (aka anterolateral system):
- What information that is transmitted?
- What is the entry site on the spinal cord?
- What area of the spinal cord do the fibers traverse (e.g., lateral, anterior, dorsal, etc)
- First, second, and third synapses?
- Site of crossing, if any?
- Type of fiber(s)?
- Pain, temperature, crude touch
- Lissauer’s tract
- Dorsal –> Medial –> Anterolateral
- # 1) Rexed laminae 1 and 5 in dorsal horn, #2) VPL of thalamus
- Anterior commissure
- C fibers, Adelta fibers (slow)
If looking at a cross-section of the spinal cord, how would you know whether that section was cervical?
- More oval shaped
- Proportionately larger than at other spinal levels
- ~ 50/50 white to grey matter ratio
- Posterior median and intermediate sulci are visible
What are denticulate ligaments?
fibrous sheet of pia mater that suspend the dural sac

Vestibulospinal Tract
- Function
- Crosses?
- Positioning head and neck, balance
- Doesn’t (ipsilateral)


- What is the function of the vestibulospinal tract?
- Does this tract cross / where?
- Positioning of head and trunk and also balance
- Mostly ispilateral
[…] % of upper motor neurons in the corticospinal tract cross in the pyramidal decussation and are part of the […] corticospinal tract, while the remaining […]% stay on the same side of the body and do not cross as part of the […] corticospinal tract.
85
Lateral
15
Anterior
For the anterior corticospinal tract:
- What information that is transmitted?
- What is the entry site on the spinal cord?
- What area of the spinal cord do the fibers traverse (e.g., lateral, anterior, dorsal, etc)
- First, second, and third synapses?
- Site of crossing, if any?
- Type of fiber(s)?
- Motor information to skeletal muscle
- Anterior (ventral) horn
- Anterior
- Only syapse = UMN on LMN in ventral horn
- Doesn’t cross
- Motor neurons
In the sympathetic NS, […] is the neurotransmitter released from preganglionic neurons onto post ganglionic neurons. […] is the neurotransmitter released from postganglionic neurons onto target tissues.
Acetylcholine
Norepinephrine
For the lateral corticospinal tract:
- What information that is transmitted?
- What is the entry site on the spinal cord?
- What area of the spinal cord do the fibers traverse (e.g., lateral, anterior, dorsal, etc)
- First, second, and third synapses?
- Site of crossing, if any?
- Type of fiber(s)?
- Motor information to skeletal muscle
- Lateral corticospinal tract
- Lateral compartment –> ventral horn
- Only synapse = UMN on LMN in ventral horn
- Pyramidal decussation in corticomedullary junction (where medulla meets brainstem)
- Motor neurons




How can you distinguish the spinal cord between levels C4 to C8?
Posterior and anterior horns get larger due to sensory input from motor innervation to upper extremity. Spinal cord is distinctly oval.

Most of the gray matter and the adjacent parts of the white matter are served by the central branches of the […]
anterior spinal artery
How can you distinguish the spinal cord between levels C3 to C4?
Horns are becoming larger as part of cervical enlargement of brachial plexus, shape of spinal cord becomes more oval.

What is the central canal of the spinal cord?
The remants of the neural tube in adults. It is lined by ependymal cells.


- What is the function of the tectospinal tract?
- Where does it cross?
- Coordination of head and eye movements
- Crosses at level of superior colliculus (midbrain) to innervate contralateral muscles
How can you distinguish the spinal cord between levels C1 - C3?
Posterior and anterior horns are small, which results in a more round than oval shape

Anterolateral (Spinothalamic) Pathway
- Ascending or descending?
- What information is conveyed in this pathway?
- Where does it cross?
- What are the fiber types for axons?
- Ascending
- Pain and temperature
- In spinal cord
- C fibers and Adelta (slow) fibers


The anterolateral sulcus is the exit point for […]
Anterior root (motor) fibers
Rubrospinal Tract
- Function
- Crosses?
- Contributes to control of movement of extremities (not as important in humans)
- Crosses at red nucleus (midbrain) to control contralateral muscles
What are the 4 essential functions of the spinal cord?
1) Sensory - receives primary sensory input (skin, muscles, tendons, viscera) and relays information to brain
2) Motor - contains somatic motor neurons that innervate skeletal, visceral and smooth muscle
3) Reflexes - somatosensory neurons enter cord and influence motor neurons in ventral horn directly or indirectly via interneurons to produce rapid involuntary contractin of skeletal muscle
4) Modulation - contains descending fibers from brain that modulate activity of spinal neurons
The spinal dura mater is separated from the periosteum-covered bone and the ligaments that form the walls of the vertebral canal by the […]
epidural space






What are the rexed laminae (general)?
A system of labeling the areas of grey matter in the spinal cord


What structures are found in rexed lamina 9?
- Lateral and medial motor neurons
- Phrenic and CN 11 nuclei at cervical levels
- Onuf’s nucleus sacral level (maintenance of micturition and defecatory continence, as well as muscular contraction during orgasm)
- What is the structure boxed in red?
- What is its function?
- What can result if it is damaged?


Which of the rexed laminae contain cell bodies responsible for proprioception and positioning of lower limbs?
3, 4
The parasympathetic NS arises from […] spinal levels
Cranial nerves (3, 7, 9, 10)
Sacral nerves (S2 - S4)
- What is contained in the epidural space? (2 things)
- What is this space often referred to as?
- Vertebral venoux plexus embedded in fatty matrix
- Potential matrix

