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41 Cards in this Set
- Front
- Back
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Describe the spinal cord duringdevelopment |
SC Outgrows the spinal cord during development
During 3rd mon the cord fills the vertebral canal Caudal end of the SC is located at L3 in the newborn |
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What are the two enlargements of the SC |
Cervical - C4-T1 Lumbosacral - L1-S2 |
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What is the anterior median fissure? |
Penetrates deeply into the cord, extending almost ot the middle. Contains sulcal branches of the anterior spinal artery |
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What is the anterolateral Sulcus |
Location where ventral roots leave the cord |
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What is the posterolateral sullcus |
Site of entry of the dorsal roots (Dorsal entry zone) |
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Where do the spinal nerves emerge from? |
C1-7 Pass above the corresponding numbered vertebrae C8 between C7 and T1 All the rest emerge from the vertebrae below |
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What is a dermatome? |
Any area of skin that is innervated by dorsal roots arising form a single spinal cord segment |
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What is a myotome |
The skeletal muscle that is innervated by motor fibers arising from a single spinal cord segment |
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What are the components of a spinal nerve? |
Somatic Sensory fibers (GSA) Visceral sensory fibers (GVA) Visceral Motor Fibers (GVE) |
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Describe Visceral and Somatic sensory fibers |
GSA: Located in DRG and send info from skin muscles tendon and jointss GVA: From mechanoreceptors and nociceptors within the viscera. Found in DRG |
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Describe Visceral and Somatic Motor fibers |
GSE: arises from motor neurons within the spinal cord (ventral horn) and innervate body musculature invovolved in purposeful movement GVE: Axons of neurons within the SC that terminate in autonomic ganglia. |
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How does the pia mater stabilize the sc |
Denticulate ligaments and filum terminale |
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What are denticulate ligaments? |
Found between the ventral and dorsal spinal roots. Pierce the arachnoid and attach to the dura 21 on each side |
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What is the filum terminale Internum? |
thin thread of pia mater that arises from the caudal end of the SC and travels inferiorly to caudal tip of the thecal sac |
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What is the Lumbar cistern? |
Expansion of the spinal subarachnoid space causal to the conus medullaris |
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What is the filum terminale externum |
Continuation of the pial thread that pieces through the thecal sac and extends caudally |
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Describe Gray matter?
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butterfly shaped Dorsal horn, ventral horn = Intermediate zone |
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Describe input for Dorsal Horn Lamina |
Lamina 1 and 5: nociceptive input via lightly myelinated, small diameter affarents Lamina 3 and 4: non-noxious input via myelinated large diameter afferents. Lamina 2: input from nociceptive afferents and collaterals from large afferents Lamina 6: input from descending motor pathways and proprioceptive input from the periphery |
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Where is the intermediolateral cell column |
found in spinal segments T1-L2 in the small lateral horn of the intermediate zone Give rise to preganglionic sympatethic efferent fibers |
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Where are the sacral autonomic nuclei found? |
Found laterally in lamina 7 in segments S2-S4 Give rise to preganglionic parasympathetic fibers that exit the sc via ventral roots to form pelvic nerves |
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Describe Lamina 9 |
Main somatic motor area of the spinal gray matter. Contains large alpha motorneurons and smaller gamma motor neurons that innervate skeletal muscles |
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Neurons that innervate flexor vs extensor muscles |
F: Dorsally E: Ventrally |
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Neurons that innervate the Trunk vs Extremities |
T: Medially E: Laterally |
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What is a reflex |
Automatic motor response to sensory stimuli applied in the periphery and transmitted to the CNS |
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What are muscle spindle organs |
attached parallel to skeletal muscles. Contain specialized muscle fibers that detect the static and dynamic properties of stretch |
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Describe the white matter |
Composed of myelinated axons organized into tracts. Convey info between spinal segments and to and from higher centers |
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What is the dorsal funiculus |
Located between the dorsal root entry zone and posterior median septum. |
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What is the lateral funiculus |
Located between the dorsasl foor entry zone and the site where the ventral roots emerge from the spinal cord. |
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Where is the ventral funiculus |
found between the anterolateral sulcus and anterior median fissue Contains motor pathways from the cerebral cortex and brainsstem that control axial and neck musculature |
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What are the 3 major "long tracts" |
1. Lateral corticospinal tract - motor 2. Dorsal column medial lemniscal system - two point touch (sensory) 3. Anterolateral system - pain/ temp (sensory) |
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What are the spinocerebellar tracts |
convey muscle and some cuatneous information to the cerebellum for motor control. Damage to this pathway can cause significant dysfunction. (Sensory, unconscious) |
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What section of the brain coordinates movements? |
Spinocereellar tracts carry info to the cerebellum and it will process the information and send it to the motor areas of the cerebral cortex |
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What is the rubrospinal tract |
originates in the brainstem and affects primarily flexor muscles . Primary function appears to be facilitation of flexor activity in the arm and forearms |
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What are the reticulospinal and vestibulospinal tracts? |
Descending tracts that primarily control extensor muscles. Neurons sending axons in these tracts are in the brainstem. |
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What movements are the reticulospinal tracts involved in |
Less conscious activities like regulating posture and muscle tone |
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What movements are the Vestibulospinal tracts involved in |
Act to maintain upright body posture and orientation in space. Putting your arm out when you are suddenly off balance |
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How do injuries to the dorsal column present? |
Loss of sense of vibration, position, 2 pt discrimination |
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How do central cord syndromes occur? |
Intrinsic tumors Lesions beginning at the central canal |
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Symptoms of Central cord syndromes |
Segmental loss of pain and temp (bilaterally) Cape distribution with cervical lesion affecting multiple degments |
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What is Brown-sequard syndrome |
Classically involves 1/2 of the spinal cord although clinically complete hemisection is rare |
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Brown Sequard signs |
Dorsal columns: signs present below level of lesion on the same side Lateral corticospinal tract: UMN signs below level of lesion on same side Ventral horn: LMN signs at the involved segmental level on the same side Anterolateral system: loss of pain temp |
