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NeuroScience (WUSM)
Block 1
Question | Answer |
---|---|
What makes the CNS? | Brain and spinal cord. |
What makes the PNS? | 12 Cranial nerves, 12 spinal nerves and their respective ganglion. |
What is the spinal cord a continuation of? How many segments does the continuation have? | Continuation of the brain stem: midbrain, pons, and medulla oblangata. |
How long is the spinal cord? How long is the vertebral column? | Spinal cord is about 45 cm/18 inches; vertebral column is about 65 cm b/c lower 1/3 doesn't have the spinal cord. |
Where does the spinal cord end in adults? What about in the fetus? | Between L1 and L2 in adults; in the fetus, both the spinal cord and vertebral column are the same size; infants at L2/L3 |
What is the end of the spinal cord? | Conus medularis (L1-L2) |
Name the two enlargements and where they are present. | Cervical enlargement: C3-T2 Lumbosacral enlargement: L2-S3 |
How many pairs of spinal nerves are there? How many spinal segments are there? | 31 pairs of both; 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal |
What is the cauda equina? | The lower 4 lumbar, all of sacral and coccygeal extend down the verterbal column to reach their respective foramen to supply those areas. |
Where is a lumbar puncture conducted? How can it cause damage? | L2-L3/L3-L4; It can damage the lower lumbar, sacral, and coccygeal spinal nerves. |
What is the purpose of a lumbar puncture? | Spinal anethesia and CSF sampling for pathological or microbiology analysis. |
What position is the lumbar puncture conducted in? What layers does the needle pierce? | Extreme flexion/"laterl decubitus" to move the spinal cord up; Pierces 7 layers: skin, connective tissue, supraspinous ligaments, interspinous ligaments, ligamentum flavum, dura mater, arachnoid mater (finally reaches subarachnoid space) |
How many vertebral segments are there? | 30; 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal |
To determine the spinal segment for the vertebral segment, what needs to be added? | Cervical region: +1 Upper Thoracic (T1-T6): +2 Lower Thoracic (T7-T12): +3 11th thoracic: +5 12th thoracic: +6 Below thoracic: add what's needed |
What is a rhizotomy and a laminectomy? | Rhizotomy is severing the roots of spinal nerves to lose senstations. Laminectomy is removal of the medually tumor on the lamina to relieve pressure. |
What are the three layers of the spinal cord? | -Dua mater (epidural space b/c no endosteal layer) -Arachnoid layer(covers the spinal cord; from foramen magnum to S2) -pia mater (deepest) |
Three modifications of pia mater | linea splendence (become thickened, fills the fissure) ligamentum denticulatum: teeth like extensions and attaches to inner aspect of duar mater after piercing the arachnoid mater |