Spinal Cord Anatomy Flashcards
How many cranial, thoracic, lumbar, sacral, and coccygeal nerves?
8 cranial, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal.
Where are the cervical and lumbar enlargements?
Cervical: C5-T1. Lumbar: L1-S2.
Where does the fetal spinal cord end? Adult spinal cord?
L3. L1/L2
What are the dermatomes for back of head, thumb and index finger, nipples, umbilicus, knee cap, and lateral foot?
C2=back of head C6=thumb and index finger T4=nipples T10=umbilicus L3=kneecap S1=lateral foot
What are the three gray matter regions?
Posterior (dorsal) horn, intermediate gray, and anterior (ventral) horn.
Describe alar and basal plates
Alar=afferent, sensory. Basal=efferent, motor.
Describe substantia gelatinosa
In dorsal horn, modify sensory input. Valve for pain.
Describe nucleus proprius
In dorsal horn, contains cells that form spinothalamic tract, which is most important pain pathway.
Describe nucleus dorsalis
In intermediate gray, projects to cerebellum as dorsal spinocerebellar tract. Helps with proprioception/coordination.
Describe interomediolateral (IML) nucleus
In intermediate gray, origin of preganglionic sympathetic efferents. Only T1-L3. GVE
Describe medial and lateral motor nuclei
Medial controls trunk/shoulders. Lateral does fingers etc.
Where is there more white matter in the spinal cord?
More in cervical cord than lumbar or thoracic cord.
Describe free nerve endings
Nonencapsulated. Pain/temp
Describe Merkel’s disk.
Nonencapsulated. Touch in feet, hands, genitalis, lips
Describe hair follicles.
Nonencapsulated and fast adapting. Touch
