Neuro L2 Flashcards
Epineurium
Prominent around
Provides ____
Continuous with
prominent around nerve trunks
Provides tensile strength
Continuous with Dura
Perineurium
Continuous with
___-_____ barrier
Continuous with arachnoid
Blood-nerve barrier
Endoneurium
Surrounds
surrounds individual fibers
Myelin Covers up to \_\_mm of axon Produced by (CNS vs PNS)
1mm
Oligodendroglia: CNS
Schwann cells: PNS
Saltatory conduction
Depolarization occurs at nodes in either direction
Rank fiber diameter (largest to smallest) Axons to Intrafusal fibers Preganglionic autonomic Lower motor neurons Postganglioinc automic
Lower motor neurons Axons to intrafusal fibers Preganglionic autonomic Postganglionic autonomic (no myelin)
Nocireceptor
detects pain
Muscle spindles also act as this type of receptor
proprioreceptor
Two types of encapsulated receptors in muscle
Function
Muscle spindles: detect length
Golgi tendon organs: detect muscle tension
Conus medullaris
caudal end of spinal cord
Cervical enlargement level
C5-T1
Lumbar enlargement level
L2-S3
Segments of spinal cord
Cervical: 8 Thoracic: 12 Lumbar: 5 Sacral: 5 Coccygeal: 1
Dorsal rootlets enter cord in
Ventral rootles exit cord in
Posterolateral sulcus
Anterolateral sulcus
Afferent fibers my terminate in ____ or _____
posterior horn or ascend to medulla
Motor neurons modulated by
descending fibers from rostral structures
Posterior intermediate sulcus
Levels
Divides what
C1-T5
divides posterior funiculi
Posterior intermediate sulcus separates
sensory fibers arising from
Fasciculus gracilis
Fasciculus cuneatus
Sensory fibers from the leg
fasciculus gracilis
Sensory fibers from the arm
fasciculus cuneatus
Spinal cord gray matter: posterior horn
Consist mostly of
interneurons
Substantia gelatinosa
Located in (number)
Responsible for
Located in posterior horn gray matter (II)
Responsible for pain and temperature
Lissauer’rs tract
Associated with
What is it
Associated with substantia gelatinosa
Finely myelinated and unmyelinated fibers
Lamina I
Relays sensory signals
Lamina II
substantia gelatinosa (important for paint)
Lamina V
Relays sensory signals
Spinal cord gray matter posterior horn
What do they contain
contain Alpha/motor neurons that control skeletal muscle