Neuro 2 Flashcards
Interlamina adhesion
connects thalamus and hypo.
Intermediate horn
autonomics
Visceral Efferent
vessels (motor)
somatic efferent
muscles (motor)
somatic afferent
skin, muscles (sensory)
Epineurium
provides tensile strength, continuous with dura
Perineurium
continuous with arachnoid, blood-nerve barrier
Two types of encapsulated receptors:
Muscle spindles, detect muscle length
Golgi tendon organs, detect muscle tension
Filum terminale
fixed to bottom of sacrum (coccyx). Kind of the remnant of cord regression.
Dorsal rootlets enter cord in
posterolateral sulcus
Ventral rootlets leave cord from
anterolateral sulcus
Anterior white commissure
two sides of cord communicate thru it. White matter, important crossing pathway.
Posterior intermediate sulcus
Separates bundles of sensory fibers arising from the:
Leg - fasciculus gracilis (FG)
Arm - fasciculus cuneatus (FC)
fasciculus gracilis
leg
fasciculus cuneatus
arm
Lumbosacral level
Not so much ascending white matter. Generally smaller in proportion to greymatter. Anterior horns are huge, have nurons that control leg movement. No prominent intermediate sulcus .
Posterior horn
Consists mostly of interneurons – don’t project outside much. Receives projection and talks to neurons in viscinity.
Processes remain in cord and
Projection neurons,long axons collect form ascending sensory pathways. Cortex down spinal cord.
Substantia gelatinosa
pain and temperature (**) – has opiod receptors there. Continuous with trigeminal spinal nucleus (pain and temp for face.
Lissauer’s tract
finely myelinated & unmyelinated fibers
Cytoarchitechtonic cell groups of Rexed
Laminae of importance include:
Lamina I - relays sensory signals
Lamina II - substantia gelatinosa (important in pain)
Lamina V - relays sensory signals
Spinal accessory nucleus (caudal medulla to C5),
forms accessory nerve (spinal accessory nerve)
Phrenic nucleus, innervates diaphragm
makes cervical cord injury serious, patient can not breathe
Spinal cord gray matter: Intermediate
Preganglionic sympathetic neurons all in T1-L3, most located in intermediolateral cell column, lateral extension of gray matter
Axons leave thru ventral roots
S2-S4, sacral parasympathetic nucleus, does not form a distinct horn
Axons leave via anterior roots and supply pelvic viscera
Clarke’s nucleus
intermediate cord - collection of neurons on medial surface of intermediate gray matter from T1 – L2
Relay nucleus for transmission of info to cerebellum, proprioceptive info from leg. Monitors position in space.
Since sensory many consider it part of posterior horn
Spinothelamic tract
conveys pain and temp
Corticospinal tract
descending motor system
conus medullaris
caudal cone-shaped end of the spinal cord. It extends to the L1 - L2 interspace
filum terminale
consists of the pia and arachnoid that extend from the conus medullaris to the coccyx (tail bone). Track of regression of spinal cord during development.
cauda equina
consists of dorsal and ventral roots and occupies the lumbar cistern.
Suspended by denticulate ligaments
pia-arachnoid extensions
great radicular artery (artery of Adamkiewicz
found at about T12 in most individuals, is especially large and is known as the great radicular artery (artery of Adamkiewicz
Motor part of cord supplied by
anterior spinal artery
Sensory part of cord supplied by
posterior spinal artery
Autonomic nervous system
Controls visceral activity
One difference
Sympathetic & parasympathetic efferents do not reach their targets directly: a two-neuron chain is involved. They stop short and go to another.
1) Preganglionic cell body in CNS, 2) postganglionic neuron in ganglion
Sympathetics & Parasympathetics
Preganglionic fibers: thin myelin
Postganglionic fibers: unmyelinated
Sympathetic ganglia located near CNS
Parasympathetic ganglia near innervated organ
Sympatheticsystem
Preganglionic fibers from T1 to L2/3 segments
Go down ventral roots, travel in spinal nerve to sympathetic chain, prevertebral ganglia, adrenal gland
Medulla vagus nerve
Dorsal motor nucleus of the vagus
Parasympathetic preganglionic cell bodies serving GI tract and gut derivatives
Nucleus ambiguus (hard to find)
Parasympathetic preganglionic cell bodies serving heart
A little bit of a generalization and overlap
Axons exit along with other vagal nerve fibers
Terminate in:
Wall of target tissue
Viscera from thorax to transverse colon
Location of postganglionic nerve cell bodies
Sympathetic: Preganglionic fibers
Some fibers synapse in nearest ganglion
Some ascend chain, synapse in SCG or MCG
Some descend, synapse in lumbar/ sacral ganglia
Some traverse chain, emerge as splanchnic nerves
Referred Pain
Occurs when visceral structure is innervated by same cord level as surface structure
Mixing of signals at spinal cord & brainstem levels
No somatotopic maps of viscera
