Spinal cord anatomy and physiology Flashcards
Central gray matter consists of
two anterior (ventral) and two posterior (dorsal) horns united by gray commissure with central canal
Central gray matter - anterior (ventral) horns contain cell bodies that give rise to
efferent (motor) neurons
alpha motor neurons to affect muscles
gamma motor neurons to affect muscle spindles
Central gray matter - posterior (dorsal) horns contain cell bodies that give rise to
afferent (sensory neurons)
Cells bodies located in DRG
White matter - Ascending fiber systems
SENSORY PATHWAYS Dorsal columns/medial lemniscal system Spinothalamic tracts Spinocerebellar tracts Spinoreticular tracts
White matter - Descending fiber systems
MOTOR PATHWAYS Corticospinal tracts Vestibulospinal tracts Rubrospinal tracts Reticulospinal tracts Tectospinal tracts
White matter - Ascending fiber systems - DCML - conveys what
sensation of prop, vibration, tactile discrimination
White matter - Ascending fiber systems - DCML - divided into what
fasciulus cuneatus - UE tracts laterally located
fasciulus gracilis - LE tracts medially located
White matter - Ascending fiber systems - DCML - neurons ascend to where
medulla where fibers cross to form medial lemniscus - ascend to thalamus and then to somatosensory cortex
White matter - Ascending fiber systems - Spinothalamic tracts convey what
sensations of pain and temp (lateral spinothalamic tract)
sensations of crude touch (anterior spinothalamic tract)
White matter - Ascending fiber systems - Spinothalamix tracts ascend where
Ascend one or two ipsilateral spinal cord segments (lissauer’s tract) synapse, and cross in spinal cord to opposite side and ascent in ventrolateral spinothalamic system
White matter - Ascending fiber systems - Spinocerebellar tracts convey what
prop info from muscle spindles, GTOs, and touch and pressure receptors to cbm for control of voluntary movements
White matter - Ascending fiber systems - spinocerebellar tract - dorsal spinocerebellar tract ascends to
ipsilateral inferior cerebellar peduncle
White matter - Ascending fiber systems - spinocerebellar - ventrospinocerebellar tract ascends to
contralateral and ipsilateral superior cerebellar peduncle
White matter - Ascending fiber systems - spinoreticular tracts convey
deep and chronic pain to reticular formation of bainstem via diffuse, polysynaptic pathways
White matter - Descending fiber systems - Corticospinal tracts arise from
primary motor cortex, descend to brainstem, cross in medulla to ventral gray matter (ant horn cells)
10% of fibers do not cross and travel to anterior corticospinal tract to cervical and upper thoracic segments
White matter - Descending fiber systems - Corticospinal tracts are important for
voluntary motor control
White matter - Descending fiber systems - Vestibulospinal tracts arise from
vestibular nucleus and descend to spinal cord in lateral (uncrossed) and medial (crossed and uncrossed) vestibulospinal tracts
White matter - Descending fiber systems - vestibulospinal tracts important for
control of muscle tone, antigravity muscles, and postural reflexes
White matter - Descending fiber systems - Rubrospinal tracts arise from
contralateral red nucleus and descend in lateral white columns to spinal gray
White matter - Descending fiber systems - Rubrospinal tracts assist in
motor function
White matter - Descending fiber systems - Reticulospinal tracts arise in
reticular formation of brainstem and descend in ventral and lateral columns, terminates both on dorsal and ventral gray
White matter - Descending fiber systems - Tectospinal tracts arise from
Superior colliculus (midbrain) and descends to ventral gray
White matter - Descending fiber systems - Tectospinal tracts assist in
head turning responses to visual stimuli
Autonomic NS - two divisions
sympathetic and parasympathetic
Autonomic NS - sympathetic does what
fight or flight
thoracolumbar division T1-L2
Inc HR, BP, VC to redistribute blood, inhibit peristalsis
Autonomic NS - parasympathetic does what
craniosacral division, CN III, VII, IX, X, pelvic nerves
Conserves and stores homeostasis
Slows HR, BP, inc peristalsis and glandular activity
