spinal cord (part of CNS) Flashcards
what does the spinal cord run through?
vertebral canal
what is the spinal cord continuous with?
medulla oblongata
where does the spinal cord begin?
foramen magnum
where does the spinal cord taper in and what is it called?
in the lumbar region to end in the conus medullaris “cone shaped”
what is the spinal cord anchored to sacrum by?
fillum terminale (c.t)
how many pairs of spinal nerves?
31 pairs and cauda equina (spinal nerves roots) which come off the spinal cord (part of PNS)
where does the spinal cord thicken?
where many spinal nerves emerge cervical enlargement
how many meninges does the spinal cord have?
3- pia mater, arachnoid, and dura mater
what large space does the spinal cord have?
large epidural space above dura has adipose tissue, spinal anesthics go here as they are lipid soluble drugs
what circulates in spinal cord?
CSF circulates in central canal (continuous with ventricles of brain) and flows around spinal cord in subarachnoid space
what are the layers of white and grey matter
white matter is superficial to grey matter
how is gray matter organized?
organized into horns connected by central commissure
how is white matter organized?
organized into tracts which form columns
what does each spinal nerve have?
has a dorsal root and a ventral root
what does the dorsal root have?
each has a ganglion
how are posterior gray horns functionally organized?
somatic sensory input ss
visceral sensory input vs
how are lateral gray horns organized?
visceral motor output VM to cardiac smooth muscles and glands
how are the anterior gray horns organized?
somatic motor output SM to skeletal muscle
what is the white matter in the spinal cord?
bundles of myelinated axons
tracts are organized into columns
tracts ascend (sensory to CNS)
or descend (motor from CNS)
what are the two ascending tracts?
spinothalmic tracts and spinocerebellar
how do the spinothalmic tracts function?
sensations from body surface (touch pain)
goes through spinal cord
then medulla oblongata
then midbrain
to thalamus which screens info
then cerebrum
are contralateral
how do the spinocerebellar tracts function?
sensory info from muscles/joints/tendons
goes through spinal cord
to medulla
through pons
then to cerebellum (subconscious motor)
posterior tract so is ipsilateral
what is the type of descending tract and its function? (motor)
corticospinal tracts or pyramidal
brain to spinal cord
conscious control of skeletal muscle
starts in cerebrum
to midbrain -cerebral peduncles
to spinal cord
to skeletal muscle
