Week 5 Flashcards
alar plate → will become___________
interneurons
basal plate → will become _____________
lower motor neurons
posterior spinal cord= motor or sensory
senory
-anterior spinal cord= motor or senrory
motor
neural crest cells form the ___________________
dorsal root ganglia
SPinal Cord
-cord runs to____
L1/L2
-lumbar puncture is done below ________
L1/L2 (don’t want to puncture the spinal cord)
- subarachnoid space
- filled with CSF
-arachnoid matter
lumbar puncture is sued to rule out what
meningitis
-conus medullaris
= terminal portion of the spinal cord
fibrous extension of the pia mater anchors the spinal cord to the coccyx
filum terminale =
= delicate shelves of pia mater; attach the spinal cord to
the vertebrae
denticulate ligaments
continuous in 4th ventricle
central canal=
___ spinal nerves attach to the cord by _______________–
31
paired roots
cervical and lumbar enlargements = sites where nerves_______ the upper and lower limbs emerge
serving
collection of nerve roots at the inferior end of the vertebral canal
cauda equina
Signs of Cauda Equina Syndrome
-low back pain
-unilateral or bilateral radiculopathy
- saddle [perineal] paresthesia or anesthesia
- bowel and bladder disturbances [habit changes]
begin with urinary retention followed by overflow urinary incontinence
Lower extremity motor weakness
Reduced reflexes
anterior median fissure separates ____________
anterior funiculi
- posterior median sulcus divides ______________-
posterior funiculi
connects masses of gray matter; encloses central canal
Gray commisure
-posterior [dorsal] horns=
interneurons
anterior [ventral] horns=
interneurons and somatic lower motor neurons
lateral horns [T1-L2 spinal cord only]= contain
sympathetic nerve cell bodies
4 Zone of Gray Matter
- Somatic Sensory
- Visceral Sensory
- Visceral Motor
- Somatic Motor
- fibers run in 3 directions ([x-, y-, z- axes]
- divided into three funiculi [columns]= posterior, lateral, and anterior
- athways decussate/corss
Spinal Cord White Matter
somatotopy
- precise spatial relationships = orderly mapping of the body
- lower extremities = medial positions
- upper extremities are lateral
flaccid paralysis =
spastic=
flaccid=lower
spastic=upper
paresthesia [neuropraxia]
tingling, prickling, numbness on the skin surface
= posturing indicates damage to the corticospinal
tract; better prognosis than decerebrate
decorticate
Causes of decorticate
- cerebral infarction [stroke]
- intracranial hemorrhage
-1o or 2o brain tumor
- head injury
- increased intracranial pressure
-damage to cerebral hemispheres, internal capsule, thalamus, midbrain
damage to brain or cerebellum; very severs- elbows extended and hands flexed and pronated
-decerebrate=
causes of -decerebrate=
- brainstem tumor
- brainstem damage below the levels of the red nucleus; midbrain
- pontine stroke
- brain herniation
destruction of the anterior horn motor neurons by the poliovirus
Poliomyelitis
nonparalytic/preparalytic:
- generalized, non-throbbing headache
- fever of 38-40oC
- sore throat
- anorexia
- nausea/vomiting
- muscle aches
paralytic
severe muscle pain and spasms
asymmetric weakness, lower limbs affected more than upper limbs
- flaccid muscle tone
- absent reflexes
- paresthesia
cranial nerve, spinal cord, and brain involvement also possible
= most common degenerative disease of the motor neuron system
- incurable
- destruction of anterior horn motor neurons and fibers of the pyramidal tract
- can’t speak, swallow, breath
ALS
UMN Lessions
- spastic paralysis
- hyperactive reflexes
- [+] pathological reflexes
- [+] clonus
LMN Lessions
- flaccid paralysis
- hypoactive reflexes / areflexia
- [+] atrophy
- 4.[+] fasciculations
