nervous system Flashcards
General and specific
functions of the nervous system
interprets internal and external signals , facilitates coordination, reflex reactions
what does the nervous system coordinate with?
endocrine system
what does the CNS consist of
brain and spinal cord
what does the CNS do
process sensory information
somatic nervous system
controls voluntary movements
autonomic nervous system
controls involuntary movements
what does the autonomic nervous system consist of
sympathetic and parasympathetic
sympathetic
“fight or flight”
parasympathetic
“rest or digest”
motor neurons
CNS to muscle and glands
sensory neurons
carry signals from the receptors in the body to the spinal cord
sympathetic actions eg
pupils dilate, inhibits salivation, relaxes bronchi, increases heartrate
parasympathetic actions eg
constricts pupils, stimulates saliva flow, contricts bronchi, slows heart rate
relay neurons
carry messages from one part of the CNS to another
dendrites
large surface area, collection information from other neurons and passes it to the cell body
myelin sheath
speeds up conduction
resting potential of a membrane
-70 mV
voltage- gated ion channels
respond to a change in cell membrane potential
ligand- gated ion channels
respond to specific neurotransmitters and other molecules
mechanically gates ion channels
respond to changes in the mechanical force on the membrane
saltatory conduction
in myelinated neurons, the signal ‘jumps’ along the axon via the nodes of ranvier
A fibres
myelinated with a large diameter - 300mph
B fibres
light myelination with medium diameter - 30 mph
C fibres
no myelination with small diameter- 2 mph
primary somatosensory cortex
receives sensory information- proprioreceptors (muscles, joints and tendons) and sensory information from the skin up from the thalamus
prefrontal cortex
integrates sensory information from primary somatosensory cortex to relate back to past experience
somatosensory association cortex
integrates sensory information from primary somatosensory cortex to relate back to past experience, brings in prior knowledge
primary motor cortex
controls previse voluntary movement
prefrontal cortex
decision making
premotor cortex
related to planning, learned skilled motor activity
neuromuscular disorder eg
muscular dystrophy
neurodevelopmental disorder eg
autism
infection-related disorder eg
meningitis (membranes of the brain)
auto-immune disorder eg
multiple sclerosis
vascular disorder eg
vascular dementia (shrinking of the brain tissue)
psychological disorder eg
depression
dementia related disorder eg
alzheimers
trauma related disorder eg
brain haemorrhage
red flag symptoms defintion
serious condition symptoms that could indicate a spinal cord compression, metastatic disease or cauda equina
symptoms of red flag
night sweats, unintentional weight loss, bilateral weakness
cauda equina syndrome (CES)
dysfunctional of multiple lumbar and sacral nerve roots
herniated intervertebral disc
defect in annulus fibrosis, the pulpous protrudes out of the disk and impinges on a nerve root
herniated disc symptoms
sharp pain down the legs, numbness or weakness down one side of leg/arm
treatments of back pain
analgesia (pain relief), muscle relaxants, preventative measures (lifestyle changes), surgery and physiotherapy
what imaging modality is used on spinal cord injuries?
usually MRI
what imaging modality is used on stokes?
CT
spondylolisthesis
anterior slippage of a vertebral body in relation to the one below, can occur anywhere in the vertebral column
hemorrrhagic stroke
bleed on the brain, usually caused by trauma
ischemic stroke
loss of blood supply, symptoms of hypertension and atherosclerosis
why do we need to differentiate the difference between hemorrhagic and ischameic strokes asap?
as ischaemic stroke patients are given clot bursting drugs
subarachnoid haemorrhage
bleeding in the space between the brain and the surrounding membrane
subdural hematoma
collection of blood that forms on the surface of the brain
extradural haemorrhage
an acute haemorrhage between rheumatoid arthritis and dura mater and the inner surface of the skull
multiple sclerosis
loss of myelin sheath, it is caused by your immune system mistakenly attack the brain and nerves
Parkinson’s disease
lack of dopamine in the substantia nigra
neuralgia
nerve pain
SOL
space occupying lesion
TIA
transcient ischaemic attack
SAH
subarachnoid haemorrhage
CSF
cerbraspinal fluid
identify the two structures that make up the vertebral discs and describe what happens during disc herniation (4)
- nucleus pulposus and annulus fibrosus
- defect in annulus fibrosis which means the pulpous protrudes out of the disc and impinges on a nerve root
identify the three membranes which act as a protective covering (3)
dura mater, arachnoid, pia mater
identify three forces that lead to the primary injuries of the spinal cord (3)
compression stretch and shear forces
Name 3 symptoms accompanying LBP and what could this indicate? How do we image for this?
- h/o trauma, night sweats and unintentional weight loss
- neurological deficits
- bilateral weakness
- cauda equina or metastatases
- MRI
