central nervous system Flashcards
what are the 2 components of the CNS?
brain
spinal cord
cerebral spinal fluid CSF is also present
what protects the brain?
skull
where is the spinal cord?
in vertebral canal
what are meninges?
3 layers of protective tissue that provide protection to the CNS (brain and spinal cord)
what are the 3 meninges layers?
dura mater
arachnoid mater
pia mater
what is dura mater?
hard, external shell (outer layer of meninges)
what is arachnoid mater?
cushioning structure
in between dura and Pia mater
what is Pia mater?
soft, internal meninge
what are the segments of the spinal cord?
8 cervical 12 thoracic 5 lumbar 5 sacral - fused 1 coccygeal - fused
what are the 2 types of matter in the spinal cord and brain?
grey matter
white matter
what is grey matter?
contains neuron cell bodies
information received and processed
like flats/offices
what is white matter?
contains nerve axons (and myelin)
signals are transported via axons
like lifts
why is there relatively more white matter in the cervical and thoracic regions than in the lumbar and sacral?
because cervical and thoracic are closer to the brain so have more axons bundling into their white matter as you ascend the spinal cord
why is there a greater amount of grey matter in cervical and lumbar regions?
greater surface area/number of organs so need more cell bodies to deal with information volume
dorsal root ganglion and dorsal horn
in the posterior part of spinal cord
location of 1st order afferent neuron terminals
(sensorial bodies that bring information into system)
will have cell bodies of 2nd order sensory neurons
(take signal to hypothalamus)
ventral root and horn
in anterior section of spinal cord
cell bodies of efferent motor neurons at extremities
motor neuron axons leave spinal cord via ventral nerve root
nerve axon route into spinal cord
sensory 1st oder axons from peripheryinto posterior of cord via dorsal root ganglion and dorsal root
leading to dorsal horn
nerve axon route out of spinal cord
motor efferent neurons exit the anterior of the cord via ventral horn and ventral root
what is the purpose of the reflex pathway?
associated with immediate risk
no time for signal to be sent to cortex for processing
(unpractical as body can be harmed so avoid time required for cognitive response)
what is the unique component of reflex pathway?
interneuron shortcut
still part of the CNS buts stays within the spinal cord only
brain structure
grey matter on the outside - cerebral cortex
white matter on the inside/core - axons, tracts (myelin)
reverse of spinal cord
what 2 components makes the forebrain?
cerebrum
diencephalon
cerebrum roles
sensory and motor integration functions
language
memory
perceptions
emotions
diencephalon parts
thalamus
hypothalamus
hypothalamus roles
role in homeostasis e.g. thermoregulation
hormone production & associated pituitary gland (endocrine connection)
circadian rhythms
motivation
emotional responses e.g. stress
thalamus roles
sensory processing
midbrain (and brainstem) roles
visual and auditory processing
pain control
hindbrain parts
pons
medulla oblogata
cerebellum
medulla oblongata roles
vital centres regulate breathing, heart and blood vesses
cerebellum roles
balance control
what is the affect of strokes on the brain?
affect cortical sensory areas
cause misfunctioning of sensory responses
not so much the visual area - at rear of brain so more trauma affected
