1 - Nervous System Flashcards
what’s the CNS made up of
brain spinal cord S/M/R neurons
what does the brain do w sensory info
receives and processes
what is the spinal cord responsible for
reflexes as they bypass the brain, and signal co-ord to and from the brain
how is the peripheral ns different to the autonomic aand somatic
it has motor and sensory neurons whereas the other two only have motor
somatic ns is different to the autonomic branches
it’s voluntary but autonomic is automatic
name the body orientation
caudal - bottom of body
dorsal - back
rostral - top
ventral - bottom
define lateral
towards the sides of the body
define medial
towards the middle of the body
define ipsilateral
the same side of the body
define contralateral
opposite sides
how is the spinal cord divided
C1-8 - top: head, neck, hands, arms
T1-12 - middle: chest/abdomen
L1-5 - near the bottom: legs
S1-5 - properly bottom: excretion/egestion/sex
label the brain orientation
caudal - back
dorsal - top
rostral - towards nose
ventral - bottom
what are horizontal, frontal, and saggital slices
h: parallel to ground
f: parallel to forehead
s: e.g. between hemispheres
what does the forebrain contain
telenephalon and diencephalon
what ventricles are the telencephalon and diencephalon
t: lateral
d: third
what does the diencephalon contain
thalamus and hypothalamus
role of the diencephalon
sensory integration and relay
homeostasis
emotion
attention
what does the midbrain contain
tegmentum
optic tecta
roles of the midbrain
posture
alertness
AV relay
what does the hindbrain contain
cerebellum
pons
medulla
what ventricle is the hindbrain
fourth ventricle
role of the cerebellum
motor coordination
balance
muscle tone
role of the pons and medulla
involuntary body functions
cognitive motor skills
role of the basal ganglia
voluntary, learnt emotion
role of frontal lobe
motor control
exec functions
role of parietal lobe
bodily sensations
spatial relationships
what are broddman’s areas and how many of them are there
regions of cerebral cortex
47
how are the brain and spinal cord physically protected
skull; vebretal column
define meninges
protective sheaths of tough connective fibre surrounding the CNS
what are the 3 layers of the meninges
dura mater, arachnoid membrane, pia mate
what is dura mater
tough, flexible
what is arachnoid mater
soft, spongy
what does the pia mater contain
brain and spinal cord’s blood vessels
what meninges layers does the PNS have
only pia and dura mater
functions of the meninges
protect CNS from mechanical injury
provide skull and hemispheres w good blood supply
provide space for CSF
what are the functions of the CNS
reduce brain weight and shock to CNS by sudden head movement
where is the CSF
subarachnoid space and in ventricles
how are the ventricles connected
lateral connected to third which, through the cerebral aqueduct, connects to the fourth
what produces CSF and where does it flow
choroid plexus in fourth ventricle
subarachnoid spaces, then same spaces around CNS, then abosrbed into blood
what similarity is there with the medulla oblongata in species
most caudal region in the hindbrain and joins brain w spinal cord
how is nervous system formation similar across species
structures derive from neural tube’s ectoderm
what cranial nerves do species share
terminal, olfactory (I), optic (II), auditory (VIII), somatosensory, (V), and others
how are species’ midbrains similar
midbrain roof has superior and inferior colliculi
how is dopamine production similar
all dopamine cells in ventral tegmentum
how is the CNS formed
ectoderm forms neural plate and plate ridges curl together longitudinally and fuse to form a neural tube, then forming the brain and spinal cord
what does the rostral end of the neural tube form
3 chambers for the fore mid hind brains
what does the forebrain divide into
lateral and third ventricles
what does the midbrain chamber form
cerebral aqueduct
what does the hindbrain form
metencephalon and myelencephalon
how does the cerebral cortex develop
surrounds cerebral hemispheres and deepest of the 6 layers develops from stem cells first
what do progenitor cells in the ventricular zone outside the neural tube do
symmetrical division: divide into 2 more of these cells to enlarge the ventricular zone
when do progenitor cells start assymetrical division
after 7 weeks
what does asymmetrical division lead to
produces radial glia in ventricular zone which extend outwards and attach to pia mater
what happens after asymm division
progenitor cells and some radial glia undergo apoptosis where cells’ killer genes activated
how is the body mapped onto the brain
dendrites and groups of axons develop systematically so synaptic connections form
define neurogenesis
stem cells dividing to produce new neurons
