Neurology Flashcards
where are the rostral & caudal directions
rostral = angled up toward forehead
caudal= angled down toward neck
where are the dorsal and ventral directions
dorsal = above rostral caudal & rhs of brainstem
ventral = below rostral caudal direction and lhs of brainstem
what is the coronal plane
frontal plane
what is the sagittal plane
longitudal plane (separating left & right)
what is the diff. between neurons & neuroglia
neurons send and receive signals while neuroglia support & protect the neurons
what are the (5) functions of the nervous system
monitor the internal & external environment
monitor sensory input & initiate responses
regulate & coordinate internal environment
control mental activity
control muscles & glands
what organs are in the PNS
cranial nerves
spinal nerves
enteric plexuses in small intestine
sensory receptors in the skin
what is in the CNS
brain & spinal cord
what is contained within the brain & spinal cord (CNS)
neural tissue
connective tissue
blood vessels
describe & point to the 4 lobes
frontal, temporal, parietal & occipital are visible from the exterior surface
visible deep within the groove is the insular cortex/lobe
what is myleination
insulation like a cord
insulated for electrical forces to travel through the axon
what are cell membranes made of
phospholipids
what is the difference between demyelination and unmyelination
demyelination is a disease because it implies the myelination has been stripped off e.g. autoimmune disease like multiple sclerosis
Unmyelination is fine because about 5% of axons are unmyelinated
what is the difference between white & grey matter
grey matter contains the cell bodies of the neurons (unmyelinated)
white matter contains the myelinated axons
what is the function of the CNS
sensory data: internal & external
motor commands: control peripheral organs
higher functions: intelligence, memory, learning, emotion
what is conus medullaris
cone like structure where the spinal cord terminates
where does the spinal cord terminate (vertebrae numbers)
between L1 & L2 (12th rib)
how is the spinal cord different from the brain in terms of matter
the white matter is on the outside and they grey matter is on the inside because the neurons are travelling toward the brain
what is cervical enlargement
nerves of shoulders & upper limbs
what is lumbar enlargement
nerves of pelvis & lower limbs
what is conus medullaris
termination of spinal cord, cone like [finish this]
what is filum terminale
fibrous tissue (ligament) that runs down from conus medullaris to coccygeal ligament.
it’s like a bungee cord because it stops the vertical movement of the spinal cord off the coccyx
what is cauda equina
looks like a horse’s tail, nerve roots extending below conus medullaris
what is a collection of axons in CNS
tract
what is a nerve
collection of axons in PNS
what is the name for a collection of cell bodies in the CNS
nucleus (not the nucleus within a cell)
what is ganglia
collection of cell bodies in the peripheral nervous system
where do dorsal and ventral roots exit between successive vertebrae
through intervertebral foramen
explain the naming of the spinal nerves & numbers
31 spinal nerves
cervical region: 7, get their name from vertebrae caudal to them
thoracic region: get their name from the rostral vertebrae e.g. t1 below vertebrae t1, t2 below vertebrae t2
why are there 8 cervical nerves when there are only 7 cervical vertebrae
there is a nerve between c7 & t1 hence c8 because they get their names from the vertebrae caudal to them
what is a tract, and what are the names of 4 tracts
HONDA CRVS
C = CORTICO
R = RUBRO
V = VESTI
S = SPINO
- corticospinal
- spinothalamic
- rubrospinal
- vestibulospinal
what is in the PNS
- nerves: cranial & spinal (12 & 31)
- enteric plexuses in small intestine
- plexus = nerves that come together & form network
- ganglion
- sensory receptors in the skin
what are cranial nevers
nerves that exit from the brain stem (they are peripheral).
diagram for branches of the nervous system
what are the branches of the spinal nerves
ventral root = contains axons of motor neurons
dorsal root = contains axons of sensory neurons
how do axons get their energy supply / oxygen
axons can’t store enegry so they recieve it from the large blood vessels (arteries) that serve the brain
how do axons get their energy supply / oxygen
axons can’t store enegry so they recieve it from the large blood vessels (arteries) that serve the brain
define nerve, and it’s more specific name
bundles of axons with connective tissues & blood vessels, aka peripheral nerves. they carry sensory information & motor commands in the pns
what are the functional divisions of the PNS
afferent = carries sensory info from PNS to CNS
efferent = carries motor commands from CNS to muscles & glands
what is the difference between an effector & a receptor
receptor = detects changes in environment, complex sensory organs e.g. ears & eyes, neurons & specialised cells
effector = responds to efferent signals, cells & organs
what is SNS and it’s functions
controls skeletal muscle contractions (voluntary & involuntary i.e. reflexes, not autonomic because it has a stimulus)
what is the motor division of the PNS
ANS = autonomic nervous system
contains visceral motor neurons that carry info from CNS to all other peripheral receptors e.g. glands, skin, muscle
what are the 3 ANS divisions
sympathetic = fight or flight, from thoracic & lumbar SpC (thoracolumbar)
T1 –> L2
increase heart rate, respiratory rate
parasympathetic = rest or digest from cranial nerves and sacral SpC (carniosacral)
C1 –> S4
enteric nervous system =
explain the role of the ganglia in the autonomic nervous system [EXAM Q]
there are pre and post ganglionic fibres
the pre fibres are short, while the post are very long in the sympathetic nervous system so they can travel all the way to the organ
in the parasympathetic, the pre ganglionic fibres are very long, while the post are very short
when neurons exchange info and the membranes fuse together are the synaptic vesicles released?
no, only the neurotransmitters are released
how are nerve pain signals blocked
administering a small amount of anaesthetic
what are dermatomes
bilateral region of skin monitored by specific pair of spinal nerves
what is the diff. between pre & post synaptic cells
pre = neuron bringing information
post = neuron receiving information
synapse = point of info. exchange
what is the synaptic cleft
the gap between two synaptic membranes where the neurotransmitters are released, and then bind to receptors on the post synaptic cells. if they don’t bind the information won’t be received.
it also contains enzymes to break down the neurotransmitter
what are the features of neurotransmitters
- chemical messengers
- released at presynaptic membrane
- affect receptors at postsynaptic membrane
- broken down by enzymes
- reassembled at synaptic knob
what is an anaxonic neuron
can’t tell where the axon is, can only see cell body
what is a bipolar neuron
two poles from body, seen in retina
what is a unipolar neuron
sensory neurons in dorsal root ganglia, only one pole
what is a multipolar neuron
2+ processes, single axon, multiple dendrites
what are the 3 functional classifications of neurons
sensory, motor, inter
inter = ability to stop information from travelling to motor
what are the functions of sensory neurons
afferent neurons of the PNS i.e. they bring info into the CNS
what are the types of sensory receptors
based on stimulus:
- inter
- exter
- proprio = postition & movement of muscles & joints
what are afferent fibrres
sensory & ascending pathways