Anatomy: Nervous System Flashcards
2 types of motor function
voluntary, involuntary
skeletal muscle movement is (voluntary/involuntary)
voluntary
what are involuntary motor functions
smooth and cardiac muscle, glands
what are the two anatomical subdivisions of the nervous system
- central nervous system
- peripheral nervous system
what makes up the central nervous system
brain, spinal cord, central controller
what makes up the peripheral nervous system
nerve tissue NOT associated with the CNS - spinal nerves, cranial nerves, autonomic nerves
what nerves make up autonomic nerves
sympathetic, parasympathetic, visceral afferents
where do autonomic nerves supply
organs, smooth muscle, glands
ganglion
collection of nerve cell bodies
what is a bundle of axons called in the CNS
tract
what is a bundle of axons called in the PNS
nerve
where do dendrites come off of
nerve cell body
what surrounds nerve axons and what is its function
- myelin sheath
- insulation
what makes up a peripheral nerve
bundles of axons wrapped in connective tissue
bundles leave peripheral nerves as
branches
what are the 6 modalities an AP can be conducted as
- somatic sensory
- somatic motor
- special sensory
- visceral afferent
- sympathetic
- parasympathetic
axons can either be: all from the same modality or mixed - true/false
true
an efferent is a _ nerve and goes towards
- motor
- body wall, structure or organ
an afferent is a _ nerve and goes towards
- sensory
- brain
what is the cortex of the brain
outermost later of cerebral hemispheres
the cortex consists of
sulci and gyrus
sulci
shallow grooves surrounding gyrus
gyrus
ridge-like elevation of cerebral cortex
name the 4 lobes of the cerebral cortex
- occipital
- parietal
- temporal
- frontal
name CN I
olfactory
name CN II
optic
name CN III
oculomotor
name CN IV
trochlear
name CN V
trigeminal
name CN VI
abducent
name CN VII
facial
name CN VIII
vestibulocochlear
name CN IX
glossopharyngeal
name CN X
vagus
name CN XI
spinal accessory
name CN XII
hypoglossal
what is the acronym for the CN modality
Some Say Marry Money But My Big Brother Says Big Boobs Matter More
what is the big foramen in the skull called
foramen magnum
describe the course of a cranial nerve
CNS part of course -> intracranial part of course -> exit via foramen -> extracranial part of course
where does the spinal cord connects to and pass through
connects to the brain through foramen magnum
how is the spinal cord connected
vertebral canal
name the 4 segments of the vertebral canal
- cervical
- thoracic
- lumbar
- sacral/coccygeal
how many vertebrae does the cervical section of the vertebral column have
8 - C1-C8
how many vertebrae does the thoracic section of the vertebral column have
12 - T1-T12
how many vertebrae does the lumbar section of the vertebral column have
5 - L1-L5
how many vertebrae does the sacral section of the vertebral column have
5 - S1-S5
how many vertebrae does the coccygeal section of the vertebral column have
1 - C0
what are the two enlargements of the vertebral column
cervical and lumbosacral
at what level does the spinal cord end and what is it called
- inferiorly at L1/2
- conus medullaris
the adult vertebral column is shorter than the spinal cord - true/false
false
what does the spinal cord become when it ends
cauda equina
how do lumbar and sacral spinal nerves reach their respective foramen
they have to descend in the vertebral column
how many vertebrae are there overall
33
how many vertebrae does each section of the vertebral column have
C7 T12 L5 S5 Co4
what is special about the sacral vertebrae
they are fused to form 1 sacrum but still have foramen
what is special about the coccygeal vertebrae
they are fused to form 1 coccyx
how are spinal nerves named and whats the exception
named according to the vertebrae above it, except that of the cervical region where they are named according to the one below it
where does the C8 spinal nerve exit
between C7 and L1
where do spinal nerves supple
soma
spinal nerves are only located where
within the intervertebral foramen
from foramen where do spinal nerves connect to via what
- spinal cord via roots and rootlets
- soma via rami
where do the posterior rami supply
a small posterior strip of soma
where do anterior rami supply
rest of the posterior, lateral and anterior strip of soma
how do spinal rami supply the limbs and what type of rami
via plexus
- anterior
dermatome
strip of skin supplied by anterior and posterior rami of spinal nerves (bilateral)
T4 dermatome
male nipple
T10 dermatome
umbilicus
nerve plexuses
networks of intertwined anterior rami (or nerves)
what spinal nerves are in the cervical plexus and where does it supply
C1-C4
posterior scalp, neck wall and diaphragm
what spinal nerves are in the brachial plexus and where does it supply
C5-T1
upper limb
what spinal nerves are in the lumbar plexus and where does it supply
L1-L4
lower limb
what spinal nerves are in the sacral plexus and where does it supply
L5-S4
lower limb, gluteal region, perineum
what are the two functional subdivisions of the nervous system
- somatic nervous system
- autonomic nervous system
what does the soma include
head, neck and chest walls, diaphragm, back, abdominal and pelvic walls, limbs
what structures are included in the soma
skin, fascia, skeletal muscles, skeleton, internal lining of body cavities
what does the somatic nervous system innervate and sense
soma and external environment
what does the autonomic nervous system supply and sense
visceral motor system and internal environment
where does the autonomic nervous system supply
viscera, glands, smooth and cardiac muscle, external lining of organs
what structures are included in the autonomic nervous system
- internal organs in body cavities - chest, pelvic, abdominal
- body wall organs - sweat glands, arrector smooth muscles, arterioles
what are the three types of receptors in the body wall
mechanoreceptors, thermoreceptors, nociceptors
what do mechanoreceptors sense
coarse and fine touch, vibration, proprioception
what do nociceptors sense (describe how its felt)
- pain
- sharp, stabbing, well-localised
describe how an AP is conducted via somatic sensory nerves
- receptors at dermatome stimulated
- APs conducted along anterior ramus
- APs conducted via posterior root ganglions
- APs arrive at posterior horn of the spinal cord segment
- APs cross over midline and ascend to brain
describe how a motor AP is conducted
- somatic motor axons cross over in brainstem and descend to anterior horn
- APs conducted along axons in anterior rootlets -> roots -> spinal nerves
- APs conducted along named nerves plexus
- APs synapse and produce movement
reflexes are _ and miss out the _
rapid, brain
describe the course a reflex AP takes
sensed -> spinal nerve -> P roots -> A rootlets -> spinal nerve -> motor function
the actions of the autonomic nervous system are (voluntary/involuntary)
involuntary
the ANS’ sensory neurones are _ and its motor neurones are _
- visceral afferents
- visceral efferents
most autonomic organs contain both
parasympathetic and sympathetic neurones
ANS motor neurones contain both sympathetic and parasympathetic neurones - this is called
dual motor control
what are the types of pain sensed by visceral afferents
- ischaemic (decreased blood flow)
- colicky (obstruction)
how is visceral pain descrived
dull, achy, nauseating, poorly localised
colicky pain is different in that
it can be sharp/localised and referred to the body wall
where does the sympathetic division of the ANS supply
internal and body wall organs, arterioles
the sympathetic nervous system is also known as
fight or flight
describe the route of a sympathetic nerve
- originates in the autonomic centres in brain
- passes down the spinal cord exiting at T1-L2 with spinal nerves and anterior roots and rootlets
- paravertebral ganglion in the sympathetic trunk
- then passes into all spinal nerves and runs with A/P rami, artery or splanchnic nerve to organ
why do sympathetic nerves exit at T1-L2
only T1-L2 vertebrae have lateral horns for cell bodies on synaptic sympathetic neurones
where does the parasympathetic nervous system supply
same internal organs as sympathetic however not body wall organs or arterioles
the parasympathetic nervous system is also known as
rest and digest - return to homeostasis
describe parasympathetic outflow
- leave CNS via CNs III, VII, IX, X and sacral spinal nerves
- ganglia in head goes to lacrimal and salivary glands
- CN X (vagus) supplies organs of neck, chest and abdomen as far as the midgut
- sacral spinal nerves carry P nerves to axons in the hindgut, pelvis and perineum
craniosacral outflow
parasympathetic nerves leaving via cranial nerves and sacral spinal nerves
