Anatomy 1 (basics) Flashcards
what makes up the PNS
cranial and spinal nerves
what makes up a neuron
dendrites
cell body
axon
what do you call a collection of neural bodies in the PNS
ganglion
what do dendrites do
receive information
what do axons do
transmit impulses to communicate with another neuron or effector cell
what is a multipolar neuron
most common kind
multiple dendrites to one axon
what is a unipolar neuron
one cell body with two processes - looks like a straight line
what type of neuron are motor neurons
multipolar neurons
what type of neuron are sensory neurons
unipolar
where is the cell body of multipolar neurons found
in the CNS
sends info out of the CNS into the PNS towards muscles
where is the cell body found in unipolar neurons
PNS
sends info up into the CNS to the brain
what is a nerve
axons surrounded by connective tissue and blood vessels
what is a single modality nerve
a nerve where all the axon bundles have the same function (eg. all somatic motor)
what are the types of function a nerve can have
somatic motor somatic sensory special sensory sympathetic parasympathetic visceral afferent
what is a mixed modality nerve
most nerves!!
mix of axon bundles with different functions
what are the 12 cranial nerves
I - olfactory II- optic III- oculomotor IV - trochlear V- trigeminal VI- abducens VII- facial VIII- vestibulocochlear IX - glossopharyngeal X - Vagus XI- spinal accessory XII- hypoglossal
how many spinal nerves are there
31 pairs
8 cervical 12 thoracic 5 lumber 5 sacral 1 coccygeal
where are the spinal nerves found
ONLY in the intervertebral foramina
How do the spinal nerves connect to the vertebrae
via roots and then rootlets
how to spinal nerves leave the intervertebral foramina
anterior and posterior rami
which rami is smaller anterior or posterior
posterior
what travels along posterior roots
SENSORY information (push ur feelings to the back xx)
what travels along anterior roots
MOTOR information
main difference between roots and rami
Rami have mixed motor and sensory information
Roots always have either sensory or motor NEVER MIXED (posterior = sensory, anterior = motor)
what path do all motor axons take
From anterior horn of spinal cord into anterior rootlets then into anterior root then into spinal cord
what path do all sensory axons take
From posterior horn into posterior rootlets then into posterior root and into spinal cord
what do each spinal nerve pair supply a body segment with
general sensory supply to all structures
somatic motor supply to skeletal muscles
sympathetic nerve supply to skin and smooth muscle of arterioles
what is a dermatome
area of skin supplied with sensory info from a single spinal nerve
what is a myotome
skeletal muscles supplied with motor innervation from a single spinal nerve
what dermatome is the nipple
T4
what dermatome is the umbilicus
T10
what dermatomes cover the upper limbs
C5-T1
what dermatomes cover the lower limb, gluteal region and perineum
L2-Co1
what are nerve plexuses
intermingled anterior rami from a number of spinal nerves (cross over between the nerves at the rami)
what spinal nerves form the cervical plexus
C1-C4
where does the cervical plexus innervate
posterior scalp
neck
diaphragm (C3,4,5 keeps the diaphragm alive)
what nerves form the brachia plexus
C5-T1
upper limb
What nerves form the lumbar plexus
L1-L4
lower limb
what nerves form the sacral plexus
L5-S4
lower limb, gluteal region and perineum
where does sympathetic outflow leave the spinal cord
thoracolumbar
T1-L2
what makes T1-L2 different
they have lateral horns - sympathetic nerve cell bodies
what are the 4 paths that can be taken by sympathetic nerves
- Ascend up sympathetic trunk and then synapse
- Synapse at level of entry
- Descend down sympathetic trunk and then synapse
- Don’t synapse in sympathetic trunk and enter an abdominopelvic splanchnic nerve
how do parasympathetic axons leave the CNS
Crania-Sacral
CN III, VII, IX and X
sacral nerves
what is Horner’s syndrome
Impaired sympathetic innervation to head and neck
Symptoms of Horner’s syndrome
root of neck trauma carotid distension internal jugular vein engorgement deep cervical node metastases pancoast tumour (In lung apex)
