Download spinal cord - Dr Magrann

There are 12 pairs of cranial nerves, numbered with Roman numerals.
I Olfactory
II Optic
III Occulomotor
IV Trochlear
V Trigeminal
VI Abducens
VII Facial
VIII Vestibulocochlear
IX Glossopharyngeal
X
Vagus
XI Accessory Nerve
XII Hypoglossal
1
I.
OLFACTORY nerves
Transmits the sense of smell.
II. OPTIC NERVE: Transmits visual information from the eye’s retina.
III Occulomotor Nerve: this controls most of the extrinsic muscles of the
eye (that move the eyeball). They also have parasympathetic innervation
in the iris (pupil) and cilliary (controls the lens).
2
IV. Trochlear Nerve: supplies one of the extrinsic eye muscles
V. Trigeminal Nerve: This is the main sensory nerve of the face.
It has a large branch that passes through the foramen ovale of the skull.
Problems with CN-5 are called TRIGEMINAL NEURALGIA, which is
excruciating pain in the face from nerve inflammation.
3
VI: Abducens controls one of the eye muscles (lateral rectus).
VII Facial Nerve: This innervates the muscles of facial expression and
salivary glands.
A person who cannot blink or smile may have damage to what nerve?
VII Facial Nerve
A person who cannot easily taste sweet, sour, or salty substances has damage
to what nerve? VII Facial Nerve
BELL’S PALSY is damage of the facial nerve Needs to be distinguished
from a stroke.
4
VIII. VESTIBULOCOCHLEAR nerve transmits hearing and balance.
IX: GLOSSOPHARYNGEAL
a) signals the pharynx to constrict (along with X) during swallowing.
b) Innervates top of tongue
c) Has baroreceptors
5
X Vagus Nerve
a) Parasympathetic supply to organs
b) Moves the larynx during speech
c) Signals pharynx to constrict during swallowing (with CN IX)
.
This is the only cranial nerve that travels into the abdomen.
The majority of the parasympathetic outflow from the head is by the vagus
nerve.
6
XI: ACCESSORY NERVE enters the skull through foramen magnum and
leaves through the jugular foramen. It just supplies the shoulder muscles.
XII. HYPOGLOSSAL NERVE (hypo=under; glossal=tongue) - supplies
the under surface of the tongue. Damage causes impairment of speech.
7
The SACRAL PLEXUS is made up of the spinal nerves exiting the spinal
cord from the level of L4 to S5.
There are 31 pairs of spinal nerves. They come out of all regions of the spinal
cord. They are a mixture of sensory and motor.
white matter is white because myelin surrounds many of the axons
8
Ganglion = a group of neuron cell bodies.
Some are motor, some are sensory. The ganglions in the dorsal root are
always sensory. The Autonomic ganglia are always motor
All ganglia are in the PNS only. There is no such thing as a CNS ganglia
9
Posterior root ganglion
Most synapses are in the CNS
10
SENSORY NEURONS cell body is in the posterior root ganglion, and its
axon synapses in the posterior horn of the rey matter.
It also sends a branch to an area of the white matter called the DORSAL
COLUMN PATHWAY, which goes into the brain (thalamus).
Thalamus
11
Their cell bodies are in the dorsal half of the gray matter in the spinal cord.
They receive signals from the sensory neuron and then synapse on the cell
body of the motor neuron.
The complexity of the CNS can be attributed to the large number of
interneurons in the CNS
12
Spinothalamic tract carries pain and temperature
Nerves lie outside the CNS and tracts are inside the CNS
13
Upper motor neurons carry motor commands to the skeletal muscluature: cell
body is in the brain, synapses on a lower motor neuron (in the spinal cord)
Lower motor neurons carry motor commands to the skeletal musculature:
cell body is in the spinal cord, synapses on the skeletal muscle
14
rami, trunks, divisions, cords
15
Close eyes and touch finger to nose, or knowing if your fingers are up or
down when your eyes are closed.
16
Upper motor neuron lesion: Cannot move hand on own (paralysis) but
reflexes work
Lower motor neuron lesion: Cannot move hand on own (paralysis) and
reflexes do not work
17