Learning Outcome 9 PNS Flashcards
Define ganglia
is a group of neuron cell bodies in the periphery.
What types of cell bodies are in the dorsal root ganglion?
The most common type of sensory ganglion is a dorsal (posterior) root ganglion. These ganglia are the cell bodies of neurons with axons that are sensory endings in the periphery, such as in the skin, and that extend into the CNS through the dorsal nerve root.
How are nerves structured? How many coverings surround them?
-Bundles of axons in the PNS are referred to as nerves.
-epineurium (outer fibrous CT layer)
-Within the nerve, axons are further bundled into fascicles, which are each surrounded by their own layer of fibrous connective tissue called perineurium. Finally, individual axons are surrounded by loose connective tissue called the endoneurium
-3
Cranial Nerves, How many?
-The nerves attached to the brain are the cranial nerves, which are primarily responsible for the sensory and motor functions of the head and neck
-12
-motor, sensory or mixed
Use mnemonics to help remember the namesand types of cranial nerves
- Make a chart and for each cranial nerve, note its number (include the roman
numeral, ie. CN I, II, III, IV), its functions, if it is sensory, motor, or mixed (contains both sensory and motor functions)
“On Old Olympus’ Towering Tops/A Finn And German Viewed Some Hops,”
“Some Say Marry Money But My Brother Says Brains Beauty Matter More,”
olfactory nerve and optic nerve
olfactory nerve I
optic nerve II
-sense of smell and vision,
oculomotor nerve
oculomotor nerve III
-responsible for eye movements by controlling four of the extraocular muscles. It is also responsible for lifting the upper eyelid when the eyes point up, and for pupillary constriction.
trochlear nerve and the abducens nerve
trochlear nerve IV
abducens nerve VI
- are both responsible for eye movement, but do so by controlling different extraocular muscles.
trigeminal nerve
trigeminal nerve V
-is responsible for cutaneous sensations of the face and controlling the muscles of mastication.
facial nerve
facial nerve VII
- is responsible for the muscles involved in facial expressions, as well as part of the sense of taste and the production of saliva.
vestibulocochlear nerve
vestibulocochlear nerve VIII
- is responsible for the senses of hearing and balance.
glossopharyngeal nerve
glossopharyngeal nerve IX
- is responsible for controlling muscles in the oral cavity and upper throat, as well as part of the sense of taste and the production of saliva.
vagus nerve
vagus nerve X
-is responsible for contributing to homeostatic control of the organs of the thoracic and upper abdominal cavities.
spinal accessory nerve
spinal accessory nerve XI
- is responsible for controlling the muscles of the neck, along with cervical spinal nerves.
hypoglossal nerve
hypoglossal nerve XII
- is responsible for controlling the muscles of the lower throat and tongue.
Textbook 13.4 Cranial Nerves chart
Spinal Nerves – how many pairs are there? Are spinal nerves sensory, motor or mixed? Why?
The nerves connected to the spinal cord are the spinal nerves.
-31
All of the spinal nerves are combined sensory and motor axons that separate into two nerve roots.
What is contained in the dorsal root? What is contained in the ventral root?
-The sensory axons enter the spinal cord as the dorsal nerve root.
-The motor fibers, both somatic and autonomic, emerge as the ventral nerve root.
How are spinal nerves named?
-named for the level of the spinal cord at which each one emerges.
What is a nerve plexus?
-Axons from different spinal nerves will come together into a systemic nerve. This occurs at four places along the length of the vertebral column, each identified as a nerve plexus
Identify four major plexuses in the body.
- cervical plexus - is composed of axons from spinal nerves C1 through C5 and branches into nerves in the posterior neck and head
- brachial plexus - Spinal nerves C4 through T1 reorganize through this plexus to give rise to the nerves of the arms, as the name brachial suggests.
- lumbar plexus - rises from all the lumbar spinal nerves and gives rise to nerves enervating the pelvic region and the anterior leg L1 to L4
4.sacral plexus - comes from the lower lumbar nerves L4 and L5 and the sacral nerves S1 to S4.
What plexus does the phrenic nerve come from? What does it supply?
Cervical Plexus
phrenic nerve - which connects to the diaphragm at the base of the thoracic cavity.
What plexus does the femoral nerve come from?
Lumbar Plexus
What is a dermatome?
areas of skin that connect to a specific nerve root on your spine
Reflexes – define a reflex
o What are the components of a reflex arc?
How is a simple reflex different from a complex reflex?
Give an example of a withdrawal reflex.
vestibulocochlear nerve
vestibulocochlear nerve is responsible for the senses of hearing and balance.
facial nerve
facial nerve is responsible for the muscles involved in facial expressions, as well as part of the sense of taste and the production of saliva.
Abducens nerve
abducens nerve are both responsible for eye movement, but do so by controlling different extraocular muscles.
Parasympathetic nerves originate
brain stem and sacral spinal cord
Sympathetic nervous system originate
in the thoracic and lumbar spinal chord
