12: PNS & ANS Flashcards
CN I
Olfactory nerve
CN II
Optic Nerve
CN III
Oculomotor Nerve
CN IV
Trochlear nerve
CN V
Trigeminal nerve
CN VI
Abducens nerve
CN VII
Facial nerve
CN VIII
Vestibulocochlear nerve
CN IX
Glossopharyngeal nerve
CN X
Vagus nerve
CN XI
Accessory nerve
CN XII
Hypoglossal nerve
What cranial nerve is the oculomotor nerve? What are its motor functions?
CN III
Extrinsic eye muscles (Superior rectus, medial rectus, inferior rectus, inferior oblique), constrict pupil
What cranial nerve is the trochlear nerve? What are its motor functions?
CN IV
Extrinsic eye muscle (Superior oblique)
What cranial nerve is the trigeminal nerve? What are its sensory functions? What are its motor functions?
CN V
Sensory: Face, teeth, tongue
Motor: Muscles of mastication
What cranial nerve is the abducens? What are its motor functions?
CN VI
Extrinsic eye muscle (Lateral rectus)
What cranial nerve is the facial nerve? What are its sensory functions? What are its motor functions?
CN VII
Sensory: Taste (anterior 2/3 of tongue)
Motor: Muscles of facial expression, secretion of saliva and tears
What cranial nerve is the vestibulocochlear nerve? What are its sensory functions?
CN VIII
Hearing and balance
What cranial nerve is the glossopharyngeal nerve? What are its sensory functions? What are its motor functions?
CN IX
Sensory: Taste (Posterior 2/3 of tongue)
Motor: Swallowing and secretion of saliva
What cranial nerve is the vagus nerve? What are its sensory functions? What are its motor functions?
CN X
Sensory: Visceral sensation (thoracic and abdominal cavities)
Motor: Swallowing, control of respiratory system, heart and digestive system
What cranial nerve is the accessory nerve? What are its motor functions?
CN XI
Sternocleidomastoid and trapezius
What cranial nerve is the hypoglossal nerve? What are its motor functions?
CN XII
Tongue muscles
How many pairs of spinal nerves?
31
Where are cell bodies for the sensory nerves of the PNS found?
Posterior root ganglion
What are the 4 principle plexuses?
Cervical
Brachial
Lumbar
Sacral
What spinal nerves are involved in the brachial plexus?
C5-T1
What nerves are involved in the lumbar plexus? What does it innervate?
L1-L4
Innervates the anterior and medial thigh
What nerves are involved in the sacral plexus? What does it innervate?
L4-S4
Innervates all of the lower limb except the anterior/medial thigh
What kind of reflex is the stretch reflex?
Monosynaptic
What is a monosynaptic reflex?
A reflex involving one CNS synapse (like in the spinal cord)
What kind of reflex is the withdrawal reflex?
Polysynaptic
In the autonomic nervous system, which neurons are myelinated and which are not?
Preganglionic neurons are myelinated
Postganglionic neurons are not myelinated
How many neurons are used to reach the target muscle in the somatic nervous system?
one
How many neurons are used to reach the target muscle/gland in the autonomic nervous system?
2
Preganglionic and postganglionic
Where do preganglionic neurons synapse with other neurons in the ANS?
Autonomic ganglia
What is the sympathetic division autonomic nervous system’s nickname? What is its function?
Fight or flight system
Activated in emergency situations and when excited or stressed
Where does the sympathetic nervous system exit from the CNS?
Thoracic and lumbar spinal cord
T1-L2
Where are parasympathetic ganglia found?
Near or within the target organ
Where do preganglionic axons synapse in the parasympathetic nervous sytem?
Parasympathetic ganglia
What is the enteric nervous system?
Large network of neurons in the wall of the digestive tract
What is the relationship between the ANS and the enteric nervous system?
The enteric nervous system can be influenced by the ANS, but the system can also function independently of the brain and spinal cord
What is the nickname for the parasympathetic division of the ANS?
Rest-and-digest
What is the function of the parasympathetic division?
Rest-and-digest
Conserves energy and replenishes energy stores
What are sympathetic ganglia called? Where are they?
Near the CNS and vertebral column (sympathetic trunk)
Called sympathetic chain ganglia and prevertebral ganglia
What are parasympathetic ganglia called near the target organ? Within the target organ?
Terminal ganglia
Intramural ganglia
In the parasympathetic nervous system, which of the two axons are longer?
Pre-ganglionic axons
The parasympathetic ganglia are in or near the target organ
Where does the parasympathetic nervous system exit the CNS?
Brainstem (CN III, VII, IX, X)
Sacral spinal cord
What is dual innervation?
Most organs are innervated by both sympathetic and parasympathetic divisions. The two divisions often oppose each other
How can a dual innervation effect be achieved if there is only innervation from parasympathetic or sympathetic nervous system?
Increasing or decreasing activity in the one division
How many neurons does the enteric nervous system have?
Contains as many neurons as the spinal cord
