PNS Flashcards
I Olfacory Nerve
Transmitting Foramen: cribriform foramina of ethmoid bone
Function: VA neurons - sense of smell (olfaction)
Neuron Type and Location of Cell Bodies:
Bipolar neurons in nasal mucosa (olfaction)
II Optic Nerve
Transmitting Foramen: optic canal of sphenoid bone
Function: SA neurons - vision
Neuron Type and Location of Cell Bodies:
Bipolar neurons in retina
III Oculomotor nerve
Transmitting Foramen: superior orbital fissure
Function:
. SA/SE neurons - motor to superior, medial, and inferior rectus mm., inferior oblique m., levator palpebrae superioris m. of the eye
. VE neurons - motor to ciliary m. of eye and pupillary sphincter m. of the iris
Neuron Type and Location of Cell Bodies:
SA/SE - Multipolar neurons in nucleus of oculomotor nerve in mesencephalon
VE - Multipolar neurons in accessory oculomotor nucleus within mesencephalon (pre-ganglionics), and within ciliary ganglion (post-ganglionics)
IV Trochlear Nerve
Transmitting Foramen: superior orbital fissure
Function: SA/ SE neurons - motor to superior oblique m. of the eye
Neuron Type and Location of Cell Bodies:
Multipolar neurons in motor nucleus of trochlear n. within mesencephalon
V Trigeminal Nerve
- Ophthalmic nerve
Transmitting Foramen: superior orbital fissure
Function: SA neurons - sensory from and around the eye
Neuron Type and Location of Cell Bodies:
Pseudounipolar neurons in the trigeminal ganglion of the trigeminal nerve
- Maxillary Nerve
Transmitting Foramen: foramen rotundum of the sphenoid bone
Function: SA neurons - sensory from upper lip and surrounding skin, upper teeth and gums, and palate
Neuron Type and Location of Cell bodies:
Pseudounipolar neurons in the trigeminal ganglion of the trigeminal nerve
- Mandibular Nerve
Transmitting Foramen: foramen ovale of sphenoid bone
Function:
SA neurons: sensory from lower lip and surrounding skin, lower teeth and gums, tongue, and floor of oral cavity
SA/SE neurons: motor to mm. of mastication
Neuron Type and Location of Cell Bodies:
(SA) - Pseudounipolar neurons in the trigeminal ganglion of the trigeminal nerve
(SA/SE) - Multipolar neurons in the motor nucleus of the trigeminal nerve within the pons
Indicate which cranial nerves are sensory only.
Six Sailors Made Merry But My Brothers Said
Bad Business My Man
SA (vision, audition, and general sensation from skin, muscles, bones, and joints)
- CN II, V, VIII, IX, and X
VA (olfaction, gustation, and sensation from deep body systems)
- CN I, VII, IX, and X
Overall: 1, 2, 5, 7, 8, 9, 10
Indicate which cranial nerves supply skeletal muscles. (carry SE fibers)
Six Sailors Made Merry But My Brothers Said
Bad Business My Man
All except 1, 2, 8
Indicate which cranial nerves carry gustatory fibers. (gustation)
7,9,10
Indicate which cranial nerves do not emerge from the skull.
8
Indicate which cranial nerves supply involuntary effectors.
3,7,9,10
Indicate which cranial nerves supply muscles that move the eyeball.
3,4,6
Indicate which cranial nerves originate from the superior (posterior) aspect of the brain.
4
Sketch the origin of a spinal nerve from the spinal cord and label the rootlets, roots, branches, and sensory ganglion.
(pg. 306)
List the general kinds of information (sensory from and motor to) carried by: anterior branches of spinal nerves, posterior branches of spinal nerves, anterior roots of spinal nerves, posterior roots of spinal nerves.
Anterior roots: sends motor impulses from spinal cord
Posterior roots: sends sensory impulses into spinal cord
Anterior branches of spinal nerves: motor to and sensory to hypaxial muscles
Posterior branches of spinal nerves: motor and sensory to epaxial muscles
Explain why severance of a nerve at a given location does not disrupt the functions of the nerve proximal to the site of injury.
Nerves have many axons that branch off from it. It a nerve is severed, the axons distal to the nerve will be disrupted. The axons proximal to where the nerve was severed will not be disrupted.
Explain why nerve damage may be permanent.
Nerve damage may be permanent if the myelin and the nerve can’t be reconnected due to c.t. blocking
- c.t. can scar over so that the nerve and myelin can’t join together
Explain why severance of a nerve at a given location does not disrupt the functions of the nerve proximal to the site of injury.
Nerves have many axons that branch off from it. It a nerve is severed, the axons distal to the nerve will be disrupted. The axons peripheral to where the nerve was severed will not be disrupted.
Explain why nerve damage may be permanent.
nerves have slow regenerative capacity
Define the brachial plexus and state the sensory and motor functions of its four most significant derivatives.
Brachial Plexus: supply nerves to the superior limb
Musculocutaneous Nerve:
- motor to: biceps brachii m. , corocobrachialis m., brachialis m.
- sensory from: skin of the anterior antebrachium and skin on the lateral half of the posterior antebrachium
Ulnar Nerve:
- motor to: anterior antebrachial muscle and the m. of the manus
-sensory from: skin of the manus
( lateral 2/3 of manus)
Medial Nerve:
- motor to: anterior antebrachial m. and the m. of the manus
- sensory from: skin of the manus
(medial 1/3 of manus)
Radial Nerve:
- motor to: posterior m. of brachium and antebrachium (the extensors of elbow, carpal, and digital joints)
Define lumbosacral plexus and state the sensory and motor functions of its largest derivatives. Include the two named branches of the latter.
Lumbosacral plexus: nerves that supply the inferior limbs (consists of lumbar plexus combined with sacral plexus)
Femoral Nerve:
- motor to: the pectineus and sartorius muscles, and the quadriceps femoris muscle
(also goes to medial crus)
Obturator Nerve:
- motor to: the medial muscles of the thigh and external obturator muscle
- sensory to: skin on medial aspect of thigh
Sciatic Nerve: (largest nerve in the body)
- motor to: posterior thigh muscles
- Tibial Nerve (posterior muscles of crus and few muscles of the pes)
- Common Fibular Nerve (anterior muscles of crus and few muscles of pes)
(also motor to skin of the foot and most skin on the anterior, lateral, and posterior aspects of the crus)
Compare sensory and autonomic ganglia in regard to the presence of synapses, the functional types of neurons present, and the cranial nerves which have them.
Sensory Ganglia:
- no synapses
- Pseudounipolar and Bipolar neurons
- on posterior roots of spinal cord and found in most of the cranial nerves (5,7,8,9,10)
Autonomic Ganglia:
- synapses
- Sympathetic Trunk Ganglia: occur along sympathetic trunk and are synaptic sites for pre and post ganglionic sympathetic neurons
- Named peripheral ganglia: cranial nerves 3,7,9,10 (as well as named ganglia within the thoracic and abdominal cavities)
- Terminal (intramural ganglia): in the walls of the organs innervated
Divide the senses into general and special categories.
General Categories: pain, pressure, heat, cold, touch
Special Categories: audition, vision, olfaction, gustation, equilibrium
Classify Sensory Receptors based on type of energy transduced.
Mechanoreceptors: pressure, vibration, touch, stretch, hair movement
Chemoreceptors: activated by specific chemicals (taste buds and olfactory cells)
Photoreceptors: light
Thermoreceptors: heat, cold
Nociceptors: pain receptors, respond to chemicals released during tissue damage
Classify sensory receptors based on locus of sensory information.
Exteroreceptors: external environment
- ex) skin, taste, hearing, vision, smell)
Visceroreceptors (interoceptors) : in deep body organs (visceral organs)
- ex) hunger, thirst, nausea
Proprioceptors: joints, tendons, muscles bellies, internal ear
- ex) balance, body position, and movement
