Chap 1 Peripheral and Autonomic Nervous Systems Flashcards
PNS
collection of nerves outside the spinal column and skull, carries sensory and motor impulses back and forth from the brain to various parts of the body. Consists of the 12 cranial nerves, 31 pairs of spinal nerves
Consists of 3 types of nerves: cranial, spinal, and autonomic
Cranial Nerve 1
Olfactory, sense of smell (sensory)
not concerned with speech
Cranial Nerve 2
Optic, vision (sensory), originating in the retina
not concerned with speech
Cranial Nerve 3
Oculomotor, eye movement (motor), originate in the midbrain area and innervate muscles corresponding to eye movements
not concerned with speech
Cranial Nerve 4
Trochlear, eye movement (motor),originate in the midbrain area and innervate muscles corresponding to eye movements
not concerned with speech
Cranial Nerve 5
trigeminal, face, (sensory) and jaw (motor)
unilateral damage will cause the jaw to deviate towards the affected side when the mouth is closed. Bilateral damage may result in the inability to close the mouth and difficulty in chewing.
Cranial Nerve 6
abducens, eye movement (motor), mixed nerve
not concerned with speech
Cranial Nerve 7
tongue (sensory, face (motor)
Cranial Nerve 8
acoustic, hearing and balance (sensory)
has two branches: vestibular and acoustic)
Cranial Nerve 9
glossopharyngeal, tongue and pharynx (sensory), pharynx only motor
The sensory component assists in processing taste sensations from the posterior third of the tongue. Also provides general sensation for the tympanic cavity, ear canal, Eustachian tube, faucial pillars, tonsils, soft palate, and pharynx.
The motor fibers innervate the stylopharyngeus, a muscle that raises and dilates the pharynx.
Lesions may create difficulty I swallowing, unilateral loss of the gag reflex, and loss of taste and sensation from the posterior third of the tongue
Cranial Nerve 10
Vagus, larynx, respiratory, cardiac, and gastrointestinal systems (sensory and motor)
AKA the wandering nerve
Motor nerve supply the digestive system, heart, lungs, pharynx, and the larynx
Sensory convey information from the digestive system, heart, trachea and bronchi, lower pharynx, larynx, and epiglottis. They also transmit pain, touch, and temperature sense from the skin covering the tympanic membrane and ear canal
Damage to the vagus nerve includes a variety of sequelae, such as difficulty swallowing, paralysis of the velum (resulting in nasality issues), and voice problems (aphonia, breathiness, roughness, hoarseness, etc) if the RLN is damaged.
Cranial Nerve 11
spinal accessory, shoulder, arm, and throat movements (motor)
both a cranial and spinal nerve.
Spinal root supplies the trapezius and the sternocleidomastoid muscles, which assist in the head and shoulder movements
Lesions of the spinal accessory may result in neck weakness, paralysis of the sternocleidomastoid and consequent inability to turn the head, as well an inability to shrug the shoulders or raise the arm above shoulder level.
Cranial Nerve 12
Hypoglossal, mostly tongue movements (motor)
a mixed nerve
responsible for taste sensations on the anterior 2/3 of the tongue,
motor fibers innervate muscles for facial expression and speech.
unilateral upper motor neuron lesion will only paralyze the lower face.
Bilateral damage to the facial nerve will be unable to move his upper and lower face and will often have a mask like appearance with minimal or no facial expression.
Unilateral damage the smile is drawn to the undamaged side.
lesions can result in tongue paralysis, diminished intelligibility and swallowing problems
Cranial Nerves
emerge from the brainstem and are attached to the base of the brain. They exit through the foramina, or holes, in the pyramidal system.
Sensory Nerves
cranial nerves that carry sensory information from a sense organ to the brain.
AKA afferent nerves
Motor Nerves
carry impulses from the brain to the muscles that make those muscles move.
AKA efferent nerves
Mixed Nerves
they carry both sensory and motor impulses
sensory fibers
composed of three branches, the ophthalmic, maxillary, and mandibular
Ophthalmic Branch
has sensory branches from the nose, eyes, and forehead
Maxillary branch
has sensory branches from the nose, upper lip, maxilla, upper cheek area, upper teeth, maxillary sinus, nasopharynx, and palate.
Mandibular branch
sensory branches from the mandible, lower teeth, lower lip, tongue, part of the cheek, and part of the external ear. It transmits tactile, pain, and temperature (but not taste) stimuli from the anterior two thirds of the tongue.
Trigeminal Neuralgia
sharp pain in the facial area
vestibular branch of CN VIII
primarily responsible for maintenance of equilibrium, or balance
damage results in hearing loss, problems with balance or both
acoustic branch of CN VIII
transmits sensory information from the cochlea of the inner ear to the primary auditory cortex of the brain, where it is interpreted.
Recurrent laryngeal nerve (RLN)
a branch of the vagus nerve, regulates the intrinsic muscles of the larynx, excluding the criothyroid, which is supplied by the SLN branch.
May be damaged during thyroid surgery, resulting in total or partial paralysis of the vocal folds.
The left courses under the heart and back up to esophagus , trachea, and larynx. May be damaged during cardiac surgery, resulting in paresis or paralysis of the left vocal fold.
Pharyngeal Branch
supplies the pharyngeal constrictors . It also supplies all the muscles of the velum except the tensor veli palatini, which is innervated by the trigeminal nerve. Also transmits sensory information from the base of the tongue and pharynx.
Superior laryngeal nerve (SLN)
divided into internal (sensory) and external (motor) branches.
Internal receives sensory information from the larynx above the vocal folds.
External innervates the cricothyroid muscle, damage to this branch results in the inability to change pitch.
Spinal Nerves
can be motor, sensory, or mixed. They transmit motor information from the CNS to the muscles and carry sensory information from peripheral receptors to the CNS.
31 pairs of spinal nerves divided into segments. They are named after the region of the spinal cord to which they are attached.
Conus Medullaris
where the spinal cord ends at the L1 vertebra level
Cauda Equina
lowermost nerves, “horse’s tail”
film terminale
“end filament” where there are no spinal cord segments
Autonomic Nervous System (ANS)
generally viewed as part of the PNS, controls and regulates the internal environment of our bodies with its 2 branches, the sympathetic and parasympathetic.
Sympathetic Branch of the ANS
mobilizes the body for “fight or flight” situations. Accelerates the heart rate, dilates the pupils, raises the blood pressure, increases blood flow to the peripheral body structures. Also part of emotional arousal
Parasympathetic Branch of the ANS
helps bring the body back to a state of relaxation. Lowers blood pressure, slows heart rate, increases activity within the stomach, and generally relaxes the body. Humans feel relaxed ad calm when activated.
