Test 3 Flashcards
what is a neuron?
is the cellular component of the nervous system and is composed of a cell body and neural processes
what is a nerve?
is a bundle of neural
processes outside the central
nervous system and in the
peripheral nervous system.
define the nervous system
an extensive intricate network of neural structures that activates, coordinates, and controls all functions of the body
what does the nervous system cause/allow in the body?
- muscles to contract
- sensations to be perceived
the nervous system does what?
stimulates glands to secrete and regulates many other systems (vascular and digestive)
Define synapse
the junction between
two neurons or between a neuron
and an effector organ, where neural
impulses are transmitted.
A nerve allows information to be
carried to and from the brain, which is
the central information center.
An accumulation of neuron cell
bodies outside the central nervous
system is a
ganglion
afferent nerve or sensory nerve carries information
from the
periphery of the body to the brain (or spinal cord).
examples of sensory information?
taste
pain
proprioception
efferent nerve or motor nerve carries information
away from the
brain (or spinal cord) to the periphery of the body.
efferent nerve carries information to
the muscles in order to activate them, often in response to information received by way of the
afferent nerves
2 main divisions of nervous system?
central and peripheral
One of the major divisions of the
nervous system, includes
both the brain and spinal cord.
the central nervous system (CNS)
The system of membranes is the
meninges
three layers of menings
dura mater- outermost
arachnoid mater- middle
pia mater-innermost
describe where subarachnoid space is found and what is found it in
underneath arachnoid mater; contains cerebrospinal fluid
CNS surround by what?
bone
skull or vertebrae
and membrane layers (mennings)
Dura mater also surrounds and supports?
the large venous channels (dural sinuses) carrying blood from the brain toward the heart such as the cavernous sinus in the head
major divisions of the brain?
the cerebrum,
the cerebellum,
the brainstem,
the diencephalon
largest division of the brain?
cerebrum
cerebrum consist of how many cerebral hemispheres?
2 cerebral hemispheres
function of longitudinal fissure?
separates right & left cerebral hemispheres (a fissure is a deep groove
function of Central Sulcus
separates frontal & parietal lobes (a sulcus is also a groove, but not as deep as a fissure)
Precentral Gyrus location
-located on frontal lobe anterior to central sulcus (gyrus is brain tissue that protrudes between grooves)
Postcentral gyrus location
located on parietal lobe posterior to central sulcus
Corpus Callosum
inferior to longitudinal fissure broad band of nerve fibers that joins the right and left cerebral hemisphere
Cerebral Lobes
named according to the bone in the skull to which they are most closely related
2nd largest division of brain?
cerebellum
location of cerebellum?
posterior cranial fossa (inferior to occipital lobes
function of cerebellum?
muscle coordination and maintenance of equilibrum
injury of cerebellum results in?
lose of coordination- can still perform movement but not very well
division of the brainstem
medulla
pons
midbrain
part of brainstem closest to spinal cord
medulla
what connects the medulla with the cerebellum and with higher brain centers?
pons
what includes relay stations for hearing, vision, and motor pathways?
midbrain
what part of the brain is superior to brainstem?
diencephalon
what does the diencephalon include?
primarily the thalamus and hypothalmus
thalamus serves as?
central relay point for incoming nerve impulses (pain, pressure, temperature, touch)
where do sensations go after leaving the thalamus?
postcentral gyrus in cerebrum
function of hypothalamus
regulates homeostasis (thirst, hunger, body temp, water balance, blood pressure)
hypothalamus located?
directly above pituitary gland
where is pituitary gland located?
in the hypophyseal fossa
location of spinal cord
runs along the dorsal side of the body and links the brain to the rest of the body
Cerebrospinal Fluid is?
fluid that surrounds the brain & spinal cord; acts as a protective shock absorber; produced, circulated, & reabsorbed by the ventricles of the brain, which are cavities in the interior of the brain
Peripheral nervous system includes?
all the nerves stretching their pathway among the CNS and the receptors, muscles, and glands
PNS further divided into?
afferent nervous system
efferent nervous system
afferent nervous system or sensory nervous system carries?
which carries information from receptors to the brain or spinal cord
the efferent nervous system or motor nervous system carries?
carries information from the brain or spinal cord to muscles or glands
somatic nervous system SNS
- efferent division and afferent of pns
- motor:all nerves controlling the muscular system and
- sensory:external sensory receptor
SNS involves?
both receptors and effectors
autonomic nervous system ANS
s the other subdivision of the efferent division of the peripheral nervous system
autonomic fibers are what type of nerves?
efferent nerves
nerves chains of autonomic fibers?
the first nerve carries autonomic fibers to a ganglion, where they terminate near the cell bodies of the second nerve
which nerve system actions without conscious control as the caretaker of the body?
autonomic nervous system
The sympathetic nervous system involved in?
is involved in “fight-or-flight responses” such as the shutdown of salivary gland secretion with certain medications.
The parasympathetic nervous system is involved in ?
“rest-or-digest” responses such as the stimulation of salivary gland secretion
how many pairs of cranial nerves ? apart of what system?
12 important part of PNS
cranial nerves connected where?
brain at its base and pass through the skull by fissures or foramina
cranial nerves are what types of nerves?
can be afferent, efferent, or both
which are used to designate cranial nerves?
both roman numerals and anatomic terms
First Cranial Nerve?
- (I) Olfactory Nerve
- sensory (afferent)
- smell
- enters perforations in cribriform plate
- joins olfactory bulb in the brain
- nasal olfactory mucosa
2nd Cranial nerve?
- (II) Optic Nerve
- sensory (afferent)
- retina of eye
- enters optic canal of sphenoid bone from retina
3rd cranial nerve
- (III) oculomotor nerve
- motor (efferent)
- 1 muscles move eyeball and smooth m.
- Lies in lateral wall of cavernous sinus
- exits superior orbital fissure of sphenoid on way to orbit
4th cranial nerve
- (IV) trochlear nerve
- motor (efferent)
- 1 eye muscle and proprioception
- runs in lateral wall of the cavernous sinus
- exits superior orbital fissure of the sphenoid bone on its way to the orbit
5th cranial nerve
- trigeminal nerve
- both efferent/afferent
- motor=mastication/cranial muscles
- sensory=teeth, tongue, oral cavity, skin of face and head
3 nerve divisions of sensory roots (trigeminal)
- ophthalmic
- maxillary
- mandibular
6th cranial nerve
- (VI) abducens nerve
- motor (efferent)
- one eye muscle
- exits: superior orbital fissure of sphenoid
7th cranial nerve
- (VII) Facial Nerve
- (motor)=facial expression, sublingual and submandibular salivary glands; lacrimal gland, and minor salivary glands
- sensory=skin around ear and 2/3 anterior of tongue for taste
- internal acoustic meatus
- exits stylomastoid foramen
8th cranial nerve
- (VIII) vestibulocochlear nerve
- afferent nerve
- hearing and balance
- inner ear
- enters internal acoustic meatus
9th Cranial Nerve
- IX Glossopharyngeal
- both
- Motor: pharyngeal and stylopharyngeus muscle, parotid gland and mucosa of pharynx
- Afferent: skin around ear, mucosa of middle ear and pharynx; taste for posterior tongue (gag reflex)
- passes through jugular foramen
10th Cranial Nerve
- X Vagus
- Motor: large component of soft palate, pharynx, and larynx; parasympathetic: many organs in thorax and abdomen: thymus gland, heart, and stomach;
- Afferent: small amount of skin around ear and taste sensation for epiglottis;
- passes through jugular foramen
11th Cranial nerve
- XI Accessory
- Motor Trapezius and sternocleidomastoid muscle and muscles of soft palate and pharynx
- muscles of neck
- exits through jugular foramen
12th Cranial Nerve
- XII Hypoglossal
- Motor: Somatic efferent nerve for intrinsic and extrinsic tongue muscles; (muscles of tongue)
- exits through hypoglossal canal in occipital bone
facial nerve both sensory and motor fibers attach to brain where?
pons; from there take separate routes
facial nerve leaves skull through?
internal acoustic meatus
ophthalmic division on trigeminal nerves exits; type; function
- through superior orbital fissure
- sensory: receives PPTT for upper part of face
maxillary division of trigeminal nerve (V2) exits; type for what
- exits foramen rotundum
- sensory-receives PPTT from middle part of face
anterior superior alveolar nerve (ASA) type; function to what
sensory-maxillary sinus, maxillary incisors and canines, facial gingiva area
middle superior alveolar nerve type and function for
sensory; from maxillary sinus, maxillary premolar, mesiobuccal root of max. 1st molar, buccal gingiva
posterior superior alveolar nerve type; function for
-sensory for maxillary molars (3rd, 2nd, palatal, and distobuccal roots of 1st) buccal gingiva and maxillary sinus
posterior superior alveolar nerve very close to ?
pterygoid plexus of veins
pterygopalatine ganglion branches
- pharyngeal
- greater palatine
- lesser palatine
- nasopalatine
- posterior superior lateral nasal
lesser palantine nerve type and function for
sensory from tonsils and mucosa of soft palate
greater palatine nerve
sensory from posterior 2/3 of hard palate and lingual gingiva (canines, premolars, and molars)
pharyngeal (type; from)
sensory for pharynx
nasopalatine type and function for
sensory from anterior 1/3 hard palate (lingual gingiva of maxillary incisors)
posterior superior lateral nasal nerve type and function
nasopharynx and nasal conchae
zygomatic nerve
zygomaticofacial- skin over zygoma
zygomaticotemporal
mandibular nerve is sensory or motor branches?
both
inferior alveolar nerve; type and function; travels thru
-sensory
-travels thru mandibular foramen
-receives from mandibular premolars and molar teeth
(MOST IMPORTANT IN DENTISTRY)
Inferior alveolar nerve continues as?
incisive nerve
incisive nerve type and function from
sensory from mandibular incisors, canines, and facial/buccal gingiva
mental nerve type and function
sensory from mucosa membranes and skin of lower lip and chin
lingual nerve type and function for
sensory for anterior 2/3 of tongue (PPTT only), lingual mandibular gingiva, mucosa for floor (travels along lateral surface of tongue)
auriculotemporal nerve; type function for
parotid branch: sensory for parotid gland (NOT secretion)
long buccal nerve: type and function for
sensory from buccal gingiva of mandibular premolars and molars, buccal mucosa, and skin of lower cheek
masseteric nerve type and function
masseter: motor
TMJ- sensory
nerve to lateral pterygoid muscle
motor to both heads
anterior and posterior deep temporal type and function for
motor to temporalis muscle
medial pterygoid nerve
motor to medial pterygoid muscle
mylohyoid nerve type and function for
motor: mylohyoid muscle and anterior belly of digastric (branch of inferior alveolar nerve) (may have some sensory fibers)
nerve to tensory veli palatini muscle
motor(mandibular) to muscle of soft palate called tensor veli palatini
trigeminal neuralgia (as tic douloureux)
- often unknown
- tumor or blood vessel pressing on trigeminal nerve
- involves afferent nerves
symptoms of trigeminal neuralgia? More frequent in? Triggered by?
facial pain (one side)
- electric current
- more frequent in women over 40
- episodes triggered by light touch or cold around mouth, talking, eating, brushing
treatments for trigeminal neuralgia
seizure meds- block nerve
- microvascular decompression
- gamma knife radiosurgery
facial nerve travels thru what bone?
temporal bone
while in temporal bone facial nerve gives off how many branches
3
main trunk of facial nerve passes thru
stylomastoid foramen for temporal bone
after passing through stylomastoid foramen facial nerve then does what?
gives off 2 branches (posterior auricular nerve and branch to digastric belly of the digastric muscle and stylohyoid muscle)
facial nerves passes thru parotid gland doing what?
does not innervate but divides gland into superficial and deep lobes
chorda tympani joins what nerve
lingual nerve (mandibular div. of trigeminal nerve)
chorda tympani type and function for
mixed
-sensory: continues with lingual nerve; receives info on taste from anterior 2/3 of tongue (sweet, sour, salty)
inferior alveolar nerve block numbs?
numbs lingual nerve, sensory portion of chorda tympani
chorda tympani motor
- branch off before reaching tongue
- regulate secretion from mandibular and sublingual glands
3 branches of facial nerve
- digastric nerve
- stylohyoid nerve
- 3rd travels through parotid gland an divides into 2 divisions
digastric nerve type and function for
motor; posterior belly of digastric (depress mandible)
stylohyoid nerve type and fucntion for
motor; stylohyoid muscle
temporofacial branches
temporal
zygomatic
buccal
zygomatic type and function
motor to zygomaticus major and minor
buccal branch type and function
motor to levator facial muscles (levator labii superioris, orbicularis oris, levator labii superioris alaque nasi, levator anguli oris, risorius, buccinator)
cervicofacial branches?
buccal
mandibular
cervical
buccal branch type and function
motor to levator muscles
mandibular branch type and function
motor to depressor facial muscles (depressor labii inferioris, depressor anguli oris, mentalis)
cervical branch type and function
motor to platysma
damage to facial nerve causes?
facial paralysis
what can damage to facial neve be caused by?
- stroke (cerebrovascular accident)
- cancer to parotid
- injury to nerve
- (common bc of superficial location)
symptoms of facial paralysis
- partial or complete paralysis of affected side
- lateral angle of eye may droop
- unable to close eye
- eye infection
- later angle of mouth droop
- speech and eating difficultly
bell palsy
- symptoms: facial paralysis on one side, no numbness, pain in TMJ
- unknown cause
- temporary or permanent
- no specific treatment
glossopharyngeal nerve (IX) is attached to brain where?
medulla
glossopharyngeal nerve efferent branches?
- lesser petrosal nerve: secretion of saliva from parotid
- stylopharyngeal nerve: stylopharngeus muscle (contracts during swallowing)
glossopharyngeal nerve sensory branches
- lingual: receives PPTT sensation on bitter taste from posterior 1/3
- pharyngeal: PPTT sensation from pharynx
- carotid sinus: blood pressure regulation (info from chemoreceptors and pressoreceptors)
lesions to glossopharyngeal
- rare
- damage to lingual nerve: loss of taste and PPTT posterior 1/3 tongue
- damage to pharyngeal- loss of gag reflex
- damge to carotid sinus: loss of cardiovascular reflex
what is carotid sinus syndrome
hyperactive carotid sinus reflex (often in elderly patience)
what can carotid sinus syndrome be triggered by
slight increase in BP
pressure applied externally under angle of mandible
vagus nerve (X) attaches? Travels where after?
- attaches at medulla
- descends each side of neck with carotid sheath
how many branches of vagus nerve
ONLY 3 are IMPORTANT in dentistry
3 branches that are important of vagus nerve
- pharyngeal
- superior laryngeal
- inferior laryngeal
pharyngeal branch of vagus nerve
- sensory: PPTT sensation from pharynx
- motor: all but one muscle of soft palate (contracts during swallowing)
superior laryngeal nerve of vagus nerve
- sensory: receives bitter taste from posterior 1/3 of tongue
- sensory and motor to larynx
inferior laryngeal nerve
sensory and motor to larynx
