Anatomy Block 5 Flashcards
flat bones of cranium formed
by intramembranous ossification
irregular bones of cranium formed
by endochondrial ossification
parts of cranium
viscerocranium and neurocranium
anterior cranial fossa
frontal bone - frontal crest, orbital part
ethmoid bone - crista galli, foramina and cribiform plate
sphenoid bone - lesser wing and anterior clinoid
middle cranial fossa
sphenoid bone - greater wing, foramen spinosum, foramen ovale, foramen rotundum, superior orbital fissure, foramen lacerum, dorsum sellae, prechiasmatic sulcus
temporal bone - trigeminal impression, arcuate eminence, groove/hiatus for greater petrosal n
posterior cranial fossa
temporal bone - internal acoustic meatus, jugular foramen, superior border of petrous part, groove for sigmoid sinus
occipital bone - clivus, jugular tubercle, hypoglossal canal, groove for inferior petrosal sinus, foramen magnum, internal occipital protuberance, internal occipital crest, groove for transverse sinus
carotid canal
internal carotid artery
stylomastoid foramen
CN7 facial nerve
foramen magnum
spinal cord, vertebral aa, roots accessory nerve (CN 11)
foramen ovale
CN 5 trigeminal mandibular division
foramen spinosum
middle meningeal artery
hypoglossal canal
CN12 hypoglossal n
jugular foramen
CN9 glossopharyngeal n, CN10 vagus n, CN11 accessory n, internal jugular v
hyoid
doesnt articulate other bones
important attachment for neck muscles
CN1
olfactory
special visceral afferent
olfaction/smell
exits cribiform plate
anosmia
loss of smell
naegleria fowler
brain eating amoeba
CN2
optic
special somatic afferent
exits optic canal
vision from retina
CN3
oculomotor
exits superior orbital fissure
general somatic efferent - extrinsic eye muscles
general visceral efferent - parasympathetic fibers to control pupil
CN4
trochlear
general somatic efferent
exits superior orbital fissure
innervates superior oblique
CN6
abducens
general somatic efferent
exits superior orbital fissure
innervates lateral rectus
CN5
trigeminal
ophthalmic - general somatic efferent, exits superior orbital fissure
maxillary - general somatic efferent, exits foramen rotundum
mandibular - exits foramen ovale, general somatic efferent and muscles of mastication
CN7
facial
special visceral efferent - muscles of fascial expression
general visceral efferent - parasympathetics to submandibular and sublingual salivary glands, lacrimal glands, nose and palantine glands
general somatic afferent - sense to external acoustic meatus
special visceral afferent - taste to anterior 2/3 of tongue
CN8
vestibulocochlear
special somatic afferent - orientation/balance and hearing
exits internal acoustic meatus
CN9
glossopharyngeal
all types of fibers
innervation of stylopharyngeus
parasympathetics to parotid gland
sense to posterior 1/3 tongue
sense from carotid body/sinus
taste to posterior 1/3 tongue
CN10
vagus
all types of fibers
innervation of palatoglossus
parasympathetics to thorax and abdomen
sense to larynx
sense to thorax and abdomen
taste from epiglottis and palate
exits jugular foramen
CN11
spinal accessory
general somatic efferent
exits jugular foramen
motor to SCM and trapezius
CN12
hypoglossal
general somatic efferent
muscles of tongue
exits hypoglossal canal
boundaries of the neck
superior - base of skull, inferior mandible
inferior - clavicle, manubrium, C7 to acromia, base of neck
C1 (atlas)
no body
pivots around axis
C2 (axis)
dens
ligaments hold C1 in place - cruciate (superior and inferior longitudinal bands, transverse), alar, apical, atlantoaxial
breaks at pars interarticularis
cervical vertebrae
small bodies
C2-6 have bifid spinous processes
transverse foramen
anterior and posterior tubercles
uncinate processes
scalene muscles
anterior: C3-6 to rib 1, innervated by C4-7
middle: C2-7 to rib 1, innervated by C3-7
posterior: C4-7 to rib 2, innervated by C5-7
assist breathing
flex neck to ipsilateral side
longus muscles
colli: innervated by C2-6, flex neck
capitis: innervated by C1-3, flex AO joint
rectus capitis muscles
anterior: innervated by C1-2, flex OA joint
lateralis: innervated C1-2, flex OA joint
hyoid bone
body, lesser horn, greater horn
suprahyoid muscles
mylohyoid (CNV3)
stylohyoid (CN7)
anterior digastric (CNV3)
posterior digastric (CN7)
glenohyoid
pull hyoid up
infrrahyoid muscles
omohyoid (shoulder to hyoid)
sternohyoid (sternum to hyoid)
thyrohyoid (thyroid to hyoid)
sternothyroid (sternum to thyroid)
pull hyoid down
sternocleidomastoid
mastoid to sternum
CN11
turn head to contralateral side
platysma
facial expression
CN7
carotid sheath
carotid arteries, internal jugular veins, vagus nerves
prevertebral fascia
nerves, vertebral arteries, pre/para vertebral muscles
pretracheal fascia
infrahyoid muscle (musclular)
visceral - recurrent laryngeal nn, parathyroid glands, thyroid
buccalpharyngeal fascia - esophagus
posterior triangle of neck
posterior to SCM anterior to trapezius superior to clavicle
subdivided into occipital triangle and omoclavicular triangle
anterior triangle of neck
anterior to SCM, inferior to mandible, lateral to midline of neck
subdivided into submandibular, submental, muscular, and carotid triangles
thyrocervical arteries
thyrocervical trunk - inferior thyroid, subscapular, transverse cervical (dorsal scapular)
cervical arteries
common carotid gives
internal carotid
external carotid - superior thyroid, ascending pharyngeal, lingual, fascial, occipital, maxillary, posterior auricular, superficial temporal
jugular veins
same path as carotid except posterior auricular drains into internal carotid
blood to brain
vertebral arteries, internal carotid artery
cervical lymph
spinal accessory (posterior lateral superficial cervical nodes)
suboccipital triangle
rectus capitis posterior major and minor
obliquis capitis superior and inferior
embryonic origins of skeletal elements
neural crest - frontal, nasal, lacrimal, zygomatic, maxilla, incisive, mandible, sphenoid, squamous temporal, hyoids
lateral plate mesoderm - laryngeals
paraxial mesoderm - parietal, pet temporal, occipitalis
arch 1
temporalis, stylohyoid, mylohyoid
meckels cartilage, incus, malleus
CNV
arch 2
orbicularis oculi, orbicularis oris, frontalis, auricularis, buccinator, stylohyoid, posterior digastric, platysma
stapes, styloid process, stylohyoid ligament, lesser horn of hyoid
CNVII
arch 3
stylopharyngeus
hyoid bone and greater horn of hyoid
CN IX
arch 4
middle/inferior constrictor of pharynx, cricothyroid
thyroid cartilage
CN X
arch 6
CN X
cricoid cartilage, tracheal rings
external ear development
auricular hillocks to cymba conchae, helix, concha, antihelix, antitragus, tragus sep
tongue and larynx
arch 1 - lateral lingual swellings and median lingual swelling
arch 2 - copula
arch 4 - hypopharyngeal eminence
intrinsic tongue muscles
from occipital somites and innervated by hypoglossal nerve (CN XII)
mylohyoid and glenohyoid
thyroid gland
foramen cecum creates thyroglossal duct, thyroid precursors attached
tympanic membrane
combination of endoderm of 1st pharyngeal pouch and extoderm of 1st pharyngeal cleft
palantine tonsils
endoderm of 2nd pharyngeal pouch invaded by mesoderm and infiltrated by lymph cells
pharyngeal pouch 3
ventral wing - thymus
dorsal wing - inferior parathyroid gland
pharyngeal pouch 4
ventral wing - ultimobranchial body - parafollicular cells
dorsal wing - superior parathyroid gland
cervical cyst
proliferation of 2nd arch covers 2nd-4th cleft
humor filled spaces
anterior segment - aqueous humor, provide nutrients to avascular lens and cornea, divided into anterior and posterior chambers
posterior segment - vitreous humor, protects retina, holds lens and retina in place, maintain structural integrity
tunics of the eye
fibrous - corneoscleral coat
vascular - uvea (choroid, ciliary body, iris)
nervous - retina (neural retina: nonphotosensitive and photosensitive parts, retinal pigment epithelium: RPE)
fibrous tunic
sclera - opaque white of the eye, dense fibrous CT with microvasculature, attachment for extrinsic eye muscles
cornea - transparent convexity (window), primary refractive surface of eye (focuses rays), no blood or lymph vessels, 5 layers
corneosclera limbus (junction) - transition zone between cornea and sclera, corneal stem cells, barrier between cornea and sclera
sclera histology
episclera - external layer of loose CT, adjacent periorbital fissure
episcleral space - freedom for eyeball movement
substantia propria (sclera proper) - investing fascia of eye, dense network of thick collagen fibers, some elastic fibers and ground substance, scattered fibroblasts, attachment points for tendons of extraocular muscles
suprachorois lamina - external to choroid, thinner collagen and elastic fibers, melanocytes, macrophages
cornea histology
-corneal epithelium - nonkeratanized stratified squamous epithelium, basal proliferation (low columnar cells with round nuclei), surface has squamous cells with flat nuclei, 7 day turnover, limited proliferation, microvilli on surface, highly sensitive
-bowmans membrane - basal lamina of randomly oriented collagen, strength and barrier to infection, abruptly ends at sclera
-corneal stroma - 90% cornea thickness, parrallel bundles highly ordered collagen fibrils, sheets flattened fibroblasts, transparent bc arrangemen
-descements membrane - thick basal lamina of collagen, extends beneath sclera to pectinate ligament to maintain corneal curvature
-corneal endothelium - single squamous layer, metabolic exchange between cornea and aqueous humor, corneal swelling
limbus histology
bubar conjunctiva (Cj) - conjuctival epithelium (irregular thickness), loose vascular CT (replace Bowmans membrane)
stroma (S) - flat collagen bundles, fine networks of elastin and ground substance, scattered fibroblasts, highly vascularized
trabeculae network - decements and endothelium dissappear, reabsorb aqueous humor from anterior chamber into canal of schlemm
transition zone - corneolimbal stem cells (maintain corneal epithelium), proliferate/differentiate/migrate to cornea, cells prevent conjunctival epithelium to cornea, conjunctivalization of cornea upon injury (unstable epithelium)
uvea
choroid (dark brown vascular sheet between sclera and retina, nutrients to retina), ciliary body (thickened anterior aspect of vascular tunic), iris (thin anterior aspect of vascular tunic, contractile diaphram infront of lens, arises from anterior border of ciliary body, attached to sclera)
choroid histology
highly vascularized and pigmented with melanin, choriocapillaries (bed of highly fenestrated capillaries providing nutrients to retina), Bruchs membrane (elastin and collagen hyalin membrane between chorioreceptors and RPE of retina)
ciliary body histology
ciliary smooth muscle (changes in contraction determine flatness of lens), ciliary process (lined on inner surface by double layer ciliary epithelium, production of aqueous humor), zonular fibers (suspensory ligament of lens)
aqueous humor
derived from blood plasma with similar ionic content to plasma, maintain intraocular pressure, provides nutrients and removes metabolites of lens and cornea, prouced in posterior chamber and moves to anterior chamber where its reabsorbed by iridocorneal angle, turnover 1.5 to 2 hours
iris histology
posterior side (melanin containing cells, posterior pigment epithelium), anterior to PE (pigment myoepithelium with anterior contractile elements for dilator pupillae muscle), around pupil is smooth muscle (sphincter pupillae muscle), anterior iris is mostly stroma (highly vascularized CT with scattered melanocytes, pigment limits light through iris, muscle increases and decreases the size of the pupil to change the amount of light entering)
lens
lens capsule - thick basal lamina, elastic type 4 collagen and proteoglycans, attachment for zonule fibers
subscapular lens epithelium - single layer of cuboid epithelial cells, only anterior lens surface
lens fibers - elongated/thin/flat cells, lack organelles, filled with crystallin (protein), differentiating lens fibers, mature lens fibers
adaptation
changing pupil size with light intensity
accomidation
change lens thickness when viewing near vs distance
pupil
sympathetics to dilate, parasympathetics to constrict
focus
distance relaxes ciliary muscles and tightens suspensory ligament to flatten lens
near contracts ciliary muscles and relaxes suspensory ligaments to thicken lens
retina layers
RPE and neural retina
primary conducting cells
photoreceptors (detect photons of light)
to
bipolar cells (receive signals from photoreceptors about light)
to
ganglion cells (receive signals from bipolar cells and send to brain, axons form optic nerve)
association neurons
amocrine cells - process bipolar cell signal to control what ganglion cell receives
horizontal cells - process photoreceptor signal to control what bipolar cells receive
muller cells (supporting cells)
extend nearly the length of neural retina, modified astrocytes (regulate water, waste, ions, blood flow), form adherent junctions with photoreceptor cells to form outer limiting membrane, extensions internal to ganglion cell axons from inner limitin membrane
retinal pigment epithelium (supporting cells)
most outer retinal layer, simple cuboidal epithelium attached to Bruchs membrane, removes free radicals and supports photoreceptors, phagocytoses used photoreceptor discs, junctional complexes between RPE cells create barrier (blood retinal barrier) that governs selective entry of blood components from choroid vessels into posterior retina
10 layers of retina (9 neural 1 RPE)
10 - inner limiting membrane
9 - optic nerve fibers
8 - ganglion cell layer
7 - inner plexiform layer
6 - inner nuclear layer
5 - outer plexiform layer
4 - outer nuclear layer
3 - outer limiting membrane
2 - photoreceptor outer segments
1 - RPE
fovea
highest density of photoreceptors, all cone receptors, other retina layers pushed aside to minimize light scattering, part of macula
optic disc
spot ganglion cell axons converge and exit as optic nerve “blindspot”
ora serrata
irregular border of ciliary body, anterior edge optic retina
blood supply of retina
layers 6-10 central artery of retina
layers 1-5 choroid vessels
eyelids
protect and lubricate eye, anterior covered with epidermis, orbicularis oculi beneath, tendon of levator palpebrae superioris opens eyelid, tarsal palate of dense fibrous elastic CT, lid margin with apocrine sweat glands, tarsal glands and lacrimal glands, superior border attachment for superior tarsal muscle for eyelid elevation, eyelashes with sebacious glands, posterior covered in palpebral conjunctiva
conjunctiva
thin tansparent mucous membrane, numerous goblet cells, palpebral (posterior eyelid), conjunctival (where eyelid ends), bulbar (outer sclera from conjunctival fornix to corneoscleral limbus)
lacrimal glands
produce tears to lubricate conjunctival surface, tubuloacinar serous glands (acinar with large lumens filled with columnar cells), tears drain through lacrimal apparatus into nasal cavity below inferior nasal concha
embryology
nervous tissue of eye from second superior vesicle in development, rest of eye from surface ectoderm and mesoderm
optic vesicle extends and interacts with overlying ectoderm signaling it to become lens and cornea
as retinal ganglion cells develop they extend axons out stalks to become optic nerve
ventral folding internalizes hyaloid vessels and creates choroid fissure
colomba
failure of fusion of choroid fissure
regression of hyaloid vessels
leave empty hyaloid canal through vitrous body (lens doesnt need blood around week 10 of development)
boundaries of temporal fossa
superior/posterior - temporal lines
anterior - zygomatic and fromtal lobes
lateral - zygomatic arch
inferior - infratemporal crest of greater wing of sphenoid
floor - pterion
boundaries of infratemporal fossa
lateral - ramus of mandible
medial - lateral pterygoid plate and pharynx
anterior - posterior surface of maxilla
posterior - tympanic plate
superior / roof - greater wing of sphenoid
inferior - insertion medial pterygoid muscle on lower mandibular ramus
temporal fossa contents
temporal fascia, temporalis muscle, pterion, deep temporal arteries, deep temporal nerve of V3, zygomaticotemporal branch of zygomatic nerve of V2, auriculotemporal branch of V3
infratemporal fossa contents
medial and lateral pteygoid, sphenomandibular ligament and tendon temporalis muscle, mandibular nerve branches (inferior alveolar, buccal, chordatympani), otic ganglia, maxillary artery, pterygoid venus plexus
CN V
supraorbital foramen (V1 ophthalmic)
infraorbital foramen (V2 maxillary)
mental foramen (V3 mandibular)
main nerve in infratemporal fossa
mandibular which gives auriculotemporal, inferior alveolar, lingual, buccal
chorda tympani
joins lingual in infratemporal fossa
parotid gland
largest salivary gland
anteroinferior to external acoustic meatus in parotid sheath
parotid duct
crosses over masseter
pierces buccinator
opens into vestibule of mouth opposite second upper molar
parotid sympathetic innervation
preganglionic neurons in interomediolateral cell column of T1 and T2
post ganglionic fibers reach gland through external carotid nerve plexus on external carotid artery
parotid parasympathetic innervation
preganglionic neurons in inferior salivatory nucleus in medulla
fibers project via tympanic plexus to otic ganglia
postsynaptic fibers conveyed by auriculotemporal nerve
muscles of mastication
temporal fascia, temporalis, masseter, lateral pterygoid, medial pterygoid
innervation - branches of mandibular nerve (V3)
blood supply - maxillary artery
maxillary artery
divided into 3 parts by lateral pterygoid muscle
1. deep auricular, anterior tympanic, inferior alveolar, middle meningeal, acccessory meningeal
2. middle pterygoid, masseteric, posterior anterior deep temporal, buccal
3. posterior superior alveolar, infraorbital, descending palatine, sphenopalatine, pharyngeal, pterygoid canal
temporal fascia
superior temporal lines to zygomatic arch
temporalis
temporal lines to coronoid process of mandible
masseter
maxillary process of zygomatic bone / anterior 2/3 process of zygomatic maxilla to lateral surface of ramus and angle of mandible
lateral pterygoid
upper head : roof of infratemporal fossa
lower head : lateral surface of lateral pterygoid plate
both to TMJ capsule articular cartilage, neck of mandible
medial pterygoid
deep head : medial surface of lateral plate pterygoid
superficial head : tuberosity of maxilla
both to mandible
tempomandibular joint
surface covered by fibrocartilage
divided into 2 by fibrous articulardisc
lower is hinge
upper is glide
lined by synovial membrane
ligaments: tempomandibular, sphenomandibular, stylomandibular
nasal cavity
anterior nostrils (between nasal septum and ala), posterior choanae, superior ethmoid bone, inferior hard palate, medial nasal septum, lateral nasal wall with conchae (turbinate bones)
ethmoid bone
top of nasal cavity and parts of medial and lateral walls, cross shape, crista galli (upper cross) separates left and right olfactory bulbs, perpendicular plate (lower cross( to nasal septum
lateral nasal wall
3 turbinate bones
superior/middle turbinates part of ethmoid bone
inferior concha its own bone
inferior/lateral to each turbinate is a meatus, there is opening between each meatus and a neighboring sinus/passage
turbinate bones sinuses and passages
superior meatus - ethmoidal air cells
middle meatus - ethmoidal bulba, frontal/maxillary sinus within semilunar hiatus
inferior meatus - nasolacimal duct
oral cavity
palatoglossal arch, uvula, palatopharyngeal arch (muscles deep to arches)
tonsils
adenoids, tubal, palantine, lingual
tongue muscles
genioglossus, styloglossus, hypoglossus, palatoglossus
lingual artery and nerve (CN V3 and XII)
genioglossus
pulls tongue out, CN XII
styloglossus
CN XII
hypoglossus
CN XII
palatoglossus
CN X
salivary glands
parotid CN IX
submandibular CN VII
sublingual CN VII
pterygopalatine fossa
maxillary artery and nerve (CN V2)
medial wall of pterygopalatine fossa
sphenopalatine foramen (door)
medial/lateral pterygoid process of sphenoid
palatine bone
lateral wall of pterygopalatine fossa
pterygomaxillary fissure (door)
anterior branches of maxillary nerve
zygomatic branches innervate zygomatic region of face
infraorbital branch innervates skin in region of infraorbital foramen
superior alveolar nerves innervate teeth and gums lining maxilla
pterygopalatine ganlion
CN VIII carries parasympathetic fibers from brain stem
greater petrosal erve leaves CN VIII at geniculate ganglia, breifly transverses ,iddle cranial fossa entering pterygoid canal merged with sympathetic fibers, in PT fossa parasympathetic fibers synapse PT ganglia and go to glands and mucose of viscerocranium
bones of the orbit
ethmoid, lacrimal, palatine, maxilla, zygomatic, sphenoid, frontal
5 layers of scalp
skin
connective tissue
aponeurosis
loose CT
pericranium (periosteum of bone)
aponeurotic layer
connects occipitofrontalis (pulls scalp anterior, wrinklesforehead, raises eyebrows) and temporalis/superior auricular muscle (elevates aurical of external ear)
all innervated by CN VII (other muscles this innervates are stapedius, posterior belly of digastric, stylohyoid)
3 groups of face muscles
orbital, nasal, oral
orbital muscles of face
orbicularis oculi - outer orbital encircles orbital orifice, inner palpebral part in eyelids from medial corner to attach laterally
correugator supercili - medial end superciliary arch to skin on medial 1/2 eyebrow
nasal muscles of face
nasalis - flares nares, transverse part (compressor naris) and alar part (dilator naris) maxilla to alar cartilage
procerus - nasal bone to between eyebrows, draws medial eyebrows down
depressor septi nasi - maxilla to lower part of nasal septum, pulls nose inferiorly which opens nares
oral muscles of face
orbicularis oris - encircles mouth, purses lips, maxilla/mandible/buccinator to skin/mucous membrane of lips
buccinator - posterior maxilla/mandible to orbicularis oris, resists distention of cheeks
levator labii superioris alaeque nasi - snarl
innervation of scalp
anterior to auricles CN V
posterior to auricles spinal cutaneous nerves from C2/3
trigeminal nerve (CN V)
sensory root consists of central process of neurons in trigeminal ganglion
motor root is supplying muscles of mastication (temporalis, lateral and medial pterygoid, masseter)
branches of facial nerve
To - temporal
Zanzabar - sygomatic
By - buccal
Motor - mandibular
Car - cervical
blood supply of face
facial artery
gives off superior and inferior labial arteries and lateral nasal arteries (becomes angular arteries distal to lateral nasal artery)
facial veins
supratrochlear and supraorbital drain into angular vein
angular vein drains into facial vein
facial vein communicates with the ophthalmic vein and deep facial veins
lymph of face
submental nodes drain medial lower lip and chin
submandibular nodes drain medial orbit, external nose, medial cheek, upper lip
preauricular/parotid nodes drain eyelids, external nodes, lateral cheeks
all drain into deep cervical nodes which drain to jugular trunch which drains to thoracic duct
pharynx has 3 parts
nasopharynx - choana to soft palate CN V2
oropaharynx - soft palate palatoglosal arch to epiglottis CN IX
laryngopharynx - epiglottis to cricoid cartilage CN X
piriform recess
swallowed items can get lodged and inflamed
superior laryngeal nerve
thyroid cartilage
superior and inferior horn
cricothyroid joint
trachea
cricotracheal ligament (C6), carina (T4/5), trachealis muscle, C-shaped hyalin cartilage rings
external pharyngeal muscles
superior pharyngeal constrictor - occipital bone/medial pterygomandibular plate
middle pharyngeal constrictor - hyoid bone
inferior pharyngeal constrictor - thyroid/cricoid cartilage
all to pharyngeal raphe CN X
internal pharyngeal muscles
palatopharyngeus - hard palate/palatine aponeurosis to thyroig cartilage/pharyngeal wall
saplingopharyngeus - cartilagenous pharyngotympanic tube to pharyngeal wall
stylopharyngeus - styloid process of temporal bone to thyroid cartilage od pharyngeal wall
all pull pharynx up CN IX
palatini muscles
tensor veli palatini - soft palate to pharyngotympanic tube, CN V3, tense palate (aid in swallowing)
levator veli palatini - soft palate to pharyngotympanic tube, CN X, elevate palate/close opening between naso/oropharynx
gag reflex
CN IX (sensory efferent), CN X (motor afferent), pharynx/soft palate sensory
gap below inferior pharyngeal constrictor
recurrent laryngeal nerve, inferior laryngeal artery
gap between inferior and middle pharyngeal constrictor
inferior laryngeal nerve, superior laryngeal artery, superior laryngeal vein
gap between middle and superior pharyngeal constrictor
stylopharyngeus, glossopharyngeal nerve, stylohyoid ligament passes here
gap between superior pharyngeal constrictor and pharyngobasilar fascia
levator veli palatini, pharyngotympanic tube, ascending palatine artery
lymph
tonsils
pharyngeal (adenoids)
palatine
lingual
tonsilar bed
palatoglossal and palatopharyngeal arch, superior pharyngeal constrictor
arytenoid cartilages
muscular process, vocal process, can slide anterior/posterior/medial/lateral
recurrent laryngeal nerve and vocal cords
damage on 1 side - paralyzed muscle assumes paramedian position, functional side past midline to speak, litle deficit
damage on both sides - paralyzed muscle assumes paramedian position, can usually breath but touble speaking, sometimes cords move medially making speaking possibel but breathing hard
cricothyroid muscles
recurrent laryngeal nerve
thyroarytenoid - relaxer
vocalis - minute adjustment to vocal cords
posterior cricoarytenoid - opens airway
lateral cricoarytenoid - close airway
transverse arytenoid - close airway
aryepiglottic and oblique arytenoid - like sphincter, close glottis
3 parts of ear
external - auricle, external auditory meatus
middle - in temporal bone, lateral tympanic membrane, communicates with nasopharynx via pharyngotympanic tube
function of external and middle ear
collect sounds and transfer to internal ear
inner ear
contain specialized structures for hearing and posture equilibrium
extrinsic auricular muscles
superior auricular - pull pinna up
anterior auricular - pull pinna forward
posterior auricular - pull pinna back
intrinsic auricular muscles
pass between cartilagenous ridges of auricle, change shape of auricle, CN VIII
auricle blood supply
posterior auricular artery from external carotid, anterior auricular branches from superficial temporal artery, branch from occipital artery
venous drainage of auricle
veins follow corresponding arteries
lymph drainage of auricles
lateral surface of superior half to superficial parotid nodes
cranial surface of superior half to mastoid nodes/deep cervical nodes
remainder to superficial cervical nodes
sensory innervation of external ear
CN X, VII, lesser occipital (C2), greater auricular (C2/3)
external auditory meatus
concha to tympanic membrane
lateral 1/3 is cartilage
medial 1/3 is bony
tympanic membrane
connective tissue with skin on outside and mucous on inside
attached to temporal bone by fibrocartilagenous rings
umbo (concavity from attachment to handle of malleus)
lateral process (superior part of handle)
posterior and anterior malleolar folds extending
above is pars flaccida and the rest is pars tensa
external surface CN VII
internal surface CN IX
middle ear
air filled, 2 segments (epitympanic recess superiorly, tympanic cavity adjacent to tympanic membrane)
malleus
attaches tympanic membrane, moves with membrane vibration, chorda tympani crosses it
incus
between malleus and stapes
stapes
smallest
attaches incus to oval window of tympanic cavity, increases force and decreases amplitude of vibration
tensor tympani
cartilage of eustachian tube to handle of malleus
CN V3
draws malleus and tempanic membrane medially increasing tension
stapedius
internal walls pyramidal eminence to neck of stapes
CN VII
tilts stapes and dampens vibration
boundaries of middle ear
roof - tegmen tempani
inferior wall - opening for CN IX jugular wall
posterior mastoid wall - gap connecting middle ear with mastoid antrum, pyramidal eminence and chordatympani nerve opening
anterior carotid wall - chorda tympani foramen, separate carotid arteries, opening for eustachian tube and tensor tympani nerve
medial wall - oval window, tympanic plexus, round window
inner ear
mechanical to electrical signals
receptors for motion and position
bony labrinth
vestibule
3 semicircular canals (anterior, posterior, lateral)
cochlea
fluid filled
membranous labrynth
interconnected sacs and ducts filled with endolymph, 3 parts
cochlear duct - hearing
vestibular area - utricle and saccule
semicircular ducts
adnexa of eye
bony orbit, lacrimal system and eyelids, muscles and ligaments, nerves, blood vessels
bony orbit bones
frontal, sphenoid, ethmoid, palatine, lacrimal, maxilla, zygomatic
supra orbital notch, supra orbital fissure, ethmoid foramina, optic canal, lacrimal groove, infra orbital fissure, infra orbital foramen
extrinsic muscles of eye
superior rectus, inferior rectus, medial rectus, inferior oblique, levator palpebrae superioris, superior tarsal muscles (CN III)
lateral rectus (CN VI)
superior oblique (CN V)
intrinsic muscles of eye
ciliary, sphincter pupillae, dilator pupillae
common tendinous ring
point of origin for rectus muscles
nerves
optic canal: optic nerve
supraorbital fissure:CN III (oculomotor), CN IV (trochlear), CN V (trigeminal), ophthalmic nerve (frontal-supratrochlear/supraorbital, nasociliary - ethmoidal/infratrochlear, lacrimal), CN VI (abducens)
autonomic: intrinsic eye muscles and lacrimal glands
CN III: superior branch (levator palpebrae superioris, superior rectus), inferior branch (medial rectus, inferior rectus, inferior oblique, ciliary autonomic ganglion)
sensory from globe - cell bodies in trigeminal but not CN V fibers, its autonomic
autonomic parasympathetic - innervation of intrinsic eye muscles, increase lacrimal fluid in lacrimal gland
blood vessels
optic canal - ophthalmic artery
supraorbital fissure - superior ophthalmic vein
infraorbital fissure - inferior ophthalmic vein
arteries of orbit - supraorbital, central retinal, supratrochlear, dorsal nasal, ethmoidal, long posterior ciliary, short posterior ciliary, lacrimal, ophthalmic
veins of orbit - superior ophthalmic, supraorbital, inferior ophthalmic, vorticose, infraorbital, angular, pterygoid plexus
eye movement
adduct - medial rectus (CN III)
abduct - lateral rectus (CN VI)
up and medial - inferior oblique (CN III)
down and medial - superior oblique (CN IV)
up and lateral - superior rectus (CN III)
down and lateral - inferior rectus (CN III)
autonomics of head target tissues
ciliary muscle, sphncter pupillae, dilator pupillae, lacrimal glands, glands of mucosa, submandibular and sublingual glands, parotid glands
sympathetic origins
upper thoracic spinal cord (stimulate post ganglionic neurons in sympathetic chain, specifically superior cervical ganglia)
parasympathetic origins
brainstem, part of CN III, VII, IX, X
discrete ganglion prior to tissue (CN III = ciliary, CN VII = pterygopalatine ganglion, CN IX = submandibulat, CN X = otic)
sympathetics pass through ganglia but dont synapse
ciliary ganglion
CN III
ciliary muscle, sphincter and dilator pupillae
pterygopalatine ganglion
CN VII
lacrimal glands, nasal glands
submandibular ganglion
CCN VII
submandibular and sublingual glands
otic ganglia
CN IX
parotid glands
CN III
parasympathetics - preganglionic soma in brainstem, transverse supraorbital fissure and synapse ciliary ganglion, postganglionic axons enter eye as short ciliary nerves and innervate sphincter pupillae and ciliary muscle
sympathetics - preganglionic soma in upper thoracic cord, synapse in superior cervical ganglia, post ganglionic axons make carotid plexus and pass through ciliary ganglia to eye as short ciliary nerves or travel with nasociliary branch of V1 to eye as long ciliary nerves to innervate dilator pupilaae
CN VII
lacrimation: parasymp as greater petrosal nerve through pterygoid canal as nerve of pterygoid canal, enter pterygopalatine ganglia then run s=with maxillary fibers and merge with lacrimal nerve ending in lacrimal gland /// symp as deep petrosal nerve and join as nerve of pterygoid canal then goes to lacrimal gland
mucosa: parasymp exits ganglia to innervate mucose /// symp follow external carotid and some bypass ganglia
submandibular/sublingual: parasymp branch into chorda tympani and run with lingual nerve and enter submandibular ganglion, exit to glands /// symp patht o carotid plexus follow external carotid and bypass ganglia
CN IX
parasymp: branch into tympanic nerve (travel in tympanic plexus) becomes lesser petrosal, enter otic ganglia, exit with auriculotemporal and jump in parotid gland /// symp to carotid plecus and follow external carotid bypassing ganglia
thyroid gland
sympathetic - superior, middle, inferior cervical ganglia, increase secretion
parasympathetic - superior laryngeal and recurrent laryngeal nerevs
superior tarsal muscle in eyelid
sympathetic fibers from superior cervical ganglion up internal carotid and join CN III in cavernous sinus
-loss of sympathetics (Horners) = miosis (constricted pupil), patial ptosis (drooping lid), anhydrosis (decreased sweat)
meninges
protect brain, form compartmental vascular framework, form space filled with cerebrospinal fluid
3 meninges layers
dura mater, arachnoid mater, pia mater
leptomeninges = arachnoid = pia
dura mater
periosteal - adhered to inside of skull
meningeal - adrhered to periosteal except where they separate to form pockets of venous blood
reflections - falx cerebri, tentorium cerebelli, falx cerebelli, diaphram sellae
tentorial notch
opening for brainstem
tentorium cerebelli - separates brain into 2 compartments (supratentorial and infratentorial)
dura innervation
each branch of trigeminal and C2-3
arachnoid mater
held against dura by subarachnoid fluid
below is subarachnoid space filled with cerebrospinal fluid, blood vessels, and archnoid trabeculae
pia mater
single cell thick, tight to brain, highly vascularized by subarchnoid vessels
blood for dura/inner skull
blood vessels in dural layers
blood for brain/pia
blod vessels in subarachnoid space
meningeal arteries
between periosteal and meningeal layers
anterior, middle, posterior meningeal arteries
skull fracture
tears meningeal arteries leading to epidural hemmorhage
venous drainage of meninges
anterior, middle, posterior eningeal veins, pterygoid plexus
arteries supplying brain
internal carotid entering skull through carotid canal, vertebral arteries entering skull through foramen magnum
both pass duraarachnoid and enter subarachnoid space (rupture here is intracerebral hemmorhage)
venous drainage of brain
large veins from surface of brain drain blood returning from sinuses, bridging veins pass meningeal layers (tear can cause subdural hematoma)
dural venous sinuses
pockets of venous blood between periosteal and meningeal dura layers that collect blood from brain parynchema and CSF
confluence of sinuses
superior sagittal, inferior sagittal, vein of galen, stright sinus, occipital sinus, cavernous sinus, sigmoid sinus
emmisary veins
pass through skill and trransmit blood to dipploic veins in skull which empty into dural sinuses
