HEAD/NECK:HEAD/NECK: Throat/ PharynxThroat/ Pharynx

Overview: Overview: SagittalSagittal view of view of nose/mouth/throatnose/mouth/throatNasal Cavity and BreathingNasal Cavity and BreathingMouth and ChewingMouth and ChewingThroat and SwallowingThroat and SwallowingLarynx and Singing Larynx and Singing

SagittalSagittal Section HeadSection HeadCranial cavityCranial cavityBrain/Spinal cordBrain/Spinal cordVertebral bodiesVertebral bodiesEpaxialEpaxial musclesmusclesHard/soft palateHard/soft palateOral cavityOral cavityEsophagusEsophagusTracheaTracheaEpiglottisEpiglottisNasoNaso--OroOro--LaringoLaringo--

pharynx

Nose/Nasal Cavity and BreathingNose/Nasal Cavity and Breathing

Function:Function:Inlet for air to Inlet for air to lunglungWarm/filter airWarm/filter air(mucous membranes on (mucous membranes on ethmoidethmoid conchaeconchae))

SmellSmell(nerve endings on nasal (nerve endings on nasal membranes)membranes)

M&M, Fig. 21.1

ConchaeConchae of of EthmodEthmod BoneBone

ScrollScroll--like boneslike bonesCovered in mucous membrane Covered in mucous membrane f–– SmellSmell–– Filter airFilter air–– Warm airWarm air

M&M, Fig. 7.10

SinusesSinusesAll connected to All connected to nasal cavitynasal cavityAll lined with All lined with mucous mucous membranesmembranesCold/allergiesCold/allergies——fill fill with mucous=sinus with mucous=sinus headacheheadache

• Maxillary• Ethmoid• Frontal• Sphenoid

M&M, Fig. 7.11

Mouth/Oral Cavity and ChewingMouth/Oral Cavity and Chewing

COMPONENTSCOMPONENTSLipsLipsCheeksCheeksPalatePalateJaws and teethJaws and teethSalivary glandsSalivary glands

FUNCTION• Bite and chew food• Form words• Taste• Kiss

Vestibule—in front of teethOral cavity proper—behind teeth

Lined by thick stratified squamousepithelium (almost no keratin)

LipsLipsFUNCTIONFUNCTIONClose mouthClose mouthKeep food inKeep food inMake speech soundsMake speech soundsTactileTactile

STRUCTURESTRUCTURECore of Core of sphinchtersphinchter--shape shape skeletal muscle (skeletal muscle (orbicularisorbicularisorisoris))““Red marginRed margin”” transition from transition from keratinized skin to oral keratinized skin to oral mucosamucosa–– Red because clear color lets Red because clear color lets

underlying vessels show throughunderlying vessels show through–– No sweat or sebaceous glands, No sweat or sebaceous glands,

thus needs to be wet (or lip thus needs to be wet (or lip balm)balm)

M&M, Fig. 11.6

CheeksCheeksFUNCTIONFUNCTION

Form side of mothForm side of moth

STRUCTURESTRUCTUREBuccinatorBuccinator musclemuscle——instrumental in instrumental in swallowing, connects swallowing, connects back to pharyngeal back to pharyngeal constrictorsconstrictors

M&M, Fig. 11.6

PalatePalate

Hard palate anteriorHard palate anterior–– MaxillaMaxilla–– PalatinePalatine

Soft palate is Soft palate is posterior extension, posterior extension, soft tissuesoft tissuePalatoglossalPalatoglossal archarch(palate to tongue) (palate to tongue) PalatopharyngealPalatopharyngealarcharch(palate to pharynx)(palate to pharynx)Tonsils between Tonsils between archesarchesUvulaUvula……??????

M&M, Fig. 22.7

JawsJaws

FUNCTIONFUNCTIONHold teethHold teethOcclude in Occlude in chewingchewing STRUCTURE

•Upper jaw—maxillary bone

•Lower jaw--mandible

M&M, Fig. 7.3

TeethTeethDeciduous teethDeciduous teeth——””milkmilk”” or or ““babybaby””teethteethEmerge 6 mos. Emerge 6 mos. –– 2 2 yrs.yrs.Replaced by Replaced by permanent teeth 6permanent teeth 6--12 yrs.12 yrs.Wisdom teeth (3Wisdom teeth (3rdrd

molar) erupts 17molar) erupts 17--25 25 yrs or remains in jawyrs or remains in jaw

Key to healthy teeth and gums: •Flossing•Visiting dentist regularly (every 6 mos.) and starting at young age (3-4 yrs.)

Structure of individual toothStructure of individual tooth——itit’’s alive!!s alive!!

Jaw musclesJaw musclesMasseterMasseter, , temporalistemporalis——elevate mandible (elevate mandible (““close close jawjaw””))Medial Medial pterygoidpterygoid——lateral lateral (side(side--toto--side) chewingside) chewingLateral Lateral pterygoidpterygoid——translates mandible translates mandible anteriorlyanteriorly (part of (part of opening)opening)DigastricDigastric (not shown)(not shown)——depresses mandible depresses mandible ((““opens jawopens jaw””))Chewing is circular Chewing is circular motionmotion

M&M, Fig. 11.7

TongueTongueFUNCTIONFUNCTION

Position food Position food between teethbetween teethForm words in Form words in speechspeech

STRUCTURESTRUCTUREIntrinsic muscles Intrinsic muscles (allow for shape (allow for shape change with fibers change with fibers in various in various directions)directions)Extrinsic musclesExtrinsic muscles——attach tongue to attach tongue to skeletonskeleton–– GenioglossusGenioglossus–– hyoglossushyoglossus M&M, Fig. 22.7

Salivary glandsSalivary glandsIntrinsicIntrinsic——all over all over mucous mucous membranes of membranes of tongue, palate, tongue, palate, lips, lining of lips, lining of cheekcheekExtrinsicExtrinsic——secrete secrete more saliva when more saliva when eating (or eating (or anticipating)anticipating)–– ParotidParotid–– SubmandibularSubmandibular–– sublingualsublingual

M&M, Fig. 22.10

SalivaSalivaMoistens mouthMoistens mouthDissolves food to be tastedDissolves food to be tastedWets and binds foodWets and binds foodContains amylase to start starch Contains amylase to start starch digestion (saltine to sugar experiment)digestion (saltine to sugar experiment)Contains bicarbonate to neutralize cavityContains bicarbonate to neutralize cavity--causing acids produced by bacteriacausing acids produced by bacteriaContains antiContains anti--bacterial and antibacterial and anti--viral viral enzymes and cyanideenzymes and cyanide--like compound to like compound to kill harmful microkill harmful micro--organismsorganismsContains proteins that stimulate growth Contains proteins that stimulate growth of beneficial bacteria in the mouthof beneficial bacteria in the mouth

Throat/Pharynx and SwallowingThroat/Pharynx and SwallowingBack of mouth to larynxBack of mouth to larynxFood and air mix and crossFood and air mix and cross

•When it goes wrong—choking!!

FoodPHARYNX

Air

Trac

hea

Esop

hagu

s

STRUCTURES•Entry—pharyngeal arches•Exit—glottis (epiglottis is lid)•Pharyngeal constrictors squeeze food through

Pharynx and SwallowingPharynx and Swallowing

Focus on muscles and arrangement of mouth cavity, pharynx, larynx, epiglottis, trachea Pharynx/Swallowing

in detail!!

Descent of the larynx Descent of the larynx

Larynx and SingingLarynx and Singing

FUNCTIONFUNCTIONChannel air out of tracheaChannel air out of tracheaVibrate to produce sound for Vibrate to produce sound for speech/songspeech/song

STRUCTURESSTRUCTURESExternal skeleton or frame External skeleton or frame (cartilage)(cartilage)Internal vocal cords and associated Internal vocal cords and associated musclesmuscles

Skeleton of larynxSkeleton of larynx

CricothyroidCricothyroid ligament is usual site of emergencyligament is usual site of emergencytracheotomy (feel on selftracheotomy (feel on self——SURFACE ANATOMY)SURFACE ANATOMY)

M&M, Fig. 21.5

Vocal cordsVocal cords

M&M, Fig. 21.6

COMING SOON!!COMING SOON!!Head/Neck III: Special Head/Neck III: Special

SensesSensesHead/Neck IV: Cranial Head/Neck IV: Cranial

NervesNerves