Human Anatomy, Frolich, Head II: Throat/Larynx

HEAD/NECK II: Throat/ Pharynx

• Overview: Sagittal view of nose/mouth/throat

• Nasal Cavity and Breathing

• Mouth and Chewing

• Throat and Swallowing

• Larynx and Singing

Human Anatomy, Frolich, Head II: Throat/Larynx

Sagittal Section Head• Cranial cavity• Brain/Spinal cord• Vertebral bodies• Epaxial muscles• Hard/soft palate• Oral cavity• Esophagus• Trachea• Epiglottis• Naso-• Oro-• Laringo-

pharynx

Human Anatomy, Frolich, Head II: Throat/Larynx

Nose/Nasal Cavity and Breathing

Function:• Inlet for air to lung• Warm/filter air

(mucous membranes on ethmoid conchae)

• Smell(nerve endings on nasal membranes)

M&M, Fig. 21.1

Human Anatomy, Frolich, Head II: Throat/Larynx

Conchae of Ethmod Bone

• Scroll-like bones• Covered in mucous membrane for

– Smell– Filter air– Warm air

M&M, Fig. 7.10

Human Anatomy, Frolich, Head II: Throat/Larynx

Sinuses• All connected to nasal

cavity• All lined with mucous

membranes• Cold/allergies—fill

with mucous=sinus headache

• Maxillary• Ethmoid• Frontal• Sphenoid

M&M, Fig. 7.11

Human Anatomy, Frolich, Head II: Throat/Larynx

Mouth/Oral Cavity and Chewing

COMPONENTS• Lips• Cheeks• Palate• Jaws and teeth• Salivary glands

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

Vestibule—in front of teethOral cavity proper—behind teeth

Lined by thick stratified squamous epithelium (almost no keratin)

Human Anatomy, Frolich, Head II: Throat/Larynx

LipsFUNCTION• Close mouth• Keep food in• Make speech sounds• Tactile

STRUCTURE• Core of sphinchter-shape skeletal

muscle (orbicularis oris)• “Red margin” transition from

keratinized skin to oral mucosa– Red because clear color lets

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

needs to be wet (or lip balm)

M&M, Fig. 11.6

Human Anatomy, Frolich, Head II: Throat/Larynx

CheeksFUNCTION• Form side of moth

STRUCTURE• Buccinator muscle—

instrumental in swallowing, connects back to pharyngeal constrictors

M&M, Fig. 11.6

Human Anatomy, Frolich, Head II: Throat/Larynx

Palate

• Hard palate anterior– Maxilla– Palatine

• Soft palate is posterior extension, soft tissue

• Palatoglossal arch

(palate to tongue) • Palatopharyngeal arch

(palate to pharynx)• Tonsils between arches• Uvula…???

M&M, Fig. 22.7

Human Anatomy, Frolich, Head II: Throat/Larynx

Jaws

FUNCTION• Hold teeth• Occlude in chewing

STRUCTURE

•Upper jaw—maxillary bone

•Lower jaw--mandible

M&M, Fig. 7.3

Human Anatomy, Frolich, Head II: Throat/Larynx

Teeth• Deciduous teeth—”milk”

or “baby” teeth• Emerge 6 mos. – 2 yrs.• Replaced by permanent

teeth 6-12 yrs.• Wisdom teeth (3rd

molar) erupts 17-25 yrs 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.)

Human Anatomy, Frolich, Head II: Throat/Larynx

Structure of individual tooth—it’s alive!!

Human Anatomy, Frolich, Head II: Throat/Larynx

Jaw muscles• Masseter, temporalis—

elevate mandible (“close jaw”)

• Medial pterygoid—lateral (side-to-side) chewing

• Lateral pterygoid—translates mandible anteriorly (part of opening)

• Digastric (not shown)—depresses mandible (“opens jaw”)

• Chewing is circular motion

M&M, Fig. 11.7

Human Anatomy, Frolich, Head II: Throat/Larynx

TongueFUNCTION• Position food between

teeth• Form words in speechSTRUCTURE• Intrinsic muscles

(allow for shape change with fibers in various directions)

• Extrinsic muscles—attach tongue to skeleton– Genioglossus– hyoglossus

M&M, Fig. 22.7

Human Anatomy, Frolich, Head II: Throat/Larynx

Salivary glands• Intrinsic—all over

mucous membranes of tongue, palate, lips, lining of cheek

• Extrinsic—secrete more saliva when eating (or anticipating)– Parotid– Submandibular– sublingual

M&M, Fig. 22.10

Human Anatomy, Frolich, Head II: Throat/Larynx

Saliva• Moistens mouth• Dissolves food to be tasted• Wets and binds food• Contains amylase to start starch digestion

(saltine to sugar experiment)• Contains bicarbonate to neutralize cavity-

causing acids produced by bacteria• Contains anti-bacterial and anti-viral enzymes

and cyanide-like compound to kill harmful micro-organisms

• Contains proteins that stimulate growth of beneficial bacteria in the mouth

Human Anatomy, Frolich, Head II: Throat/Larynx

Throat/Pharynx and Swallowing• Back of mouth to larynx• Food and air mix and cross

•When it goes wrong—choking!!

FoodPHARYNX

Air

Tra

chea

Eso

phag

us

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

Human Anatomy, Frolich, Head II: Throat/Larynx

Pharynx and Swallowing

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

Pharynx/Swallowing in detail!!

Human Anatomy, Frolich, Head II: Throat/Larynx

Descent of the larynx

Human Anatomy, Frolich, Head II: Throat/Larynx

Larynx and Singing

FUNCTION• Channel air out of trachea• Vibrate to produce sound for

speech/songSTRUCTURES• External skeleton or frame (cartilage)• Internal vocal cords and associated

muscles

Human Anatomy, Frolich, Head II: Throat/Larynx

Skeleton of larynx

• Cricothyroid ligament is usual site of emergency tracheotomy (feel on self—SURFACE ANATOMY)

M&M, Fig. 21.5

Human Anatomy, Frolich, Head II: Throat/Larynx

Vocal cords

M&M, Fig. 21.6

Human Anatomy, Frolich, Head II: Throat/Larynx

COMING SOON!!

Head/Neck III: Special Senses

Head/Neck IV: Cranial Nerves