Mouth and Throat Anatomy & Physiology

Function of Mouth and Throat

• The mouth and throat facilitate ingestion, taste, and food preparation for digestion.
• They aid in speech and serve as an airway for the respiratory tract.
• The mouth and throat act as a muscular passage for food and air, and help to protect against infection.

Parts of the Mouth

• Hard palate is the firm, front part of the roof of the mouth, and is vital for tasting, chewing, and speaking.
• Soft palate is the soft, back part of the roof of the mouth that rises during swallowing to close off the nasal passages.
• Tongue is the muscular organ on the floor of the mouth, and is vital for tasting, chewing and speaking.
• Tip (apex) is the front, mobile part of the tongue, often used in articulating sounds like "t" and "d."
• Dorsum is the top surface of the tongue.
• Base is the back part of the tongue, which extends down the throat.
• Taste buds are small sensory structures on the tongue that allow the experience of sweet, salty, sour, bitter, and umami flavors.
• Frenulum is a small piece of connective tissue that joins the tongue to the floor of the mouth.
• Incisors are teeth at the front of the mouth, mainly used for cutting food.
• Canines are the pointed teeth between the incisors and premolars, useful for tearing food.
• Molars are large teeth at the back of the mouth, used for grinding and crushing food.
• Gums are the soft tissue in which the teeth are embedded; they can be sensitive or bleed if not properly cared for.
• Buccal pertains to the cheek or sides of the mouth, often related to the area between the gums and cheeks.
• Mandible is the lower jawbone.
• Maxilla is the upper jawbone that holds the upper teeth in place.
• Tonsils are two small masses of lymphoid tissue at the back of the throat that can become swollen with infection.
• Uvula is the small, teardrop-shaped piece of tissue that hangs down at the back of the throat; it plays a role in speech and preventing food from entering the nasal passage.

Parts of the Nose

• The external nose has a bridge, tip, and two oval openings called nares.
• The nasal cavity sits between the roof of the mouth and the cranium, extending from the anterior nares/nostrils to the posterior nares, which open into the nasopharynx.
• The nasal septum divides the cavity into two halves.
• Kiesselbach's area is located near the front of the nasal septum and has many blood vessels and is a common site for a nosebleed.

Sinuses

• Air-filled cavities decrease the skull's weight and act as resonance chambers during speech.
• Paranasal sinuses lined with ciliated mucous membrane, trapping debris and propelling it outward.
• Sinuses are prone to infection due to the ease of blockage.
• Ethmoidal and sphenoidal sinuses are smaller, located deeper in the skull, inaccessible for examination
• Sinuses include:
• Frontal sinus
• Ethmoid sinus
• Maxillary sinus
• Sphenoid sinus

Parts of the Throat and Neck

• Hard palate separates the nose from the mouth
• Soft palate is the back of the roof of the mouth
• Epiglottis keeps food and liquids out of the trachea while swallowing
• Larynx (voice box) makes sound for speaking
• Eustachian tube connects the throat to the ear
• Nasopharynx is the area at the top of the throat behind the nose
• Oropharynx is the area at the middle of the throat behind the mouth
• Hypopharynx is the area at the lower part of the throat
• Esophagus carries food and liquids from the throat to the stomach
• Trachea carries air between the throat and the lungs
• Lymph nodes are bean-shaped organs that help the body fight infections.

Assessment of the Mouth and Tongue

• If a patient experiences sores or lesions on the tongue or mouth, explore the symptoms using COLDSPA:
• Characteristics
• Onset
• Locations
• Duration
• Severity
• Palliative/relieving factor
• Associated Factors

Assessment of Throat: Questions and Rationale

• Difficulty swallowing or painful swallowing may increase the risk for aspiration, and may require consultation with a speech therapist.
• Difficulty chewing, swallowing, or moving the tongue or jaws can be a sign of oral cancer.
• Malocclusion may also cause difficulty chewing or swallowing
• Sore throat is commonly seen with viral infections such as the flu, colds, measles, chicken pox, whooping cough, croup, or infectious mononucleosis.
• Hoarseness can be associated with upper respiratory infections, allergies, hypothyroidism, overuse of the voice, smoking or cancer of the larynx. Hoarseness that lasts 2 weeks or longer needs evaluation.
• Oral, nasal, or sinus surgery and current personal history including sinus infection history may be related to present symptoms
• Seasonal/environmental allergies or a genetic history of sinus cancer can indicate certain conditions
• Current treatments/medications including nasal sprays may cause irritation, nosebleeds, or rebound swelling.
• Lifestyle habits, such as smoking, drinking alcohol, or grinding the teeth (bruxism), can relate to oral cancer, TMJ and pain
• Oral hygiene including how often teeth are brushed and flossed for preventative measures
• Denture fitting including the daily intake can lead to poor eating habits, reluctance to speak freely, and mouth sores or leukoplakia
• Poor nutrition increases the risk for oral cancer

Preparing the Client, Equipment, and Techniques for Mouth, Nose, and Tongue Assessment

• To prepare the client for an assessment, ask them to assume a sitting position with the head erect.
• Explain the structures to be examined and provide a comfortable experience
• A gentle, yet confident and matter-of-fact approach may reduce client anxiety
• Necessary equipment for an exam includes;
• Nonlatex gloves
• 4 x 4-inch gauze pad
• Penlight
• Short, wide-tipped speculum attached to the head of an otoscope
• Tongue depressor
• Nasal speculum
• Be attentive and knowledgeable of the relationships between the structures of the mouth, throat, nose, and sinuses.
• Also be aware of age related changes, ethnocultural considerations, and refine examination techniques

Mouth Inspection

• First inspect the lips, a normal finding for the lips are smooth and moist without lesions or swelling, otherwise abnormal findings are:
• Pallor around the lips
• Bluish cyanotic
• Reddish from ketoacidosis, carbon monoxide poisoning, and COPD with polycythemia
• Swelling from a local, systemic allergic or anaphylactic reaction
• Next is the inspection of the teeth and gums, a normal finding are 32 pearly whitish teeth with smooth surfaces and edges, otherwise abnormal findings are:
• Yellow or brownish color
• Tooth decay
• Missing teeth
• Malocclusion of the teeth
• Red and swollen gums
• Next inspect the buccal mucosa, the normal finding here is a tissue is smooth and moist without lesions, otherwise abnormal findings are:
• Leukoplakia may be seen in chronic irritation and smoking
• Whitish, curd-like patches that scrape off over reddened mucosa and bleed easily which may indicate oral candidiasis
• Koplik's spots are tiny whitish spots that lie over reddened mucosa and are a sign of measles
• Canker sores or even brown patches inside cheeks w can be seen w/ adrenocortical insufficiency.
• Next, inspect and palate the tongue, which should be pink, moist and of adequate size with small papillae but no lesions, or abnormal findings can be:?
• Deep longitudal fissures from dehydration
• Black tongue from bismuth toxicity.
• Enlarged tongue from hypothyroidism, acromegaly, or Down's syndrome, and angioneurotic edema of anaphylaxis
• atrophied tongue or fasciculations which point to cranial nerve (hypoglossal or CN 12) damage.
• The ventral surface of the tongue, with it normally being smooth, shiny, pink or slightly pale, with visible veins, but no lesions. Otherwise, abnormal findings are:
• Leukoplakia, persistent lesions, ulcers, or nodules which may indicate cancer
• Induration which increases the likelihood of the cancer being referred out.

Structures in the Mouth

• Normal findings for inspection of Wharton's ducts the frenulum is midline, ducts visible with saliva or flow in the area, but no swelling, redness or pain. For abnormal, its ulcers nodules lesions are present near the frenulum.
• For observing the sides of the tongue, no lesions, ulcers or nodules are apparent, but abnormal is canker sores with chemo, or cancer lesions/nodules that require follow ups
• The tongue offers strong resistance, but abnormal is defect of CN XII affecting tongue strength with motion Taste normally present on the tongue being able to strongly resist, otherwise abnormal findings are the loss of taste or discrimination due to zinc deficiencies, etc
• Hard palate normally is pale/white with firm and transverse rugae folds, and the soft palate Intact or soft tissue should be pinkish
• Abnormal for the hard and soft is white plaque, deep purple lesions may indicate cancer can be from collagen or cleft palate
• Normally the odor should be unremarkable.
• Foul odor may be an infection. Fecal or sulfur indicates obstruction.

Assessing and Inspecting the Sinuses

• Fleshy uvula should be a midline position but if there is trauma or the uvula deviates you must inspect
• Tonsils are pink and normal size even one sized is considered normal but abnormalities include red exudate and enlargement, which are common signs of tonsilitis
• Inspection of the throat in general should have the pharyngeal wall pink and unremarkable with abnormal findings of any exudate redness or drainage
• Nose- tenderness can be seen with local allergic or inflammatory conditions when palpating and there should be unremarkable nasal tenderness
• Normally the septum and turbinates will not be visible or obstructive and the mucous wont b exudate if there are polyps or deformities follow up is necessary
• Maxillary and frontal sinuses inspected for tenderness and are not tender, but sinus infection and allergies cause tenderness and crepitus.
• When transilluminating the sinuses, it is normal for a red-glow to be illuminated through mouth. But for absence, or red low it represents fluid or pus.