Head/Neck--Oral Cavity, Pharynx,Larynx Flashcards
What are the boundaries of the oral cavity
- anteriorly: opens at the lips
- posteriorly: opens into oropharynx
- laterally: checks
Vermillion border
-part of the lips where hair, sweat glands, and mucous glands ceases
What is the philtrum of the lips
-it is the embryological border where the two sides of the upper lip meet
***cleft lip
What is the labial frenulum of the lips
It is the attachment of the lips to the gum
Which nerve Innervates the upper lip
The maxillary branch of the trigeminal nerve (CN V2)
Which nerve innervates the bottom lip
The mandibular branch of the trigeminal nerve ( CN V3)
Characteristics of the cheeks
- first layer is skin
- second layer is muscle
- third layer is mucous membrane
Which nerve innervates the skin of the cheeks
-the trigeminal nerve (CN V2 & CN V3)
Describe the muscle of the cheeks
- buccinator
- it is a muscle of facial expression so it is innervated by the facial nerve (CN VII)
- used in suckling reflex
- aids in chewing
Which nerve innervates the mucous membrane of the cheeks
- The trigeminal nerve (CN V)
* *like the skin of the cheeks
Describe the oral cavity
- oral cavity is made up of two parts
1) vestibule (between cheeks and gums/teeth)
2) oral cavity proper (between dental arches)
* **oral cavity proper is filled by tongue at rest
Features of the oral cavity proper (be able to label)
1) palatoglossal arch (first arch)
2) palatine tonsils (in between)
3) palatopharyngeal arch
Palatine tonsils
- one of the mucosa-associated lymphoid tissues (MALT)
- it is located at the entrance to the upper respiratory tract and gastrointestinal tract in order to protect the body
- consequently, site of potential infection (tonsillitis)
Describe the gums
- there are two parts of the gums:
1) free gingiva
2) attached gingiva
-gums have the same innervation as the teeth around them
Describe the teeth
There are two sets of teeth:
1) maxillary (upper jaw)
- CN V2 innervation
2) mandibular (lower jaw)
- CN V3 innervation
Functions of the tongue
1) move food into the pharynx
2) aid in phonation
Parts of the tongue
- made of two parts
1) oral portion (body)
2) pharyngeal portion (root or base)
- base is anchored, immovable
Describe the inferior surface of the tongue
- it is attached tot he floor of the oral cavity by the “lingual frenulum”
- location of lingual vein
Describe the superior surface of the tongue
- known as the dorsum and is covered by finger-like projections called papillae
- papillae occur only on the body (anterior 2/3 of the tongue)
What is the clinical significance of the lingual vein
- thin membrane covering it allows for easy/rapid uptake
- not all drugs can be taken sublingually because some drugs are activated by digestive enzymes (timed release)
Types of papillae
1) filiform papillae
2) fungiform papillae (taste buds)
3) foliage papillae (have taste buds and are on lateral tongue)
4) vallate papillae (taste buds; posterior body)
* **there are taste buds in posterior 1/3 of tongue even though no papillae
Other features on dorsum of tongue (be able to label)
1) median sulcus (groove)
- few nerves just septum with fat
2) sulcus terminalis
- base of tongue and body of tongue junction
3) foremen cecum
- where thyroid gland developed
4) lingual tonsil
- lymphoid tissue in the base of tongue
Innervation of the body of the tongue
- body is innervated by the mandibular branch of the trigeminal nerve (CN V3)
- taste buds are innervated by facial nerve (CN VII)
Innervation of the base/root of the tongue
-the base or root of the tongue along with its taste buds is innervated by the glossopharyngeal nerve (CN IX)
Describe the intrinsic muscles of the tongue
- within the body of the tongue and control movement of oral cavity
- innervated by the hypoglossal nerve (CN XII)
Describe the extrinsic muscles of the tongue
- they act on the body of the tongue
- aid in digestion
- primary movements
1) protrusion
2) retraction
3) depression - innervated by the hypoglossal nerve (CN XII)
Functions of saliva
- saliva is produced by salivary glands and contains enzymes that begin the breakdown of food
- also helps moisten the mouth to help chew and swallow
Name the salivary glands
1) parotid gland (largest)
2) submandibular gland
3) sublingual gland
Parotid gland
- parotid duct crosses the masseter to end in the vestibule of the oral cavity adjacent to the upper second molar
- it is under parasympathetic innervation by the glossopharyngeal nerve (CN IX)
Submandibular glands
- located along the body of the mandible adjacent to the lingual frenulum
- open at the sublingual papilla a
- under parasympathetic innervation by the facial nerve (CN VII)
Sublingual glands
- lie in the floor of the mouth deep t o the tongue
- these glands open via many ducts directly into sublingual fossa
- they are under parasympathetic innervation by the facial nerve (CN VII)
Pharynx
- the pharynx serves as a general passageway for the GI tract and respiratory system
- a fibromuscular tube that lies anterior to the vetebral column
- it begins at the posterior aperture of the nose and ends at the esophagus
Regions of the pharynx (be able to label)
1) nasopharynx
2) oropharynx
3) laryngopharynx
Pharyngeal tonsil
-lymphoid tissue located on the “roof” of the nasopharynx aka adenoids
***enlarged pharyngeal tonsil (adenoid) can completely block airflow through the nasal passages
Auditory tube
- also known as the eustachian tube or pharyngotympanic tube
- it links the nasopharynx to the middle ear
- it is the lateral wall of nasopharynx
- it is approximately 1/3 bone & 2/3 cartilage
Functions of the auditory tube
1) pressure equalization
- equalizing pressure between the middle ear and the atmosphere
2) mucus drainage
- drains mucus form the middle ear
***pressure difference across middle ear causes temporary conductive hearing loss
Otitis media
- inflammation of the middle ear (commonly affects the auditory tube)
- children under 7 are more susceptible likely due to shorter and more horizontal angle
Wall of the pharynx
-lined with mucous membrane continuous with the cavity that it lies in
Constrictor muscles of the wall of the pharynx
- 3 sets of overlapping semicircular constrictor muscles that function to push bolus down to esophagus
1) superior
2) middle
3) inferior
-innervated by the vagus nerve (CN X)
Longitudinal muscles of the pharynx
- 3 sets of strap-like muscles that function to help open the pharynx for eating
1) salpingopharyngeus
2) stylopharnygeus
3) palatopharyngeus
-longitudinal muscles are innervated by the vagus nerve ( CN X)
Sleep apenia
- Intrinsic and extrinsic muscles relax causing blockage
- there is loss of negative pressure that normally pulls structures forward to allow air down pharynx
Describe the larynx
- called the voice box or organ of speech
- acts to hold the airway open (cartilagenous)
- anteriorly covered by the strap muscles (longitudinal muscles of the pharynx) and thyroid
- adjacent to C3-C6
- visible on the surface of the neck as the laryngeal prominence (adam’s apple)
Describe the skeleton of the larynx
- composed of cartilage 3 paired and 3 unpaired and membranes
- unpaired: thyroid cartilage, cricoid cartilage, and epiglottis
- paired: arytenoid cartilages, corniculate cartilages, cuneiform cartilages
- relationship with the hyoid bone
Unpaired cartilages of the larynx
- all made of hyaline cartilage except for the epiglottis (elastic cartilage)
1) thyroid cartilage: largest, opens posteriorly, midline is laryngeal prominence
2) cricoid cartilage: complete ring
3) epiglottis: leaf-shaped, elastic cartilage
Paired cartilages of the larynx
1) arytenoid cartilages: pyramid shaped (snow boots)
- contain muscular process and vocal process
- anterior attachment for vocal ligaments
2) corniculate cartilages: on top of arytenoid
3) cuneiform cartilages
Membranes of the skeleton of the larynx
- membranes hold the cartilage together to the hyoid bone
- they have names that match the attachment points
Muscle relations to cartilages of the larynx
- skeletal muscles control the cartilage
- movement of the cartilages cause movement of the vocal ligaments
- under innervation of the vagus nerve (CN X)
***Vagus nerve damage can result in voice hoarseness
Production of sound
- abduction and adduction of the arytenoid cartilages open and close the space between the vocal ligaments
- air along with vibration of the ligaments creates sound
Pitch production
- movement between the thyroid and cricoid ligaments change the length of the vocal ligaments (shorter vs. longer)
- this affects pitch
Laryngitis
- inflammation of the larynx (overuse, irritation, or infection)
- causes voice hoarseness distorts sound
***laryngeal polyps and nodules also distort sound/cause pain
