OCB04-2005 Flashcards
Where is the entry point to the alimentary canal?
Mouth
What are the two main regions of the oral cavity?
Oral cavity proper
Vestibule
What separates the oral cavity proper and the vestibule?
Teeth/alveolar ridge
What are the boundaries of the mouth?
Roof/superiorly = maxilla (anterior 2/3s) and palatine bones (posterior 1/3) of hard palate
Anteriorly = maxilla and mandible
Floor/inferiorly and posterior wall = soft tissues/muscles
Laterally = buccinator
Which bone separates the oral and nasal cavities?
Maxilla
Which bones form the hard palate?
Maxilla (ant 2/3)
Palatine (post 1/3)
What muscles form the floor of the mouth?
Mylohyoid
Geniohyoid
Anterior belly of digastric
What is the function of the lips?
Act as a sphincter to grasp food, suckle, speech
Describe the lips (muscle).
Musculofibrous folds containing the orbicularis oris and its accompanying vessels and nerves
What blood vessels supply the lips?
Superior and inferior labial arteries
What vessel do the labial arteries branch from?
Facial artery
What innervates the lips?
Infraorbital nerve from V2 = upper lip
Mental nerve from V3 = lower lip
Describe the cheeks.
Continuous with lips and make up the movable walls of the oral cavity
Contain muscle (principally the buccinators) encapsulated by fat
What is the function of the cheeks?
Suckling, facial expression, speech, eating
What arteries supply the cheek and what are they branches of?
Buccal arteries
From the maxillary artery
What innervates the cheeks afferently?
Buccal branches of V3
What are the lips and cheeks covered with?
Externally = skin
Internally = mucous membrane
What is the vermillion border?
Transitional zone between skin and mucous membrane (edge of lips)
Why do we need to lick the vermillion border regularly?
No salivary glands so lick to prevent dryness
How are the cheeks and lips involved in eating/chewing?
Buccinator pushes cheeks toward teeth to prevent food squeezing into vestibule
Lips prevent food going into vestibule and from falling out of mouth
What innervates the cheeks efferently?
Facial nerve
What innervates the geniohyoid?
Fibres from C1 (travel with C.XII)
What innervates the mylohyoid?
V3
What innervates the anterior belly of the digastric?
V3
What innervates the mucous membrane of the roof of the mouth?
V2
What innervates the mucous membrane of the lateral walls and floor of the mouth?
Lingual branch of V3
What is the function of the teeth?
Cut/incise food and break food down mechanically
Assist with speech
What innervates the teeth?
Alveolar branches of V2 for upper teeth
Alveolar branches of V3 for lower teeth
How do nerves reach the pulp?
Apical foramina
What are the functions of the tongue?
Taste, mastication, deglutition, speech, oral cleaning
What are the three parts of the tongue?
Root
Body
Apex/tip
What is the tongue dorsum?
Superior surface of the body of the tongue
How is the tongue split into body and root?
Anterior 2/3 = body, found within oral cavity
Posterior 1/3 = root, found in oropharynx
Describe the tongue.
Collection of muscles that together make a mobile, muscular organ, covered by mucosa
What do the extrinsic tongue muscles do?
Change tongue position
What do the intrinsic tongue muscles do?
Change tongue shape
Describe the sensory innervation of the tongue.
Anterior 2/3 = lingual nerve of V3 for general sensation and chorda tympani of facial/C.VII for taste
Posterior 1/3 (and vallate papillae) = lingual branch of glossopharyngeal/C.IX for taste and general sensation
Describe the motor innervation of the tongue.
Hypoglossal nerve (C.XII) for all muscles of the tongue except palatoglossus
Pharyngeal branch/plexus of vagus for palatoglossus
Describe the blood supply of the tongue.
Primarily via lingual artery (from external carotid) which runs deep to the hyoglossus muscle and enters at root of tongue
What is the lingual artery a branch of?
External carotid artery
Describe the venous drainage of the tongue.
Dorsum and sides of tongue = posterior lingual veins that lead to the lingual vein which drains into the internal jugular
Remainder = deep lingual veins and sublingual veins that lead to the lingual vein which drains into the internal jugular
Describe the lymphatic drainage of the tongue.
Each region has different routes but they all ultimately drain towards the deep cervical lymph nodes
Passes into general circulation at “venous angles”
Where are the venous angles?
Where jugular and subclavian veins meet
What are the functions of the salivary glands?
Keep mouth moist
Moisten food and dissolve chemicals to taste
Forms bolus to aid swallowing
Enzymes begin digestion
What are the functions of the nose and nasal cavity?
Form upper part of respiratory tract
Moisten and warm inspired air
Filter air
Act as a resonating chamber for speech
Describe the nose.
Cartilage frame covered with skin protruding from the face
Varies in size but all have thick skin covering cartilage and extending into the nasal openings (nares) where thick hairs help filter the incoming air
Describe the nasal cavity.
Irregularly shaped, high, deep and narrow chamber within skull, divided by the nasal septum
What are the boundaries of the nasal cavity?
Roof = cribriform plate of ethmoid
Floor = palatine bones
Anteriorly = nose
Posteriorly = nasopharynx
Describe the walls of the nasal cavity.
Lined by mucosal layer that produces mucus to cover surface and trap dust
Cilia propel particles and mucus towards nasopharynx
What are the conchae and their function?
3 pairs of circular, tube-like protrusions in the lateral wall of the nasal cavity
Force incoming air to swirl around and slow it down enough to be warmed and filtered
What are the paranasal sinuses?
Air-filled cavities
Walls composed of mucus-secreting epithelium
Empty into nasal cavity and help to moisten surface of nasal cavity
What are the four pairs of paranasal sinuses?
Maxillary
Ethmoidal
Frontal
Sphenoidal
Which arteries supply the nasal cavity?
Ophthalmic
Maxillary
Facial
Which veins drain the nasal cavity?
A plexus of veins leading to the ophthalmic, sphenopalatine and facial veins
What is the innervation of the nasal cavity?
Anterosuperiorly = ophthalmic/V1
Posteroinferiorly = maxillary/V2
How many frenal attachments are there?
3 (sup/inf labial, lingual)
Where does the maxillary sinus drain into the nasal cavity?
Middle conchae
What is ankyloglossia?
“Tongue-tie”
Lingual frenulum extends too far
Which tonsillar structures form Waldeyer’s Ring of lymphoid tissue?
Palatine tonsils
Lingual tonsils
Pharyngeal tonsil
Tubal tonsils
Where are the palatine tonsils found?
Between the fauces (palatoglossus and palatopharyngeus)
Where are the lingual tonsils found?
Posterior 1/3 of tongue dorsum
Where is the pharyngeal tonsil found?
Roof of nasopharynx
Where are the tubal tonsils found?
Roof of nasopharynx
Which structures of Waldeyer’s Ring are covered in respiratory epithelium?
Pharyngeal tonsil
Tubal tonsils
What epithelium covers the palatine and lingual tonsils?
Stratified, non-keratinising squamous epithelium
What is another term for the tubal tonsils?
Gerlach’s tonsils
What is another term for the pharyngeal tonsil?
Adenoids
Do the adenoids have crypts?
No
What muscle is found in the uvula?
Musculus uvulae
Which muscle is the anterior pharyngeal arch?
Palatoglossus
Which muscle is the posterior pharyngeal arch?
Palatopharyngeus
Which muscles attach to the soft palate?
Tensor palati(ni)
Levator palati(ni)
Musculus uvulae
Which muscle tenses the soft palate?
Tensor palati(ni)
Which muscle elevates the soft palate?
Levator palati(ni)
