Lecture 17

Question 1

Nasal and oral cavities

Answer 1

Both have structural features that contribute to smell and taste, air and food modification as they pass through the body and refine laryngeal sounds.

Question 2

Nasal cavity

Answer 2

Nostrils to choanae.

Question 3

Vestibule

Answer 3

Nose entrance, inside the nose, not external part

Question 4

Choanae

Answer 4

Provide the delineation of a boundary from the nasal cavity to the nasopharynx.

Question 5

Nasal septum

Answer 5

Medial wall separating the nasal cavities composed of cartilage and t

Question 6

Nasal cavity floor

Answer 6

Composed of maxilla and palatine bone

Question 7

Nasal cavity roof

Answer 7

Nasal bone, frontal bone, ethmoid bone and sphenoid bone.

Question 8

Piriform aperture

Answer 8

the pear-shaped opening of the skull.

Question 9

Features of nasal cavity

Answer 9

Lined with highly vascularised mucosa so that it can moisten air before it enters lungs. Also, filters air. Roof mucosa is innervated of olfactory bulb allowing for smell. Also, covers conchae to increase SA for filtration.

Question 10

Chonchae

Answer 10

superior, middle and inferior. Underneath is meatuses (superior, middle and inferior)

Question 11

Paranasal sinuses

Answer 11

Air filled, mucose membrane lined pockets in the frontal, ethmoid and sphenoid bone and maxilla. Frontal sinus, ethmoidal sinuses, sphenoid sinuses and maxillary sinus. Sinuses communicate with nasal cavity through appertures which drain under the chonchae in meatuses

Question 12

Frontal sinus

Answer 12

Middle meatus

Question 13

Ethmoidal sinuses

Answer 13

middle and superior meatus

Question 14

Sphenoid sinuses

Answer 14

Above superior choncae in subethmoidal recess

Question 15

Maxillary Sinus

Answer 15

Middle meatus

Question 16

Inferior meatus

Answer 16

Nasolacrimal duct (tears from eyes)

Question 17

Oral cavity

Answer 17

inferior to nasal cavity, sharing the maxillary and palatine bone as it’s roof. Extends from oral fissures to the oropharyngeal isthmus which is anterior to pharynx. Divided by horse shoe shaped dental arches. Roof of oral cavity formed by maxilla, palatine bone, soft palate and uvula. Floor is composed of soft tissue incl. muscular diaphragm and tongue. Lateral walls formed by cheek mucosa, teeth and gingiva.

Question 18

Oral vestibule

Answer 18

Between inner surface of lips and cheeks and outer surface of teeth and gums

Question 19

oral cavity proper

Answer 19

Internal to teeth and gums.

Question 20

Teeth and gingivae

Answer 20

Dental arches formed by protruding ridges of bone on maxilla and mandible. Teeth attach by their roof into dental arches via alveoli. 32 adult teeth (16 on mandible and 16 on maxilla, 8 on LHS and 8 on RHS of each). 2 incisors, 1 canine, 2 premolars and 3 molars. Dental arches covered by gingivae which are specialised continuations of mucosa that surrounds tooth roots and alveoli.

Question 21

Tongue

Answer 21

Skeletal muscle attached at one end to cavity floor. Taste (cranial nerve 9), food manipulation, chewing, swallowing and speech. Apex is point of tongue and it is free. Sits directly behind incisors. Tongue root is attached by muscles to the soft palate, mandible and hyoid bone. Anterior 2/3 is oriented in the horizontal plane and forms most of the floor of the oral cavity. The posterior 1/3 is oriented in the vertical plane and forms part of the anterior wall of the oropharynx. Division between anterior 2/3 and posterior 1/3 marked by sulcus terminalis.

Question 22

sulcus terminalis

Answer 22

V-shaped horizontal groove marking the inferior boarder of oropharyngeal isthmus. Aligns with 3rd lower molar. Mucous membrane on superior tongue surface forms papillae which increases SA for taste. 8-12 villate papillae arranged infront of sulcus terminalis. Lingual tonsil behind sulcus terminalis (in oropharynx) as lymph tissue.

Question 23

Inferior tongue surface

Answer 23

Lacks papillae covered with smooth mucosa that is continuous with oral cavity floor. Lingual frenulum attaches free of apex of tongue features sublingual folds and sublingual papillae which reflects presence of salivary gland opening into the oral cavity.

Question 24

Salivary glands

Answer 24

Produce and secrete saliva to lubricate and moisten food for digestion. Many small glands on oral mucosa and three larger pairs of salivary glands.

Question 25

Parotid glands

Answer 25

Outside oral cavities boundaries. Lies under skin, anterior to ear, overlying posterior mandible.

Question 26

Submandibular glands

Answer 26

Inside and outside oral boundaries. Hooked, lying inferior and medial to middle mandible.

Question 27

sublingual gland

Answer 27

In oral boundaries. Inferior to floor, immediately posterior to anterior mandible. Bulges to form sublingual fold.

Question 28

Sublingual drainage

Answer 28

Sublingual drain via small numerous sublingual ducts which open onto the elongated crest of sublingual folds under tongue. Short

Question 29

Parotid drainage

Answer 29

Parotid drains via parotid duct which penetrates cheek muscles and opens into oral cavity adjacent to 2nd upper molar.

Question 30

Submandibular drainage

Answer 30

Submandibular drains into Submandibular ducts which passes forward and medially to open at the summit of the sublingual papillae positioned at the base of the lingual frenulum under tongue.

Question 31

Oropharyngeal isthmus

Answer 31

Posterior oral cavity opens into pharynx via oropharyngeal isthmus. Boundaries incl. soft palate and uvula posteriorly, sulcus terminalis of tongue inferiorly, palatine arches laterally. The palatine arches consist of soft palate mucosa.

Question 32

Palatoglossal arches

Answer 32

Extends from soft palate to tongue.

Question 33

Palatopharyngeal arches

Answer 33

extends from soft palate to pharynx.

Question 34

Uvula

Answer 34

Swings to close oral cavity from nasal cavity to ensure you swallow downwards.

Question 35

Pharynx

Answer 35

musculofascial tube anterior to vertebral column but posterior to nasal and oral cavities and larynx. Conducts air and food between head and neck. Extends from choanae to larynx.

Question 36

Nasopharynx

Answer 36

Choanae to soft palate

Question 37

oropharynx

Answer 37

soft palate to epiglottis

Question 38

laryngopharynx

Answer 38

epiglottis to larynx or to oesophagus.

Question 39

Pharynx walls

Answer 39

Pharyngeal walls are made up of a sling of muscle which overlap and interlocks. The superior, middle and inferior constrictor muscle wrap around from behind and attach to ligaments/bones/cartilage related to nasal and oral cavities and larynx.