DS: Oral Cavity

Question 1

What are the 4 boundaries of the oral cavity?

Answer 1

1. Lips: anterior boundary
2. Cheeks: lateral boundary
3. Palate: superior boundary
4. Tongue: anterior boundary

Question 2

Describe the epithelium and structure of the oral cavity

Answer 2

Lined by stratified squamous epithelium and. A dense lamina propria. Regions of the oral cavity that are exposed to severe friction, such as the gums, are covered by. A protective layer of keratinised epithelial cells to protect against abrasion.

Question 3

What is the palate?

Answer 3

The palate anatomically seperates the nasal cavity from the oral cavity and structurally has a bony (hard) anterior component and a muscular. (Soft). Posterior component, ending with the uvula.

Question 4

What are clefting palates?

Answer 4

Clefting palates are common congenital disorders that result in the malformation of the hard palate due to complications in the embryonic development of the hard palate from cranial neural crest cells (CNCCs). During embryonic development the palatine shelves of the maxilla do not fuse properly, leaving a gap in the hard palate and often a connection between the oral and nasal cavities.

Question 5

What is e treatment for clefting palates?

Answer 5

Usually multiple surgeries are required, along with speech therapy, orthodontic treatment and chronic use of a prosthesis.

Question 6

What causes clefting palates?

Answer 6

Insufficient fusion of the palatine shelves with the primary palate, preventing the separation of the oral and nasal cavities.
Defects in the cellular or molecular mechanisms that drive the growth and/or fusion of lnps, mnp and mx processes will result in congenital clefting of the palate.

Question 7

How is the oral cavity formed?

Answer 7

The hard and soft palates are formed separately and then joined together. CNCCs in the developing maxillary (upper jaw) and mandibular (lower jaw) processes help to form the 2 parts of the oral cavity.

Question 8

How many live births are. affected by clefting palate?

Answer 8

1 in 600 live births in the UK

Question 9

What are the complication of clefting palate?

Answer 9

Defects lead to suckling difficulty. In babies as they cannot create the negative pressure needed to draw milk into the oral cavity.
Can also lead to difficulty with swallowing and the potential for food to enter the nasal cavity and respiratory tract.

Question 10

What enhances risk of developing a clefting palate?

Answer 10

Teratogens such as ethanol (alcohol) and methotrexate. Folic acid deficiency during pregnancy is also linked to clefting as folic acid is needed for DNA synthesis

Question 11

When is the palate formed?

Answer 11

downwards within the oral cavity and the palatine shelves elevate to occupy horizontal positions relative to the tongue. Fusion of the palatine shelves with the primary palate separates the oral cavity from the nasal cavity, thus preventing food from entering the respiratory tract.

Question 12

Describe the structure and function of the hard palate

Answer 12

The hard palate separates the oral cavity and the nasal cavity. A thick ridge runs through the hard palate called the palatine raphe. The mucosa on each side of the raphe is corrugated to aid in the formation of the food bolus.

Question 13

What is the purpose of the hard palate?

Answer 13

The hard palate and the palatine raphe facilitates deglutition by providing a surface against which the tongue can apply force on food to propel it towards the gastrointestinal tract.

Question 14

Wh is the soft palate?

Answer 14

The soft palate is a flexible flap of skeletal muscle tissue. A finger-like structure called the uvula dangles from the free edge of the soft palate

Question 15

What is the function of the uvula?

Answer 15

The uvula is involved in deglutition and helps to prevent food from entering the pharynx prematurely and also closes the nasal cavity temporarily.

Question 16

How is the soft palate attached to the oral cavity?

Answer 16

The soft palate is attached to the tongue and pharyngeal wall by 2 pairs of lateral muscular pharyngeal arches- palatoglossal (anterior) arch and the palatopharyngeal (posterior) arch. The structure located between the arches is called the palatine tonsi

Question 17

What is the role of tonsil tissue?

Answer 17

Ring of tonsil tissue around the oral pharynx helps to remove microbes. Waldeyers tonsil ring is an arrangement of lymphoid tissue (MALT) in the pharynx made up of the pharyngeal tonsils, tubal tonsils, palatine tonsils and the lingual tonsils.

Question 18

Describe the structure of the tongue

Answer 18

The tongue consists of intercalating bundles of intrinsic and extrinsic skeletal muscle fibres.

Question 19

What is the function of the tongue?

Answer 19

Manipulating food between the teeth for mechanical processing and also mixes food with saliva to form boluses and aid in initial chemical digestion.

Question 20

What are the 2 muscle groups of the tongue?

Answer 20

4 intrinsic muscles

4 paired extrinsic muscles

Question 21

What is the role of the intrinsic muscles of the tongue?

Answer 21

Alter the shape of the tongue. Intrinsic muscles are not attached to the bone

Question 22

What is the role of the extrinsic muscles of the tongue?

Answer 22

Change the position of the tongue. Muscles are anchored to the bone.

Question 23

Describe how the tongue is attached to the oral cavity

Answer 23

The tongue is anchored into the hyoid bone at the anterior and the tongue is attached to the floor of the oral cavity by a thin mucosal tissue called the lingual frenulum.

Question 24

What is the role of the lingual frenulum?

Answer 24

Attaches tongue to the floor of the oral cavity. Also limits the posterior movements of the tongue.

Question 25

What is ankyloglossia?

Answer 25

Ankyloglossia is a condition that results in the fusion of the tongue; tongue is abnormally short and taunt. Complications include difficulty with speech, deglutition and breastfeeding. Corrected through surgery.

Question 26

What are the tiny bump along the surface of the the tongue and how are they formed?

Answer 26

Tiny bumps called papillae, formed by protrusions of the lamina propria, give the tongue its rough texture.

Question 27

What are taste buds?

Answer 27

Taste buds are collections of nerve-like cells that connect to nerves running into the brain.

Question 28

What are the 3 types of papillae?

Answer 28

1. Filliform Papillae
2. Fungiform Papillae
3. Circumvallate Papillae

Question 29

What are the filliform papillae?

Answer 29

T hread-like projections arrranged in parallel rows in the anterior part of the tongue. Contain receptors for touch and contain keratin, which stiffens their core and gives the tongue it’s rough texture.

Question 30

What are the fungiform papillae?

Answer 30

Mushroom-like projections that are extensions of the tongues lamina propria. Fungiform papillae are interspersed between the filiform papillae but are more numerous at the tip if the tongue. Non-keratanised but have a highly vascularised core. Contains gustatory (taste) receptors which detect different main taste modalities.

Question 31

What are the 5 main taste modalities?

Answer 31

1. Sweet
2. Sour
3. Bitter
4. Salty
5. Umami- results from tasting glutamate (present in MSG).

Question 32

What are the Circumvallate Papillae?

Answer 32

Arranged in an upside-down V array in the posterior surface of the dorsum. Contains gustatory (taste) receptors which are embedded in the stratified squamous epithelium. Circumvallate papillae have taste buds in the medial walls of the cleft. These papillae are larger than the other two types of papillae. Glands, called Von-Ebner’s glands (serous glands) open into the cleft.