1. GI tract Oral Cavity .pptx

Question 1

Describe the bones and structures that form the boundaries of the oral cavity

Answer 1

Anteriorly: The cavity extends from the upper and lower lips
Posteriorly: To the palate-glossal arches
Laterally: To the cheeks

The cavity “proper” is between the teeth, the vestibule is outside the teeth

Bones: Hard palate (made up of maxilla and horizontal plate of palatine), Teeth, Mandible

Question 2

Describe the orientation of the B, R, A of the mandible

Answer 2

The Body and Ramus is divided by the Angle.

The Ramus then divides into condylar and coronoid processes

Question 3

What is the importance of the Retromolar fossa on the medial aspect of the mandible?

Answer 3

Retromolar fossa for attachment of the lower end of the pterygomandibular raphe, between buccinator and superior constrictor

Question 4

What is the importance of the mandibular foramen on the medial aspect of the mandible?

Answer 4

Mandibular foramen for the inferior alveolar or dental nerve to the lower teeth

Question 5

What is the importance of the submandibular fossa on the medial aspect of the mandible?

Answer 5

Submandibular fossa for the submandibular gland

Question 6

What is the importance of the mylohyoid line on the medial aspect of the mandible?

Answer 6

Mylohyoid line, for the attachment of mylohyoid muscle, forming the
floor of the mouth

Question 7

What is the importance of the sublingual fossa on the medial aspect of the mandible?

Answer 7

Sublingual fossa for the sublingual gland

Question 8

What is the importance of the sublingual fossa on the medial aspect of the mandible?

Answer 8

Sublingual fossa for the sublingual gland

Question 9

What actions at the temporomandibular joint allow opening and closing of the mouth?

Answer 9

Closing: Retraction and elevation
Opening: Protrusion and depression

Question 10

Opening of the mouth:
What is the primary muscle of the action and how?
Which joint cavity does the movement occur in?
What contributes the movement and how?

Answer 10

Primary muscle of opening: Lateral pterygoid muscle by drawing the draw + condyle forwards and downwards
Cavity: Movement in upper cavity
Gravity and digastric muscle contribute by rotation occurring the in lower joint cavity

Question 11

Closing of the mouth (elevation):

Main muscles?

Answer 11

Main muscles: Medial pterygoid, masseter and temporalis

Question 12

Facial muscles:
Name 4 main muscles?
Name their general attachment?

Answer 12

Main muscles: Buccinator, depressor anguli oris, orbicularis oris, lavator anguli oris

Question 13

What is the structural similarity of the lips and cheeks?

Answer 13

The lips and cheeks are a “sandwich” of muscles of facial expression, with skin externally and non-keratinised, stratified squamous epithelium lining the mucous membrane internally

Question 14

Buccinator:
Relation between fibres and lips
Modiolus?
How does it allow continuity between the oral cavity and the pharynx?

Answer 14

The upper fibres contribute to the upper lip and cross over to into the lower lip. Vice versa for the lower fibres
Modiolus= The point of cross over between the upper and lower buccinator fibres
Buccinator attaches to the maxilla and mandible but also fuses with the superior pharyngeal constrictor at the pterygo-mandibular raphe

Question 15

What is the upper and lower attachments for the pterygo-mandibular raphe?

Answer 15

Lower: Over the retromolar fossa
Upper: Pterygoid hamulus (at the lower end of the medial pterygoid plate)

Question 16

Sensation to the skin of the cheeks and lips, and the corresponding, internal mucous membrane is by branches from ???

Answer 16

By branches from the Maxillary and Mandibular divisions of the Trigeminal Nerve (Cranial V), V2 and V3

Question 17

What is the main muscle of the floor of the mouth?

Answer 17

Muscular diaphragm of mainly mylohyoid (left and right)

Question 18

Tongue muscles:
Made up of which main muscles?
Nervous supply?
Muscular interplay?
Actions of extrinsic muscles?

Answer 18

Within tongue: Genioglossus plus intrinsics
Attach to bone: Extrinsics i.e. palatoglossus; hyoglossus; styloglossus

Tongue muscles are supplied by the Hypoglossal nerve (Cranial XII), except palatoglossus which is supplied by vagus (CN X)

Muscular interplay: extrinsics alter position; intrinsics alter shape.

Upwards and backwards: Palatoglossus (from the palatine aponeurosis) and
Styloglossus (from the styloid process)
Draws the sides down: Hygoglossus

Question 19

What structure divides the tongue?

Answer 19

The terminal sulcus divides it into an anterior 2/3 and a posterior 1/3, or pharyngeal part

Question 20

Nervous supply of tongue sensation?

Answer 20

Ant 2/3 is via lingual (V3) for general sensation and taste
Post 1/3 glossopharyngeal (Cranial IX) for both general sensation and taste

Question 21

Arterial and venous supply of the tongue?

Answer 21

Lingual artery (from external carotid)
Deep and dorsal venous systems, then converging on the internal jugular

Question 22

Tongue lymph drainage

Answer 22

• -> Inferior deep cervical lymph nodes
• -> Submandibular lymph nodes
• -> Submental lymph nodes
• -> Superior deep cervical lymph nodes

CROSSES MIDLINE

Mainly to deep cervical nodes to then drain into the internal jugular vein

Question 23

What are the 3 salivary glands?
What is their function?
What is their nervous supply?

Answer 23

Parotid, submandibular and sublingual
Function: Commence digestion, lubricate food, maintain teeth/gum health
Nervous supply: Receive a parasympathetic, secretomotor supply from the Glossopharyngeal nerve (IX) and Facial nerve (VII)

Question 24

Where and how does the sublingual gland drain?

Answer 24

Via separate ducts into the floor of the mouth

Question 25

Where and how does the submandibular gland drain?

Answer 25

Submandibular ducts which are beside the sublingual glands but open at the papillae, either side of the frenulum

Question 26

What 3 structures are contained within the parotid gland?

Answer 26

1. Facial nerve
2. Retro-mandibular vein
3. External carotid artery

Question 27

Two muscles of the palate?

Answer 27

Tensor palati

Levator palati

Question 28

What makes up the Pillars of the Fauces?

Answer 28

Palatoglossal and Palatopharyngeal Arches with Palatine Tonsil between

Question 29

Tensor palati

Answer 29

Attaches to the fossa above the medial pterygoid plate and to the cartilage of the auditory tube

Lies outside the med. pter. plate and outside the pharynx, until it becomes tendinous, curves around the pterygoid hamulus and flares into the soft palate as the palatine aponeurosis that attaches to the hard palate, but is free posteriorly

Question 30

Levator palati

Answer 30

Arises from the apex of the petrous temporal bone and from the cartilage of the auditory tube
Lies inside the pharynx and inserts into the upper aspect of the palatine aponeurosis

Question 31

Nervous and arterial supply of palates?

Answer 31

The greater and lesser palatine branches of the maxillary nerve and artery supply the hard and soft palates respectively, with an addition from the nasopalatine anteriorly

Question 32

The glossopharyngeal nerve (IX) supplies the ___ and may encroach on to the soft palate – referred pain to middle ear

Answer 32

The glossopharyngeal nerve (IX) supplies the TONSILS and may encroach on to the soft palate – referred pain to middle ear

Question 33

The Uvula receives the ___ ___ and hangs off the soft palate, contributing to its functions

Answer 33

The Uvula receives the MUSCULUS UVULAE and hangs off the soft palate, contributing to its functions

Question 34

Changes that occur in the oral cavity during chewing and swallowing?

Answer 34

While chewing food, the oropharyngeal isthmus must be closed –
palatoglossus and palatopharyngeus contract to draw the palate down and the tongue slightly upwards, (i.e. towards each other), as well as drawing the palatoglossal and palatopharyngeal arches downwards and medially – like curtains

When swallowing, tensor palati makes the aponeurosis tense so that levator palati can lift it to close the nasopharyngeal isthmus

Question 35

Teeth:
4 quarters of teeth?
Total?
Nervous supply?

Answer 35

Each quarter:
Molars – 3
Premolars – 2
Canine – 1
Incisors – 2

Total – 8
X4 = 32

The upper teeth are supplied by the alveolar (dental) branches of the maxillary nerve (V2) that also supply the maxillary sinus. The lower teeth are supplied by the inferior alveolar (dental) branch of V3