Oral and Nasal Cavity Flashcards Preview

Sc 23 - Head and neck Neuroanatomy > Oral and Nasal Cavity > Flashcards

Flashcards in Oral and Nasal Cavity Deck (22)
Loading flashcards...
1
Q

Two parts of the Oral Cavity

A
  1. Vestibule
  2. Oral Cavity Proper
2
Q

Vestibule

A

Space between the teeth and the mucosal inner lining of the cheeks and lips

3
Q

Oral cavity proper

A

Space contained within the upper and lower dental arches

filled by the tongue

4
Q

Oral Cavity

  • Roof
  • Anterior boundary
  • Floor and Posterior Walls
A

Roof:

  • maxilla bones
  • palatine bones

Anterior boundary: (teeth + front bit of mandible)

  • Maxilla
  • Mandible with their dental arches

Other boundaries (floor & post walls):

  • Made up of soft tissues
  • Rami of mandible (post boundary)
5
Q

Floor of the mouth

A

Made up of a muscular sling and mucous membrane

Muscles:

  • Mylohyoid
  • Geniohyoid
  • Anterior belly of digastric
6
Q

Lips - Orbicularis Oris

  • Mobile, muscular folds
A
  • Covered externally by skin and internally by mucous membrane
  • Transitional zone between the two:
    • Vermillion Border:
      • Doesn’t contain any glands
      • therefore lips need to be licked to be moistened

N.B. Cheeks have a similar construction, Buccinator muscle in between the two layers

7
Q

Muscles of facial expression

  • Functions in mouth
A

Buccinator:

  • pushes cheek towards teeth during mastication
  • ensures food doesn’t fall into vestibule

Lips:

  • form a seal preventing food falling out of the mouth during mastication
  • form a seal around any vessel pressed against it ensureing liquid enters the mouth and doesn’t drip between the mouth and cup

Closure of hte mouth and sealing of lips - vital to swallowing

8
Q

Oral cavity

Contents:

A
  • Teeth
  • Tongue
  • Ducts of Salivary glands

Posteriorly mouth communicates with the Oropharynx

9
Q

Nerve Supply to the Oral Cavity

  • Oral cavity is supplied by a number of cranial nerves
A
  • Mucous membrane of roof: branch of maxillary nerve
  • Lateral walls & floor: Luingal branch of the mandibular branch of the Trigeminal
  • Muscles in lateral wall: Facial nerve
  • Muscles in floor:
    • Genohyoid - CN I
    • Mylohyoid & Ant belly of digastric - Mandibular branch (nerve to Mylohyoid) of of the Trigeminal
  • Teeth:
    • Alveolar branches of the Maxillary nerve (upper teeth)
    • Mandibular nerve (lower teeth)
      *
10
Q

Tongue

  • Ant 2/3rds lie in oral cavity
  • post 1/3rd lie in oropharynx
A

Extrinsic muscles: Change position of the tongue

  • Palatoglossus
  • Styloglossus
  • Hyoglossus
  • Genioglosus

Intrinsic Muscles: Change the shape of the tongue

  • Sup & inf longitudinal muscles
  • Vertical and transverse muscle
11
Q

Nerve supply to the Tongue

A

All the extrinsic and intrinsic muscles of the tongue are supplied by the:

Hypoglossal nerve CN XII

Apart from Palatoglossus which is supplied by the:

Vagus nerve CN X (via the pharyngeal branch to the pharyngeal plexus

12
Q

Where do the ducts of the major salivary glands enter the oral cavity?

A
  • Parotid Salivary Gland:
    • Near the 2nd upper molar tooth
    • Secretion : Serous
  • Submandibular Gland:
    • Enters Floor of the mouth
    • Mixed gland - has both serois and mucous secretions
  • Sublingual Gland:
    • between 16 to 20 short ducts which open into the floor of the mouth
    • Secretes mucus

Minor glands: v. imp in maintaining oral hygiene as continual background level of secretion flushes oral surfaces and helps to control the level of bacteria

13
Q

Major Artery of the Tongue

A

Lingual Artery

  • originates from the External Carotid Artery adjacent to tip of greater horn of the hyoid bone
  • Forms an upward bend then loops downwards to pass under the Hyoglossus muscle
  • Supplies:
    • Tongue
    • sublingual gland
    • gingiva
    • oral mucosa in the floor of the oral cavity
14
Q

Venous Drainage of the Tongue

Follows 2 routes:

Posterior lingual veins & deep lingual veins

A

Posterior Lingual Veins:

  • Drain the dorsum and sides of tongue
  • join the lingual vein which accompanies the artery
  • Near the greater cornu of the Hyoid bone the lingual vein joing the internal jugular vein

Deep Lingual Vein:

  • Begins near the tip of the tongue and runs backwards on its interior surface
  • Near border of hyoglossus, it joins the Sublingual vein, which runs along the course of the Hypoglossal nerve and joins the Facial Vein
15
Q

Lymphatic Drainage of the Tongue

A

Anterior to the Vallate Papillae:

Drained into central and marginal lymph vessels

Posterior 1/3rd:

Drain into posterior lymph vessels

From here they enter a series of nodes the efferent vessels of which drain to nodes surrounding the SCM

16
Q

Functions of the Nose & Nasal Cavity

A
  • provides an airway for respiration
  • moistens and warms the inspired air
  • filters air to remove foreign particles
  • houses the Olfactory Receptors
  • Acts as a resonating chamber for speech
17
Q

Nose

A

External part:

  • consists of cartilages covered by skin

Internal part:

  • Covered by skin too abd contains hair which filters the air
18
Q

Nasal Cavity

A
  • Made of pseudostratified ciliated columnar epithelium with goblet cells
  • Air:
    • warmed by capillary plexuses in the lamina propria
    • moistened by the glandular secretions
  • Irregular shaped cavity; lies btwn the bony plate of the floor (which separates it from the oral cavity below) and the cribiform plate (which separates it from the cranial cavity above).
  • Cavity is high, deep but narrow and divided into R&L by the nasal septum
  • Ant part of nose in formed by cartilage in life
  • communicates post with nasal part of pharynx; ant with environment; sup with cranial cavity. orbit and paranasal sinuses
19
Q

Nasal conchae

A

Project from the lateral wall of the nasal cavity

as the inhaled air passes over the conchae, the tubercle greatly increases amount of contact btwn mucosa and inspired air.

Particles >4mm rarely get past the nasal cavities

20
Q

Paranasal Sinuses

A

Surround the nasal cavity

lined by Resp Epithelium

Empty their secretions into the nasal cavity

21
Q

General sensory fibres to the nasal cavity

A

Branches of the Maxillary and Ophthalmic division of the Trigeminal nerve supply this.

22
Q

Where are the receptors for the Olfactory nerve located?

A

In the superior part of the Nasal Cavity