The presence of proliferative
centres for B –and T-lymphocyte
production (follicles and
parafollicular zones, respectively)
Proximity to an epithelial
surface, the lymphoid tissue
being essentially situated within
the mucosal lamina propria
The lack of a fibrous capsule
The provision of high –
endothelium venules (HEVs) for
immigration of lymphocytes.
The presence of efferent
lymphatics but virtual absence of
afferents.
Lies in the roofof
the oral cavity
Has two parts:
•Hard(bony)
palate
anteriorly
•Soft(muscular)
palate
posteriorly
hard
soft palate
Attached to the posterior
border of the hard palate
Covered on its upper and
lower surfaces by
mucous membrane
Composed of:
•Muscle fibers
•Anaponeurosis
•Lymphoid tissue
•Glands
•Blood vessels
•Nerves
Fibrous sheath
Attached to posterior
border of hard
palate
Is expanded tendon
of tensor velli
palatini
Gives origin &
insertion to palatine
muscles
Tensor veli palatini
•Origin: spine of sphenoid;
auditory tube
•Insertion: forms palatine
aponeurosis
•Action:Tenses soft palate
Musculus uvulae
•Origin: posterior border of
hard palate
•Insertion: mucosa of uvula
•Action: Elevates uvula
Palatoglossus
•Origin:palatine aponeurosis
•Insertion:side of tongue
•Action:pulls root of tongue
upward, narrowing
oropharyngeal isthmus
Palatopharyngeus
•Origin: palatine aponeurosis
•Insertion: posterior border of
thyroid cartilage
•Action:Elevates wall of the
pharynx
Palatopharyngeus
Mostly by the
maxillarynerve
through its
branches:
•Greater palatine
nerve
•Lesser palatine nerve
•Nasopalatine nerve
Glossopharyngeal
nerve supplies the
region of the soft
palate
All the muscles, except tensor veli
palatini, are supplied by the:
•Pharyngeal plexus
Tensor veli palatini supplied by the:
•Nerve to medial pterygoid, a branch of
the mandibular division of the
trigeminal nerve
Branches of the maxillary
artery
•Greater palatine
•Lesser palatine
•Sphenopalatine
Ascending palatine,
branch of the facial
artery
Ascending pharyngeal,
branch of the external
carotid artery
Cleft palate:
•Unilateral
•Bilateral
•Median
Paralysis of the soft
palate
•The pharyngeal
isthmus can not be
closed during
swallowing and
speech
Pharyngeal
isthmus
The lymphoid tissue in the pharyngeal
aponeurosis aggregates in some areas
forming tonsils:
1-onenasopharyngeal tonsil
2-twopalatine tonsils
3-twolingual tonsils
Location
The palatine tonsil is an ovoid
mass of lymphoid tissue
Tonsillar fossa in lateral wall of
oropharynx
Boundaries of tonsillar fossa
Anterior pillar-Palatoglossal arch
Posterior pillar-Palatopharyngeal
arch
Apex-Soft palate where both arches
meet
Base –Dorsal surface of posterior
one –third of tongue
External features
2 surfaces-medial, lateral(tonsillar
bed)
2 Poles-upper, lower
Stratified squamous non keratinising
epithelium
Dips into the crypts
The crypts are 12-15 in number
cryptamagna
It represents the ventral part of second
pharyngeal pouch
External features-Medial surface
Fibrous capsule of the tonsil
Loose areolar tissue
The tonsillar bed
External features-Lateral surface
Superior constrictor muscle
Styloglossus muscle
Glossopharyngeal nerve
styloid process (if enlarged)
Facial artery
Medial pterygoid muscle
Angle of mandible
Submandibular salivary gland
Tonsillar bed
External features-Poles
Upper pole-extends into soft palate
Lower pole-attached to tongue
The tonsil is supplied by 5 arteries:
Tonsillar branch of facial artery (main supply)
Ascending palatine branch of facial artery
Ascending pharyngeal artery
Dorsal linguae branch of lingual artery
Descending palatine branch of maxillary artery
Arterial supply
Lymphatics from the tonsil
pierce the superior
constrictor and
Drain into the upper
cervical lymph nodes
especially jugulodigastric
(tonsillar)
lymph node
Lymphatic drainage
Lesser palatine branch
of sphenopalatine
ganglion
Glossopharyngeal
nerve
Nerve supply