PALATINE TONSIL

TOMSON THOMASPG STUDENT

ORAL PATHOLOGY

Palatine tonsils are two oval masses of lymphoid tissue which represents the largest accumulation of lymphoid tissue in the Waldeyers ring .

Waldeyer’s lymaphatic ring

SITUATION: The palatine tonsils occupy the tonsillar sinus or fossa between the diverging palatoglossal and palatopharyngeal arches.

SURFACE MARKING SIZE:

Variable, 10-15 mm in transverse diameter and 20-25 mm in vertical dimension.

FEATURES Two surfaces Two poles Two borders

Medial surface

It is lined by stratified squamous non keratinising epithelium which dips into the crypts

The crypts are 12-15 in number

Secondary crypts arise from the primary crypts and extend into the substance of the tonsil

On of the crypts located in the upper part are larger than the rest – crypta magna

The crypts serve to increase the surface area of the tonsil

The crypts may be filled witth cheesy material – epithelial debris, food particles and bacteria

Lateral surface

It is covered by the fibrous capsule of the tonsil The tonsillar bed is separated from the capsule by loose areolar tissue

This makes it is easy to dissect the tonsil from its bed during tonsillectomy

It is the site of collection of pus in peritonsillar abscess (quinsy)

Some fibers of palatoglossus and palatopharyngeus gets attached to capsule of tonsil

Bed of tonsil

It is formed by the 2 muscles

Superior constrictor

Styloglossus

Upper pole

It extends into the soft palate

There is a semilunar fold of mucous membrane which covers the medial part of the upper pole

It extends from anterior pillar to posterior pillar

It encloses a potential space – supratonsillar fossa

Lower pole

It is attached to the tongue A triangular fold of mucous membrane extends from the anterior tonsillar pillar to the lower pole

It encloses a space – anterior tonsillar space

The lower pole is separated from the tongue by the tonsillo-lingual sulcus

This sulcus may harbour carcinoma

BLOOD SUPPLY Three arteries enter the lower pole of tonsil: -Tonsilar branch of facial artery -Tonsilar branch of dorsalis lingual artery -Tonsilar branch of ascending lingual artery

Two arteries enter the upper poleof tonsil: -Tonsilar branch of lesser palatine artery -Tonsilar branch of ascending pharyngeal

artery

Venous drainage

Blood from the tonsil drains into the paratonsillar vein which in turn drains into the common facial vein and pharyngeal venous plexus

Lymphatic drainage

Lymphatics from the tonsil pierce the superior constrictor and drain into the upper cervical lymph nodes especially jugulodigastric (tonsillar)lymph node

Enlarged non tender jugulodigastric lymph node is a sign of chronic tonsillitis

Nerve supply

Lesser palatine branch of sphenopalatine ganglion Glossopharyngeal nerve

PS: Palatine / External palatine / Paratonsillar vein

HISTOLOGY OF PALATINE TONSIL  covered with stratified squamous epithelium

and separated from the pharynx by a capsule of dense irregular connective tissue.

Septa from the capsule project deeply into the tonsil in regions between crypts.

The entire space between the capsule and the epithelium (lamina propria) is filled with lymphocytes

Functions of tonsil

It has a protective function in that it prevents entry of pathogens through the nasal and oral route

The crypts on the surface of the tonsil serve to increase the surface area and increase the efficiency of protection against pathogens It forms a part of Waldeyer’s lymphatic ring

APPLIED ANATOMY

Tonsils prevent infection. Infected tonsils act as septic focusDamage of paratonsillar vein during tonsillectomy leads to excessive venous haemorhhageDamage to glossopharygeal nerve leads to loss of taste sensationInfected tonsillar pain may be referred to middle ear because ofSame nerve supply

ACUTE TONSILITIS

FOLLICULAR TONSILITIS

KISSING TONSILITIS

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