2. Nasopharyngeal tonsil is
commonly called as
“adenoids”
The adenoid is a median
mass of mucosa
associated lymphoid
tissue situated in the
posterior wall of
nasopharynx
3.
4. It is composed of vertical
ridges of lymphoid tissue
separated by deep clefts
5. The adenoids –
It is a single mass of pyramidal tissue
with its base on the posterior nasopharyngeal
wall and it’s apex pointed toward the nasal
septum.
The surface is invaginated in a series of folds.
The epithelium is pseudostratified ciliated
epithelium and is infiltrated by the lymphoid
follicles.
6. EMBRYOLOGY
The formation of the adenoids begins in the 3rd month of
fetal development. This starts with glandular primordia in
the posterior nasopharynx becoming associated with
infiltrating lymphocytes.
In the 5th month sagittal folds are formed which are the
beginnings of pharyngeal crypts. The surface is covered
with pseudostratified ciliated epithelium.
By the 7th month of development the adenoids are fully
formed
7. Arterial supply
Ascending palatine branch of facial
artery
Ascending pharyngeal branch of
external carotid artery
Pharyngeal branch of third part of
maxillary artery
Ascending cervical branch of
inferior thyroid artery
8. Venous drainage is through the
pharyngeal plexus and the
pterygoid plexus flowing
ultimately into the facial and
internal jugular veins.
9. Nerve supply is through
glossopharyngeal and vagus nerves
They carry sensations.
Lymphatics from adenoids drain
into upper juglar directly and or
indirectly via retropharyngeal and
pharyngeal nodes
10. HISTOLOGY
The adenoid is covered by a
pseudostratified ciliated columnar
epithelium that is plicated to form
numerous surface folds.
The nasopharyngeal epithelium lines a
series of mucosal folds, around which the
lymphoid parenchyma is organized into
follicles and is subdivided into 4 lobes by
connective tissue septa .
11. Seromucous glands lie within the connective
tissue, and their ducts extend through the
parenchyma and reach the nasopharyngeal
surface. of adenoid showing lymphoid
follicle
12. CLINICAL CORRELATION
The nasopharyngeal tonsils are
prominent in children upto 6 years
of age,then gradually undergo
atrophy at puberty and almost
completely disappear by the age
of 20
13. Adenoiditis:
Infections involving adenoids are known as adenoiditis.
Enlargement of adenoid tissue shows the following
symptoms:
1. Snoring
2. Mouth breathing
3. Vomiting immediatly after feeds - adenoid hypertrophy
causes nasal block, this causes the child to swallow air when
they are fed. This causes stomach of the child to bloat up
which gets releived only when the child vomits.
14. IT can be enlarged due to allergy
infections
16. Differences between adenoid and tonsils
TONSILS :-
1) Tonsils are paired.
2) Tonsils are situated in oropharynx.
3) The covering epithelium of Tonsils is stratified squamous.
4) In Tonsils the crypts are present on the medial surface.
5) In Tonsils the capsule is present on the lateral surface.
6) Tonsils are present right up to old age.
