topic13 : The functional anatomy and histology of the tonsils.

Question 1

functional anatomy

Answer 1

-type of mucosa associated lymphoid tissue, that surrounds openings of nasal & oral cavities
-contains aggreagation of lymphoid nodules with Bcells T cells & macrophages. Which play an important role in immunological protection against pathogens entering pharynx

4types:
1.palatine -lat x2
2.adenoids/pharyngeal - sup
3.lingual-inf
4.tubal - lat x2

together they form the Waldeyer’s ring:

Question 2

palatine

Answer 2

-one commonly known as tonsil
-form lat. border of pharyngeal lymphoid ring
-located in isthmus of fauces
-b/w palatoglossal arch (ant) & palatophrayngeal arch (post)
-penetrated with 15-20 crypts; their lumens have lymphocytes & desquamted epithelial cells

n: tonsillar br. of glossopharyngeal nerve

Question 3

adenoid/
pharyngeal

Answer 3

-most superior component of lymphoid ring
-in superior vault of nasopharynx
-attached to periosteum of sphenoid bone by CT
-covered with respiratory epithelium i.e ciliated pseudostratified columnar
-covering capsule thinner than palatine
-no crypts, but rather epithelium has folds
-lamina propria has mass of lymphoid tissue

n: branches of pharyngeal plexus

Question 4

lingual

Answer 4

-small elevation on most posterior part of base of tongue
-collection of lymphoid tissue that vary in size & shape
-covered stratified squamous epithelium
-invaginated by a single crypt

n: branches of glossopharyngeal n.

Question 5

tubal

Answer 5

-post to pharyngeal opening of the auditory tube in nasopharynx
-forms lateral part of pharyngeal lymphoid ring
-covered w/ repsiratory epithelium

Question 6

histology of palatine tonsils
(only one we studied in histo)

Answer 6

-tonsillar epithelium: stratified Nk squamous epithellium
-crypt: deep invaginations of epithelium that increase s.a to facilitate trapping of pathogens
-has lymphoreticular tissue: that contains lymphoid follicles
-follicles have: a. germinal center & cap zone-with restig B cells (darker part)

has mucous glands to secrete mucus
and striated muscles that facilitate movemnts with swallowing & speaking

Question 7

functions of tonsils

Answer 7

Immune Surveillance: Crypts and infiltrating lymphocytes trap and sample antigens.

Lymphocyte Activation: Lymphoid follicles with germinal centers are sites of B-cell activation and proliferation.

Secretion and Protection: Mucous glands provide lubrication, while the stratified epithelium and lymphoreticular tissue offer structural and immune support.

Structural Support: Striated muscles around the tonsils help in maintaining their position and facilitating their function during swallowing and speech.