Histo of Tongue, Tonsils, Lymph Nodes

4 types of papilla

• Filliform: must numerous, keratinized

• Fungiform: non-keratinized, scattered, contain few taste buds

• Foliate: leaf-like folds across posterolateral border, katerally

• Circumvallate: walled, circular

  • 10-12 in number

  • Front of sulcus termanalis

  • Many taste buds

Von Ebner glands

Minor serous glands opening into troughs of circumvallate papilla

secretions flush debris, lipid hydrolysis

Where are taste buds most numerous?

Circumvallate papillae

Two population of cells in taste buds

Taste cells, supporting or sustentacular cells

Taste buds are in all but?

filiform

Innervation of tongue:

• Posterior 1/3: CN IX

• Anterior 2/3:

  • sensory: lingual branch V3

  • Taste: chorda tympani of CN VII

What surface of the tongue is concerned with immune protection>?

Dorsal surface (lingual tonsils) of posterior third

What is Waldeyer’s ring?

tonsiliar tissue surrounding oral cavity made of inner and outer rings

Inner ring of Waldeyer’s (4)

Pharyngeal tonsil, tubal tonsil, Palatine tonsil, Lingual tonsil

Outer ring of Waldeyer’s ring (5)

Cervical lymph nodes: Retropharyngeal node, jugulodigastric node, jugular chain, submandibular, submental

Function of Tonsils

• production of lymphocytes

• Protection from inhaled and/or swallowed microbes and allergens

  • T-cell immunity

  • Phagocytosis

  • B cell mediated immuniglobin production: IgA in saliva

Palantine Tonsils:

__ reach into lymphocyte rich CT

__ are active sites of lymphocyte production

Deep clefts

Germinal centers

palantine and lingual tonsils are covered by what epithelium?

Tubal and pharyngeal tonsils are covered by ?

Tonsils do/do not have afferent lymphatic supply, they do have a what?

stratified squamous

pseudostratified ciliated columnar

Do not, lymphatic drain (unlike lymph nodes)

Lymph node functions

produce cells of immune cells

filter and trap microorganisms, foreign material, cancer cells

Lymph node levels: how is it divided?

SCM is divided by hyoid bone and cricoid cartilage

• posterior triangle = 5

• under chin = 1

• Anterior triangle = 6

• 7 is suprasternal

Cortex = __ layer

What 3 things?

Outermost:

• Lymph from vessels drain into sub scapular sinus and then into cortical sinuses

• Lymphoid nodules with/without germinal center: Sites of B cell synthesis and activity

• Antigen processing cells encounter immune cells here and in paracortex

Paracortex (4)

• middle layer

• Lacks lymphoid nodules

• T cells rich here

• Cortical sinuses reach into paracortex

• Antigens encounter immune cells here

Medulla

Deepest layer

• Adjacent to hilum

• Medullary cord: areas that contain mix of B, T, plasma cells

  • main site of antibody production

• Medullary sinuses: dilates spaces lined by endothelium

  • final site for filtration of lymph before it exists via efferent lymphatic

Tonsils vs Lymph nodes

Tonsils dont have afferent lymphatic supply but have efferent lymphatic drain

Tonsisl dont have capsules, have epithelial surface, tonsillar crypts