Download Pharynx, Larynx and Trachea

Pharynx, Larynx and Trachea (L3)
2012
Pharynx
Pharynx = nasopharynx +oropharynx +laryngopharynx
Part of respiratory and digestive systems
Epithelium
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Either unkeratinized stratified squamous OR
Pseudostratified ciliated columnar epithelium and goblet
cells
Lamina propria
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Dense connective tissue with elastic and collagen fibers
Mucinous gland, especially around the opening of the
Eustachian tube
muscularis externa is skeletal muscle and forms the
constrictor muscles of the pharynx
Contains the tonsils
Tonsils
Tonsils consist of a number of lymph follicles
All part of the Waldereyers ring
Tonsilla lingualis
 Base of the tongue
 Smaller and numerous lymphoid follicles
 Associated with a single crypt
 Stratified squamous epithelium
Tonsilla palatina (Palatine tonsils)
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Surface squamous epithelium
Part of oral mucosa
Folds and forms crypts
Often contain bacteria, food particles, mucous (immunity
(antigen presentation) + tonsillitis)
Lymphoid follicles with connective tissue septa
 Outer –B lymphocytes
 Inner-T lymphocytes
Deep fibrous capsule –(facilitates tonsillectomy)
Palatine tonsil
Tonsilla pharyngealis (adenoids)
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Single tonsil
Wall of the nasopharynx
Ciliated pseudostratified columnar epithelium
No crypts
Thin capsule
Diffuse lymphoid tissue and nodules
Larynx
Epithelium
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Unkeratinized stratified squamous epithelium on the
anterior and upper part of the posterior surface of the
epiglottis as well as the vocal cords
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Pseudostratified columnar epithelium containing cilia and
goblet cells on the inferior part of the posterior surface of
the epiglottis and the walls of the larynx
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Skeletal muscle layer (swallowing)
Cartilaginous skeleton of hyaline or elastic cartilage that
keeps tube open
Trachea
Mucosa
 Pseudostratified columnar cells with cilia
 Serous cells
 Kulchitsky cells (part of diffuse neuroendocrine system)
 Stem cells able to divide and replace other cells
Lamina propria
Loose highly vascular supporting tissue
Submucosa
 Mixed seromucinous glands
 Submucosa merges with perichondrium of the underlying
hyaline cartilage rings (C-shaped)