Week 6: Anatomy-Pharynx and Larynx Flashcards
What are ectodermal derivatives in the upper digestive and respiratory tracts?
- Oral and naval cavities
- lined by somatically innervated mucosa
What is the bucopharygeal membrane?
- membranous partition in development
- separates ectodermally lined oronasal cavity and endodermally lined gut tube
What are the endodermal derivatives in the upper digestive and respiratory tracts?
- foregut: pharynx, esophagus, larynx, and trachea
- viscerally innervated mucosa
- includes derivatives of pharyngeal arches
- thyroid gland (from thyroglossal duct)
- foramen cecum (depression in dorsal tongue): point of attachment of the thyroglossal duct
- trachea-develops from ventral midline of pharynx, inferior to thyroglossal duct, at laryngeal inlet
- upper part of tracheal becomes larynx while lower part bifurcates to primary bronchi
Describe the general orientation of the pharynx and larynx.
- Nasal cavity: from anterior nares (nostrils) to posterior nasal aperture
- Oral cavity: mouth to oropharyngeal isthmus between palatoglossal folds (arches)
- pharynx: first part of foregut, divided into 3 parts (covered in another flashcard)
- Esophagus: begins at lower edge of cricoid cartilage
- Larynx: upper part of lower respiratory tract
- trachea: begins at lower edge of cricoid cartilage
Describe the divisions of the pharynx.
- Nasopharynx
- behind nasal cavity and above soft palate, extends down to back of soft palate and uvula
- lateral wall: Eustachian tube (opening of auditory canal), medial end of tube is torus tubarius
- pharyngeal recess-slit behind torus tubarius
- pharyngeal tonsil: roof of nasopharynx - Oropharynx
- behind oral cavity and below soft palate
- extends down to tip of epiglottis
- palantine tonsils between palatoglossal (connects with uvula) and palatopharngeal folds
- posterior 1/3 of tongue: lingual tonsil, foramen cecum
- vallecula: depressions between base of tongue and epiglottis - Laryngopharynx
- behind larynx
- compressed space that extends from tip of epiglottis to lower border of cricoid
- piriform recess: space on either side of laryngeal inlet
What is the nasopharynx innervated by (sensory)?
-CN IX
also includes middle ear and eustachian tube
What is the nasal cavity innervated by (sensory)?
anterior: V1
posterior: V2
What is the oral cavity innervated by (sensory)?
hard palate: V2/V3
What is the oropharynx innervated by (sensory)?
- gag reflex
- CN IX
What is the laryngopharyx innervated by (sensory)?
CN X Vagus
What is the Larynx innervated by (sensory)?
CN X Vagus, cough reflex
What is the esophagus innervated by (sensory)?
CN X Vagus
What is the trachea innervated by (sensory)?
CN X Vagus
Describe the facia of the pharynx and larynx.
- prevertebral fascia: most posterior, lying next to vertebral column
- visceral (pretracheal) fascia: surrounds pharynx and larynx
- deep cervical (investing) fascia: most anterior
- Retropharyngeal space is between the pre vertebral fascia and visceral fascia
Describe the tonsils of the pharynx.
These form Waldeyer’s ring
- pharyngeal tonsils: roof of nasopharynx
- palatine tonsils: between palatoglossal and palatopharyngeal folds. these are tonsils removed during tonsillectomy
- lingual tonsils: posterior of tongue, in back of sulcus terminals