Throat
Components covered in this throat section:
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Oral Cavity
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Tongue
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Salivary Glands
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Palate
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Pharynx
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Larynx
Oral Cavity
Relations to oral cavity:
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Superiorly- hard palate
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Infeirorly- tongue
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Laterally- cheeks
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Anteriorly- oral fissure
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Posteriorly- soft palate opening into oropharynx
Tongue
Components covered in tongue subsection:
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General structure
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Surface projections
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Muscles
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Neurovasculature
General Structure
General structure:
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Terminal sulcus- divides tongue into anterior 2/3 & posterior 1/3
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Foramen cecum
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Lingual papillae
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Lingual frenulum
Surface Projections
Surface projections:
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Valate/circumvallate papillae
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Filiform papillae
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Fungiform papillae
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Foliate papillae
Taste buds are present in these surface projections
except on the filiform papillae.
Muscles
Muscles of the tongue are of 2 types:
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Intrinsic muscles- originate and inset within the tongue
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Extrinsic muscles- attach from tongue to surrounding bones or soft palate
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Genioglossus
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Hyoglossus
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Styloglossus
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Palatoglossus
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All innervated by CN XII (hypoglossal nerve) except palatoglussus (innervated by CN X (vagus nerve)).
Genioglossus- protrudes tongue to opposite side
Hyoglossus- depresses tongue
Styloglossus- elevates & retracts tongue
Palatoglossus- depresses soft palate & elevates back of tongue
Neurovasculature
Arteries
Arteries of the tongue- lingual artery via ECA.
Veins
Veins of the tongue- linguals veins- via IJV.
Nerves
Tongue nerve innervation:
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Sensory
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General sensation
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Anterior 2/3- CN V3 (mandibular nerve)
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Posterior 1/3- CN IX (glossopharyngeal nerve)
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Special sensation- taste
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Anterior 2/3- CN VII (facial nerve)
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Posterior 1/3- CN IX (glossopharyngeal nerve)
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Motor
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CN XII (hypoglossal nerve)- innervates genioglossus, hyoglossus and styloglossus
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CN X (vagus nerve)- innervates palatoglossus
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Lymphatics
Lymphatics of tongue- submental & submandibular glands.
Palate
Palate:
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Hard palate
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Soft palate
Muscles of the palate:
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Uvula
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Palatoglossus
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Palatopharyngeus
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Tensor veli palatine- attached to medial pterygoid plate
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Levator veli palatine
All muscles elevate the soft palate.
All innervated by CN X (vagus nerve).
Pharynx
Components covered in pharynx subsection:
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Components
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Muscles
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Waldeyer's lymphoid ring
Components
Components:
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Nasopharynx
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Oropharynx
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Laryngopharynx
Muscles
Muscles:
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Outer circular layer
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Inner longitudinal layer
Outer circular layer:
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Superior constrictor muscles
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Middle constrictor muscles
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Inferior constrictor muscles
Constrict walls of pharynx during swallowing.
All innervated by CN X (vagus nerve).
Inner longitudinal layer:
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Stylopharyngeus
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Salpingopharyngeus
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Palatopharyngeus
Elevate pharynx during swallowing.
All innervated by CN X (vagus nerve) except stylopharyngeus
(innervated by CN IX (glossopharyngeal nerve).
Waldeyer's Lymphoid Ring
Waldeyer's lymphoid ring:
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Pharyngeal/adenoid tonsil
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Platine tonsil
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Lingual tonsil
Larynx
Components covered in larynx subsection:
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Relations
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Skeleton
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Membranes
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Laryngeal inlet
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Lumen
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Nerves
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Vocal cords
Relations
Relations:
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Superiorly- continious with oropharynx
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Inferiorly- contiues as trachea
Skeleton
Skeleton of the larynx:
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Epiglottic cartilage
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Thyroid cartilage
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Cricoid cartilage- forms a complete ring
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Arytenoid cartilage- paired cartilage
Membranes
Membranes of the larynx:
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Thyrohyoid membrane
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Cricothyroid membrane
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Cricotracheal membrane
Laryngeal Inlet
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Laryngeal inlet
Lumen
Lumen of larynx divided into 3 parts:
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Supraglottis/Vestibule/Upper part
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Glottis/Middle part
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Subglottic/Infraglottic/Lower part
Other structures to note:
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Laryngeal ventricle
Nerves
Recurrent laryngeal nerve positions vary:
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Right recurrent laryngeal nerve- loops from right vagus nerve below right braciocephalic trunk
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Left recurrant laryngeal nerve- loops from left vagus nerve below the aortic arch
Innervate intrinsic muscles of the larynx
Vocal Cords
Salivary Glands
There are 3 salivary glands:
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Parotid gland- innervated by CN IX (glossopharyngeal nerve)
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Submandibular gland- innervated by CN VII (facial nerve)
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Sublingual gland- innervated by CN VII (facial nerve)