Muscles of the pharynx aid the passage food from the mouth into the oesophagus. Excepting stylopharyngeus which is innervated by the glossopharyngeal nerve (CN IX), the rest are innervated via the pharyngeal plexus by the pharyngeal branch of the vagus nerve (CN X). The muscles are divided into inner and outer layers. Outer layer The outer layer comprises three circularly oriented muscles known as the … Continue reading Pharyngeal muscles
The pharynx is a fibromuscular tube from the base of the skull to to the lower border of the cricoid cartilage. It is divided into three parts: Nasopharynx: behind the nasal cavity Oropharynx: behind the oral cavity Laryngopharynx: behind the larynx Innervation The pharyngeal muscles are supplied by the pharyngeal branch of the vagus nerve via the pharyngeal plexus. The accessory nerve contributes to the … Continue reading Pharynx
Waldeyer’s ring consists of four groups of mucosa-associated lymphoid tissue (MALT) at the entrance of the digestive and respiratory tracts. These are the tonsils, namely: pharyngeal (adenoid) tonsil tubal tonsils at the medial end of the Eustachian tube palatine tonsils between palatine arches lingual tonsil on the posterior surface of the tongue PLAT (palatine, lingual, adenoid, tubal) Acronym (Waldeyer’s ring) As lymphoid tissue, the tonsils … Continue reading Tonsils
The glossopharyngeal, vagus and cranial accessory nerves (CN IX, X, XI) can be considered as a group, passing through the jugular foramen, and are commonly damaged together. Jointly, they supply: motor innervation to the pharynx and larynx (CN X, joined by fibres from the cranial root of XI) parasympathetic supply to the parotid gland (CN IX) and thoracic and abdominal viscera (CN X) taste from … Continue reading CN IX, X & XI
The vocal cords are formed by the vocal ligaments (free superior edge of the cricothyroid membrane) that are covered in mucous membrane. Although crucial for phonation, the vocal folds are constantly held open at other times by the posterior cricoarytenoids for breathing. Only when speaking do the vocal folds intermittently close, vibrating and causing sound waves as air is pushed out. When closed for phonation, … Continue reading Vocal cords
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