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Mastication and Deglutition Nasywa Azzahra S. - 2306173731 - Coggle…
Mastication and Deglutition
Nasywa Azzahra S. - 2306173731
Muscle anatomy and mucosal mastication
Mastication mucosa
Keratinized masticatory mucosa : keratinized stratified squamous epithelium, providing toughness and resistance to wear; covering areas: gingiva , palatal mucosa, and dorsum of the tongue
Non-keratinized lining mucosa : non-keratinized stratified squamous epithelium, offering flexibility and ease of movement; covering areas : labial mucosa, buccal mucosa, mucosa of soft palate, alveolar mucosa
Specialized mucosa in lingual papillae : covers areas with taste buds in lingual papillae, facilitating gustatory perception, contains nerve endings enabling sensory perception
Lingual papillae
Folliate : folds located on the lateral edges of the posterior tongue containing taste buds, covered by non-keratinized stratified squamous epithelium
Fungiform : mushroom-shaped papillae found predominantly on the anterior part of the tongue containing taste buds, covered by non-keratinized stratified squamous epithelium
Circumvallate : large dome-shaped papillae located in the posterior region of the tongue, encircled by a serous secretion from Von Ebner's glands
Filiform : small, thread-like papillae covering most of the dorsal surface of the tongue, assist in mechanical functions without containing taste buds, covered by keratinized stratified squamous epithelium
Accessory muscles of mastication
Suprahyoid : raise and depress the hyoid bone and larynx
Infrahyoid : raise and depress the hyoid bone and larynx
Buccinator : keeping food pushed back within the oral cavity
Primary mastication muscles
Pterygoid medial : assist with elevation and protrusion of the mandible
Pterygoid lateral : causes depression of the mandible (lower the mandible)
Temporalis : elevates and retracts the mandible
Masseter: elevates the mandible. the intermediate and deep muscle fibers of the masseter function to retract the mandible
Function of saliva in mastication process
Water in saliva moistens the ingested food, also aids digestion, moistens your mouth, reduces infections in the mouth and throat, and helps protect your teeth and gums
Enzymes in saliva can also help start the digestion for macromolecules like carbohydrates done by amylase in saliva
Food mixes with the saliva to form a bolus, a smooth mass of mechanically broken down food particles
Physiological aspect of mastication
Taste perception : taste receptors on the tongue to perceive flavors such as sweet, salty, sour, bitter, and umami
Bolus formation : as food is chewed, it is combined with saliva to produce a bolus
Salivary glands and salliva production
Neurological control : CNS regulates mastication process
Teeth : mechanically break down food into smaller bits
Swallowing reflex : bolus moves from the oral cavity to the pharynx and finally into the esophagus for digestion
Jaw movement : primary cause of mastication, TMJ permits mandible to move
Biochemical aspect of mastication
Lipase: Another enzyme present in saliva is lipase, which plays a role in the digestion of fats
Buffering action : bicarbonate ions in saliva help maintain the pH of the oral cavity
Amylase in saliva : breaks down complex carbohydrates into simpler sugars such as maltose
Lactoperoxidase in seliva has antibacterial properties
Nerves in deglutition
CN V3, CN IX, CN X, CN XII, Ansa cervicalis, recurrent laryngeal nerves
Innervation and kinesiology of tongue
Kinesiology
Intrinsic muscles
Inferior longitudinal muscle : shortens the tongue and turns the tip downward
Transverse muscle : narrows and elongates the tongue
Superior longitudinal muscle : shortens the tongue and turns the tip upward
Vertical muscle : flattens and broadens the tongue
Extrinsic muscles
Genioglossus : protrudes tongue
Hyoglossus : depresses and retracts the sides of the tongue
Styloglossus : elevates and retracts the tongue
Palatoglossus : elevates the back of the tongue and closes off the oral cavity from the pharynx during swallowing
Innervation
sensory innervation of the tongue is divided into anterior and posterior regions. The anterior two-thirds of the tongue is supplied by the lingual nerve and the chorda tympani of the facial nerve (CN VII), while the posterior one-third is supplied by the glossopharyngeal nerve (CN IX)
Coordinated movements
Manuplation of food
Swallowing
Speech
composed of intrinsic and extrinsic muscles, which are innervated by the hypoglossal nerve (CN XII) and the vagus nerve (CN X)
Phases of deglutition
Pharyngeal phase
Esophagus phase
Oral phase (mastication)
