THE DIGESTIVE SYSTEM Title: THE ORAL CAVITY , PHARYNX, and ESOPHAGUS Let’s dive in! Title: THE ORAL CAVITY , PHARYNX, and ESOPHAGUS Notes in Notebook

Hard and Soft Palate HARD PALATE  forms anterior roof of mouth *bony ridges of hard palate are called palatine RUGAE SOFT PALATE  forms posterior roof *Uvula  projection of soft palate

VESTIBULE Space between teeth and gums of mouth

FRENULUM Fold of membrane that secures tongue to the floor of the mouth (lingual frenulum)

PAPILLAE On tongue surface, some contain taste buds Types of Taste buds: sweet, sour, bitter, salty… react to different molecules of food

Salivary Glands Masseter Muscle Parotid Gland Facial Nerve, Dorsal Branch Facial Nerve, Ventral Branch Submaxillary Gland External Maxillary Vein Stensen’s (Parotid) Duct.

Opening to Naso-Parynx Nostril Oral Cavity Hard Palate Soft Palate Epiglottis Opening to Naso-Parynx Corner of Mouth (cut surface) Tongue Papillae of Tongue

TONSILS Palatine tonsils (posterior of oral cavity) Lingual tonsil (covers base of tongue)  Act as part of body’s immune system

SALIVARY GLANDS 3 pairs: Parotid glands (largest salivary glands; anterior to ears) Submandibular glands (below mandible) Sublingual glands (below tongue) *Salivary amylase in saliva begins breakdown of starch. *Salivary lipase begins breakdown of lipids/fats. - Over 99% of saliva is H2O.

EPIGLOTTIS Cartilage at back of throat; covers glottis during swallowing Glottis is the opening in the larynx (voice box) *The esophagus is located DORSAL to the trachea

. PHARYNX: Tube from nasal cavities to esophagus Skeletal muscle layers make up pharynx which contract to propel food into esophagus 3 DIVISIONS OF PHARYNX: Nasopharynx (extends from internal nares) Oropharynx (posterior to oral cavity) Laryngopharynx (connected to larynx & esophagus)

ESOPHAGUS Tube that conducts food to stomach – “food chute” No digestion/ absorption occurs here

SWALLOWING Part of FOOD PROPULSION TONGUE pushes food BOLUS (undigested food mass in mouth) against soft palate SOFT PALATE (uvula) rises & closes of nasal passages Bolus enters PHARYNX *EPIGLOTTIS covers larynx Food moves through pharynx to ESOPHAGUS to stomach by process of peristalsis