06/14/2023 Notes Flashcards
What is the entrance to the GI tract?
Oral cavity (mouth)
What is the initial site of mechanical digestion through mastication and chemical digestion?
mouth
What are the 2 distinct regions found within the oral cavity?
Vestibule and oral cavity proper
What is the vestibule in the mouth?
Space between the cheeks/lips and gums
What is the oral cavity proper found?
Central to the alveolar processes of the mandible and maxillae
What forms the lateral walls of the oral cavity?
Cheeks
What does the buccinator muscles do?
Compress the cheeks against the cheeks to hold solid materials in place while chewing
What are the lips?
Area where the cheeks terminate and are formed by the orbicularis oris muscle and are covered by a thin layer of keratinized stratified epithelium
Why do lips have a reddish hue?
Abundant supply of superficial blood vessels and reduced amount of keratin within the outer skin
What are gingivae?
Gingivae are the gums; they are composed of dense regular connective tissue with an overlying stratified epithelium covering the alveolar processes of the upper and lower jaws
What is the labial frenulum?
A thin mucosal fold that attaches the superior and inferior lips to the gingivae at the midline
What does the palate separate the oral cavity from?
Nasal cavity
What is the hard palate?
Anterior 2/3 of the palate formed by the palatine processes of the maxillae and palatine bones
What do the transverse palatine folds (friction ridges) perform?
Assist the tongue in manipulating ingested materials prior to swallowing
What does the soft palate and uvula do during swallowing?
Soft palate and uvula elevate to close off the posterior entrance to the nasopharynx and prevent ingested materials from entering the nasal region
What are palatine tonsils?
Early line of defense that monitors ingested food/drink for antigens and can initiate an immune response if necessary
What is the tongue?
An accessory digestive organ formed by skeletal muscle that participates in sound production
What does the tongue do in digestion?
Manipulate and mix ingested materials during shewing and helps compress the partially digested materials against the hard palate to turn materials in bolus
What is a bolus?
Globular mass of partially digested materials
What is the lingual frenulum?
A thin, vertical mucous membrane that attaches the inferior surface of the tongue to the floor of the oral cavity
What do salivary glands do?
Produce and secrete saliva
How much saliva is secreted daily?
1-1.5 L a day
What are the functions of saliva?
Moisten ingested food, moisten and clean oral cavity structures, aid in chemical digestion, inhibit bacterial growth, and dissolves food to stimulate taste
What is amylase?
A salivary enzyme that begins chemical digestion by breaking down starch
What are lysolyzes?
an antibacterial substance that inhibits bacterial growth in the oral cavity
What are the 3 pairs of salivary glands?
Parotid salivary glands, submandibular glands, and sublingual salivary glands
What are the largest salivary glands?
Parotid salivary glands
When infected with mumps, what happens to the parotid salivary glands?
Become swollen
Which salivary gland is used in “gleeking”?
Submandibular salivary glands
What division of the ANS innervates salivary glands?
Parasympathetic
CN VII innervates what salivary glands?
Facial nerve innervates submandibular and sublingual glands
Glossopharyngeal nerve innervates which salivary gland?
Parotid
What do parasympathetic and sympathic innervation do to salivary glands?
Parasympathetic stimulates salivary gland secretion while sympathetic innervations inhibit secretion and cause dry mouth in frightened people
What are teeth responsible for in mechanical digestion?
Mastication
What are the 3 components of a tooth?
Crown, Neck, and Roots
Where do the root of teeth fit into?
Dental alveoli
What form the gomphosis joint?
Root of teeth, dental alveoli, and periodontal ligaments
What are deciduous teeth?
Milk teeth that erupt 6-30 months after births
What are permanent teeth?
32 teeth that replace deciduous teeth starting with the anterior teeth and moving to the posterior teeth
what are the last teeth to appear?
3rd molars (wisdom teeth)
What are incisors?
Anteriorly placed teeth designed for slicing/cutting into food that are shaped like a chisel
What are canines?
Posterolateral teeth to the incisors with a pointed tip responsible for puncturing and tearing food; “eye teeth”
What are the premolars (bicuspids)?
Teeth with flat crowns that have ridges (cusps) that crush and grind ingested materials