Chapter 15: Digestive Tract Flashcards
Its function is to obtain molecules from the the ingested food that are necessary for the maintenance, growth, and energy needs of the body
Digestive system
Carbohydrates and lipids are broken down by _____ in the oral cavity
Saliva
A mass of striated muscle covered by mucosa
Tongue
CT between small fascicles of muscle penetrated by the ___ ____, which makes the mucous membrane strongly adherent to the muscular core
Lamina propria
The ____/____ surface of the tongue is smooth, with typical lining mucosa
Lower/ventral
The ____/____ surface of the tongue is irregular, having hundreds of papillae
Upper/dorsal
The papillary and tonsillar areas of the tongue are separated by a V-shaped groove called the ____ ____
Sulcus terminalis
___ ____ are very numerous, have an elongated conical shape, and are heavily keratinized which gives their surface a gray or whitish appearance
Filiform papillae
Provide a rough surface that facilitates movement of food during chewing - mechanical
Filiform papillae
____ ____ are much less numerous, lightly keratinized, and interspersed on the tongue. They are mushroom-shaped and taste buds are present
Fungiform papillae
Ovoid structures within the stratified epithelium on the tongue’s surface, which sample the general chemical composition of ingested material
Taste buds
The taste bud is made up of 3 types of cells: ____, ____, and ____
Gustatory, supportive, and basal stem cells
___ ___ cells give rise to gustatory and supportive cells in teh taste bud
Basal stem
At the apical ends of the gustatory cells, ____ project toward a point in the structure called the taste ___
Microvilli; pore
The crown of a tooth is covered by very hard, acellular _____ and the roots by a bone-like tissue called _____
Enamel; cementum
The bulk of the tooth is composed of another calcified material called _____
Dentin
Dentin surrounds an internal ___ ___
Pulp cavity
The pulp cavity narrows in each root as the ___ ___, which extends to an opening at the tip of the root for the blood vessels, lymphatics, and nerves of the pulp cavity
Root canal
Opening at the tip of each root
Apical foramen
Dentin is a calcified tissue harder than bone, consisting of 70% _______
Hydroxyapatite
The organic matrix, hydroxyapatite, contains type I collagen and proteoglycans secreted from the the apical ends of ________
Odontoblasts
Tall polarized cells derived from the cranial neural crest that line the tooth’s pulp cavity
Odontoblasts
Long apical odontoblast processes extend from the odontoblasts within ___ tubules
Dentinal tubules
In a developing tooth bud, the matrix for the enamel rod is secreted by tall, polarized cells called
Ameloblasts
The ______ comprises the structures responsible for maintaining the teeth in the maxillary and mandibular bones, and includes the cementum, the periodontal ligament, and the alveolar bone with the associated gingiva
Periodontium
Covers the dentin of the root and resembles bone, but is avascular
Cementum
_____ maintain their surrounding matrix and react to stresses by gradually remodeling; less labile than bone
Cementocytes
The _____ ____ is fibrous CT with bundled collagen fibers (Sharpey fibers) binding the cementum and the alveolar bone
Periodontal ligament
The alveolar bone is surrounded by the ____ ____, which serves as its periosteum
Periodontal ligament
The _____ ____ has osteoblasts and osteocytes engaging in continuous remodeling of the bony matrix
Alveolar bone
Keratinized oral mucosa that is firmly bound to the periosteum of the maxillary and mandibular bones
Gingiva (gum)
The mucosa is made of three layers: ____, __ ___, and ___ ___-
Epithelium, lamina propria, and muscularis mucosae
Peritoneal cavity that secretes fluid; simple squamous mesothelium
Serosa
Outer layer of CT that connects certain parts of the digestive system (esophagus and anal canal) to the body walls
Adventitia
Transport food from the mouth to the stomach; strong muscular tube; is mainly skeletal muscle
Esophagus
The submucosa of the esophagus contains small mucus-secreting glands, ____ ____, which lubricate and protect the mucosa
Esophageal glands
Digestion of carbohydrates initiated by the _____ of saliva
Amylase
In the stomach, food undergoes mechanical and chemical breakdown into a viscous mass called
Chyme
Stomach begins digestion of triglycerides by a secreted ____
Lipase
Stomach promotes the initial digestion of proteins with the enzyme _____
Pepsin
The ____ is a narrow transitional zone between the esophagus and the stomach
Cardia
The ____ is the funnel-shaped region that opens into the small intestine
Pylorus
The ____/___ regions are the sites of gastric glands releasing acidic gastric juice
Fundus/body
The mucosa and submucosa of the empty stomach have large, longitudinally directed folds called ____, which flatten when the stomach fills food
Rugae
____ cells secrete hydrochloric acid; are large rounded or pyramidal with large round blue/purple centrally located nucleus
Parietal cells
____ ____ converts carbon dioxide and water into bicarbonate and protons; also releases Cl- to produce HCl
Carbonic anhydrase
Parietal cells also secrete ___ ____, a glycoprotein required for uptake of vitamin B12 in the small intestine
Intrinsic factor
