Upper Digestive System Flashcards
Two main groups of digestive organs
- Alimentary canal
- Accessory organs
Alimentary canal is also called _______, a continuous muscular tube that digests and absorbs food.
Gastrointestinal (GI) tract
______ of the GI tract include mouth, pharynx, esophagus, stomach, small intestine, and large intestine, which terminates in anus.
Organs
_______ include teeth, tongue, gall bladder, and glands such as salivary glands, liver, and pancreas. Glands produce saliva, bile, and digestive enzymes.
Accessory digestive organs
Function of Digestive system
- Propulsion
- Secretion
- Absorption
- Excretion
- Immunologic protection
- Hormone production
For convenience, the digestive system can be divided into _____ and ______.
Upper and lower tracts
The ________ includes the oral cavity (lips, teeth, palate, tongue, cheeks), pharynx, and esophagus.
Upper digestive tract
The ________ deals mostly with digestion, absorption, and excretion, and includes stomach, small and large intestines, and anal canal.
Lower tract
The oral cavity is the ______ the the digestive system. It is a ______ in which the food is mechanically fragmented by teeth, chemically modified by enzymes, and lubricated by saliva.
- Entrance
- Chamber
The oral cavity contains a narrow space between lips and teeth called ______. It is bounded by _____ and _____ palates above, back of _____ and _____ anteriorly, and ________ of cheeks laterally.
- Vestibule
- Hard and Soft
- Gums and teeth
- Palatoglossal folds
Four layers of the GI wall
- Mucosa (epithelium, lamina propia, muscularis mucosae)
- Submucosa
- Tunica muscularis or muscularis externa
- Serosa (in esophagus=adventitia)
Three types of oral mucosa
- Lining
- Masticatory
- Specialized
_______ forms inner lining of lips, cheeks, soft palate, floor of mouth, and undersurface of tongue. The specific tissue is _______.
- Lining mucosa
- Nonkeratinized stratified squamous epithelium
_______ is found in gingivae (gums) and hard palate. The specific tissue is ________.
- Masticatory
- Lightly keratinized stratified squamous epithelium
_____ is found on the dorsal surface of tongue. The specific tissue is _______.
- Specialized mucosa
- Nonkeratinized stratified squamous epithelium
Much of the oral cavity is occupied by _____, a highly mobile muscular structure.
Tongue
In humans, the tongue engages in _____, ______, ______, and ______.
- Mastication
- Swallowing
- Speech
- Taste
The epithelium of the tongue is ________.
Smooth nonkeratinized stratified squamous
The tongue consists of ______ oriented vertically, horizontally and longitudinally and intersecting at right angles providing _________.
- Striated muscles
- High degree of mobility
The tongue has a V-shaped groove called ______ between the anterior (oral) 2/3rd and the posterior (pharyngeal) 1/3rd.
Sulcus terminalis
The three main types of surface projections called _______ that are seen on the roughened _____ surface of the ________ of the tongue are ______, ______, and ______.
- Lingual papillae
- Dorsal
- Anterior two-thirds
- Filiform
- Fungiform
- Circumvallate
_______ are the most numerous, slender and conical projections, have heavily keratinized cells. The grey color is due to keratin.
Filiform
_______ have narrow base, widely scattered among filiform papillae and have connective tissue core.
Fungiform
_______ is one row of 8-12 on the posterior side of tongue, largest in size, epithelium nonkeratinized or incompletely keratinized, with _________.
- Circumvallate
- Serous glands of von Ebner
The taste buds are small ________ organs embedded in lateral surfaces of the epithelium of _______ and _______ papillae.
- Intraepithelial
- Fungiform
- Circumvallate
In humans there are about ____ taste buds on tongue, about _____ on soft palate, _____ on epiglottis, and _____ in larynx and pharynx.
- 5000
- 2500
- 900
- 600
The taste buds are special sensory receptors that _____ chemical stimuli into nerve impulses which brain perceives as _____ sensations.
- Transduce
- Gustatory
The taste buds are pale ovoid bodies with 50-75 _____ cells - wider on the base and narrower on the apex which has a ______.
- Fusiform
- Taste pore
The three cell types of taste buds can be identified by ________.
Staining properties
_____ have long microvilli, apical cytoplasmic granules, found to be supporting cells and lie in periphery.
Dark cells (Type I)
______ lie centrally, have long microvilli, granules, abundant smooth ER and little rough ER.
Light cells (Type II)
______ are light staining, long apical processes that are several times the diameter of microvilli – believed to contain _______.
- Pale cells (Type III)
- Gustatory cells
Four basic taste sensations
- Sweet
- Salty
- Bitter
- Sour
Taste buds abundant near tip of tongue are ________.
Sweet and Salty
Taste buds abundant in the back of tongue are ________.
Bitter and Sour
The adult human has ____ permanent teeth. - 4 incisors, 2 canines, 4 premolars, and 6 molar teeth in each jaw.
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The _____ is the portion of tooth that projects above gum or gingiva.
Crown
The _____ is the portion in between crown and root(s).
Neck
The _____ is the portion that fits into the underlying bone, one or more roots are embedded in a bony socket or alveolus of the jaws.
Root
Teeth develop by a complex process called ________ derived from 2 embryonic sources: the ______ and _______.
- Odontogenesis
- Ectoderm
- Mesenchyme
The ______ arises from oral ectoderm.
Enamel
Dentin, pump, cementum & periodontal membrane arise from _______.
Mesenchyme
Bulk of tooth consists of ______ that is covered by ______ in the crown area.
- Dentin
- Enamel
Enamel is ______ in root area and the dentin here is covered by a thin layer of ______ enclosed in a ________.
- Absent
- Cementum
- Periodontal membrane
The crown of tooth has a small ______ which continues down into the root as _______.
- Central pulp cavity
- Root canal
Acid forming bacteria that dissolve enamel cause tooth decay or _______.
Dental caries
________ has dramatically reduced the incidence of caries. _______ containing substances are added to drinking water or oral hygiene products.
- Fluoridation
- Fluoride
Fluoride ions replace hydroxyl ions in the ______ crystals of enamel to form _______.
- Hydroxyapatite
- Fluoroapatite
________ is chemically more stable, less soluble, and more resistant to breakdown by acid bacteria in plaque.
Fluoroapatite
The dentin is an _______, mineralized tissue, ______ than the bone mineral but similar in composition
- Avascular
- Harder
About 70% of the dentin’s mass is inorganic made of _______, about 18 % is organic made of mostly ________ and the rest about 12 % is _____.
- Hydroxyapatite
- Type I collagen
- Water
Dentin is synthesized by _______, which are _____ _____ cells that line the pulp cavity.
- Odontoblasts
- Tall columnar
Enamel is the _____ substance in the body. About 96% of it is ________, the rest (4%) is organic made of unique glycoproteins called ______ and _____ - it lacks collagen.
- Hardest
- Hydroxyapatite
- Amelogenins
- Enamelins
Enamel is composed of ____ or _____ that radiate from dentin and is produced by a layer of columnar cells called _______, which ______ after the complete formation of enamel.
- Rods or prisms
- Ameloblasts
- Degenerate
The periodontal membrane or ligament is a layer of ______ enveloping roots of tooth. It is ______ between the cementum and the surrounding alveolar bone and it firmly _____ the tooth into its socket.
- Collagen
- Interposed
- Anchors
The gingiva is the _______ of the oral mucous membrane which is firmly bound to the periosteum.
Thicker portion
Around the base of the crown of each tooth, gingiva is separated from enamel forming ________ with gingival squamous epithelium. The seal between epithelium and enamel prevents ________.
- Gingival crevice
- Entry of bacteria
The two categories of salivary glands are _____ and _____.
Minor and major
______, which are numerous in mucosa, open directly or via short ducts on surface of oral epithelium, secrete continuously, and contribute to saliva that moistens and lubricates oral cavity.
Minor salivary glands
_____ consists of three pairs ______, _____, and ______.
- Major salivary glands
- Parotid, Submandibular, and Sublingual
_____ are located away from oral epithelium and are connected to it by a branching system of ducts.
Major salivary glands
_____ produce a large volume of secretions on mechanical and chemical stimulation of nerve endings in mucosa - some secrete in response to olfactory stimuli.
Major salivary glands
Minor salivary glands are short consisting of _______.
Mucous cells
Major salivary glands are ______ - mucous, serous, and sero-mucous - secretions from these salivary glands differ in composition.
Mixed glands
Mucous _____ are single layers of pyramidal cells, cytoplasm filled with mucigen – a precursor of mucus; abundant RER – ______ secretion.
- Acini
- Viscous
Serous acini consist of columnar cells, apical cytoplasm filled with secretory granules, have intercellular secretory canaliculi, abundant RER – products: amylase, lysozyme, peroxidase, DNAse, RNAse – ______ secretion.
Watery
Mixed acini have both _____ (proximal) and _____ (distal) acini.
- Mucous
- Serous
The saliva is a ____ of the products of several kinds of salivary glands. It is _____, colorless, and opalescent fluid.
- Mixture
- Vicsous
Saliva is composed of:
- 97-99% _____,
- ______ (Na+, K+, Ca++, Cl-, traces of Fe++),
- ______ (mucoproteins, immunoglobulins (IgA), enzymes –salivary amylase or ptyalin for digestion of carbohydrates
- ________(degenerating granulocytes and lymphocytes)
- Water
- Inorganic ions
- Proteins
- Salivary corpuscles
The basal rate of salivary secretion is _____ ml / minute – but increases many fold in response to presence of food in mouth. The total daily secretion is _____.
- 0.5 to 1
- 1 liter or more
Functions of saliva:
- ______ and lubricates mouth
- ______ digestion of carbohydrates (starch)
- ______ bacterial flora in oral cavity by lysozymes, thiocyanate and immunoglobulin A secreted by lymphocytes
- Moistens
- Initiates
- Controls
The tonsils are the _____ lymphoid organ with obvious ______.
- Simplest
- Germinal centers
5 tonsils form ____ of lymphatic tissue around entrance to the pharynx and are named according to their location.
- A ring
- Location
_____ are paired. They are the largest and most often infected.
Palatine tonsils
_____ are paired at the base of the tongue.
Lingual tonsils
______ are single and called adenoids if enlarged.
Pharyngeal tonsils
The ______ surround the openings of the auditory tubes into the pharynx.
Tubal tonsils
Tonsils are not fully _______ and have _____ that trap bacteria.
- Encapsulated
- Crypts
The pharynx is the _____ of the oral cavity, the merger of air and food tubes, and has 3 regions: ____, ____, and ____.
- Posterior continuation
- Nasal, oral, laryngeal
The 4 layers that compose the pharynx
- Mucosa
- Lamina propia
- Submucosa
- Muscularis externa
The pharynx mucosa is composed of _______ in oral and laryngeal pharynx and ______ with _____ in the nasal pharynx.
- Stratified squamous epithelium
- Stratified ciliated columnar with goblet cells
The pharynx _______ has loose CT and no muscularis mucosae.
Lamina propia
The pharynx _______ has loose CT.
Submucosa
The pharynx _________ has an inner longitudinal skeletal and outer oblique or longitudinal with fibroelastic tissue in between.
Muscularis externa
Four layers of the GI wall
- Mucosa
- Submucosa
- Tunica muscularis or muscularis externa
- Serosa (adventitia in esophgus)
Mucosa layers in GI wall
- Epithelium
- Lamina Propia
- Muscularis Mucosae
The GI wall Mucosa _____ varies in different parts of GI, is conductive, secretory or absorptive.
Epithelium
The GI wall Mucosa _______ is a vascular loose CT with fibroblasts, reticular and elastic fibers, macrophages and lymphoid tissue.
Lamina Propia
The GI wall Mucosa _______ has two layers of smooth muscle fibers – ________ and _______.
- Muscularis mucosae
- Inner circular
- Outer longitudinal
The ______ of the GI wall is moderately dense CT with many blood vessels and a plexus of sympathetic nerves – _______- for control of motility
- Submucosa
- Meissner’s plexus
The ______ of the GI wall has moderately thick smooth muscles – ________ and a plexus of sympathetic nerves in between these two layers– ________ for peristalsis.
- Tunica Muscularis or Muscularis Externa
- Inner circular and outer longitudinal
- Auerbach’s plexus
The ______ of the GI wall consists of mesothelium – squamous epithelium lining abdominal cavity and organs - _____ lines stomach and _____ lines intestine.
- Omentum
- Mesentery
The _______ is a muscular tube about 10 inches or 25 cm, greater portion in thorax (chest), terminal 2-4 cm in abdominal cavity that conveys food from pharynx to stomach.
Esophagus
The Esophagus Wall layers
- Mucosa
- Submucosa
- Muscularis externa
- Tunica adventitia
The Mucosa of the esophagus wall is made of ______ epithelium. At the junction of esophagus and stomach an abrupt transition from stratified squamous to ________. It also contains a _______ – loose CT with collagen and elastic fibers.
- Stratified Squamous
- Simple Columnar
- Lamina propia
The ______ of the esophagus wall is a dense CT with collagen and elastic fibers and many small blood vessels
that forms numerous folds that smooth out during transport of food.
Submucosa
The _____ of the esophagus wall is inner circular and outer longitudinal, also oblique.
Upper third striated, middle third mixture of striated and smooth and lower third all smooth muscles.
Muscularis externa
The ______ of the esophagus wall is loose CT, not serosa.
Tunic Adventitia
Two kinds of esophageal glands
- Mucosal
- Submucosal
______ or cardiac esophageal glands are ______ and limited to lamina propria - Found only in upper esophagus and at esophagus-stomach junction.
- Mucosal
- Simple tubular
The _____ glands are ______, more widespread, and contain mucus droplets.
- Submucosal
- Compound tubular
The _______ exhibit great muscular tone, not anatomically distinct but physiological significant, and are important in preventing reflux of food.
Pharyngeo- and gastroesophageal sphincters
Inflammation of the esophagus with damage to the epithelium is called _______.
Most common cause is __________ into lower esophagus.
- Esophagitis
- Reflux of gastric contents
_________ is a common chronic condition – common in adults over 40 years.
Gastroesophgeal reflux disease (GERD)
GERD often accompanies _______ which causes failure of gastroesophageal sphincter to close resulting in reflux of acidic food into the esophagus causing ______.
- Hiatal hernia
- Heart burns
