v Omental bursa – a long, double fold of
DIGESTIVE SYSTEM mesentery that extends inferiorly from
§ With the help of the circulatory system, is like a the stomach before looping back to the
gigantic ‘meals on wheels’, serving 100 T transverse colon to create a
customers the nutrients they need cavity/pocket
§ Has its own quality control and waste disposal v Mesentery proper – attaches the small
methods intestine to the posterior abdominal wall
FUNCTIONS (IDEA) Retroperitoneal – abdominal organs that have no
1. Ingestion of food. mesenteries; duodenum, pancreas, ascending +
2. Digestion of food. descending colon, rectum, kidneys, adrenal glands,
3. Elimination of wastes. urinary bladder
4. Absorption of nutrients.
ORAL CAVITY, PHARYNX, AND ESOPHAGUS
ANATOMY AND HISTOLOGY Anatomy of Oral Cavity
Digestive Tract / Gastrointestinal Tract § Bounded by the lips and cheeks ++ contains the
§ Oral cavity, pharynx, esophagus, stomach, small teeth and tongue
intestine, large intestine, anus
Lips – muscular structures formed by the orbicularis
Four Tunics oris muscle
1. Mucosa
§ Innermost tunic Cheeks – buccinators muscles flatten the cheeks against
§ Consists of mucous epithelium, lamina propria teeth
(loose CT), muscularis mucosae (thins SM layer)
§ Mouth, esophagus, anus; resists abrasion Mastification – begins the process of mechanical
digestion
§ Stomach, intestine; absorbs and secrets
Tongue – plays a major role in the process of
2. Submucosa
swallowing; major sensory organ for taste; one of the
§ Thick layer of loose CT, consists of nerves, blood
major organs of speech
vessels, small glands
v Frenulum – thin fold of tissue inferior to the
§ Plexus – extensive network of nerve cell
tongue
processes (innervated by the autonomic nerves)
Teeth
3. Muscularis
§ 32 teeth in normal adult mouth
§ Consists of circular SM (inner), longitudinal SM
(outer) § Located in the mandible and maxillae
§ Enteric nervous system – composed of the
1. Incisor – to cut
nerve plexuses of the submucosa and
2. Canine – to tear
muscularis; controls movement and secretion
3. Premolars
within the tract
4. Molars
5. Wisdom teeth – third molars
4. Serosa
§ Outermost layer Permanent teeth – secondary teeth
§ Consists of the peritoneum (smooth epithelial
layer + underlying CT) Primary teeth – deciduous teeth; milk or baby teeth
§ Adventitia – connective tissue; regions of the DT
not covered by the peritoneum Parts
a. Crown
Peritoneum b. Cusps
1. Visceral Peritoneum / Serosa – serous c. Neck
membrane that covers the organs d. Root
2. Parietal Peritoneum – serous membrance that Pulp cavity – center of the tooth; contains blood vessels
covers the wall of the abdominal cavity nerves, and pulp (connective tissue)
Mesenteries – CT sheets that hold the abdominal cavity Dentin – bonelike tissue that surrounds the pulp cavity
organs in place
a. Lesser omentum – connects the lesser curvature Enamel – extremely hard, acellular substance that covers
of the stomack to the liver and diaphragm the dentin of the tooth drown
b. Greater omentum – connects the greater Cementum – covers the surface of the dentin in the root;
curvature of the stomach to the transverse colon anchors the tooth in the jaw
and posterior body wall
M A V M .
, Alveoli (along the alveolar process of mandible x Esophagus
maxillae) – where the teeth are rooted § Muscular tube that ransports food from the
pharynx to the stomach
Gingiva – dense fibrous CT and most stratified § Esophageal sphincters – regulate the movement
squamous epithelium that covers the alveolar processes of food into and out of the esophagus
§ Cardiac sphincter – lower ES
Periodontal ligaments – CT fibers that extend from the
alveolar walls that hold the teeth in place Swallowing / Deglutition
1. Voluntary Phase
Dental caries / Tooth decay – result of the breakdown of § Bolus (mass of food) us formed in the mouth
enamel by acids produced by bacteria on tooth surface § Bolus is pushed by the tongue forcing in into the
oropharynx
Periodontal disease – inflammation x degeneration of
the periodontal ligaments, gingiva, alveolar bone 2. Pharyngeal Phase
§ A reflex initiated when a bolus of food
Palate and Tonsils stimulates receptors in the oropharynx
Palate – roof of the oral cavity; prevents food from
§ Epiglottis – tipped posteriorly to cover the
passing into the nasal cavity during chewing and
larynx
swallowing
a. Hard palate – anterior part that contains bone
3. Esophageal Phase
b. Soft palate – posterior portion that consists of
skeletal muscle _ CT § Responsible for moving food form the pharynx
to the stomach
v Uvula – grape-like; posterior extension of the
soft palate § Peristaltic waves – muscular contractions of the
esophagus
Tonsils – protect against pathogens from entering the
STOMACH
nose and mouth
§ Functions primarily as a storage and mixing
Salivary Glands chamber for ingested food
§ Produce saliva (serous + mucous fluids)
Anatomy
3 Pairs of SG Gastroesophageal opening – opening from the
1. Parotid glands – largest; serous glands located esophagus ino the stomach
anterior to each ear
Cardiac region – region of t around the
2. Submandibular glands – produce more serous
gastroesophageal opening; near the heart
than mucous secretions
3. Sublingual glands – smallest; produce
primarily mucous secretions Fundus – most superior part of the stomach
Mumps – inflammation of the parotid gland caused by Body – largest part of the stomach
viral infection v Greater curvature
v Lesser curvature
Saliva
§ Helps keep the oral cavity moist Pyloric opening – opening from the stomach into the
small intestine
§ Contains enzymes that begin the process of
digestion
Pyloric sphincter – thick ring of smooth muscle
Salivary amylase – a digestive enzyme that breaks the
Pyloric region – region near the pyloric opening
covalent bonds bet. glucose molecules (starch) and other
polysaccharides; enhances the sweet taste of food
Outer longitudinal, middle circular, and inner obique
Lysozyme – enzyme that has weak antibacterial action layer – produce a churning action in the stomach
Mastification Rugae – large folds where the submucosa and mucosa
are thrown into when the stomach is empty
§ Breaks large food particles into many small ones
§ Increases the efficiency of digestion Gastric pits – openings for the gastric glands; formed by
simple columnar epithelium
Pharynx
§ Throat Epithelial cells of the Stomach
§ Connects the mouth with the esophagus 1. Surface mucous cells – inner surface of stomach
§ Oropharynx + laryngopharynx – transmit food & lining the gastric pits; coats and protects the
§ Contains pharyngeal constrictor muscles stomach lining
2. Mucous neck cells – produce mucus
M A V M .
DIGESTIVE SYSTEM mesentery that extends inferiorly from
§ With the help of the circulatory system, is like a the stomach before looping back to the
gigantic ‘meals on wheels’, serving 100 T transverse colon to create a
customers the nutrients they need cavity/pocket
§ Has its own quality control and waste disposal v Mesentery proper – attaches the small
methods intestine to the posterior abdominal wall
FUNCTIONS (IDEA) Retroperitoneal – abdominal organs that have no
1. Ingestion of food. mesenteries; duodenum, pancreas, ascending +
2. Digestion of food. descending colon, rectum, kidneys, adrenal glands,
3. Elimination of wastes. urinary bladder
4. Absorption of nutrients.
ORAL CAVITY, PHARYNX, AND ESOPHAGUS
ANATOMY AND HISTOLOGY Anatomy of Oral Cavity
Digestive Tract / Gastrointestinal Tract § Bounded by the lips and cheeks ++ contains the
§ Oral cavity, pharynx, esophagus, stomach, small teeth and tongue
intestine, large intestine, anus
Lips – muscular structures formed by the orbicularis
Four Tunics oris muscle
1. Mucosa
§ Innermost tunic Cheeks – buccinators muscles flatten the cheeks against
§ Consists of mucous epithelium, lamina propria teeth
(loose CT), muscularis mucosae (thins SM layer)
§ Mouth, esophagus, anus; resists abrasion Mastification – begins the process of mechanical
digestion
§ Stomach, intestine; absorbs and secrets
Tongue – plays a major role in the process of
2. Submucosa
swallowing; major sensory organ for taste; one of the
§ Thick layer of loose CT, consists of nerves, blood
major organs of speech
vessels, small glands
v Frenulum – thin fold of tissue inferior to the
§ Plexus – extensive network of nerve cell
tongue
processes (innervated by the autonomic nerves)
Teeth
3. Muscularis
§ 32 teeth in normal adult mouth
§ Consists of circular SM (inner), longitudinal SM
(outer) § Located in the mandible and maxillae
§ Enteric nervous system – composed of the
1. Incisor – to cut
nerve plexuses of the submucosa and
2. Canine – to tear
muscularis; controls movement and secretion
3. Premolars
within the tract
4. Molars
5. Wisdom teeth – third molars
4. Serosa
§ Outermost layer Permanent teeth – secondary teeth
§ Consists of the peritoneum (smooth epithelial
layer + underlying CT) Primary teeth – deciduous teeth; milk or baby teeth
§ Adventitia – connective tissue; regions of the DT
not covered by the peritoneum Parts
a. Crown
Peritoneum b. Cusps
1. Visceral Peritoneum / Serosa – serous c. Neck
membrane that covers the organs d. Root
2. Parietal Peritoneum – serous membrance that Pulp cavity – center of the tooth; contains blood vessels
covers the wall of the abdominal cavity nerves, and pulp (connective tissue)
Mesenteries – CT sheets that hold the abdominal cavity Dentin – bonelike tissue that surrounds the pulp cavity
organs in place
a. Lesser omentum – connects the lesser curvature Enamel – extremely hard, acellular substance that covers
of the stomack to the liver and diaphragm the dentin of the tooth drown
b. Greater omentum – connects the greater Cementum – covers the surface of the dentin in the root;
curvature of the stomach to the transverse colon anchors the tooth in the jaw
and posterior body wall
M A V M .
, Alveoli (along the alveolar process of mandible x Esophagus
maxillae) – where the teeth are rooted § Muscular tube that ransports food from the
pharynx to the stomach
Gingiva – dense fibrous CT and most stratified § Esophageal sphincters – regulate the movement
squamous epithelium that covers the alveolar processes of food into and out of the esophagus
§ Cardiac sphincter – lower ES
Periodontal ligaments – CT fibers that extend from the
alveolar walls that hold the teeth in place Swallowing / Deglutition
1. Voluntary Phase
Dental caries / Tooth decay – result of the breakdown of § Bolus (mass of food) us formed in the mouth
enamel by acids produced by bacteria on tooth surface § Bolus is pushed by the tongue forcing in into the
oropharynx
Periodontal disease – inflammation x degeneration of
the periodontal ligaments, gingiva, alveolar bone 2. Pharyngeal Phase
§ A reflex initiated when a bolus of food
Palate and Tonsils stimulates receptors in the oropharynx
Palate – roof of the oral cavity; prevents food from
§ Epiglottis – tipped posteriorly to cover the
passing into the nasal cavity during chewing and
larynx
swallowing
a. Hard palate – anterior part that contains bone
3. Esophageal Phase
b. Soft palate – posterior portion that consists of
skeletal muscle _ CT § Responsible for moving food form the pharynx
to the stomach
v Uvula – grape-like; posterior extension of the
soft palate § Peristaltic waves – muscular contractions of the
esophagus
Tonsils – protect against pathogens from entering the
STOMACH
nose and mouth
§ Functions primarily as a storage and mixing
Salivary Glands chamber for ingested food
§ Produce saliva (serous + mucous fluids)
Anatomy
3 Pairs of SG Gastroesophageal opening – opening from the
1. Parotid glands – largest; serous glands located esophagus ino the stomach
anterior to each ear
Cardiac region – region of t around the
2. Submandibular glands – produce more serous
gastroesophageal opening; near the heart
than mucous secretions
3. Sublingual glands – smallest; produce
primarily mucous secretions Fundus – most superior part of the stomach
Mumps – inflammation of the parotid gland caused by Body – largest part of the stomach
viral infection v Greater curvature
v Lesser curvature
Saliva
§ Helps keep the oral cavity moist Pyloric opening – opening from the stomach into the
small intestine
§ Contains enzymes that begin the process of
digestion
Pyloric sphincter – thick ring of smooth muscle
Salivary amylase – a digestive enzyme that breaks the
Pyloric region – region near the pyloric opening
covalent bonds bet. glucose molecules (starch) and other
polysaccharides; enhances the sweet taste of food
Outer longitudinal, middle circular, and inner obique
Lysozyme – enzyme that has weak antibacterial action layer – produce a churning action in the stomach
Mastification Rugae – large folds where the submucosa and mucosa
are thrown into when the stomach is empty
§ Breaks large food particles into many small ones
§ Increases the efficiency of digestion Gastric pits – openings for the gastric glands; formed by
simple columnar epithelium
Pharynx
§ Throat Epithelial cells of the Stomach
§ Connects the mouth with the esophagus 1. Surface mucous cells – inner surface of stomach
§ Oropharynx + laryngopharynx – transmit food & lining the gastric pits; coats and protects the
§ Contains pharyngeal constrictor muscles stomach lining
2. Mucous neck cells – produce mucus
M A V M .
