Digestive system Flashcards
Breakdown of ingested food
Absorption of nutrients into the blood
Digestion
Production of cellular energy (ATP)
Constructive and degradative cellular
activities
Metabolism
– continuous coiled hollow
tube
Alimentary canal
Two main groups; Organs of the Digestive System
Alimentary canal
accessory digestive organs
Organs of the Alimentary Canal (7)
Mouth
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
Anus
Mouth (Oral Cavity) Anatomy: 9
Lips (labia);
Cheeks;
Hard palate;
Soft palate;
Uvula;
Vestibule;
Oral cavity;
Tongue;
Tonsil
Mouth (Oral Cavity) Anatomy:
– protect the anterior opening
Lips (labia)
Mouth (Oral Cavity) Anatomy:
– form the
lateral walls
Cheeks
Mouth (Oral Cavity) Anatomy:
– forms
the anterior roof
Hard palate
Mouth (Oral Cavity) Anatomy:
– forms
the posterior roof
Soft palate
Mouth (Oral Cavity) Anatomy
– fleshy
projection of the
soft palate
Uvula
Mouth (Oral Cavity) Anatomy:
– space
between lips
externally and teeth
and gums internally
Vestibule
Mouth (Oral Cavity) Anatomy:
___– area
contained by the
teeth
Oral cavity
Mouth (Oral Cavity) Anatomy:
– attached at
hyoid and styloid
processes of the
skull, and by the
lingual frenulum
Tongue
Tonsils (2)
Palatine tonsils
Lingual tonsil
Processes of the Mouth:
___(chewing) of food
Mixing masticated food with ____
Initiation of swallowing by the ___
Allowing for the sense of ___
Mastication;
saliva;
tongue;
taste
Pharynx Anatomy (3)
Nasopharynx
Oropharynx
Laryngopharynx
Pharynx Anatomy:
___not part of the
digestive system
Nasopharynx
Pharynx Anatomy:
posterior to oral
cavity
Oropharynx
Pharynx Anatomy:
below the oropharynx
and connected to
the esophagus
Laryngopharynx
Serves as a passageway for air and food
pharynx
Food is propelled to the esophagus by two muscle layers:
Longitudinal inner layer
Circular outer layer
Food movement is by alternating
contractions of the muscle layers
(___)
peristalsis
Runs from pharynx to stomach through the diaphragm; Conducts food by peristalsis;
Passageway for food only
esophagus
Layers of Alimentary Canal Organs (4)
Mucosa
submucosa
Muscularis externa
serosa
Layers of Alimentary Canal Organs (Mucosa)
Innermost layer
Moist membrane
Surface epithelium
Small amount of connective tissue
(lamina propria)
Small smooth muscle layer
Moist membrane (mucosa`)
Layers of Alimentary Canal Organs:
beneath the mucosa; Soft connective tissue with blood vessels,
nerve endings, and lymphatics
Submucosa
Layers of Alimentary Canal Organs:
– smooth muscle
Muscularis externa
layers of Muscularis externa
Inner circular layer
Outer longitudinal layer
Outermost layer– ___
Layer of serous fluid-producing cell
serosa: peritoneum
All are part of the autonomic nervous
system
Alimentary Canal Nerve Plexuses
Three separate networks of nerve fibers of alimentary canal
Submucosal nerve plexus
Myenteric nerve plexus
Subserous plexus
__- Located on the left side of the abdominal cavity
Food enters at the ___
stomach;
cardioesophageal
sphincter
Regions of the stomach (4)
Cardiac region
Fundus
Body
Phylorus
Regions of the stomach:
– near the heart
– funnel-shaped terminal end
Cardiac region;
Phylorus
Food empties into the small intestine at
the _____
pyloric sphincter
– internal folds of the mucosa of stomach
Rugae
External regions of stomach
Lesser curvature
Greater curvature
Layers of peritoneum attached to the stomach (2)
Lesser omentum;
Greater omentum
____– attaches the liver to the
lesser curvature
____– attaches the greater
curvature to the posterior body wall
Lesser omentum;
Greater omentum
Contains fat to insulate, cushion, and
protect abdominal organs
Layers of peritoneum
Stomach Functions (4)
storage tank for food;
Site of food breakdown;
Chemical breakdown of protein;
Delivers chyme (processed food) to the small intestine
Specialized Mucosa of the Stomach
Simple columnar epithelium
Simple columnar epithelium (5)
Mucous neck cells;
Gastric glands;
Chief cells;
Parietal cells;
Endocrine cells
____– produce a sticky
alkaline mucus
____– secrete gastric juice
Mucous neck cells;
Gastric glands
cells:
___– produce protein-digesting
enzymes (pepsinogens)
____– produce hydrochloric acid
____– produce gastrin
Chief cells;
Parietal cells;
Endocrine cells
Structure of the Stomach Mucosa
____ formed by folded mucosa
Glands and specialized cells are in the ___
Gastric pits;
gastric gland region
The body’s major digestive organ Site of nutrient absorption into the blood
Small Intestine
small intestine is a Muscular tube extending from the ____ to the ___
pyloric sphincter;
ileocecal valve
____ is Suspended from the posterior abdominal wall by the ___
small intestine; mesentery
Subdivisions of the Small Intestine (3)
Duodenum;
Jejunum;
Ileum
Attached to the stomach
Curves around the head of the pancreas
Duodenum
Attaches anteriorly to the duodenum
Jejunum
Extends from jejunum to large intestine
Ileum
Source of enzymes that are mixed with chyme for chemical digestion in s. intestine
Intestinal cells
Pancreas
Bile enters from the ____
gall bladder
Fingerlike
structures formed
by the mucosa
Give the small
intestine more
surface area
vili (s. intestine)
Small projections of the
plasma membrane
Found on absorptive cells
Microvilli (s. intestine)
Structures Involved in Absorption of Nutrients (3):
__
__
__- specialized
lymphatic capillaries
Absorptive cells
Blood capillaries
Lacteals
Folds of the Small Intestine
circular folds or plicae circulares
Deep folds of the mucosa and
submucosa
Do not disappear when filled with food
circular folds or plicae circulares
The submucosa has ____
(collections of lymphatic tissue
Peyer’s patches
Larger in diameter, but shorter; Frames the internal abdomen
large intestine
Functions of the Large Intestine (4)
water absorption
Eliminates indigestible food from the body as feces
Does not participate in digestion of food
produce mucus to act as a
lubricant (Goblet cells)
Structures of the Large Intestine (5)
Cecum;
Appendix;
Colon;
Rectum
Anus
–saclike first part of the large
intestine
Cecum
Hangs from the cecum
Appendix
Accumulation of lymphatic tissue that sometimes becomes inflamed
(___)
appendicitis
Colon (4)
Ascending
Transverse
Descending
S-shaped sigmoidal
– external body opening
Anus
Modifications to the Muscularis
Externa in the Large Intestine:
Smooth muscle is reduced to ___
____ have some degree of tone
Walls are formed into pocketlike sacs
called ___
three bands (teniae coli);
Muscle bands;
haustra
