Digestive System Flashcards
Absorption
Movement of nutrients into the bloodstream
Ingestion
Taking in food
Defecation
Rids the body of indigestible waste
Mechanical digestion
Breaking down physically
Chemical digestion
Break down chemically
Alimentary canal (GI tract)
Continuous hollow tube that runs from mouth to anus
Accessory digestive organs
Organs that the food doesn’t directly enter but helps with digestion
Ex: liver, pancreas
Organs of the alimentary canal
Mouth to pharynx to esophagus to stomach to small intestine to large intestine to anus
Mouth anatomy: lips
Protect anterior opening
Mouth anatomy: cheeks
Form the lateral walls
Mouth anatomy: hard palate
Forms anterior roof
Mouth anatomy: soft palate
Forms posterior roof
Mouth anatomy: uvula
Fleshy projection of the soft palate
Mouth anatomy: tongue
Attached at hyoid bone and styloid processes of the skull and by the lingual frenulum to the floor of the mouth
Mouth anatomy: tonsils
Palatine lingual
Pharynx physiology
Serves as a common passageway for air and food
Pharynx physiology
Serves as a common passageway for air and food
Esophagus: Anatomy
About 10 in long
Runs from pharynx to stomach through the diaphragm
Esophagus: physiology
Conducts for peristalsis (slow rhythm squeezing)
Passageway for food only (respiratory system branches off after the pharynx)
Stomach anatomy
Located on the left side of the abdominal cavity
Food enters at the cardiac sphincter (valve)
Food empties into the small intestine at the pyloric sphincter (valve)
Regions of the stomach
Cardiac region
Fundus
Body
Pylorus
Cardiac region
near the heart
Fundus
Expanded portion lateral to the cardiac region
Body
Mid portion
Layers of peritoneum attached to the stomach
Lesser omentum
Greater omentum
Lesser omentum
Attaches to the liver to the lesser curvature
Greater omentum
Contains fat to insulate, cushion, and protect abdominal organs
Attaches the greater curvature to the posterior body wall
Has lymph nodules containing macrophages
Stomach physiology
Temporary storage tank for food Site of food breakdown Chemical breakdown of proteins begin Delivers chyme (processed food) to the small intestine
Structure of the stomach mucosa
Mucosa is simple columnar epithelium Mucous neck cells Gastric glands Chief cells Parietal cells Enteroendocrine cells
Mucosa neck cells
Produce a sticky alkaline mucus
Gastric glands
Situated in gastric pits and secrete gastric juice
Chief cells
Reduce proteins digesting enzymes (pepsinogens)
Parietal cells
Produce hydrochloric acid
Enthroned octane cells
Produce gastrin
Small intestine
The bodies major digestive organ
Site of nutrient absorption into the blood
Muscular tube extending from the pyloric sphincter to the ileocecal valve
Suspended from the posterior abdominal wall by then mesentiery
Subdivisions of the small intestine
Duodenum
Jejunum
Ileum
Duodenum
10 inches long
Attached to the stomach
Curves around a hold of the pancreas
Jejunum
8 feet long
Attaches anteriorly to the duodenum
Ileum
12 feet long
Extends from jejunum to large intestine
Chemical digestion begins in the small intestine
Enzymes are produced by intestinal cells and the pancreas
Pancreatic ducts carry enzymes to the small intestine
Bile, formed by the liver, enters via the bile duct
Small intestine anatomy
Structural modifications that increase surface area
Micro villi
Villi
Microvilli
Tiny projections of the plasma membrane (create a brush border appearance)
Villi
Fingerlike structures formed by the mucosa
Large intestine
Large in diameter, but shorter in length, then the small intestine
Frames the internal abdomen