Digestive System Flashcards
What is the function of the mouth
Mastication occurs
What is the Pharynx
Passageway for food fluid and air
Nasopharynx
Passageway for air from nasal cavity
Oropharynx
Where food enters first, posterior to oral cavity
Laryngopharynx
Inferior to the oropharynx, continues to the esophagus by propulsion of peristalsis
Laryngopharynx skeletal muscles
Longitudinal outer layer
Circular inner layer
What is peristalsis
The involuntary contraction and relaxation of longitudinal and circular muscles throughout the digestive tract
What is the Esophagus
Passageway for food and fluids
What is the esophagus made of
Stratified Squamous Epithelium lining to help against friction
How does the esophagus push food into the stomach
Uses peristalsis to conduct slow rhythmic squeezing for bolus to reach stomach
What does the stomach do
Churns and chemically breaks down food into chime
Beigns Protein to amino acid breakdown
Lesser Omentum
Double layer of peritoneum, extends from liver to lesser curvature
Greater Omentum
Extension of the peritoneum
Covers, insulates, cushions and protects abdominal organs
What allows the stomach to stretch
Rugae in mucosal layer
Cardial Region
Near the heart
Surrounds cardioesophageal sphincter
Fundus region
Expanded portion
Lateral to cardiac region
Body Region
Greater curvature is the convex lateral surface
Lesser curvature is concave medial surface
Pylorus Region
Funnel-shaped terminal end
Greater and lesser curvature
What is pepsinogen
Inactive protein digesting enzyme
Secreted by chief cells
How is pepsinogen activated
HCL exposure turns pepsinogen into pepsin allowing for protein digestion
What is intrinsic factor
A substance needed for vitamin b12 absorption
Secreted by chief cells
What do parietal cells produce
Hydrochloric acid ( HCL)
What do Mucous neck cells produce
Thin acidic mucus
What do enteroendocrine cells prodcude
Gastric - regulates digestive acitivity
Where does the small intestine start
At the pyloric sphincter
Where does the small intestine end
At the ileocecal valve at the large intestine
Layers of the mucosal lining walls
Villi
Microvilli
Circular folds
Peyers patch
What does Villi contain
Contains capillary beds and lacteral
Microvilli
From the plasma membrane
Contains enzymes that complete digestion of proteins + carbohydrates
Circular folds
Increase surface area to force chyme to travel slow and allow nutrient absorption
Peyer’s Patch
Prevents food residue from causing bacterial infections
3 Segments of the small intestine
Duodenum
Jejunum
Ileum
What happens in the duodenum
Chemical digestive begins
Enzymes produced by intestinal cells + pancreas sent through pancreatic duct
Liver bile is sent through bile duct
What is hepatopancreatic ampulla
Formed by the pancreatic dict and the common bile duct that leads to the duodenum
What does Jejunum contain
All plicae circulares and villi
Absobs all the nutrients from digested (sugars, amino and fatty acids)
Ileum
Contains villi to absorb vitamin b12 and bile acids
Reabors missed nutrients by the jejunum
Compartments of the large intestine stool formation: Ascending Colon 1st Segment
Travels up right side of abdomen and turn at right colic
Formation of stool is watery, water absorption begins
Compartments of the large intestine stool formation: Transverse Colon 2nd Segment
Travels across abdominal cavity, turns at left colic
Stools have started becoming semi-solid
Compartments of the large intestine stool formation: Descending Colon 3rd segment
Travels down left side, stores feces to be sent to sigmoid colon
Stools have solidified
Compartments of the large intestine stool formation: Sigmoid Colon 4th segment
S-Shaped tube connecting from descending colon to the rectum
Muscular walls contract to assist moving feces to rectum
Compartments of the large intestine stool formation: Rectum
Temporary storage site for feces
Walls expand to hold
Rectum Spincters: Internal anal sphincter
Ensures that stools do not backflow into colons
Involuntary
Rectum Sphincters: External anal sphincter
Partners with internal sphincter to help muscle contraction to start defecation
Voluntary
Compartments of the large intestine stool formation: Anus
End of anal canal, feces released from here after defecation
Walls of digestive tract: Mucosa
Innermost layer, moist mucus that lines hollow cavity
Walls of digestive tract: Submucosa
Vascular connective tissue with blood vessels, lymphatic vessels and nerves
Contains peyer patches
Walls of digestive tract: Muscularis
Muscle layer, allows for peristalsis
Layers of the muscularis
Longitudial outer layer
Circular inner layer
Walls of digestive tract: Serosa
Covers the organs in the cavity, contains fluid producing cells
