Ch. 23- The Digestive System Flashcards
Selective intake of food
Ingestion
Mechanical and biochemical breakdown of food into a form usable by the body
Digestion
Uptake of nutrient molecules into the epithelial cells of the digestive tract, and then into the blood or lymph
Adsorption
Elimination of undigested residue
Defecation
What are the major functions of the omentum?
Fat deposition, immune contribution, infection and would isolation
Milky spots in the omentum indicate what?
Macrophage collection
How many permanent teeth do you have?
32
How many deciduous teeth are there?
20
What are the 3 glands outside the oral cavity?
Submandibular, parotid, and sublingual
Intrinsic salivary glands are also called…
Buccal glands
Most saliva is produced by…
The extrinsic salivary glands
How much saliva is produced per day?
1-1.5 liters
What two nerves make up the autonomic innervation present with the salivary glands?
Facial and glossopharyngeal
What is another word for swallowing?
Deglutition
The vagus nerve is…
Parasympathetic
The celiac ganglia is…
Sympathetic
Peristalsis is…
A wave of muscular contraction
What is the celiac ganglia?
Two, large irregularly shaped masses of nerve tissue in the upper abdomen. They innervate most of the digestive tract
Where does protein digestion begin?
In the stomach
What do the parietal cells secrete?
HCL and intrinsic factor
How many liters of gastric juice is produced daily by the gastric glands?
2-3 liters
What is gastric juice composed of?
Water, HCL and pepsin
What is the purpose of the intrinsic factor?
It is required for vitamin B12 absorption and hemoglobin synthesis
What is a gastric secretion stimulated by?
Acetylcholine, histamine, and gastrin
Acetylcholine, histamine and gastrin all cause the production of ________, ______________ and ___________
HCL, intrinsic factor, and pepsinogen
The ________________ is active during the receptive relaxation of the stomach in response to swallowing of food
Vagovagal reflex
The vagovagal reflex allows for…
Large amounts of food in the gastrointestinal tracts
Provides motor innervation to both layers and secretomotor innervation to the mucosa, having both parasympathetic and sympathetic input
Auerbach’s plexus (myenteric plexus)
What is found in the muscles of the esophagus, stomach and intestine?
Auerbach’s plexus
The major nerve supply to the gastrointestinal tract and controls GI tract motility
Auerbach’s plexus (myenteric plexus)
What do chief cells secrete?
Pepsinogen
Stimulates gastric glands to secrete HCl and other enzymes; stimulates intestinal motility; relaxes iliocecal nerves
Gastrin
Gastrin is what kind of secretion?
Paracrine
Stimulates gastric motility
Serotonin
Stimulates HCl secretion
Histamine
Inhibits gastric secretion and motility, delays emptying stomach, inhibits secretion by pancreas, inhibits gall bladder contraction and secretion, reduces blood circulation and nutrient absorption in small intestine
Somatostatin
What is required to emulsify fat?
Bile
What makes up the hepatic triad?
Hepatic portal vein, hepatic artery, bile ductule
Which organ produces bile?
The liver
Where is bile stored?
The gallbladder
What does bile do?
Breaks up fats into smaller particles that are more accessible to digestive enzymes
Liver produces about ________ ml of bile per day
500-1000ml
Only these two parts of bile function in digestion
Bile salts and phospholipids
This is produced by intestinal cells and causes release of bile
Secretin
What is the major stimulus for contracting the gallbladder?
Cholecystokinin
What relaxes the hepatopancreatic sphincter??
Cholecystokinin
Where is protein digestion completed?
Small intestine
What is the function of pancreatic proteases?
Digest proteins and peptide
What are the pancreatic proteases?
Trypsin, chymotrypsin, carboxypeptidase
Digests carbohydrates
Amylases
Digests lipids and fats
Lipases
Digests nucleic acids, DNA and RNA
Nucleases
What are the hormones produced by the pancreas?
Somatostatin, glucagon, insulin
Under sympathetic control, inhibits gastric secretion, motility, and emptying
Somatostatin
Raises blood glucose levels
Glucagon
Transport glucose to cells, lowers blood glucose levels
Insulin
Beta cells produce…
Insulin
Alpha cells produce…
Glucagon
This structure absorbs and transports fats
Lacteal
Fat droplets are processed into…
Micelles
Micelles are rearranged into __________ and these can be absorbed by _________
Chylomicrons; lacteals
Because the tenia coli is shorter than the length of the large intestine, these pouches are created.
Haustra
Haustral contractions are slow or fast?
Slow
Activates small intestine motility
Gastroileal reflex
Activates propulsive colon contraction
Gastrocolic reflex
What reflex moves content from one haustra to the next?
Gastrocolic reflex
Defecation is a __________ process
Parasympathetic