Chapter 2. Gastrointestinal System Flashcards
- Tongue has what bony attachments?
- attached to the floor of the mouth by frenulum.
- (styloid process, hyoid bone)
- Frenulum
- Mechanical breakdown, plus WHAT chemical secretion?
- does hydrolysis of starch and glycogen into maltose.
- ptyalin, enzyme in saliva
- Saliva amylase
How long is the esophagus?
Food moves thru esophagus by?
10” long
Peristalsis
- This guardes the stomach entrance from esophagus.
- Surface area increased by what, which serves as temporary store for food?
- These are recognised as distinct regions of the stomach?
- Cardioesophageal sphincter
- Rugae
- Fundus, body and pylorus
- Lubricant, protects surface from acid.
- Vitamin B12 absorption (in small intestine ilium).
- Kills bacteria, breaks down food, converts pepsinogen.
- Broken down to pepsin (a protease)
- Stimulates acid secretion (in response protein)
Mucus- Mucus cell Intrinsic factor- Parietal cell Acid (H+)- parietal cell Pepsinogen- Chief cell Gastrin- G cell
- Gastric acid secretion mechanism.
- The caudad region of stomach contract to propel food into the duodenum. The rate of gastric emptying time is fastest if gastric content is isotonic. Fat inhibits gastric emptying time (i.e. increase gastric emptying time
-IntheparietalcellsCO andHOareconvertedH+andHCO- 223
catalyzed by carbonic anhydrase. The parietal cells secrete HCl into the lumen and absorb HCO3- into the blood stream.
-Gastric emptying time.
Gastric acid stimulations. Gastric acid production is stimulated by three mechanisms.
Vagal stimulation. V nerve innervates p. cells and stimz H+ secre.
Histamine release. H released from mast cells in gastric mucosa and diffuses to parietal cells, secrete H+
Gastrin release: response to eating (protein), stim. p. cells to sec. H+
Small intestine parts and length
Duodenum: 1st part of s.i., C-shaped 10” (inch) long and curves around the head of pancreas and entry of common bile duct.
Jejunum: 8 to10 feet long.
Ileum: 12 feet long. Towards end of s.i.
- Highest drug absorption
- A large glandular organ attached near the stomach and enz helps in carb digestion
- Bile secretions are?
Duodenum
- Pancreas- secretes intestinal enzymes (pancreatic lipase, amylase, protease),
- Bile secretions are bile salts, bilirubin, phospholipids, and cholesterol.
The majority of food absorption takes place here. Define secretions.
Jejunum
• Secretin stim. pancreas to prod. watery fluid, high in bicarb conc
• Pancreozymin stim. pancreas to prod. a viscous fluid low in bicarb conc
This is also known as the large intestines.
Consists of what bacteria and what vitamin does it produce?
• Colon consists of higher flora and fauna in GI tract 90 to 99% anaerobic bacteria. Example B.
fragilis and C. difficle anaerobic and aerobic E. coli.
• Vitamin K2 (menaquinone).
What causes the ff:
-Oral thrush
• Gingivitis (gum inflammation)
- C albicans and moniliasis
- Fusobacterium sp
This is reflux of gastric acid contents into esophagus, heartburn, or regurgitation. Common and extra esophageal symptoms?
Gastro esophageal reflux disease (GERD)
Extra esophageal symp: cough, laryngitis and asthmatic syndrome
Common: heartburn, regurgitation of acid or bile and hyper salivation
What causes: Gastritis and peptic and duodenal ulcer
- Gastritis: NSAIDs, cigarette smoking, heavy alcohol
- PU/DU: Helicobacter pylori and NSAIDs
Diseases of the stomach.
Gastritis (inflammation of gastric or stomach lining) and heavy alc.
• Gastroenteritis: Inflamm of entire GI tract
• Peptic ulcer