Lec 23- Digestive System and Fuel Metabolism; Pancreas Flashcards
Carbohydrate
Turn into monosaccharides (primarily glucose).
Monosaccharide
“one sugar” molecules.
Primarily glucose in the body.
Polysaccharide
Simple sugars linked together in chains.
Sucrose and lactose.
Glucose
Monosaccharide
FA - fatty acid
used for energy or stored as triacylglycarides
Monoglycerides
A fat
Ketone bodies
A fat. Are the breakdown products of fatty acids.
Liver convert fatty acids to ketone bodies, which are released into the bloodstream.
Used for energy or stored as triacylglycerides.
Acetacetic acid
FIND
Acetone
FIND
Ketoacidosis
Common in Type I diabetes; rare in Type II diabetes.
Proteins
Break down into amino acids for the body
Amino acids
- new protein synthesis
- excess converted to acetyl-CoA -> FA’s
- In liver, can be converted to glucose -> for energy or storage as glycogen, or triacylglycerides for storage.
Motility
Refers to the digestive tract’s muscular contractions, of which there are two basic types; propulsive movements and mixing movements.
Ingestion
Taking in food?
Mastication
chewing
Deglutition
The action or process of swallowing
Peristalsis
refers to ringlike contractions if the circular smooth muscle that move progressively forward, pushing the bolus into a relaxed area ahead if the contraction.
Secretion
Juices secreted by the stomach to help with digestion.
Exocrine
Glands that secrete through ducts to the outside of the body or into a cavity that communicates with the outside.
Endocrine
FIND
Absorption
The transfer of digested nutrients and ingested liquids from the digestive tract lumen into the blood or lymph.
Esophagus
A straight muscular tube that extends between the pharynx and the stomach.
Salivary gland
exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual) as well as hundreds of minor salivary glands. Salivary glands can be classified as serous, mucous or seromucous (mixed).
Liver
Secretes bile.
Bile salts facilitate fat digestion and absorption in the duodenal lumen.
Gallbladder
Stores bile between meals.
Pancreas
Exocrine pancreas secretes digestive enzymes which accomplish digestion in the duodenal luman.
Gastroesophageal sphincter AKA cardiac sphincter
The lower esophageal sphincter (LES) is a bundle of muscles at the low end of the esophagus, where it meets the stomach. When the LES is closed, it prevents acid and stomach contents from traveling backwards from the stomach.
Chyme
Ingested food mixed with gastric secretions.
G cells
Secrete gastrin. Stimulated by protein products and ACh.
Gastrin
Secreted by G cells.
Stimulates the parietal and chief cells, promoting secretion of a highly acidic gastric juice.
Chief cells
Secretes pepsinogen. Stimulated by ACh and gastrin.
Pepsinogen
Once activated, begins protein digestion.
ECL - enterochromaffin - like Cells
secrete the paracrine histamine.
HCl - hydrochloric acid
Parietal cells secrete HCl. Does not digest anything. Activates the enzyme precursor for pepsinogen. Denatures proteins. Kills microorganisms.
D cells
Secretes Somatostatin.
Stimulated by Acid.
Somatostatin
inhibitory effects, gastric secretion declines.
Mucus
Protects stomach from eating itself.
Prostaglandins
Local chemical mediators that are derived from a component of the plasma membrane, arachidonic acid.
NSAID - non-steroidal Anti-inflammatory drug
PG blockers. Can cause ulcers.
Peptic ulcers
When the gastric mucosal barrier is broken and the gastric wall is injured by its acidic and enzymatic contents.
Helicobactor pylori
The bacterium most responsible for peptic ulcers.
Acute gastritis
Acute gastritis is a sudden inflammation or swelling in the lining of the stomach. Gastritis only directly affects the stomach, while gastroenteritis affects both the stomach and the intestines. The most common causes of acute gastritis are nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids.
Pyloric sphincter
The juncture between the stomach and the duodenum.
Duodenum
First part of the small intestine.
Most absorption and digestion takes place.
Secretin
A hormone released from the duodenal mucosa primarily in response to the presence of acid; inhibits gastric motility and secretion and stimulates secretion of NaHCO3 solution from the pancreas and liver.
CCK
A hormone released form the duodenal mucosa primarily in response to the presence of fat; inhibits gastric motility and secretion, stimulates pancreatic enzyme secretion, stimulates gallbladder contraction, and acts as a satiety signal.
Zymogen granules
Most pancreatic enzymes are produces in inactive form zymogens. Tripsin activates other zymogens.
Acinar cells
Stimulated by CCK.
Increases secretion of pancreatic digestive enzymes into duodenal lumen. Which leads to the digestion of fat and proteins products in the duodenal lumen.
Zymogen
Most pancreatic enzymes are produces in inactive form zymogens. Tripsin activates other zymogens.
Enterohepatic circulation
The recycling of bile salts and other bile constituents between the small intestine and liver by means of the hepatic portal vein.
Bile
An alkaline solution containing bile salts and bilirubin secreted by the liver, stores in the gallbladder, and emptied into the small intestine lumen.
Emulsify
make into or become an emulsion
Chylomicrons
Large, coated fat droplets.
Large intestine
Colon; basically stores stool before in needs to be excreted.
Osmotic diarrhea
increase undigested solutes
Secretory diarrhea
lot of fluid secreted by cells in walls of large intestine (Cl- + Na+ + H2O)
The amount is increased by mechanical irritation or by bacterial toxins i.e. cholera. As a result in loss of fluid can cause 1. decrease in electrolytes.
2. acidosis.
3. dehydration.
Metabolic rate
MR. is total rate of body metabolism = amount of O2 consumed by body/min
BMR - basal metabolic rate
Is MR of awake relaxed person 12-14 hrs after eating and at a comfortable temperature.
Assessing what is the baseline amount of energy that the person is using.
Metabolism
All chemical reactions in the body.
Anabolism/anabolic
Synthesis and energy storage reactions.
Catabolism/catabolic
energy liberating reactions
Absorptive state
4 hours period after eating.
Energy substrates from digestion are used and deposited in storage forms (anabolism)
Postabsorptive (fasting) state
follows absorptive state,
Energy is withdrawn from storage (catabolism)
Insulin
Insulin is a hormone made by the pancreas that allows your body to use sugar (glucose) from carbohydrates in the food that you eat for energy or to store glucose for future use. Insulin helps keeps your blood sugar level from getting too high (hyperglycemia) or too low (hypoglycemia).
Glucagon
Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It works to raise the concentration of glucose and fatty acids in the bloodstream, and is considered to be the main catabolic hormone of the body.
a cells
produce glucagon
b cells
site of insulin synthesis and secretion
Diabetes mellitus
Includes type I and type II
Hypoglycemia
Hypoglycemia is a condition caused by a very low level of blood sugar (glucose), your body’s main energy source. Hypoglycemia is often related to the treatment of diabetes. However, a variety of conditions — many rare — can cause low blood sugar in people without diabetes.
Type I - IDDM (insulin dependent diabetes mellitus)
accounts for 10% of diabetes cases.
Characterized by a lack of insulin secretion because of erroneous autoimmune attack against the pancreatic B cells.
Type II - NIDDM (non-insulin dependent diabetes mellitus)
insulin secretion normal. Insulin target cells are less sensitive than normal to this hormone for elusive reasons presently under intense investigation.
Diabetes Insipidus
characterized by excretion of a large amount of severely diluted urine that cant be reduced when fluid intake is reduced. Urine is NOT sweet.
Parietal cells
secrete HCl and intrinsic factor; stimulated by ACh, gastrin, and histamine.
