Pages 51-58 Flashcards
How is the pancreas both and endocrine and exocrine gland?
Endocrine-hormones insulin and glucagon
Exocrine-digestive juice called pancreatic juice
What are acinar cells?
The cells that make up most of the pancreas and release pancreatic juice
What does pancreatic juice contain?
Enzymes needed to digest carbohydrates, fats, proteins, and nucleic acids
Function of pancreatic glucagon?
Raises blood glucose levels
Pancreatic lipase?
Breaks down triglycerides
Trypsin, chymotrypsin, and carboxypeptidase?
Digests proteins (released in inactive form)
Nucleases?
Digest nucleic acid
Bicarbonate ions function?
Make pancreatic juice alkaline to buffer stomach acid
What is the largest internal organ?
Liver
How is the liver divided?
Into four lobes
What is the functional unit of the liver?
Hepatic lobules
What are hepatic sinusoids?
Filters for blood
What are the five functions of the liver?
Carb/lipid/protein metabolism
Storage
Blood filtering
Detoxification
Secretion
What is bile?
A yellowish/greenish alkaline solution
What are bile salts?
Substance produced from cholesterol that emulsifies fats
Gall bladder?
Pear-shaped sac that stores and concentrates bile
What causes gallstones?
Excess bile concentration (Cholesterol precipitates and forms solid crystals. Those crystals enlarge.)
What are the fat soluble vitamins?
A,D,E, and K
Where does the small intestine begin and end?
Pyloric sphincter and large intestine
What occurs in the small intestine?
The majority of nutrient absorption
What are the three parts of the small intestine?
-Duodenum
-Jejunum
-Ilium
What is mesentery?
A folded membrane that attaches the intestine to the abdominal wall and holds it in place
What does the small intestine have to increase surface area?
Intestinal villi
What do the villas of the small intestine consist of/are made of?
Simple columnar epithelium
What does each epithelial cell contain in the small intestine to increase surface area?
Microvilli
What are the three enzymes do break down disaccharides?
Sucrase, maltase, and lactase
What enzyme breaks down fats?
Lipase
What are the three layers of folds in the small intestine?
-Plicae circulares
-Villi
-Microvilli
Steps to break down protein?
-Protein is broken into polypeptides by pepsin
-Pancreatic proteases break down polypeptides (and protein) into smaller peptides
-Intestinal peptidases breakdown peptides into amino acids
What are fats broken into?
Glycerol and fatty acids
What is a lacteal?
Lymphatic vessel in the small intestine
What two mechanical functions does the small intestine perform?
Peristalsis and segmentation
What causes diarrhea?
Strong peristaltic rush from small intestine because it is distended or irritated
What does the large intestine absorb?
H2O and electrolytes
What are the four layers of the large intestine?
Same as the rest of the alimentary canal
-Mucosa
-Submucosa
-Muscularis mocousa
-Serosa
What are the three functions of the large intestine?
-Absorb water
-House intestinal flora
-Form and store feces
What four components make up the large intestine?
-Cecum
-Colon
-Rectum
-Anal canal
How are the mechanical actions of the large and small intestines similar?
Both perform mixing and peristalsis just the large intestine performs these actions slower
What must relax for defecation to occur?
Internal anal sphincter
What composes feces?
Materials neither digested or absorbed
What are the 5 changes that occur in the digestive system with age?
-Teeth decay
-Peristalsis slows
-More frequent constipation
-Nutrient absorption decreases
-Slowing of gastric secretions
