Gastro-part 2- Exam 3 Flashcards
once a substance is eaten it must first go through the _____, what is the exception
goes to liver first
unless it is fat (fat goes to the lymph system)
In the sinusoids what is mixing?
portal vein blood and hepatic artery blood
What is the responsibility of the liver plate cells?
produce LDL, HDL and converts glucose to glycogen, coagulation
the space of disse surrounds ____
liver plate cells
space of disse empties into the ____
lymph ducts
where do the bile canaliculi empty?
empty into the bile ducts
What is the major component of the bile salt?
cholesterol
venous sinusoids are lined by ____ and ____ cells
endothelial and Kupffer cells
What is the role of the Kupffer cells?
resident phagocytes, helps filter the blood through the liver
What are the vasodilator substances that are released from the mucosa of the intestinal tract during digestion
CCK
Vasoactive instestinal peptide
gastrin
secretin
_____ and ____ are the vasodilators released from the GI glands
kallidin
Bradykinin
What are the only three things that goes through the gut and into the bloodstream are ____, ____ and _____
glucose
fructose
galactose
______ increase the surface area in the small intestine
Brush border microvilli (20x), villi (10x) on the valvulae conniventes (3x)
total surface area increases 1000X
____ are part of the lymph system that the triglycerides go into
lacteals
_____ causes the relaxes of the stomach
large quantities of food
CCK and secretin have ___ effect on the stomach? What does this cause?
increase sympathetic drive
causes a decrease in gastric emptying time
_____ is released from the chief cells. What is in inactive form?
pepsin
pepsinogen
How does pepsinogen become active?
gets activated by HCl
there is very little ____ happening in the stomach. What are the 2 exceptions?
absorption
alcohol and aspirin
what is it called when the food stretches the stomach?
vagovagal reflex: helps to accommodate larger amounts of food
What two things does parietal cells excrete?
HCl and intrinsic factor
What do pyloric glands secrete?
gastrin
What does a Vit B12 deficiency lead to ?
pernicious anemia
What are some duodenal factors that inhibit stomach emptying?
- degree of duodenal distention
- irritation of duodenal mucosa
- degree of acidity of the duodenal chyme
- degree of osmolality of the chyme
- presence of certain breakdown products in the chyme, proteins and fats**
Does the duodenum have a mucous protecting layer?
No
What 2 substances help to neutralize the pH in the duodenum?
secretin and CCK
____ and _____ are released into the bloodstream from the duodenal epithelium and then come back to the duodenum. What is the effect?
CKK and GIP (Gastric inhibitory peptide)
inhibitory hormones, makes you not want to eat
Acini cells secrete _____
bicarbonate
What are the enzymes responsible for digesting proteins?
Trypsin
Chymotrypsin
Carboxypolypeptides
What enzyme is responsible for digesting carbs?
pancreatic amylase
What enzymes are responsible for digesting fats?
pancreatic lipase
cholesterol esterase
phospholipase
What are the simple sugars?
Glucose and Fructose
______ is 1/2 of the lactose found in milk. Does it occur freely in nature?
galactose
No
_____ is the most common disaccharide
Sucrose
What is the main way carbohydrates are separated?
through the process of hydrolysis
What are the 3 main sources of CHO that exist in the normal human diet?
Sucrose
Lactose
Starches
What are the 3 intestinal epithelial enzymes located within the brush border?
lactase
sucrase
maltase
When digestion is complete, what percentage is glucose? Galactose and fructose?
80% glucose
less than 10% galactose and fructose
Do we need to know this diagram?
ask during the review
Do we need to know this diagram?
ask at the review
What is the first step in the digestion of fats?
break the fat globules into small sized so the water-soluble digestive enzymes can act on the globular surfaces
Where does the emulsification of fats occur?
in the duodenum under the influence of bile salts and lecithin (phospholipid)
What is enteric lipase?
an additonal lipase found in the small intestine
What is the end product of the digestion of fats?
free fatty acids and 2-monoglyceride
What are micelles?
Triglycerides that are broken down by lipase into fatty acids and monoglycerides. small lipids + cholesterol + vitamins = micelles
What is a chylomicron?
triglycerides are re-formed, with other fats enclosed by a membrane. coated with proteins to form a chylomicron
What is the process of digesting fats?
gallbladder- bile salts- emulsification- production of micelles- chylomicron- goes into lacteal
What are the chylomicron made of?
protein coating, phosolipids, cholesterol and triglycerides
What is the special enzyme that lines the epithelial walls?
lipoprotein lipase
What is the job of the lipoprotein lipase?
grabs chylomicrons and starts pulling out triglycerides and puts them into the cell
How are adipose tissue formed?
Chylomicron triglycerides are hydrolyzed by lipoprotein lipase to form fat, fat is stored in the adipose tissue
Do we need to know this diaphram?
Ask at the review
Where are the 2 major sites for fat deposits?
adipose tissue
liver
What makes up 80-95% of the entire cell volume in a fat cell?
triglycerides
What do cholesterol levels measure?
type, size and amount of fat that is floating around in the blood
Under what conditions will large amounts of triglycerides appear in the liver
-During the early stages of starvation
-In diabetes mellitus
-In any other condition in which fat instead of carbohydrates is being used for energy
What is a low-density lipoprotein (LDL) composed of?
LOTS of lipids compared to protein coating surrounding it
What is a high-density lipoprotein (HDL) composed of?
lots of protein coating WITHOUT that much fat
Is LDL or HDL associated with heart disease?
LDL
After all chylomicrons have been removed from the blood.More than 95% of all lipids in the plasma are in the form of _____
lipoprotein
Do we need to know this diagram?
ask during the review
What get digested in the stomach?
10-20% of the total digestion of proteins
what 2 enzymes should we associate with the microvilli brush border?
Aminopolypeptidases
Dipeptidases
