CH. 4: Human digestion and absorption
The main function of the large intestine include what?
-houses gut microbiota that keep the GU tract healthy -absorbs water -forms and expels feces
The role of beneficial bacteria in the large intestine is to
-protect against infection -synthesize vitamins -digest and metabolize complex carbs, fibers, and starches
The largest intestine absorbs about--- percent of the water
10%
Salty foods
NaCl or KCL (potassium chloride)
Bitter
diverse compounds such as caffeine and quinine
swallowing moves from the mouth to the
esophagus
the parietal cells of the stomach secrete
hydrochloric acid
The primary function of the pyloric sphincter is to control the flow of food contents from the
stomach
digestive enzymes revery specific with regards to the
-vitamin or mineral cofactors -ph of the environment -type of chemical reaction the catalyze
Sour foods
acids such as citric acid
umani
from amino acids
the chief cells of the stomach secrete
gastric lipase
identify three organs that are important parts of the digestive system, even though they do not come in direct contact with four matter in the gastrointestinal tract.
1)liver 2)gallbladder 3)pancreas
the smallest functional unit of the body is called
a cell
How much digestive fluid (including water, acid, mucus, digestive enzymes, bile, and hormones) is secreted into the GI tract over the course of a day?
about 29 cups
prevent defecation until person desires to do so
anal sphincters
HCL destroys most harmful ---- and viruses in foods.
bacteria
The pancreatic juices are very ----- to neutralize the acidic chyme arriving from the stomach
basic, alkaline
what are some healthy bacteria that reside in the large intestine?
bifidobacteria and lactobacilli
which of the following yields energy?
carbs, protein, and fat
nutrients absorbed in the small intestine are delivered to which circulatory systems in the body?
cardiovascular or lymphatic
what is needed to facilitate active absorption?
carrier protein and ATP
What is the order in which a substance would pass through the large intestine?
cecum, ascending colon, transverse colon, descending colon, and sigmoid colon
The liquid contents of the stomach are a mixture of acid, enzymes, and partially digested food known as....
chyme
in developing countries, each year more children die from
diarrhea
In healthy individuals, the largest influence on guy microbial composition is
diet
protein molecules produced in the salivary glands stomach, pancreas, and intestine that speed up digestion by catalyzing chemical reactions are called
digestive enzymes
What are examples of organ systems? (11)
digestive, nervous, cardiovascular, endocrine, lymphatic & immune, urinary, integumentary, skeletal, muscular, respiratory, reproductive.
order of the small intestines as they appear in the GU tract
duodenum > jejunum > ileum
The gallbladder secretes bile into the duodenum and reabsorbs it in the ileum. this recycling of bile by the liver is part of the----- circulation?
enterohepatic circulation
The process of converting sugars and starches to lactic and other acids by bacteria, yeast, or fungi is called
fermentation
Sweet
from organic compounds such as sugars
control of the flow of bile and pancreatic juice from the common bile and pancreatic ducts into the small intestine
hepatopancreatic sphincter
in a ---- reaction water is used int he breaking apart of large molecules
hydrolysis
prevents the contents of the large intestine from reentering the small intestine
ileocecal valve
ghrenlins role is to
increase appetite and food intake
The villi facilitate absorption of nutrients in the small intestine by
increasing the surface area
The substance necessary for the body to absorb vitamin B-12 is...
intrinsic factor (IF)
The ---- intestine is the main site where electrolytes, especially sodium and potassium are absorbed,
large
Feces are formed in which organ
large intestine
what nutrients would be picked up into the lymphatic system?
large molecules that cannot be absorbed by the capillary beds (most fats and fat soluble vitamins)
pancreatic lipase is responsible for breaking down ---- for digestion.
lipids (fats)
prevents back flow of stomach contents into the esophagus
lower esophageal sphincter
The resident bacteria throughout the GI tract are referred to as the gut...
microbiota
what is the order of the digestive organs when they come into contact with food
mouth > esophagus > stomach > liver > gallbladder > pancreas > small intestine > large intestine > rectum
enzyme acts on --- type of chemical process
only one
secretions from the liver, pancreas, and gallbladder are delivered into the small intestine via the
pancreatic duct bile duct
Waves of muscular contractions that propel the contents of the digestive tract are called
peristalsis
A substance that serves as fuel for bacteria in the large intestine is called a
prebiotic
fermentation has traditionally been used to...
preserve food
yogurt is considered a
probiotic
---- are live microorganisms, such as lactobacilli found in yogurt and when consumed in sufficient amounts, colonize the large intestine and provide health benefits.
probiotics
control of the flow of the stomach contents into the small intestine
pyloric sphincter
lingual lipase and salivary amylase are two components of liquid called --- which is produced by glands in the mouth
saliva
The most frequent peristalsis takes place in this organ of the GI tract
small intestine
chyme is formed in the---- as food is mixed with digestive secretions.
stomach
identify structures made up of connective tissue
tendons, cartilagem parts of the bone, arteries, and veins
Absorption
the uptake of nutrients from the GI tract into either the blood or lymph
The function of the epithelial cells are to absorb nutrients, secrete important substances, excrete -----, and protect underlying tissues
waste
which of the following nutrients are absorbed in the cardiovascular system?
water soluble nutrients (proteins, crabs, b-vitamins, and vitamin c)
what dietary components are absorbed by the cells lining in the stomach?
water, a few forms of fats, and 20% of any alcohol
