human nutrition ch03
the stomach empties in about ____ hours depending on the contents and size of the meal..
1-4
an estimated __-__% of adults have IBS characterized by a combination of bloating, abdominal pain, and irregular bowel function.
10-15
***prompt treatment of dehydration--within __ to __ hours--is critical, especially for infants and older adults.
24-48
The high-energy compound generated by the metabolism of carbohydrates, fats, and proteins in the cells
ATP
directions for making substances the cell needs, like proteins. a double strand of nitrogenous bases that are arranged in a very specific sequence. it is packaged as structures called chromosomes.
DNA
the main sites in the body used for digestion and absorption of nutrients. it consists of the mouth, esophagus, stomach, small intestine, large intestine, rectum, anus.
GI tract
Depression and stress likely contribute to the development of
IBS
What is an exocrine role of the pancreas?
Production of amylase
the turnover of many cells of the immune system is quite rapid--only:
a few hours or days.
celiac disease depends on 2 factors:
a genetic predisposition and dietary exposure to gluten (a type of protein found in certain grains)
How is the stomach lining protected by the stomach's acidic environment?
a mucus lining
important for supplying fuel for the brain. the brain can use other energy sources but generally relies on ___.
a regular supply of carbs in the form of glucose.
Which of the following are roles of the endocrine system? a. Plays a major role in the regulation of metabolism b. Produces hormones c. Converts beta-carotene to vitamin C d. Maintains water balance
a, b, d
also known as enterocytes; the intestinal cells that line the villi and participate in nutrient absorption
absorptive cells
The _____ in gastric juice destroys the biological activity of proteins, converts inactive digestive enzymes to their active form, partially digests food protein, and makes dietary minerals soluble so that they can be absorbed.
acid
Nutrients move from an area of lower concentration to an area of higher concentration, which requires both a carrier protein and energy.
active absorption
causes hemorrhoids
added stress to vessels from pregnancy, obesity, prolonged sitting, violent coughing or sneezing, straining during bowel movements
causes of IBS
alterations in some hormones that regulate movement of food matter. inflammatory responses in GI tract could be involved for some ppl. alterations in activity of gut microorganisms.
the anus contains two __ __ (internal and external), one of which in under voluntary control (external). relaxation of this one allows elimination.
anal sphincters
Regular use of ______ may cause constipation.
antacids. iron supplements. calcium supplements.
nutrition and lifestyle recommendations for care of heartburn and peptic ulcers:
avoid smoking. avoid large doses of aspirin, ibuprofen, and other NSAID compounds. achieve or maintain a healthy body weight. eat small, low-fat meals. limit alcohol consumption. limit consumption of caffeine. consume a nutritional complete diet with adequate fiber. avoid foods that worsen symptoms: acidic, spiced, foods that relax LES, carbonated, onions and garlic. avoid tight-fitting clothes. elevate the head of the bed 6 to 8 in. avoid eating at least 3 to 4 hours before lying down. wash hands often and follow safety food guidelines.
a base that neutralizes the acidic chyme as it moves from the stomach into the duodenum
bicarbonate
neutralizes stomach acids when it reaches the small intestine
bicarbonate
the strains of __ and __ are typically associated with health, whereas __ are considered problematic.
bifidobacteria and lactobacilli. clostridia
One substance that aids the digestion and absorption of fat using bile acids, cholesterol, and phospholipids in the small intestine is __. it is produced in the liver.
bile
The liver secretes unwanted substances from the blood by adding them to _____.
bile
suspends lipids in the watery chyme in the small intestine so that lipids can be more easily digested by lipase enzymes.
bile
skin secretes
calcitriol
is needed for the release of neurotransmitters from neurons.
calcium
small intestine absorbs:
calcium, magnesium, iron, and other minerals. glucose. amino acids. fats. vitamins. water (70-90% of total). alcohol (80% of total). bile acids.
The exchange of nutrients, oxygen, and waste products between the blood and the cells throughout the body occurs across the cells lining the
capillaries
poorly digested ___ are a prime suspect of IBS
carbs
what yields energy?
carbs, fat, protein
major components: heart, blood vessels, and blood. functions: carries blood and regulates blood supply. transports nutrients, waste products, hormones, and gases throughout body. regulates blood pressure.
cardiovascular system
As food passes from the small intestine through the ileocecal sphincter, it first enters the part of the large intestine known as the
cecum
the large intestine can be subdivided into 5 main segments:
cecum, ascending colon, transverse colon, descending colon, and sigmoid colon.
what's the basic structural and functional component of life? it is a self-contained, living entity, specialized to perform particular functions.
cell
what is not an organelle, but holds the cellular contents together and regulates the flow of substances into and out of the cell?
cell membrane
with he exception of RBCs, all cells have one or more ____. it is surrounded by its own double membrane. its role is to store and protect the cell's "code book" of direction for making substances (i.e. proteins) the cells needs. these directions exist in the form of DNa
cell nuclei
___-__-___ communication occurs by way of the cell membrane.
cell-to-cell
small intestine cells, brain secrete __.
cholecystokinin.
Partially digested, semiliquid food mixed with digestive enzymes and acids in the stomach. made in stomach.
chyme
energy metabolism begins in the ___ with the initial breakdown of ___.
cytoplasm. glucose.
the goal of nutrition therapy for diarrhea is to prevent ___. increasing water and ___ intake is the first line of defense.
dehydration. electrolyte.
stimulate production and/or release of acid, enzymes, bile, and bicarbonate. help regulate movement of food matter through the GI tract
digestive hormones
major components: mouth, esophagus, stomach, intestines, accessory organs like liver, gallbladder, pancreas. functions: performs the mechanical and chemical processes of digestions of food, absorption of nutrients, and elimination of wastes. assists the immune system by destroying some pathogens and forming a barrier against foreign materials
digestive system
causes of constipation:
disorders of nervous system or muscular function. a physical obstruction in GI tract. a side affect of certain medications or dietary supplements.
the three parts of the small intestine are the __ (first 10 in), __(second 4 feet), and the __(last 5 feet). __ of the digestion and absorption of food occurs in the small intestine.
duodenum, jejunum, ileum. most.
sodium and potassium are called ____ because they can conduct an electrical current when they are dissolved in water. as a neuron responds to a stimulus, these ___ minerals facilitate the transmission of an electrical impulse along the neuron.
electrolytes
major components:endocrine glands, such as the pituitary, thyroid, and adrenal glands; hypothalamus; and pancreas. functions: regulates metabolism, growth, reproduction, and many other functions by producing and releasing hormones.
endocrine system
***a continual recycling of compounds such as bile acids between the small intestine and the liver via the portal vein.
enterohepatic circulation
some proteins function as ___, which regulate chemical reactions.
enzymes
near the pharynx is a flap of tissue, __, that prevents __ of swallowed food from entering the __.
epiglottis. bolus. trachea.
arenal glands secrete __, which:
epinephrine, norepinephrine. increased body metabolism and blood glucose.
primary risk of ulcer
erode entirely through stomach or intestinal wall --> massive infection. may cause damage to a blood vessel, leading to blood loss.
major risk of untreated GERD is
esophageal cancer
a long tube that connects the ___ with the stomach
esophagus. pharynx.
nutrients that are important for the health of the immune system include:
essential fatty acids, vit A, vit C, vit D, some vit B, iron, copper, zinc
nutrients move from an area of higher concentration to one or lower concentration with the aid of a carrier.
facilitated diffusion
the lymphatic system transports ___-soluble nutrients.
fat
the gallbladder receives a hormonal signal to release bile, which is induced by the presence of ___ in the small intestine. bile is released and delivered to the ___ via a tube called the __ __.
fat. duodenum. bile duct.
components of the bile enable large portions of ___ to break into smaller bits so that they can be suspended in ___.
fat. water.
what are some examples of nutrients that move down a concentration gradient to be absorbed by passive diffusion?
fats, water, and some minerals
in CD, the autoimmune response that occurs after exposure to gluten targets the cells of the small intestines, causing a __ of the villi, which thereby reduces the absorptive surface. the production of some digestive enzymes is decreased, and the ability of the small intestine to absorb nutrients is impaired. malabsorption leads to diarrhea, bloating, cramps, flatulence.
flattening
additional __ should be consumed to facilitate fiber's action in the large intestine
fluid
bile is produced by the liver and stored in the
gallbladder
The sphincter separating the esophagus and the stomach is called the LES, cardiac sphincter, and the
gastroesophageal sphincter
a segment of DNA on a chromosome that codes for a specific protein
gene
stomach cells secrete __, which:
ghelin. increases food intake.
a hormone made by the pancreas that stimulates the breakdown of glycogen in the liver into glucose; this ends up increasing blood glucose. it also increases the generation go glucose from non-carb substances. released when blood glucose is lower than normal.
glucagon
during times of fasting, the kidneys produce ___ from certain amino acids.
glucose
pituitary gland secretes __, which:
growth hormone. promotion of amino acid uptake by cells, increased blood glucose.
Compared to the small intestine, the large intestine
houses more bacteria. absorbs fewer nutrients.
stomach produces
hydrochloric acid and intrinsic factor
phagocytosis and pinocytosis are used when an infant absorbs ___ ___ from human milk.
immune substances.
in developing nations, where food shortages are common, malnutrition ___ susceptibility to infectious diseases, such as diarrheal disease.
increases
safe and effective strategies for treating mild cases of constipation
increasing dietary intakes of fiber and fluid
two chief culprits of peptic ulcer disease are
infection of stomach by the acid-resistant bacteria H. pylori and heavy use of medication that impair mucus production by stomach. conditions that cause excessive stomach acid also play a role. cigarette smoking.
a hormone produced by the pancreas. it allows for the movement of glucose from the blood into body cells and signals the synthesis of glycogen. released when blood glucose rises above normal.
insulin
pancreas secretes
insulin (decreases blood glucose) and glucagon (increases blood glucose)
as a gland of the endocrine system, the pancreas manufactures hormones--__ and __--that are secreted into the blood to regulate blood glucose levels.
insulin and glucagon
major components: skin, hair, nails, and sweat glands. functions: protects the body. regulates body temperature. prevents water loss. produces vitamin D.
integumentary system
attacks due to gallstones are characterized by:
intermittent pain the upper right abdomen, gas and bloating, nausea or vomiting
facilitates absorption of vitamin B-12 in the small intestine
intrinsic factor
symptoms of hemorrhoids
itching, swelling, irritation, pain, bleeding, sensation of mass in anal canal.
***the lymphatic vessels that serve the GI tract are specifically known as ___. besides contributing to the defense of the body against invading pathogens, they play an important role in nutrition. most dietary fats are too large to enter the capillaries that surround the cardiovascular system. instead, most dietary fats enter the ___ and travel through the lymphatic system until lymph is emptied into the bloodstream by a duct near the heart.
lacteals.
Which digestive organ has no villi or digestive enzymes, has a number of mucus-producing cells, and absorbs water, some vitamins, some fatty acids, and the minerals sodium and potassium?
large intestine
fat tissue secretes __, which:
leptin. decreases food intake.
pancreas produces
lipase, amylase, protease, and bicarbonate
accessory organs to digestion:
liver, gallbladder, and pancreas
What must be absorbed into the lymphatic vessels before entering general circulation?
long-chain fatty acids. fat-soluble vitamins.
The function of the _____ is to prevent the acidic contents of the stomach from flowing back up into the esophagus.
lower esophageal sphincter
Large dietary fats are absorbed from the small intestine into the
lymph
major lymphatic components: lymph, lymphocytes, lymphatic vessels, and lymph nodes. major immune components: white blood cells, lymph vessels and nodes, spleen, thymus gland, and other lymph tissues. lymphatic functions: removes foreign substances from blood and lymph. maintains tissue fluid balance. aids fat absorption. immune functions: provides defense against pathogens. formation of white blood cells.
lymphatic system
The mixing of food by muscular contractions is an example of
mechanical digestion
what are the common features of a cell in a human body?
membranes, cytoplasm, organelles that perform specialized functions
endocrine system plays a major role in the regulation of ____, ____, ____ ____, and many other functions through the action of ____.
metabolism, reproduction, water balance, hormones
The role of beneficial bacteria in the large intestine is to
metabolize undigested food
IBS may lead to changes in the ___
microbiota
extensive folds on the mucosal surface of the absorptive cells
microvilli
The combined surface area of the _____ increase the surface area for nutrient absorption in the small intestine.
microvilli, folds of the mucosa, villi
sometimes called the "power plants" or the "powerhouse" of the cell. these organelles are largely responsible for converting the chemical energy in carbs, lipids, proteins, and alcohol from foods and drinks into a form of energy that cells can use. except for RBCs, all cells contain them.
mitochondria
mucus is produced in the...
mouth, esophagus, stomach, intestines.
enzymes are produced in the
mouth, stomach, small intestine, pancreas
another component of saliva, is a lubricant that makes it easier to swallow a mouthful of food.
mucus
major components: smooth, cardiac, and skeletal muscle. functions: produces body movement, heartbeat, and body heat. propels food in the digestive tract. maintains posture.
muscular system
some laxatives work by irritating the intestinal ___ junctions to stimulate peristalsis, while others that contain fiber draw water into he intestine to enlarge fecal output. ___ are the safest, they are bulk-forming fiber laxatives.
nerve. psyllium
major components: brain, spinal cord, nerves, and sensory receptors. functions: detects and interprets sensation. controls movements, physiological, and intellectual functions.
nervous system
medications for painful inflammatory conditions such as arthritis. aspirin, ibuprofen, and naproxen are common. reduce mucus secreted by stomach.
non steroidal anti-inflammatory drugs (NSAIDs)
disease precipitated by the ingestion of gluten in people who do not have celiac disease. also called gluten sensitivity or gluten intolerance.
noncebiac wheat sensitivity (NCWS)
stomach size varies and can be reduced surgically as a radical treatment for
obesity
together with the lungs, the kidneys also maintain the ___ ___ of the blood. the kidneys contribute to bone health because they convert a form of vitamin ___ into its active hormone form. the kidneys also produce a hormone that stimulates ____ ___ ___ synthesis.
pH balance. D. RBC.
bicarbonate is produced by the
pancreas and small intestine
nutrients move from an area of higher concentration to one or lower concentration without the aid of a carrier.
passive diffusion
a coordinated muscular contraction used to propel food down the GI tract.
peristalsis
fiber stimulates __ by drawing water into the large intestine and helping to form a bulky, soft fecal output.
peristalsis
a process in which a cell forms an indentation and fluid enters the indentation and is engulfed by the cell
pinocytosis
substances that increase growth of probiotic microorganisms
prebiotic
live organisms that, when administered in adequate amounts, confer health benefits not he host. once consumed, they take up residence in the large intestine and confer health benefits.
probiotics
an enzyme that breaks down the bonds in protein
protease
a deficiency of these 3 things is likely to impair immune function.
protein, zinc, vitamin A
After a meal, chyme moves from the stomach, through the __ __, and into the small intestine one teaspoon at a time.
pyloric sphincter
nervous system: the body has many ____ that receive info what what's happening within the body and in outside environment. for most part, these receptors are found in our eyes, ears, skin, nose, and stomach. we act on info from these receptors via the nervous system.
receptors
stool remains in the __ until muscular movements push it into the __ to be eliminated.
rectum. anus.
main function of kidneys is to do what? the kidneys are constantly filtering blood to control its ____. this results in the formation of urine, which is composed of what?
remove waste from the body. composition. water, dissolved waste products of metabolism--urea, and excess or unneeded water-soluble vitamins and various minerals.
major components: gonads, genitals, and breasts. functions: performs the processes of sexual maturation and reproduction. influences sexual functions and behaviors. produces human milk to nourish an infants.
reproductive system
major components: lungs and respiratory passages. functions: exchanges gases between the blood and the air. regulates blood acid-base (pH) balance.
respiratory system
virus or bacteria that cause diarrhea produce substances that cause the intestinal cells to ____ fluid rather than absorb fluid. another form of diarrhea can be caused by consumption of substances that are not readily absorbed or large amount of high-fiber source such as bran.
secrete
major components: bones, cartilage, ligaments, and joints. functions: protects organs. supports body weight. allows body movement. produces blood cells. stores minerals.
skeletal system
the __ __ ___ __ support the immune system by forming an important barrier against invading microorganisms. if either of the barriers is compromised, microorganisms can invade the body and cause illness. substances secreted by these places can also destroy pathogens.
skin and intestinal cells
large intestine absorbs:
sodium, potassium, some fatty acids, gases, water (10-30% of total)
As a signal is transmitted along a neuron, there is a change in concentration of ____ and ___ from the neuron.
sodium. potassium.
transmission of signal (nerve impulse) occurs by way of a change in the concentrations of two minerals, ___ and ___, across the cell membrane of a neuron.
sodium. potassium.
what are released by the liver and eventually into the small intestine?
some waste products. bile.
***saliva contains a ___-digesting enzyme, ___ ___ and a ___-digesting enzyme, ___.
starch. salivary amylase. fat. lipase.
Very little nutrient absorption occurs here except for some water and alcohol.
stomach
intrinsic factor is produced in the
stomach
stomach can hold about __ cups of food for several hours.
stomach
what absorbs: alcohol (20% of total) water (minor amount)
stomach
symptoms of a peptic ulcer
stomach pain 2 hrs after eating. weight loss, lack of appetite, nausea, vomiting, bloating.
digestive hormones are produced by the
stomach, small intestine, pancreas
***how do you manage Celiac disease?
strict dietary avoidance of food products containing wheat, rye, and barley.
active diffusion can be used to go against the concentration gradient. some ___, such as __, are actively absorbed, as are amino acids
sugars. glucose
most common method for treating gallstones is
surgical removal of gallbladder
The endocrine system is related to nutrition through
the effects of hormones on appetite and blood glucose regulation
produce most of the digestive enzymes, however, the mouth and stomach also contribute their own enzymes to the process of digestion.
the pancreas and small intestine
thyroid gland secretes __, which:
thyroid hormones. increased oxygen consumption, overall growth, development of the nervous system.
collections of cells adapted to perform a specific function.
tissues
T/F: Phospholipids form a double membrane, with their water-soluble heads on the exterior and their fat-soluble tails in the interior.
true
When gallstones block the duct that carries bile from the gallbladder to the small intestine, a person usually experiences pain in the
upper right abdomen
each kidney is connected the the bladder by a ___. the bladder is emptied by way of the ___.
ureter. urethra.
major components: kidneys, urinary bladder, and the ducts that carry urine. functions: removes waste products from the blood and forms urine. regulates blood acid-base (pH) balance, overall chemical balance, and water balance.
urinary system
fingerlike protrusions into the small intestine that participate in digestion and absorption of food
villi
most cases of diarrhea are of short duration and result from __ or __ infections.
viral or bacterial
plays a role in the formation of the myelin sheath, which provides insulation around specific parts of most neurons.
vitamin B-12
as an organ of the digestive system, the pancreas produces "pancreatic juice," a mixture of: capable of breaking apart: into small fragments.
water, bicarbonate, a variety of digestive enzymes. carbs, proteins, and fats.
What type of nutrients are absorbed into the hepatic portal vein and eventually to the liver before they enter the general circulation?
water-soluble compounds
once absorbed, ___-soluble compounds such as glucose and amino acids are transported by the ___ to the ___ ___ vein, which leads directly to the liver.
water. capillaries. hepatic portal.
endocrine system: ___ lymphatic system: ___
water. fat.
what remains in the feces, besides ___ and undigested ___, is tough connective tissues; bacteria from the large intestine; and some body wastes, such as parts of dead intestinal cells.
water. fiber.
what grains are not gluten free?
wheat, rye, barley, bran, graham flour, semolina, spelt, and malt
what are excellent sources of fiber?
whole grain breads and cereals, beans, and dried fruits.
