chap 4 Flashcards
chemistry
the study of the composition and characteristics of matter, and changes it can undergo
principles of ___ and ____ form the foundation for the scientific study of nutrition
chemistry, human physiology
elements cannot be
separated into simpler substances by ordinary chemical or physical means
building blocks of matter
elements
___are elements found in the earths crust
minerals
chemical bond
attraction that holds atoms together to form a molecule
molecule
forms when two or more atoms interact snd are held together by a chemical bond
compound
molecule that contains two or more different elements in specific proportions
some atoms form single bonds such as
hydrogen
solution
evenly distributed mixture of two or more compounds
solution has a ____ and one or more ___ dissolved in the ____
solvent, solutes, solvent
___ is the solvent for many solutions
water
solubility
how easily a solute forms a solution when mixed with a solvent
ion
atom/group of atoms that have an electrical charge
ions form when
an atom/group of atoms gain or lose one or more electrons
electrolytes
ions of minerals that conduct electricity when they are dissolved in water
acids
substances that donate or lose H+ ions
bases
substances that accept or remove H+ ions
pH
measure of the acidity or alkalinity of a solution
substances with low pH values contain ___ H+ and are more ____
more, acidic
substances with high pH values contain ___H+ and are more ___
less, basic
pH gastric juice
1.5-3.5
pH saliva
6.3-6.6
chemical reaction
process that changes the arrangement of atoms in molecules
digestion
process by which molecules in food are mechanically and chemically broken down into smaller ones
___ is a substance that forms when an acid reacts with a base
salt
metabolism
sum of all chemical reactions that occur in living cells
catabolism
reactions that involve breaking down molecules
anabolism
reactions that involve synthesizing new compounds
enzymes
molecule that catalyzes a particular chemical reaction but is not altered during the process
enzymes are sensitive to
environmental conditions
enzymes end in
ase
sucrose is turned to glucose and fructose via
sucrase
smallest living functional unit in an organism
cell
structures in cells that have specific functions
organelles
movement of substances into and out of the cell occurs in the
plasma membrane
organization and expression of the genetic material occurs in the
nucleus
protein synthesis occurs in the
ribosome
cytoplasm contains
organelles
site of ATP synthesis
mitochondrion
tissues
masses of cells that have similar characteristics and functions
epithelial tissue
cells that line every body surface, including skin and the inside of blood vessels
connective tissue
fat, bone, blood
organ
collection of tissues that function in a related fashion
organ system
group of organs that work together for a similar purpose
homeostasis
maintenance of an internal chemical and physical environment that is critical for good health and survival
cell–>___–>___–>____
tissue, organ, system
digestive system major organs/tissues
mouth
salivary glands
esophagus
stomach
intestines
pancreas
liver
gallbladder
circulates blood through the body
cardiovascular system
arteries
carry blood away from the heart
capillaries
smallest blood vessels
veins
vessels that return blood to the heart
enables the body to exchange oxygen and CO2
respiratory
primary structure of the respiratory system
lungs
helps defend the body against disease
lymphatic system
lymphatic system includes
lymphatic vessels, lymph nodes, lymph
urinary system includes
kidneys, bladder
kidney function
filter unneeded substances from blood and maintain fluid balance
bladder function
stores urine
muscles enable
movement to occur, provide stability for the body
skeletal system includes
bones, tendons, ligaments
bones store
certain minerals, produce RBC
nervous system includes the
brain, spinal cord, nerves
the brain produces _______ and controls ____
various intellectual functions and emotional responses
many bodily functions
nervous system cells transmit info and responses via
electrical and chemical signals
endocrine system includes organs and tissues that
produce hormones
hormones
regulate a variety of physiological activities
integumentary system includes
skin, hair, nails
largest organ of the body
skin
skin protects against
minor injuries and disease-causing agents and helps maintain temperature
main function of reproductive system
produce children
digestive system primary roles
digestion, absorption
digestion
breakdown of large food molecules into smaller components
absorption
process by which substances are taken up by the GI tract and enter the blood stream or lymph
GI tract
muscular tube that extends from mouth to anus
GI tract organs
mouth, esophagus, stomach, small intestine, large intestine
nutrients already in their simplest form are not
digested
bioavailability
extent to which digestive tract absorbs nutrients and how well the body uses them
____ food can enhance absorption
cooking
digestion begins
in the mouth
mouth mechanical digestion
biting, tearing, grinding food into smaller pieces
tongue helps form a
bolus
bolus
rounded mass of chewed food
chemical digestion
chemical breakdown of foods by substances secreted into the GI tract
saliva mixes and lubricates food with the aid of
mucus
enzyme that begins starch digestion
salivary amylase
enzyme for fat
lingual lipase
taste buds
specialized sensory structures located primarily on the tongue
6 tastes
sweet, sour, salty, bitter, umami, fatty
smell contributes to the
ability to taste food
during chewing, chemicals In food become airborne and
stimulate nasal passages
what does the brain do to identify flavors
combine sensory information relayed from the mouth and nasal passages
esophagus
tube connecting pharynx to stomach
esophagus function
move a bolus from the back of the mouth, through the esophagus, and into the stomach
epiglottis
flap of tissue that folds down over larynx when you swallow to prevent food from entering the trachea
peristalsis
muscular contraction of the GI tract that moves small amounts of food and beverages through the digestive tract
stomach
muscular sac that can expand and hold food
lower esophageal sphincter
section of the esophagus next to the stomach that controls the opening to the stomach
as food enters the stomach, the ____ constricts, which
sphincter
closes off the end of the esophagus and keeps food in the stomach
gastric juice
water, HCl, enzymes
HCl makes ___ easier to digest, activates ___ and kills _____
protein, pepsin, disease-causing organisms
stomach mechanical digestion
churning of the stomach walls
stomach chemical digestion
HCl and enzymes (pepsin)
chyme
mixture of gastric juice and partially digested food
mucus
lubricates and protects stomach walls from HCl and enzymes
pyloric sphincter
controls rate at which chyme is released into small intestine
must digestion and nutrient absorption occurs in the
small intestine
3 sections of sm intestine
duodenum, jejunum, ileum
segmentation
mixes chyme back and forth in the sm intestine
large surface area of the ___ of the small intestine
lumen
villi
tiny, fingerlike projections of the small intestinal lining that participate in digesting and absorbing food
absorptive cells
found on each villus, contain microvilli on the end of each absorptive cell
absorptive cell function
move nutrients from chyme into intestinal capillaries or lymph vessels
water-soluble nutrients enter capillaries of ___ and travel to the liver via the ______-
villi
hepatic portal vein
chylomicrons
particles formed by small intestinal cells that transport lipids in the bloodstream
most fat soluble nutrients form ____, which enter ___ and eventually the bloodstream
chylomicrons
lacteals
lacteals
structures of the lymphatic system
absorptive cells are constantly being
shed, replaced
weight loss and diarrhea are often signs of
nutrient malabsorption and chronic nutrient-deficiency diseases
the liver has many functions including
monitoring the blood nutrient content, detoxifying many harmful substances, making glucose, storing various nutrients
creates a barrier to agents of infection in food and water from being absorbed
mucus
areas of specialized cells called Peyers patches in the ileum provide
immune protection
Peters patches produce
antibodies
antibodies
proteins that recognize and help destroy agents of infection
inflammation
sign of the immune systems response to an agent of infection or a disease process
signs/symptoms of inflammation
pain, tissue redness and swelling, loss of function, fever
digestive accessory organs
pancreas, liver, gallbladder
pancreas
produces most of the digestive enzymes that breakdown carbs, protein and fay
___ stimulates pancreas to secrete digestive enzymes
cholecystokinin
pancreas secretes
bicarbonate ions, which neutralize HCl in chyme
liver
process and stores many nutrients
liver makes
cholesterol and bile
bile
substance that assists in fat digestion and absorption
gallbladder
stores bile until needed
gallstones
made from cholesterol
can cause considerable pain if block ducts where bile travels
cystic fibrosis
production of thick, sticky mucus that blocks passageways
cystic fibrosis can interfere with digestion, especially for
fat
fat malabsorption
minimal nutrient absorption occurs here
large intestine
feces
form as undigested material, becomes semisolid
rectum
lower part of large intestine where feces are stored until elimination
feces contain
large numbers of various intestinal bacteria
the large intestine contains microbes called
gut microbiota
gut microbiota can
make vitamin K, thiamin, biotin
metabolize undigested food
produce intestinal gas
___, ____, ___ and ___ can alter normal diversity of gut microbiota leading to an imbalance that results in _____
starvation, antibiotics, stress, poor diet
intestinal dysbiosis
gut microbiota transplantation
fecal transplant
treat C-diff, ulcerative colitis, chrons
probiotics
live, beneficial gut microbes that have been cultured under lab conditions
probiotics may help prevent treat
diarrhea or certain intestinal disorders
prebiotics
forms of dietary fiber that are poorly digested by humans
prebiotics can support and promote
growth of beneficial gut microbes
prebiotics found in
fruits, vegetables, whole grains
IBD
chronic diseases that cause inflammation and swelling of intestines
most common forms of IBD
UC, chrons
UC
ulcers form in the inner lining of the large intestine
signs/symptoms of UC
painful abdominal cramps, rectal bleeding, diarrhea, weight loss, anemia
chrons disease primarily affects
ileum, colon
signs/symptoms of chrons
diarrhea, abdominal cramps, loss of appetite, weight loss
constipation
difficult, infrequent bowel movements <3/week
constipation common causes
older age, pregnancy
inadequate intake of dietary fiber, water
medications, health condition
change in routine
ignoring need to defecate
chronic constipation can lead to
inflamed hemorrhoids and diverticula
_______ may help reduce constipation
increasing intake of dietary fiber and water
diarrhea
frequent bowel movements with loose stools
diarrhea causes
bacterial or viral
diarrhea treatment
consume fluids with electrolytes and simple sugars
immediate medical attention is required for (diarrhea)
severe in infant or older
blood
lasts more than a week
vomitting
abdominal muscles contract, forcibly expelling the contents of the stomach and duodenal out of the body via the mouth
vomiting causes
ingestion of toxic substance or excessive alcohol
intense pain
food allergies
motion sickness
hormonal changes
migraine headaches
vomiting treatment
avoid solid food
sip water, clear liquid
contact physician if (vomiting)
contains blood
fever, confusion, abdominal pain
dehydration signs
lasts more than a few hours (kids) or a day (adults)
GERD
heartburn
acid reflux
acid reflux damages
wall of lower esophagus, causes ulcers
GERD risk factors
pregnancy, cigarette smoking, excess body fat, alcohol, certain food
GERD dietary advice
small, more frequent meals
do not overat
limit spicy, greasy, tomato, peppermint, caffeine, alcohol, chocolate
GERD other advice
lose excess weight
do not lay down < 3 hours after eating
avoid cigarettes
elevate head of bed 6-8in
do not wear tight belts or tight waistbands
GERD medications
those that inhibit stomach acid production
peptic ulcer
sore in the lining of stomach or duodenum
peptic ulcer symptoms
dull, burning pain in upper abdominal area when the stomach is empties
peptic ulcer causes
helicobacter pylori infection in the stomach
cigarettes, heavy alcohol consumption, NSAIDs
peptic ulcer prevention/treatment
antibiotics
medication to reduce stomach acid production
IBS
intestinal cramps, bloating, gas, abnormal bowel function
IBS causes
unknown, HI infections, emotional stress
IBS treatment
low FODMAP diet
stress management
colorectal cancer
cancer that develops in either the colon or the rectum
sign/symptoms of colorectal cancer
change in bowel movements
sensation of incomplete bowel movement
bloody or dark stool
abdominal cramp, gut pain
unusual tiredness
involuntary weight loss
anemia
colorectal risk factos
> 50 years old
family history
colorectal polyps, UC, chrons, type 2 diabetes
lots of red and processed meat
excess body fat, physically inactive
smoking, drinking
African or Ashkenazi jewish ancestry
colorectal cancer treatment
surgery, chemotherapy, biological therapy, radiation therapy
The atom is the smallest living unit in the body. True or
false?
false
The stomach produces gastric juice that contains
hydrochloric acid. True or false
true
digestion begins in the stomach. true or false?
false
The gut microbiota is the various microbes, primarily the
bacteria, that live in the gastrointestinal tract. True or
false?
true
Symptoms of Irritable Bowel Syndrome (IBS) include
constipation and diarrhea. True or false?
true
