Chap 28 The Digestive and Urinary Systems Flashcards
What is the digestive system for?
to break down the nutrients in food and eliminates the solid waste as feces
What is the urinary system for?
eliminates water-soluble waste and determines the volume and composition of body fluids
The digestive system maintains homeostasis of what?
nutrients
When nutrients in the food are broken down where is it delivered?
to the blood
What delivers the nutrients to cells throughout the entire body?
the circulatory system
The urinary system maintains homeostasis of what?
body fluids
What produces urine?
kidneys
What is the purpose of producing urine?
excrete nitrogenous wastes (urea) and regulate water and electrolyte levels
What is the source of nutrients?
food
What do animals use nutrients for?
food for cellular respiration
to build their tissues
Metabolism, growth, maintenance, and repair all require what?
nutrients
What do nutrients come from?
carbohydrates proteins lipids water vitamins minerals
What is essential to good health
a varied diet
What are macronutrients?
they are required in large amounts
What items are macronutrients?
water
carbohydrates
proteins
lipids
What are micronutrients?
they are required in small amounts
What items are micronutrients?
vitamins
minerals
A varies diet prevents what?
vitamin deficiencies
mineral deficiencies
The U.S. gov’s food guidelines emphasize what?
grains fresh veggies low-fat dairy products fruits limited amounts of meat and fat
What is the consequence of a lack of vitamin C?
scurvy
What is the consequence of a lack of Vitamin A?
blindness, impaired immune function
What is the consequence of a lack of Vitamin D?
skeletal deformation (rickets)
A lack of calcium does what?
muscle cramps/twitches
weakened bones
heart malfunctions
A lack of iron does what?
anemia
learning deficits in children
A lack of phosphorus does what?
weakness
mineral loss from bones
A lack of potassium does what?
weakness loss of appetite muscle cramps confusion heart arrhythmia
A lack of sodium does what?
muscle cramps
nausea
weakness
What reflects food intake and activity level?
body weight
A healthy diet includes what?
all of the nutrients necessary to sustain life
What must balance the body’s metabolic rate and activity level?
the calorie content of food
What is Body Mass Index (BMI)?
a measure that combines weight and height
A BMI of what is considered healthy?
between 19 and 25
What is too few calories?
starvation
What makes a diet inadequate?
too few calories
fails to provide essential nutrients
What is too many calories?
obesity
Appetite is controlled by what?
hormones
Acquiring nutrients is a —- step process.
4
What are the 4 steps to acquiring nutrients?
ingestion
digestion (mechanical or chemical)
absorption
elimination
What makes up the digestive system?
organs
The human digestive system consists of what?
gastrointestinal tract
accessory structures
What underlies the digestive tract?
smooth muscles
Smooth muscle contraction is —- and stimulated by what?
involuntary
the autonomic nervous system
What are peristalsis?
rhythmic waves of smooth muscle contractions
What do peristalsis do?
move food in one direction through the digestive tract
What controls sphincters?
muscles
What are sphincters?
muscular rings that can contract to block the passage of materials
The sphincters at the mouth and anus are composed of what and are what?
skeletal muscle
voluntary control
Other sphincters are within what and are what?
the digestive tract
involuntary smooth muscle
Where does digestion begin?
the mouth
Enzymes in the saliva begin doing what?
digesting starch into sugar monomers
What do teeth do?
tear food into smaller pieces
What does the tongue do?
pushes food to the back of the mouth
Food is swallowed into the what?
pharynx
What closes when food passes through the esophagus to the stomach?
the trachea (windpipe)
What is the stomach?
a muscular bag that receives food from esophagus
What is the main function of the stomach?
mechanical and chemical digestion of food
What mechanically digests food in the stomach?
churning
What chemically digests food in the stomach?
gastric juices full of enzymes
What does the small intestine do?
digests and absorbs nutrients
What is the small intestine?
a long tubular organ lines with a highly folded layer of epithelial cells that maximize the surface area for absorbing nutrients from food
Where do digestive enzymes come from?
the pancreas
The pancreas sends what to the intestine?
pancreatic juice
What is in pancreatic juice?
trypsin and chymotrypsin
amylase
lipase
alkaline sodium bicarbonate
What does trypsin and chymotrypsin do?
break polypeptides
What does amylase do?
digest starch
What does lipase do?
breaks down fats
What does alkaline sodium bicarbonate do?
neutralizes the acid from the stomach
What from the liver helps the intestine digest fats?
bile
What does bile do?
emulsifies fast into small globules that mix with water
What stores bile and releases it into the small intestine?
the gallbladder
Does the small intestine digest most molecules?
yes
What completes absorption?
the large intestine
The large intestine receives what from the small intestine?
chyme
The lining of the large intestine does what?
absorbs water, ions, and minerals from chyme
What happens to what is not absorbed in the large intestine?
it is eliminated as feces
Animals excrete what?
nitrogenous waste
What is excretion?
the elimination of metabolic wastes
What balances ion concentrations in body fluids?
osmoregulation
What are the multiple functions of the urinary system?
filters blood
eliminates nitrogenous wastes
helps maintain the ion concentration of body fluids
produces, stores, and eliminated urine
What is the major organ that cleanses blood?
kidneys
What forms as the kidneys cleanse the blood?
urine
Where does urine formed in the kidneys travel to?
through the ureters to the urinary bladder
The body releases urine through what?
the urethra
What are kidneys made of?
nephrons
What are the functional units of kidneys?
nephrons
What regulates kidney function?
hormones
What does high levels of ADH (antidiuretic hormone) signal to the kidneys?
to decrease the amount of water lost in urine
What does aldosterone do?
promotes reabsorption of Na+ into the blood stream from the nephrons. water follows by osmosis
