THE DIGESTIVE AND
URINARY SYSTEM
P. LOBOSCO
THE DIGESTIVE SYSTEM
• The Digestive
System is a group of
organs that work
together to digest
food so that it can
be used by the
body.
ORGANS OF THE DIGESTIVE SYSTEM
• The digestive tract is
a series of tubelike
organs which food
passes through.
• The digestive tract
includes your mouth,
pharynx, esophagus,
stomach, small
intestine, large
intestine, rectum and
anus.
THE DIGESTIVE SYSTEM
CHAPTER 24-1
• Objectives:
• Compare mechanical digestions with chemical
digestion.
• Describe the parts and functions of the digestive
system.
OTHER ORGANS
• The liver,
gallbladder,
pancreas and
salivary glands are
also part of the
digestive system.
• Food does not pass
through these
organs.
BREAKING DOWN FOOD
• Digestion is the
process of breaking
down food into a
form that can pass
from the digestive
tract into the blood
stream.
TWO TYPES OF DIGESTION
• There are two types of digestion : mechanical and
chemical.
• The breaking, crushing and mashing of food is
called mechanical digestion.
• In chemical digestion, large molecules are broken
down into nutrients.
• Nutrients are substances in food that the body
needs for growth, maintenance and repair.
CATABOLIC AND ANABOLIC
• Catabolic reactions
• Proteins from your food are made up of chains of amino
acids.
• Catabolism refers to the breakdown of proteins into amino
acids.
• This process releases energy in the form of ATP
• Anabolic reactions
• Anabolism refers to the process by which simpler substances
(amino acids) are combined to form more complex
molecules.
ENZYMES
• Substances called enzymes break some nutrients
into smaller substances that the body can use.
• Proteins are changed into smaller molecules called
amino acids.
THE ROLE OF ENZYMES IN
DIGESTION
• 1. Enzymes break apart the long chains of amino
acids that make up proteins.
• 2. The small chains are then split by other enzymes.
• 3. Individual amino acids are then small enough to
enter the bloodstream where they will make new
proteins.
THE ROLE OF ENZYMES
DIGESTION
• Nutrients are the usable portions of food.
• The six nutrients are protein, fat, carbohydrates, vitamins,
minerals and water.
• Proteins are broken down into amino acids.
• Fats are broken down into fatty acids and glycerol.
• Carbohydrates are broken down into simple sugars.
• Food is pushed through the digestive system by waves of
muscular contractions called peristalsis.
• Bacteria in the large intestine make vitamins for us.
• Nutrients are absorbed in the small intestine.
• Water and vitamins are absorbed in the large intestine.
NUTRIENTS
• Chemical digestion of carbohydrates begins in the
mouth and ends in the small intestine.
• Chemical digestion of proteins begins in the
stomach and ends in the small intestine.
• Chemical digestion of fats begins and ends in the
small intestine.
•
• Fats are broken down into fatty acids and glycerol.
• Proteins are broken down into amino acids.
• Carbohydrates are broken down into simple sugars.
DIGESTION BEGINS IN THE MOUTH
• Chewing creates
small, slippery
pieces of food that
are easier to
swallow.
• Small pieces of food
are easier to digest.
DIGESTION IN THE MOUTH
•
• Palate – the “roof” of your mouth, tongue pushes against it to aid swallowing,
separates the mouth and nasal cavities
•
• Teeth - crush food into smaller pieces to aid swallowing
•
• Tongue – tastes food, mixes food with saliva, pushes food between the teeth, helps
in swallowing
•
• Salivary Glands - secrete saliva into the mouth to begin carbohydrate digestion
and moisten food
•
• Pharynx – where mouth and nasal passages meet, leads to the trachea and
esophagus
•
• Epiglottis – flap of tissue that closes over the trachea when you swallow to prevent
food or drinks from going into the trachea which prevents choking
•
• Esophagus - connects the mouth and stomach, uses peristalsis (muscular
contractions) to move food along
TEETH
• Teeth break and
grind food.
• The outermost layer
of the teeth, enamel,
is the hardest
material in the body.
• Enamel protects
nerves and softer
material inside the
tooth.
TEETH
• Your teeth have
different shapes.
• The molars are suited
for grinding food.
• The premolars are
used for mashing
food.
• Incisors and canines
are used for
shredding food.
SALIVA
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The roof of the mouth is the palate.
Saliva mixes with food in your mouth.
Saliva is made in the salivary glands.
It contains an enzyme that begins chemical
digestion of carbohydrates by changing them into
simple sugars.
ESOPHAGUS
• After the food is very
soft, the tongue
pushes it into the
throat, which leads to
the esophagus.
• The esophagus
squeezes the food
with rhythmic muscle
contractions called
peristalsis, forcing the
food into the
stomach.
STOMACH
• The stomach is a
muscular saclike
digestive organ
between the
esophagus and the
small intestine that
breaks down the
food into a liquid by
the action of
muscles, enzymes
and acids.
STOMACH
• The stomach
continues the
mechanical digestion
of your meal by
squeezing food with
muscular
contractions.
• Glands in the
stomach produce
enzymes and acid
which break food
into nutrients.
CHYME
• Stomach also kills
bacteria that you
swallow with food.
• After a few hours of
chemical and
mechanical
digestion, food turns
into chyme.
SMALL INTESTINE
• The stomach releases
the chyme into the
small intestine
through a small ring
of muscle that works
like a valve.
• The valve keeps the
food in the stomach
until it has been
mixed with digestive
fluids.
SMALL INTESTINE
• Since the stomach
releases the chyme
slowly, the small
intestine has time to
mix the chyme with
fluids from the liver
and pancreas,
• This help digest and
stop the acids in
chyme from hurting
the small intestine.
THE PANCREAS AND SMALL
INTESTINES
• When the chyme
leaves the stomach,
the chyme is very
acidic so the
pancreas makes
fluids to protect.
• The pancreas is an
oval organ located
between the
stomach and small
intestine.
SMALL INTESTINE
• The small intestine is a
muscular tube that is
about 2.5 cm in
diameter. It is about
6 m long when
stretched out.
• The inside wall is
covered with
fingerlike projections
called villi.
• The villi are covered
with tine, nutrient
absorbing cells.
DUODENUM
• The duodenum
precedes the jejunum
and ileum and is the
shortest part of the
small intestine, where
most chemical
digestion takes
place. The name
duodenum is from
the Latin duodenum
digitorum, or twelve
fingers' breadths.
THE LIVER
• The Liver is a large, reddish brown organ that help
with digestion. I human liver can be as big as a
football.
• It is located toward your right side, slightly higher
than you stomach.
• The functions of the liver are:
• Store nutrients
• Make bile to break up fat
• Break down toxins
GALLBLADDER
• Bile is stored in a saclike organ called the
gallbladder, which squeezes the bile into the small
intestine where the breaking down of fats take
place.
• The bloodstream absorbs nutrients that have been
broken down.
LIVER AND GALLBLADDER
THE END OF THE LINE
• Material that can’t be absorbed into the blood is
pushed into the large intestine.
• The large intestine absorbs most of the water in
undigested material and changes the liquid into
semisolid waste material called feces, or stool.
• Feces are stored in the rectum until they can be
expelled.
RECTUM AND ANUS
 Feces pass to the
outside of the body
through an opening
called the anus.
 It has taken each of
your meals about 24
hours to make this
journey through your
digestive system.
SUMMARY OF FUNCTIONS OF PARTS
OF THE DIGESTIVE SYSTEM
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Teeth – crush food into smaller pieces to aid swallowing
Liver – secretes bile which breaks fat into smaller pieces
Gall bladder – stores bile until needed in the small intestine
Large Intestine – absorbs water and vitamins (made by bacteria living in
the large intestine), stores waste, releases waste
•
• Small Intestine – all digestion is completed here (no nutrients are broken
down past this point), nutrients are absorbed through the villi into the
blood stream
•
• Rectum – end of large intestine, stores solid wastes until they leave the
body
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DIGESTION SUMMARY
• Anus – opening to let out wastes
•
• Mouth – allows food to enter the body, contains teeth and tongue,
carbohydrate digestion begins here due to the action of the enzymes in
saliva
•
• Salivary glands – secrete saliva into the mouth to begin carbohydrate
digestion and moisten food
•
• Esophagus – connects the mouth and stomach, uses peristalsis (muscular
contractions) to move food along
•
• Stomach – churns food into a thick liquid called chyme, protein digestion
begins here due to the action of gastric juice (enzymes and hydrochloric
acid)
•
• Pancreas – secretes pancreatic juice into the small intestine to neutralize
the acid from the stomach and to digest all types of food
THE URINARY SYSTEM
• Chapter 24-2
• Objectives:
• To describe the path and function of the urinary
system
• To explain how kidneys filter blood
• To describe three disorders of the urinary system
EXCRETION
• Excretion is the process of removing waste from the
body.
• Three of the body systems have a role in excretion.
• The integumentary system releases waste products
and water when you sweat.
• The respiratory system releases carbon dioxide and
water when you exhale.
• The urinary system contains the organs that remove
waste products from your blood.
URINARY SYSTEM
• As the body performs
the chemical
activities to keep the
body alive, waste
products, such as
carbon dioxide and
ammonia are
produced.
• The body has to get
rid of these wastes to
stay healthy.
KIDNEYS
• The kidneys act as
filters.
• They filter about
2000L of blood a
day. (You body can
only hold about 5.6
L).
• Inside each kidney
is over 1 million
nephrons.
NEPHRONS
• Nephrons are
microscopic filters.
They remove
harmful substances,
such as urea.
• Urea is formed
when cells use
protein for energy. It
contains nitrogen.
HOW THE KIDNEYS FILTER BLOOD
1. A large artery,
called the renal
artery, brings blood
into each kidney.
2. Tiny blood vessels
branch off the main
artery and pass
through part of each
nephron.
HOW THE KIDNEYS FILTER BLOOD
3. Water and other
substances are forced
out of the blood vessels
and into the nephrons.
4. The nephrons filter
the wastes out of the
blood and water, and
allow the filtered blood
and water to move
back into the blood
vessels.
HOW THE KIDNEYS FILTER BLOOD
5. As filtered blood and
water go back into the
blood vessels, waste
materials are left in the
nephrons.
6. Cleaned blood
leaves each kidney in
the renal vein to
recirculate in the body.
7. The yellow fluid that
remains in the nephrons
is called urine.
HOW THE KIDNEYS FILTER BLOOD
8. Urine leaves each
kidney through a
slender tube called the
ureter and flows into
the urinary bladder.
9. Urine leaves the body
through another tube
called the urethra.
10. Urination is the
process of expelling
urine from the body.
RENAL ARTERY, RENAL VEIN AND
URETER
WATER BALANCE IN BODY
• You drink water everyday but you lose water in
sweat and urine. You need to get rid of as much
water as you drink or your body will swell up.
• When you are too warm, you sweat. The
evaporation of water cools down the body.
• As the water content of the body drops when you
sweat, the salivary glands will produce less saliva
and you will feel thirsty.
• When you get thirsty a hormone, called antidiuretic
hormone or ADH will be released.
ADH
• ADH will signal the kidneys to take water from the
nephrons. The nephrons will return the water to the
blood stream and the kidneys will make less urine.
• When your blood has too much water, small
amount of ADH are released. The kidneys will react
by allowing more water to stay in the nephrons and
leave the body as urine.
DIURETICS
• Some beverages contain caffeine, which is a
diuretic. Diuretics cause the kidney to make more
urine, which decreases the amount of water in the
blood.
• When you drink a beverage that contains water
and caffeine, the caffeine increases fluid loss. So
your body will get less of the water from a glass of a
caffeinated beverage than from a glass of water.
URINARY SYSTEM PROBLEMS
• Since the job of the urinary system is to remove
wastes and regulate body fluids, any problems with
water regulation can become dangerous for your
body.
BACTERIAL INFECTIONS
• Bacteria can get into the bladder and ureters
through the uretha. If not treated, it can spread to
the kidneys. Infections in the kidneys can
permanently damage the nephrons.
KIDNEY STONES
• Sometimes salts and
other wastes will
collect inside the
kidney and form
stones. Some
interfere with urine
flow.
• If the body does not
pass them, they
must be removed.
KIDNEY DISEASE
• Damage to nephrons can prevent normal kidney
functioning. If the kidneys do not function properly,
a machine must be used to filter waste from the
blood.
URINARY SYSTEM SUMMARY
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The Urinary System
Kidney – filters blood, controls water levels
Ureter – carries urine from the kidneys to the bladder
Urethra – carries urine out of the body
Bladder – stores urine until it leaves the body
Blood vessels – carries blood to the kidneys to be cleaned and carries cleaned
blood to the body
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• Nephrons – filter the blood, microscopic
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• Cortex – contains the nephrons