Download IV Digestion`02 - U of L Class Index

IV. Digestion, Absorption and
Transport
• In order for food to be of any benefit to the
body, and for the body to get any nutrients
from it, food must be eaten, digested an the
resultant nutrients absorbed from the
intestinal tract and transported to designated
cells throughout the body
• This is done through the processes of
ingestion, digestion, absorption and transport
The Digestive System
• Provides two major functions; digestion and
absorption
• Nutrients such as carbohydrates, fats and
proteins are broken down into their basic
constituents and then absorbed as sugars, fatty
acids and amino acids and finally transported
to their designated destinations
• The gastrointestinal tract, a hollow tube from
mouth to anus, is the organ specifically
involved in digestion and absorption
Digestion
• Involves anatomy, physiology and
biochemistry
• It is the process of getting food ready for
absorption
• Includes both the mechanical and chemical
processes that break food down into
particles that can be absorbed
Gastrointestinal (GI) tract
• Also called the alimentary canal
• Flexible, muscular tube that gets food ready
for absorption
• Mouth---------> anus - 26 feet
• Principle organs - Stomach and Intestine
The Complete Digestive Tract
Steps Involved in Digestion
Before Digestion Begins……..
• Stimulation of the digestive processes begins even
before food enters the mouth
• The sensory input, sight, sounds and smells,
involved in preparing for and anticipating the
ingestion of food, play an important role in getting
the body ready for taking in (or ingesting) nutrients
• This cephalic response (nervous system response)
makes the body feel hungry or have the desire to
ingest nutrients
• Before digestion begins, ingestion (the taking in of
nutrients - generally through the mouth) must occur
Digestion Begins in the Mouth
• Mechanical and chemical processes of
chewing and swallowing are under
conscious control. The rest of the
mechanical processes involved in digestion
are under unconscious or involuntary
control
• Food enters the mouth where it is reduced
to a coarse mash through a process called
mastication
• Mastication - the breakdown of food by
mandibular movement (movement of the food
around the mouth by the tongue, cheeks, lips
and lower jaw) and the subsequent breakdown
of the food into smaller, swallowable pieces
• The mouth contains two fluids that are
involved in the initial digestion of food; saliva
and mucous
• Once the food has been chewed, broken
down and partially digested, it makes its
way to the back of the mouth
• The movement of the tongue helps to
position the food so that it can be
swallowed
• The chewed and partially digested food is
called a BOLUS (ball of chewed food mixed
with saliva)
Chemical Processes
• Saliva - contains salivary amylase (initial
breakdown of carbohydrates) and lingual
lipase (initial breakdown) of fats
• Mucous - slippery secretion secreted by the
mucous membranes lining the mouth;
envelopes and lubricates the food, easing
passage from the mouth to the rest of the
digestive tract
• Salivary amylase - begins starch breakdown
by hydrolyzing the glycosidic linkages
(linkages connecting the individual glucose
molecules in starch) (yielding
monosaccharides, disaccharides and shorter
polysaccharides)
• Lingual Lipase - secreted by the sublingual
salivary gland under the tongue
• - begins the breakdown of short chain fatty
acids
Mouth to the Stomach
• As the bolus is swallowed, it enters into the
pharynx.
• The pharynx is the part of the digestive tract
responsible for swallowing and is common to both
the digestive and respiratory tracts
• Food passes through here on its way to the
esophagus and air passes through here on its way
to and from the lungs
• A valve-like flap, called the epiglottis exists in the
pharynx that serves to cover the opening to the
lungs when swallowing to prevent food from
entering the lungs
• Sometimes the epiglottis gets stuck, or
doesn’t completely cover the opening and
consequently food gets stuck or lodged in the
airway
• When this happens, the person can’t breathe
and the food must be dislodged in order to
prevent suffocation
• If the food can’t be dislodged by coughing
then a process called the Heimlich can be
used
Movement of Food
• Once the bolus is swallowed, it slides down
the esophagus and is conducted through the
diaphragm to the stomach by peristalsis
• Peristalsis is the coordinated involuntary
muscular contractions and relaxations that
aides the movement of the food down the
esophagus and also through the intestine
• Vomiting - reverse of peristalsis
Peristalsis
Entrance to the Stomach
• Entrance to the stomach is gained through a
muscular valve that lies at the end of the
esophagus and the beginning of the stomach
called the Cardiac Sphincter
Cardiac sphincter
• Muscle encircling the tube of the digestive tract that
acts like a valve opening and closing to allow food in
• Under unconscious control
• Relaxes to allow the bolus to enter the stomach and
closes behind so that it can’t slip back up
• Also prevents “reflux” of the stomach contents in to
the esophagus thus preventing heartburn
• NO CHEMICAL PROCESSES AIDING DIGESTION
OCCURS IN THE ESOPHAGUS
Stomach
• The stomach is a pouch-like expanded portion of
the G.I. Tract that serves as a temporary storage
place for food.
• Approximate 1 litre capacity
• Comprised of three sets of muscles; circular,
longitudinal and horizontal
• The coordinated movement of these muscles results
in the “churning action” of the stomach. This
mixes the food with the gastric juices to form a
semiliquid mass called chyme
• Digestion occurs via mechanical processes and
chemical processes
• Mechanical processes involve the churning of the
food to mix it with the gastric juices while at the
same time breaking it down further
• The chemical processes of digestion in the stomach
occur via hydrolysis of the food by HCl and the
digestive enzymes in the gastric juices
• Enteric Coating - mucopolysaccharide (mucous)
secreted by the stomach lining that prevents
autodigestion of the stomach by the gastric juices
• Food is retained in the stomach for 2-3
hours (depending on its composition)
• After it is thoroughly mixed and liquified, it
moves to the bottom of the stomach where
it leaves to enter the small intestine by
another valve called the pyloric sphincter
Regulation of Gastric Secretion
• Secretions of the stomach are under both nervous and
hormonal control
• Governed by signals from the brain,
• stomach and small intestine
• signals work like an on/off switch - stimulation or
inhibition of gastric juice secretion
• three phases of gastric secretion
– cephalic
– gastric
– intestinal
Cephalic phase
• Occurs before food enters the stomach, even
before food enters the mouth
• nervous signals are sent by the brain to get
the stomach ready to receive food
• in this stage the gastric secretions are
stimulated by the thought,sight, smell and
taste of food
Gastric phase
• Once food enters the stomach it presence (bulk)
stimulates the secretion of the gastric juices
• The bulk stretches the local nerves at the top of the
stomach
• This stretching signals the brain that food is present
and a hormone, gastrin, is released from the upper
part of the stomach
• Gastrin stimulates the secretion of the gastric juices
containing HCl and the digestive enzymes such as
pepsinogen, gastric lipase, etc.
Enzymes
• Proteins
• Enzymes are very important in biochemical
reactions
• They speed up the rate of a specific
biochemical reaction without themselves
being altered
• Each reaction has its own specific
enzyme(s)
Components of Gastric Juice
• HCl
– deactivates salivary amylase (stops starch
digestion) (enzyme does not function in an acidic
environment
– kills many bacteria consumed with the food
– provides an acidic environment (pH 1-2) for
gastric enzyme function
– begins protein digestions by converting
pepsinogen (precursor) to pepsin (protein
digesting enzyme (enzyme requires an acidic pH)
• Gastric Lipase
– starts fat digestion
– fats leave the stomach only partially processed
• Bicarbonate
– neutralizes the acidity of the chyme before it enters
the small intestine
• Vitamin B12
– becomes attached to a protein carrier - this protects
the vitamin against the harsh environment of the
stomach
• Carbohydrates pass though the stomach to the
small intestine as the stomach does not secrete
enzymes for carbohydrate digestion and it
inactivates amylase from the mouth
• Therefore carbohydrates leave first, proteins
and fats remain behind for more extensive
processing
• Fats generally leave last which is why a high
fat meal has the “stick to your ribs” quality
Intestinal phase
• Begins when the chyme passes into the small
intestine
• Pyloric sphincter (pylorus)
– this is a valve between the stomach and the
small intestine. It prevents back-up of the
intestinal contents into the stomach and
regulates the flow of the chyme from the
stomach to the small intestine
• The passage of chyme into the small intestine
triggers a series of events that regulates the
release of chyme into the small intestine
stomach
• Motility is slowed, gastric secretions are shut
off and the release of food into the small
intestine slowed so that thorough digestion
can take place
Control of Stomach Emptying
• The amount of chyme leaving the stomach
through the pyloric sphincter is about 1-2
tsp every 30 seconds
• Consequently the stomach empties over a
period of time rather than as a bulk
emptying
• Rate is determined by the size and
composition of the meal and control from
the small intestine
• Chyme passing through the pyloric sphincter causes the
small intestine to distend which then closes the valve
(as well as stimulation by the low pH) until the food
moves down the intestine after processing thus this will
slow stomach emptying
• Large meals will take longer to leave the stomach than
smaller
• The composition (amount of protein, fat and
carbohydrate) of the meal will determine the rate of
stomach emptying due to the amount of processing
required
• In addition, out moods can affect stomach emptying
(sadness & fear -slow emptying; excitement &
aggression-increase emptying)
The Small Intestine
• 15 - 30 feet long
• approximately 95% of all digestion takes
place in the small intestine
• comprised of the
– duodenum (12 inches)
– jejunum(8 feet) (most digestion takes place here)
– ileum (11 feet)
• all three parts have different functions within
the small intestine but they are
noncompartmentalized
• Digestion within the small intestine is aided by
secretions from itself, the gallbladder and the
pancreas
• When the chyme enters the small intestine through
the pyloric sphincter, the pH is very acidic
• the nerve cells sense this and stimulate the pyloric
sphincter to close and this stops more chyme from
entering
• at any given time only about 1-2 tsp enters the
small intestine
• as it enters the small intestine, it bypasses the bile
duct
• The bile duct secretes the fluids from the gall
bladder and the pancreas
• Bicarbonate is secreted to neutralize the acidic
chyme and to provide an environment conducive
for the digestive enzymes to work in
• Once the chyme is sufficiently neutralized then the
nerve cells will stimulate the pyloric sphincter to
relax and more chyme will be allowed to enter until
the pH causes the nerve cells to contract the pyloric
sphincter
Gall bladder
• Stores and secretes bile
• bile is synthesized in the liver and excess is
concentrated and stored in the gall bladder
• necessary for fat digestion and absorption
• secretes its contents through the bile duct in
to the small intestine when required
Bile
• Contains “surfactants” to help solubilize
fats
• serves to emulsify fats
• makes them partially soluble in water thus
allowing for aqueous enzymes to break
down fat in an aqueous environment
Pancreas
• Secretes pancreatic juices into the small
intestine via special ducts
• pancreatic juices contain enzymes
(proteases, lipases and amylase) and
bicarbonate
• bicarbonate serves to neutralize the HCl
from the stomach allowing for the
functioning of the enzymes for further
digestion
Cystic Fibrosis
• Inherited disease of infants and children
• pancreas is often affected by the thick mucous that
blocks the ducts
• as a result the cells die
• pancreas can’t deliver the enzymes into the small
intestine
• carbohydrate, fat and protein digestion is affected
• no amylase, trypsin, lipase, etc.
• enzymes must be given orally otherwise the
undigested nutrients go to the large intestine
• this causes bacterial buildup, acids and gases are
produced and the individual is very uncomfortable
and in considerable pain
• the consequent result is malabsorption and eventually
severe malnutrition
As well, in the intestine, there are
• Various nutrient degrading enzymes are present
on the surface of the small intestine (ex.
Maltase)
• In the neutral pH of the small intestine bacteria
thrive
• Bacterial action leads to vitamin formation (ex.
Vitamin K) and as well, they secrete some
enzymes that aid in digestion (ex. Cellulases
for the breakdown of cellulose
• It is difficult for infections to get established
in the small intestine due to the high density
of “natural” bacteria (Natural flora)
• Defending cells (phagocytes) are also
present to confer immunity against
intestinal diseases
• Segmentation - periodic squeezing or
partitioning of the intestine by its circular
muscles. Tends to force food backward a
few inches and allows for better mixing
with the juices
• Pancreatic amylase continues the breakdown
of carbohydrate started by salivary amylase
• Protein digesting enzymes break protein down
into smaller units
• The cells lining the small intestine contain
enzymes that further break down sugars into
monosaccharides and small polypeptides into
constituent amino acids
• Fat is mixed with bile to emulsify it so that the
pancreatic enzymes containing lipases can
break down the fat
Control of Intestinal Secretions
• Two hormones control the release of bile and
pancreatic enzymes into the small intestine
• Secreted by the mucosal lining of the
duodenum
• Secretin and Cholecystokinin (CCK)
• Work together to control digestion in the
small intestine
Secretin
• Hormone
• Secreted by the mucosal lining of the
duodenum
• Stimulates the pancreas to secrete sodium
bicarbonate
• Stimulates the liver to secrete bile into the
gallbladder
Cholecystokinin (CCK)
• Hormone
• Secreted by the mucosal cells lining the
duodenum
• Stimulates the pancreas to release its
digestive enzymes
• Stimulates the gallbladder to contract thus
releasing its contents into the duodenum
Absorption in the Small Intestine
• The main function of absorption is the
transport of nutrients across cell membranes
• The small intestine is the primary site of
absorption of most nutrients from digestion
(water, vitamins, minerals, sugars, amino
acids, and fatty acids)
• Coordinated with digestion
• Although the small intestine is 10 ft long, it
has a surface area for absorption equivalent
to 1/4 of an American football field
• The intestinal wall is an extremely
convoluted surface with hundreds of folds
• Each fold has hundreds of nipple-like
projections called villi
• The villi are further covered with fingerlike
projections called the villus (brush border)
• On the surface of the villi are the microvilli which
are projections of the plasma membrane of the
underlying cells
• The microvilli are covered with hairs or cilia that
serve to trap nutrients
• Some partially digested nutrients are trapped in
the microvilli where they are digested further and
then absorbed
• Within the microvilli there are many enzymes and
pumps which recognize and absorb nutrients (ex.
Maltase, glucose transporter, etc.).
• Once absorbed they make their way to the
lymphatic system======> blood system or are
absorbed directly into the blood system
• Broken down energy nutrients are absorbed
• Water, minerals and vitamins are absorbed
• Segmentation helps to facilitate better
absorption
Illeocecal Valve
• This valve lies at the opening of the large
intestine (colon) on the lower right hand
side of the abdomen
• Once the chyme has traveled the length of
the small intestine it leaves via the
illeocecal valve and enters the large
intestine
How are Nutrients Absorbed???
Structure of Cell Membranes
• The cell membrane is comprised of lipids, proteins
and a small amount of carbohydrate
• The major component of the membrane is lipids
(generally phospholipids) and these give the cell
membrane flexibility
• Flexibility within the cell membrane is determined
by the types and amounts of fatty acids present
(saturated or unsaturated)
• Flexibility allows the cell to change shape
• Phospholipids are the specific lipids that comprise
the “lipid bilayer” (a layer of lipids on the inner and
outer surface of the cell membrane)
• Protein molecules are generally embedded in
the phospholipid bilayer with some
transversing the membrane
• Proteins serve to:
• give integrity (structural support) to the cell
membrane
• transport molecules across the membrane
• serve as surface receptors for hormones and
regulatory substances
• Carbohydrates constitute about 10% of
the cell membrane
• Play an important role in the regulatory
mechanisms of the cell membrane
Methods of Absorption
•
•
•
•
•
Can occur by one of four methods
Simple diffusion
Facilitated diffusion
Active Transport
Pinocytosis
Simple Diffusion
• Most direct method of moving nutrients across the
membrane
• Those nutrients involved in simple diffusion can
move freely in and out of the cell without any help
• Movement or diffusion of the nutrients is based on
a concentration gradient on either side of the
membrane
• Diffusion across the cell membrane keeps the
concentration of the nutrient(s) equal
• Includes H2O, O2, CO2 and other small substances
Facilitated Diffusion
• Nutrients are transported across a membrane
by means of a carrier protein
• Concentration of specific nutrients may not
be the same on both sides of the membrane
• The nutrient becomes attached to the protein
on the outside of the cell and is released on
the inside of the cell
• Includes fructose, vitamins and minerals
Active Transport
• Uses both a carrier protein and energy (ATP)
• Highly regulated means of transport
• Used to tightly control the concentration of
specific nutrients within cells
• Includes such nutrients as glucose, amino
acids, certain vitamins and minerals
Pinocytosis
• Endocytosis
• Least common form of transport
• Especially important during infancy when large
immunoglobulins are required to be absorbed from
the intestine (mother’s milk)
• Substances that enter via pinocytosis are engulfed
by the cell membrane
• The engulfed substances are released once inside
the cell
• The lost portion of the cell membrane is replaced
The Large Intestine
• Approximately 5 feet in length
• serves to collect waste products of digestion to be
excreted
• Begins with the Cecum and ends with the Sigmoid
colon
• Between is the Ascending, Transverse and Descending
portions of the colon
• Chyme enters the colon from the small intestine
through the illeocecal valve and it travels through the
large intestine to the rectum where it is eventually
excreted through another valve called the Anus
• Undigested and unabsorbed enters the large intestine
• Not much digestion takes place after the chyme leaves
the small intestine
• Very sluggish peristalsis
• Food remains in the large intestine for 24-72 hours
• This allows the intestinal bacteria to breakdown
undigested and unabsorbed nutrients further
• Also allows time for the production of some nutrients
by the intestinal microflora (such as vitamin B and K)
to be absorbed by the body
• Byproduct of bacterial metabolism is gas production or
flatulence
• Undigested materials such as fiber, body
secretions, water, bile salts, etc. are excreted in the
feces
• Water, some minerals and vitamins are absorbed in
the large intestine
• The Anus is the final sphincter muscle at the end of
the digestive tract
• Requires mass accumulation for stimulation
• “safety device”
• Defecation is the process whereby the feces
(containing the waste material) is eliminated from
the colon
Once nutrients are absorbed, how
are they transported throughout
the body????
Transport of Nutrients
• Transport is the movement of the nutrients
throughout the body once they have been
absorbed for use by the body
• It also involves the movement of those
nutrients that are not used by the body and
waste products of metabolism for excretion
• Involves the Cardiovascular system and the
Lymphatic system
Cardiovascular System
• Has a pump (heart) to move the fluid (blood) through
the system
• Closed system-blood flows continuously through
– Pulmonary circuit - circulates between the right side of the
heart and lungs
– Systemic circuit - circulates between the left side of the
heart and the other body parts
• Capillaries - Small vessels branching from an artery
(connect arteries to veins) just large enough to allow
on rbc to cross
• oxygen, nutrients, water materials are exchanged
across capillary walls
• Arteries - vessels that carry the blood away from
the heart
• Veins - vessels that carry blood back to the heart
• Blood leaves the right side of the heart via the
pulmonary artery to the lungs
• In the lungs blood loses CO2 and picks up O2.
Bood leaves the lungs and returns to the left side
of the heart (oxygenated) via the pulmonary vein
• Oxygenated blood leaves the left side of the heart
via the Aorta
• Aorta - the main artery of the body that supplies
oxygenated blood to the various organs and tissues
• Blood leaving the aorta may either go to the upper
body and head or to the lower body
• In the lower body, the blood may go either to the
digestive tract and the liver or the pelvis, kidneys and
legs
• Oxygen depleted (CO2-rich) blood returns to the
right side of the heart via veins
• Blood carries all the water soluble nutrients
• In the GI tract, blood picks up nutrients through the
capillaries, which then empties it into the venules to
the veins and then to the heart.
• Nutrients in the blood are transported by veins to the
capillaries of the tissues, etc where they are deposited
through the capillary walls
Hepatic Portal and Lymphatic System
• Nutrients from digestion can enter the blood either
via the hepatic portal circulation or the lymphatic
system
• The Lymphatic System - comprised of a system of
loosely organized vessels and ducts in which the
lymph (fluid) circulates
• No Pump - the lymph “squishes” from one tissue to
another as the muscles contract and relax
• Extremely important in the immune system
• Lymph - similar to blood but no rbc’s or platelets
• circulates between the cells of the body outside the
vascular system
In the Small Intestine
• Water soluble products of digestion
• mucosal cells of the villi
• capillaries
• capillaries merge
• venules at the base of the villi
• venules merge
• larger veins
• hepatic portal vein
• liver
• processing of absorbed nutrients
• general circulation
The Liver
• The major metabolic organ of the the body, acts as a
gatekeeper between substances absorbed from the intestine
and delivered to the rest of the body
• It has many functions:
• Storage
– glycogen
– vitamins
• Production
– bile
– non essential amino acids
• Detoxification
– site where alcohol, drugs and poisons are sequestered
and broken down
The Thoracic Duct
• The Thoracic Duct is the “Link” between the
lymphatic and vascular systems
• Nutrients are lost through the villi of the GI
tract into the lymphatic system (collected
interstially.
• The lymph is colleced via the thoracic duct
located behind the heart where it is emptied
into the subclavian vein which makes its way
to the heart via the right atrium
Which nutrients are absorbed
where?
• Water soluble nutrients are generally absorbed into
and transported by the blood
• Fat soluble nutrients and fat are absorbed and
transported by the lymph
• Lymph
– fat soluble vitamins
– most fat
– most fatty acids
• Stomach
– glucose
– alcohol
– some water
• Small Intestine
– amino acids, monoglycerides, water soluble vitamins
minerals, glycerol, most water
• Large Intestine
– water
Regulation and Control
• Coordination of digestion and absorption
involves both the nervous system and the
exocrine and endocrine glands
• Regulation is a feedback mechanism
• A feedback mechanism is one where
The Nervous System
• Comprised of the Central Nervous System and the
Peripheral Nervous System
• Central Nervous System - brain and spinal cord
• Peripheral Nervous System - vast complex of
wiring extending from the CNS
• Further divided into the Somatic Nervous System
(which gives rise to voluntary muscle control) and
the Autonomic Nervous System (which gives rise
to the involuntary functions)
• The Autonomic Nervous System is further divided
into the Parasympathetic Branch which regulates
the body between stress and the Sympathetic
Branch which helps the body respond to stress
• Exocrine glands - secrete their products via
duct into a cavity
• Endocrine glands - secrete their products
directly into the bloodstream to be
transported to the target organ or area
• Feedback inhibition - means of regulation
whereby the products (once in sufficient
amount) or the condition (once attained)
shut off the system until required again
Maintenance of Stomach pH
• Food enters the stomach
• nerve receptors in the stomach are stimulated by the
presence of the food
• Gastrin (hormone) is secreted
• Secretion of Gastrin stimulates other glands to
produce HCl
• When a pH of 1.5 is reached, Gastrin is no longer
produced and the other glands secreting HCl are
shut off
• the process is repeated when more food or fluid
enters the stomach or when the pH of the stomach
Opening of the Pyloric Sphincter
• Relaxation of the pyloric sphincter causes leakage
of the acidic chyme into the small intestine
• The pyloric muscle cells on the intestinal side sense
the stomach acid and this causes the pyloric
sphincter to close tightly and not allow more acidic
chyme through
• Pancreatic bicarbonate neutralizes the medium
around the pyloric sphincter
• When the medium is neutralized, the pyloric
sphincter relaxes and the whole process starts ovwer
• In this way a small amount of chyme is allowed into
the small intestine at a time
Neutralization of the Chyme
• The presence of the acidic chyme in the duodenum
stimulates the cells in the walls of the intestine to
secrete the hormone secretin into the blood
• The secretin circulates through the pancreas thus
stimulating the release of the pancreatic juices
(containing bicarbonate)
• This neutralizes the acidic chyme
• The pH of the intestine becomes alkaline thus
shutting off the stimulation of the duodenal cells to
produce secretin
• The pancreas then no longer secretes pancreatic
juices
When digestive process go awry
• Problems with any step along the way of digestion,
absorption and transport can inhibit the ability of the
body to obtain nutrients from food
• Can lead to many types of problems, both acute and
chronic
Ulcers
• Lining of the stomach or duodenum of small
intestine gets an ulcer or a sore as a result of the
acid eating through it
• Bacterial infections, stress, poor diet are some
causes
• Typical symptoms - pain approx. 2 hours after
eating, heartburn
• Calcium is a thought to be a culprit as it stimulates
gastrin which then stimulates HCl
• Antibiotics have been found to cure about 90% of
all ulcers (pyloric bacterial)
Heartburn
• Cardiac sphincter muscle doesn’t function as well
as it should - weak, relaxes
• Stomach contents move back up to the esophagus
(reflux)
• Stomach has a mucopolysaccharide coating but the
esophagus doesn’t - leads to a burning sensation
• Eating too large of meals, lying down after eating,
spicy foods, certain hormones (pregnancy) all
augment the problem
• Eat smaller more frequent meals, don’t lie down
after eating, drugs (Tagamet) etc.
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Constipation - motility problems in the intestine
- not enough water, high fat - low fiber diet, etc
- change in diet can help alleviate the problem
Hemorrhoids - also called piles
- swollen veins of the rectum and anus
- may develop unnoticed until a strained bowel
movement and then they become inflamed and painful
• - caused by a number of different conditions but largely
related to constipation
• - best treatment is prevention - diet
• NOTE: Many digestive problems can be treated and/or
controlled by diet modification. The best treatment is
prevention - eating a well-balanced diet, high in fiber
and low in fat.