_____________
Canal - (Gastrointestinal tract, 29 feet long) Uses mechanical and chemical
methods of digestion.
Organs include:
Mouth,
pharynx, esophagus, stomach, small intestine, Large intestine, Rectum,
Anus
Accessory
organs: teeth, tongue, gallbladder, pancreas, liver, salivary glands, appendix
Link to Picture of
the Digestive System
_____________ = study of the stomach and intestine and their diseases.
(Gastero = _____________) (enteron = _____________)
_____________ - inflamation of stomach
_____________
- inflamation of intestine
WALL OF THE DIGESTIVE TRACT
Four Layers from inside out:
1. _____________ - mucous lining
2. _____________ - contains many blood vessels
3. _____________ - uses muscles to move and mix food
4. _____________
or Serosa - outermost covering of tube (Parietal peritoneum)
_____________
- a fold of tissue that anchors the tube to the abdominal cavity.
_____________
- the empty space inside the tube
MOUTH
Oral cavity is lined with mucous membranes keeping is soft and pliable as well a moistening food.
_____________ - bony structure at the top anterior portion of mouth
_____________ - softer part of roof of mouth posterior to the hard palate.
_____________ - soft muscle that hangs down from the soft palate. Prevents food and liquid from going up the nasal cavity.
_____________ - made of muscle, covered in mucous membrane and taste buds
_____________ - a thin membrane that attaches the tongue to the floor of the mouth
Tongue-tied: frenulum is too _____________, causing an inability to pronounce properly
_____________ - small elevations on tongue surface
Taste buds
are located on the sides of papillae
TEETH:
First tooth approx. 6 mos. (varies)
20 Baby teeth (_____________ teeth) by age two.
32 permanent
teeth when mature.
Structure of teeth:
_____________ - above the gum
_____________ - in the gum
_____________ - in the bone socket
Enamel - hardest tissue in body
_____________ - softer material containing pulp cavity with nerve and blood vessels
_____________
- covers dentin in neck and root
Type of Teeth:
_____________ - for biting
_____________ (cuspids) - pierce or tear food
_____________ (bicuspids) - grinding
_____________
(Wisdom Teeth) - grinding
_____________ - (Dental Caries)
Decay occurs
where food debri, bacteria, and plaque accumulate. Acid from the bacteria
disolves enamel leading to infection, loss of teeth and gum disease
SALIVARY
GLANDS (3 pairs)
1. _____________ glands - largest, near ear at angle of jaw,
(mumps causes infection of these glands)
_____________
ducts - opening inside cheek beside upper molars
2. _____________ glands - along the lower jawbone
_____________
ducts - openings on either side of the frenulum
3. Sublingual
glands - under tongue
Saliva contains both mucus and enzymes.
Salivary amylase - breaks down _____________ (amylose) into _____________.
Mucous acini - produces mucus
Serous
acini - produces _____________
_____________
Tube-like
structure of muscle and mucous membranes, located behind mouth and nasal
cavities, functions in both digestive and respiratory systems
_____________ - food pipe
10 inches long, connects pharynx to stomach,
uses waves
of muscle contractions called _____________.
_____________ - serves as a pouch to collect food, and begin both mechanical and chemical digestion.
_____________ sphincter - valve at the bottom of the esophagus.
_____________ sphincter - valve at the end of the stomach.
3 layers
of muscle, _____________, _____________, and _____________ layers break
up food and cause peristalsis.
_____________
- semisolid mixture of food and digestive juices
3 main parts of stomach:
_____________ - upper portion
_____________ - main portion
_____________
- lower section
_____________
- folds in the lining of stomach
Lesser curvature - the inside curve of the stomach
Greater curvature - the outside curve in stomach
Gastric glands - secrete gastric juice and hydrochloric acid.
_____________ - burning sensation caused when stomach acid flows up into the esophagus.
_____________ - total emptying of stomach through the mouth (vomiting)
Food stays in the stomach for about 3 hrs.
Ulcers
- an open wound or sore in the digestive system that is acted on by acid
gastric juice, usually in the stomach or duodenum.
SMALL INTESTINE
Approximately 20 feet long.
3 sections:
_____________,
_____________, _____________
Mucous lining contains intestinal glands that secrete the digestive juices.
_____________ - folds in the intestinal lining
_____________ - finger-like projections in the plica that contain blood capillaries to absorb sugars and amino acids
_____________ - a lymphatic vessel in the villus that absorbs fats from the chyme
_____________ - brushlike border of the epithelial cells of the villi
Duodenal
papilla (major & minor) - openings from the pancreatic duct and bile
duct.
LIVER
AND GALLBLADDER:
Liver is the largest _____________ in the body; producing _____________ of bile a day.
Hepatic ducts drain bile to the duodenum through the Gallbladder and Common Bile Duct (combined ducts)
Bile _____________
fats.
Presence
of fat in chyme triggers _____________, a hormone produced by the duodenum.
CCK then triggers contraction of the gallbladder.
Gallstones
may block the bile duct. The accumulating bile causes _____________, a
yellowish skin discoloration.
Liver cells also:
1. maintain normal _____________ concentrations
2. carry on _____________ and _____________ metabolism
3. make _____________, _____________, _____________
4. _____________ blood
5. stores
_____________, vitamins ________, ________, and ________
PANCREAS
The pancreas is both an endocrine gland and an exocrine gland involved in digestion.
Pancreatic juice contains enzymes to digest
carbohydrates, proteins, and lipids, as well as _____________ to neutralize
hydrochloric acid
LARGE INTESTINE - _____________
5 feet in length.
Contains undigested, unabsorbed food.
_____________ valve - sphincter valve between
the small intestine and large intestine
Chyme changes to _____________ matter, water and salts are resorbed, bacteria continue breakdown of food, synthesis of vitamins.
Food usually takes _____________ hours
to pass through large intestine. Quicker passage causes _____________,
slower passage causes _____________.
Subdivisions of Large Intestine:
1. _____________ - pouch-like area at the beginning of the large intestine.
2. _____________ colon - goes up right side
3. _____________ colon - begins at hepatic flexure
4. _____________ colon - begins at splenic flexure
5. _____________colon - S-shaped part
6. _____________
7. Anal canal - last section in the rectum
containing 2 sphincter muscles, an inner _____________ one and an outer
_____________ one.
APPENDIX
_____________ appendix (worm-shape)
No known digestive function in humans.
Composed of _____________ tissue.
_____________ - inflammation of mucous
lining of the appendix
_____________ - large, moist, slippery sheet of serous membrane lining abdominal cavity and covering organs
_____________ layer - lines cavity
_____________ layer - covers organs
_____________ - a fan-shaped extension
of the peritoneum that anchors the small intestine to abdominal wall
Greater _____________
- extension of peritoneum from stomach that hangs over the intestine like
a large apron
DIGESTION
Mechanical digestion includes:
___________ (chewing), ___________ (swallowing),
___________, ___________
Chemical digestion includes:
breakdown of large non-absorbable food
by enzymes in saliva, gastric juice, pancreatic juice, and intestinal juice.
CARBOHYDRATE DIGESTION
(No carbohydrate digestion occurs in stomach)
AMYLOSE (starch) is broken down by _____________
in saliva (salivary amylase or ptyalin) and pancreatic juice (pancreatic
amylase) in the intestine to form _____________.
_____________ is broken down by _____________
in intestinal juice.
_____________ is broken down into _____________
and _____________ by SUCRASE in intestinal juice.
_____________ is broken down into GLUCOSE
and GALACTOSE by _____________ in intestinal juice.
The simple sugars, glucose, fructose, and
galactose are absorbed into the blood vessels in the villi.
PROTEIN DIGESTION
_____________ ACID, _____________ and _____________
in gastric juice break down proteins into smaller chains of amino acids
called _____________.
_____________ (from the pancreas) and _____________
(from the intestinal juice) break down peptides into _____________.
FAT DIGESTION
Fats are digested partially by GASTRIC
_____________ but most go undigested until _____________ emulsifies them.
_____________ from the Pancreas breaks
down fats into glycerol and fatty acids.
ABSORPTION:
Digested food moves through mucous membranes in the villi of the small intestines.
For further background information on carbohydrates, lipids, and fats, check out this page from my biology notes:
Carbohydrates,
Fats, and Lipids
Digestion
begins as saliva mixes with starch in the mouth. The saliva contains an
enzyme called amylase which breaks down starch (amylose) into the disaccharide
maltose. When the food reaches the stomach starch digestion by amylase
ceases because of the low pH of the stomach acid. In the stomach protein
digestion is the main action. The gastric glands secrete rennin and pepsin
which break proteins (polypeptides) down into dipeptides, often just called
peptides. A small amount of fat digestion occurs because of the action
of gastric lipase. However, since bile has not mixed with the food yet,
fat digestion is not complete. Further fat digestion occurs in the small
intestine after the fat has been emulsified by bile from the liver and
gall bladder, and acted upon by lipase from the pancreas. This breaks the
fats down into glycerol and fatty acids that can be absorbed into the lacteal
vessels in the villi. Further digestion of proteins and carbohydrates occurs
in the small intestine as well. The peptides that enter the small intestine
from the stomach are acted upon by chymotrypsin from the pancreas and peptidase
from the glands of the small intestine. This breaks the peptides down into
amino acids which can be absorbed into the capillaries of the villi. Carbohydrate
digestion continues in the small intestines as maltase, sucrase, and lactase
break down maltose, sucrose, and lactose. Maltose breaks down into glucose
molecules. Sucrose breaks down into glucose and fructose. Lactose breaks
down into glucose and galactose. These monosaccharides, glucose, fructose,
and galactose, can then be absorbed by the capillaries in the villi. Note:
Some individuals stop producing the enzyme, lactase, as adults. This is
common among mammals because most animals do not drink milk after they
are weaned. However, in humans this condition is known as "lactose intolerance".
METABOLISM
- the use of foods for energy or building complex molecules _____________
- break down metabolism _____________
- building metabolism
CARBOHYDRATE
CATABOLISM
Involves
3 stages: 1. _____________
- takes place in cytoplasm of cell; uses no oxygen; breaks down glucose
to pyruvic acid.
2. _____________cycle
- takes place in the mitochondria; uses oxygen; breaks down pyruvic acid
to carbon dioxide and water
3. _____________
Phosphorylation - takes place in the mitochondria; uses oxygen; transfers
energy from hydrogen protons to ATP.
CARBOHYDRATE
ANABOLISM _____________
- takes place in liver; joins glucose into chains to form glycogen, animal
starch. Excess sugar may also be converted to fats and stored in adipose
tissue.
FAT METABOLISM In the
absence of _____________, fatty acids can be converted to Acetic acid and
enter the _____________ Cycle. Glycerol can be converted to glyceraldehyde-3-phosphate
(PGAL) and enter the glycolytic pathway.
PROTEIN
METABOLISM In the
absence of _____________ or _____________, amino acids can be converted
to many of the acids of the Citric Acid Cycle and used for energy. Usually
amino acids are used to build proteins.
METABOLIC
RATES BMR (_________
Metabolic Rate) - rate at which food is catabolized under minimum conditions.
TMR (_________
Metabolic Rate) - the total amount of energy (calories) used by the body
per day.
NUTRITION
A proper
diet requires a balance of carbohydrates, fats, and proteins. In addition
the body requires vitamins, minerals, and water.
VITAMINS:
"_____________" = Latin word for life. Vitamins
are organic substances that act as _____________, chemicals that assist
the enzymes in the bodies reactions. They do not provide _____________. Vitamins
may be either _____________ Soluble or _____________ Soluble.
Fat soluble
vitamins are stored in the body's fatty tissues. Fat soluble vitamins include
the vitamins _____________, _____________, _____________, and _____________.
Vitamin
A - Found in fish, liver, eggs, butter, yellow & green vegetables,
fruits
Vitamin
D - Found in liver, fish, eggs, milk, sunlight
Vitamin
E - Found in whole grains, leafy vegetables, milk, butter, vegetable oils
Vitamin
K - Found in leafy vegetables, soybeans, made by intestinal bacteria
Water soluble
vitamins can be dissolved in water but cannot be stored in the tissues.
They must be obtained each day from food. Water soluble vitamins include
B1 (Thiamine), B2 (Riboflavin), Niacin, B6 (Pyridoxine), Pantothenic Acid,
Biotin, B12, Folic Acid, C (Ascorbic acid)
Vitamin
B1 - Found in organ meats, whole grains, vegetables
Vitamin
B2 - Found in liver, poultry, milk, eggs, cheese, fish, green vegetables,
whole grain
Vitamin
B6 - Found in meats, liver, whole grains, vegetables
Vitamin
B12 - Liver , meats, eggs, cheese, dairy products
Vitamin
C - Found in citrus and other fruits, leafy vegetables, tomatoes, potatoes
Niacin
- Found in red meats, organ meats, fish, green vegetables
Folic Acid
- Found in green vegetables, liver, whole grains, legumes
MINERALS:
inorganic substances that are used in the chemical reactions of the body.
Major minerals
needed include:
Calcium
- Found in milk, cheese, vegetables
Iodine
- Found in seafood, iodized salt
Iron -
Found in liver, meat, eggs,
Magnesium
- Found in milk, meat, whole grains, legumes
Phosphorus
- Found in milk, whole grains, meats, nuts, legumes
Potassium
- Found in whole grains, fruits, legumes, meat
Sodium
- Found in seafood, table salt
FOOD GROUPS: RECOMMENDATION: 5-9 Servings of Fresh,
Raw, Fruits and Vegetables per day.
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Needed for healthy skin, eyes, bones,
teeth.
Deficiency causes _____________ blindness,
skin disorders, kidney stones
Needed for growth, healthy bones, metabolism
of calcium & phosphorus
Deficiency causes _____________, poor
teeth and bones.
Needed for healthy cell membranes, red
blood cells
Deficiency causes _____________ rupture,
muscle disorders
Needed for normal blood clotting
Deficiency causes _____________, hemorrhaging.
Needed for proper functioning of heart,
nervous system, digestion
Deficiency causes _____________, cardiovascular
disorders.
Needed for metabolism of protein, carbohydrates,
and fats, healthy skin
Deficiency causes dim vision, premature
aging, sore _____________
Needed for sodium and phosphorus balance
Deficiency causes anemia, nausea, loss
of appetite, nervousness
Needed for red cell production, healthy
nervous system.
Deficiency causes _____________.
Needed for healthy blood vessels, resistance
to infection, healing
Deficiency causes _____________, _____________,
bleeding gums
Needed for metabolism, digestion, nerves,
skin
Deficiency causes _____________ (sore
mouth), diarrhea, depression
Needed for proteins and red blood cells,
helps prevent _____________
Deficiency causes inflamed tongue, diarrhea,
B12 deficiency.
Calcium, Iodine, Iron, Magnesium, Phosphorus,
Potassium, and Sodium.
Needed for strong _____________ and teeth,
blood clotting
Needed for normal thyroid metabolism,
prevents _____________
Needed for red cell production, prevents
_____________
Needed for proper _____________ and _____________
functioning
Needed for ________ and ________ development,
________, nucleic acids
Needed for proper nerve and muscle function
Needed for _____________ balance, proper
nerve and muscle function
1. Vegetable / Fruit,
2. Bread / Cereal ,
3. Milk / Cheese,
4. Meat / Poultry / Fish
