Food
Lesson Mans 1:
Objectives:
Examine the leading causes of illness and death in the United States.
Explore how habits affect health.
Review the quantitative aspect of nutrition.
Discover nutritional status terminology and food labeling
recommendations.
The leading causes of illness and death in the U.S. today are heart
diseases, cancers, and strokes
On a world-wide basis, estimates indicate 3 to 4 million cases of
cancer per year could be prevented by improving diet and exercise
alone. Reports in the media suggest that pesticides, cell phones,
and radiation are main causes of cancer, but only 3% to 4% of
cancers are traceable to these factors. In comparison, 30% to 40%
of all cancers may be attributed to diet and lifestyle.
The U.S. Surgeon Generals Report on Nutrition and Health lists
three habits that affect nutrition and health: tobacco, diet, and
alcohol.
It is estimated that every year one million children die due to vitamin
A deficiency and another 350,000 go blind.
Enzymes involved in biochemical synthetic pathways are not known
to be allergenic
nutrition is: the qualitative science that describes which chemicals
the body needs for optimal health and well-being, and
the quantitative science that indicates how much of each chemical
is needed by the body.
In other words, the study of nutrition considers which chemicals, and
how much, are needed to support and sustain a healthy body.
Nutrition must also define how these chemicals are ingested,
digested, absorbed, transported, metabolized, and eliminated.
Studying this information about the chemicals helps you understand
how much is needed; how much is metabolized or broken down; and
where it goes, not only in the body, but on the molecular level as well
(that is, the cell).
Nutrients-substances which are essential for the maintenance, repair, growth, and
reproduction of our body tissues. Divided into 6 categories:
1. Carbohydrates-Macronutrient (makes up the largest number of foodstuff by
weight). Most efficient source of energy. Essential component in production of
many structural and functional materials
2. Fats- Macronutrient. Two types. Saturated (solid at room temperature and
found mostly in animal tissues) and Unsaturated (liquid and found in many plant
tissues)
3. Proteins- Macronutrient. Building blocks are amino acids. Found in all foods
derived from animals and plants
4. Water-Macronutrient. 60% of our body weight
5. Vitamins. Micronutrient (Make up small percentage). Synthesized organic
compounds (mostly only by plants and bacteria). Supply comes from plant foods
and our bowel material
6. Minerals- Micronutrient. Come from inorganic matter
Nutrients perform 3 types of functions:
1. Building blocks (protein for muscle, calcium in the skeleton)
2. Energy for body and cells
3. Maintenance (Help maintain homeostasis- internal equilibrium)
Proteins and Fats do all 3 functions. Proteins are building blocks of muscle, fats of
cell membranes
Carbohydrates supply energy
Water participates in building blocks of cells
Vitamins provide maintenance/regulation
Minerals supply building blocks (calcium and phosphorus for bones and teeth)
and maintenance (iron= hemoglobin)
Approximately 40 chemicals are required by the body for optimal health and well
being
Processing food reduces its nutritional value
Qualitative nutrition is concerned with how much of a nutrient is
required. Implies measurement and value
Dimension (also used)- Physical and chemical parameter that can be
measured (length, weight, and volume)
Unit
Mass
Understanding Food Labels:
MDR (minimum daily requirement)- amount of nutrition required to
prevent a deficiency. Shows what can prevent a disease but is not
always a good marker because each individual needs a different
amount of each nutrient
Origins of the Recommended Dietary Allowance
(RDA)
Focuses on nutritional status by evaluating populations and how an
individual fits into that population. Helps provide quantitative aspect
of nutrient needs. Developed in 1930s and 40s
Component of RDA is the List of Essential Nutrients (nutrients that
cannot be made by the body and must be obtained by consuming
food). Nutrition studies ways to add these nutrients to the body
Food and Nutrition Board of the National Research Councilgoverning body that makes up RDAs based on scientific knowledge
RDA is based on a bell curve and is only for healthy people
How RDA is Determined:
Expressed in male and gender categories
Curve shows daily requirement of nutrients on x axis and number of
people on y axis.
of population is at highest point. If you point down you will get the
daily requirement for 50% of population. Move two standard
deviations to the right and you get 97.5% of population which is the
RDA value
Meeting the RDA:
Nutrition Facts on Food Labels:
Calculating Your Own Requirements:
Eat varied selection of foods
Broken down into serving size and servings per container. Calories
per serving and per fat also shown
To determine how much nutrient a food supplies, find its DRV (daily
reference value). These are expressed as a percentage of reference
values from the RDAs of the nutrients listed (Reference Daily
Intakes). This helps you determine how much of a nutrient is in a food
and how much more you need to consume for optimal health and
well-being
Daily value- based on 2,000 calorie per day diet
Divide your daily calorie intake by 2000. For example: 2500/2000=
125, meaning your percentage daily value for that nutrient is 125%.
Multiply the number of grams listed on the label by 1.25 and you have
the amount you require of that nutrient
The amount of macronutrients you consume changes based on your
daily caloric needs but the amount of micronutrients does not, nor do
the values for cholesterol and salt (300 mg and 2.4 g)
What Drives our Food Choices?:
Obesity
Todays Nutrition Experts:
Studies show that people eat larger amounts of hedonic foods
(popcorn and candy) when they are sad but that this effect is
moderated when nutritional information is present
Bmi- Adults weight divided by the square of their height
Registered Dietician- completed a bachelors degree in nutrition and
passed an exam
Public Health Nutritionist- has a bachelors degree in nutrition but is
not a dietician
Licensed Dietician- has met certain state and national criteria
Nutritionist- may not have taken credited courses
Lesson 2
Objectives:
Examine the leading causes of illness and death in the United States.
Explore how habits affect health.
Review the quantitative aspect of nutrition.
Discover nutritional status terminology and food labeling
recommendations.
Doctrine of Signatures
Individual Contributions to Nutritional ScienceDigestion
Provided an explanation for the benefits to be gained from certain
foods
Supported idea that plants and animals were derived from gods and
each organisms nutritional value was related to its appearance (ex
wine is red so it was said to be good for your blood)
Hippocrates- father of medicine. One of first men to recognize
importance of food to medicine and health
Postulated that food was made of one ailment (something that
supports or nourishes). Hence, the alimentary canal which is the tube
through which food is digested
Sanctorius- followed Hippocrates. Concerned with the effects that
food consumption and exercise had on a persons weight. Father of
metabolic balance
Conducted experiments on himself and realized that he gained weight
after eating and lost weight after exercise
Suggested that food not only moved through the alimentary canal but
something else was also happening in the body
Diet Linked to Health
Importance of Nutrients
Nutrient Nomenclature
Benefits of Nutritional Discoveries
Andrew Boorde- one of 1st dieticians
William Stark- followed Boorde. Kept a journal of everything he ate
and limited his food intake to only certain foods a week to determine
the effect that food consumption had on the body. Died of
malnutrition
James Lind- found that vitamin c in fruits would prevent scurvy
1827- William Prout stated that carbohydrates, fats, and proteins are
needed for health and well being
Gerardus Mulder- defined the chemical composition of a protein
Justus von Liebig- determined that a foods nutritional value was
related to its nitrogen content. Started the idea of the importance of
minerals in nutrition
Kazimierz Funk- first to coin the word vitamins (vital to life)
Periodically, the Department of Agriculture (USDA) and the
Department of Health and Human Services publish lists of foods and
their nutritional information
Monitoring the Worlds Food Supply
FDA monitors products grown and produced in US. Publishes info
relating to safety of food and drug products
Has encouraged other nations to do the same
Lesson 3
Objectives:
Review the traditional meaning of lifethe cell.
Identify the conditions for life to exist.
Examine nutritional cell terminology.
Define the three building blocks that nutriments furnish.
Cells in the Human Body
More Conditions Necessary for Life to Exist
The Human Body: An Orientation and Basic
Chemistry
Overview of Anatomy and Physiology
Cells need: oxygen, constant temperature, water, constant acidity (pH
of human body is 7.2 to 7.3), constant osmotic pressure (cells ability
to retain water)
Cells also need: 1. bulk for dilution (size protects one from toxins).
Adults are more protected than infants because of this. 2. Buffers
against change (needed for constant acidity). In the body there are
buffers that resist large changes in pH. 3. Chemical supply (nutrients)
Anatomy-to cut apart. Focuses on parts of the body and their
relationship to each other. Physiology-study of nature. Study of how
parts function on their own and as part of a larger system
Levels of Structural Organization
Chemical Level- Atoms and molecules that make up the bodys
structure
Cellular Level- smallest unit of all living things
Tissue Level- groups of cells that have a common function
Organ Level- structure composed of two or more tissue types and
performs a specific function in the body
Organ System
Organismal Level- Consists of 11 organ systems
Organ System Overview
Organ System Overview: Nervous, Endocrine, and
Cardiovascular
Nervous system- sends and receives messages. Divided into central
nervous system (brain and spinal cord) and the peripheral nervous
system (nerves extending to the periphery). Bones that contain spinal
cord- vertebrae
Includes special sense organs (eyes, nose, tongue, and ears)
Produces rapid electrical impulses enabling responses to changing
environmental conditions
Endocrine system- produces hormones. Includes pituitary (located
behind the brain. Regulates adrenal cortex, thyroid, gonads, water
balance etc), thyroid, adrenals, thymus (active in immune response),
pancreas (produces endocrine and exocrine secretions), pineal ovaries,
and testes
Cardiovascular system- transportation system. Brings nutrients and
other substances to the cells and transports wastes away from the
cells. Includes heart, arteries (carries blood away from heart), veins
(carries blood towards the heart), and capillaries (connects arterioles
with venules)
Integumentary system (skin)- largest organ system. Works with hair,
nails, sweat glands, and sebaceous glands (glands that empty their
sebum secretion into hair follicles). Prevents entrance of harmful
substances into the body, keeps internal organs from drying out, and
minimizes effects of heat and sunlight
Skeletal- gives body support. Stores calcium and phosphorus
Muscular system- Produces movement and heat. 3 categories of
muscles: skeletal (muscle attached to bone), visceral (smooth muscle
lining organs), and cardiac (muscle of the heart). Allows our internal
organs to move blood, food, and urine throughout the body
Organ System Overview: Lymphatic and
Respiratory
Lymphatic system- similar to cardiovascular system but instead
contains lymph, a fluid that contains lymphocytes (white blood cells
formed in the bone marrow), proteins, and fatty molecules. Composed
of lymph nodes (lymphatic tissue), lymphatic vessels, tonsils, thymus
gland (moves fluid, contains immune cells and other large molecules
around cells and takes fat related nutrient from the digestive tract back
to the blood) and spleen
Respiratory system- nasal passages, pharynx, larynx (voice box),
trachea (windpipe), bronchi (branch of trachea leading to the lungs),
and lungs. Involved in exchange of oxygen and carbon dioxide to and
from the blood
Organ System Overview: Digestive, Urinary, and
Reproductive
Digestive system- broken down into two groups: 1. Primary organs
(mouth, pharynx, esophagus, stomach, small intestine, large intestine,
rectum, and anus). 2. Secondary (teeth, salivary glands, tongue, liver,
gallbladder (used for bile storage), pancreas, and appendix
Urinary system- involved in waste removal. Includes kidneys, urthera,
and bladder
Reproductive system- you know what goes here chyea
Maintaining Life
Stable Internal Environment
Ingesting food provides the body with energy and raw materials
necessary for synthesizing biomolecules that are necessary for life
Nutrients absorbed through digestion into the blood. Blood transports
nutrients and oxygen to cells and picks up waste for excretion
Nutrients absorbed by ingestion and breakdown of food are used for
energy and cell building, such as water(obtained from ingested food
and liquids)
Metabolism- refers to all chemical processes
Homeostasis- process that allows body to maintain stable internal
environment. Body must stay at a certain temperature, oxygen levels,
heart rate, and blood pressure. Maintained by a negative feedback
loop that regulates whether your body needs to be heated or cooled
3 components involved in regulating it: 1. Receptor (responds to
changes in environment). 2. Control Center (determines what the
normal limits or range is, analyzes the information received, and
responds. 3. Effector (counteracts change)
Anatomical Position
Body Planes and Sections
Body Cavities
Abdominal Pelvic Cavity
Concepts of Basic Chemistry
Refers to body standing erect and face forward
Body, organ, or tissue samples are divided into sections using
imaginary lines called planes
Sagittal plane: Cut made lengthwise, dividing the body into right and
left parts. Midsagittal plane (cut down center of body)
Transverse plane (cut made along a horizontal plane, dividing section
into superior and inferior parts
Frontal plane: cut along a lengthwise plane that divides the body into
front and back
Dorsal cavity- located in posterior. Has two subdivisions (cranial
cavity and spinal cavity)
Ventral cavity- located in anterior. Subdivided into thoracic cavity
(chest) and abdominal pelvic cavity. Separated by diaphragm
divided into four quadrants (right upper, right lower, left upper, left
lower)
Can also be divided into regions: 1. Umbilical region (surrounds the
navel). 2. Epigastric (located above umbilical). 3. Hypogastric (under
umbilical). 4. Left and Right Inguinal Regions (on either side of
hypogastric). 5. Right and Left Lumbar Regions (on either side of
umbilical). 6. Right and Left Hypochondriac Regions (on either side
of epigastric)
Matter- anything that has weight and takes up space. Composed of
elements. Carbon, hydrogen, oxygen, nitrogen= building blocks of life
Atoms of same element combine together to form molecules
Compound- when two different elements bind together
Inorganic compounds- lack carbon and are small molecules (water)
Organic- contain carbon (carbohydrates, lipids, proteins, and nucleic
acids)
Biochemicals: DNA and RNA
Biochemicals- Enzymes
Biochemicals: ATP
Basic Parts of a Cell
Nucliec acids
DNA- genetic material found in nucleus. Replicates itself before the
cell divides and provides information on making proteins. Its building
blocks (nucleotides) form a double helix
RNA- lives outside nucleus. Carries out instructions for building
proteins given to it by the cells DNA. Single stranded
Proteins that act as catalysts (increase the rate of the chemical
reaction). Hundreds of different kinds
Provides energy required by cells to carry out tasks
Derived from food we eat. is Food broken down and transformed into
ATP through oxidation
Process of ATP: Transport (helps certain molecules across cell
membranes), Mechanical (activates certain proteins in muscle tissue
that allow it to contract and perform mechanical work), Chemical
(provides energy needed to drive energy absorbing chemical
reactions)
Plasma membrane-skin of cell. Protects the inside
Organelles- structures that perform different functions in the cell
Nucleus- holds DNA
Lysosomes- contain enzymes and help the cell digest nutrients
Mitochondrion- produces energy in cell.
Ribosomes- Aids in synthesizing proteins
Rough and Smooth Endoplasmic Reticulum- Areas where proteins
and lipids are produced. Rough indicates that ribosomes are
attached to the endoplasmic reticulum. Smooth means no ribosomes
are attached
Golgi- Helps store and transport proteins
Cytosol- Fluid part that includes water and other elements
Building Blocks
Nutritional Needs of Infants
Dietary Challenges of Adolescents
Nutritional Challenges for Adults
Carbohydrates- supply energy to our bodies
Proteins- provide structure to cell components and membranes
Lipids- fats and oils that maintain cell structure. Fats are also stored
and used as energy
At 6 months of age, infants can eat solid foods starting with a single
grain cereal such as rice. Then other single grain cereals, multigrain
cereals, vegetables and fruits. Common allergens should not be given
to them within the first year.
Adolescents experience rapid bone growth so the foods they eat are
critical. Ephiphyseal plates close and are replaced by solid bone so
this is the last chance to maximize peak bone mass. This is why
calcium and vitamin d are important because they contribute to bone
and muscle growth
Metabolic rate declines with age so older adults need fewer calories
but the need for nutrients increases
Phytochemicals reduce risk of diseases
Fiber reduces heart disease and fluids are important
Preformed vitamin A should be reduced to prevent osteoporosis
Ability to make vitamin D declines with age
Adults also cannot absorb B12 in foods
Lesson 4
Objectives:
Define terms associated with the digestive process.
Review the human anatomy and associated chemical processes required
for food digestion and absorption.
Identify the processes associated with food absorption.
Define the components that regulate digestion.
Digestive System Terminology
Absorption- when digested nutrients move into the bodys
tissues so that they can be transported and used by cells
Accessory organs (liver, gallbladder, pancreas)- release bile,
enzymes and hormones to break down food and direct digestive
activity
Bolus- chewed mass of food
Chyme-Liquid combination of partially digested food, water,
HCl, and digestive enzymes
Enzymes- substances that speed up chemical reactions
Epiglottis- protects the trachea while swallowing
Esophagus- tube used to transport food from mouth to the
stomach
Gastrin- Hormone produced in the stomach that stimulates
digestive activity
HCl- acid made in the stomach that has digestive functions
Large intestine-Tube that absorbs water and nutrients. Passes
waste out of the body
Lumen- interior of digestive tract
Mucus- secretions found in saliva
Pepsin- digestive enzyme produced in stomach that breaks
down protein
Peristalsis- Motion that moves food through digestive system
Pharynx- throat. Passsageway for respiratory and digestive
tracts
Saliva- fluid secreted by salivary glands in mouth
Small intestine- Completes digestion of food and absorption of
nutrients
Sphincters (LES, Pyloric, Ileocecal)- Keeps swallowed food
from returning to esophagus, stomach, or small intestine
Stomach- mixes food with digestive juices and breaks down
nutrients
Digestion and Absorption
Digestion breaks down food into nutrients that your body can
use (carbohydrates, fats, and proteins)
If it is not broken down, it is passed through the body (such as
fiber). The fact that it passes through prevents the risk of
intestinal disease
Ingested food is broken down into particles that can pass out of
the stomach into the small intestine. These particles are digested
by enzymes into carbohydrates, fats, and proteins
Carbohydrates: Starch is digested to glucose. Sucrose digested
to glucose and fructose. Lactose digested to glucose and
galactose. Maltose digested to glucose. Must be broken back
down into monosaccharides to be digested
Plant starch and glycogen are the most abundant dietary
carbohydrates. Long polymers of glucose (has long similar
chainlike molecules of repeating units)
Digestion of starch begins in the mouth with salivary amylase
(pH of 7)
Amylase brakes starch down into maltose, to fragments of 3
glucose molecules, and to small fragments
Amylase works with the stomach until food is mixed with
gastric juices and acidified
Proteins: digested to amino acids and small peptide chains of
two or three amino acids
Pepsin begins digestion of proteins in stomach. Pepsin is an
enzyme that is active at acidic pH
Pepsin turns proteins into peptide fragments and a small amount
of individual amino acids
Pepsin only active in stomach. When chime is neutralized in the
duodenum, pepsin is denatured
Fat: Most fat consists of trigylcerides where are digested to
monoglycerides and free fatty acids
Nonpolar products of digestion can be absorbed by intestine
through diffusion (movement of particles from higher to lower
concentration)
Polarsubstances absorbed by carrier-mediated transport
(transport of ions or organic substances across cell membranes
by integral proteins)
Most digestion and absorption occurs in small intestine.
Pancreas supplies digestive enzymes for food stuffs
Humans lack digestive enzymes for the plant polysaccharide
cellulose (forms the basis of digestive fiber)
Most salt and water that enters the GI tract is absorbed by small
intestine
Salt and water may be absorbed by transcellular transport
through intestinal epithelial cells (depends on active transport(movement of materials across a cell membrane against a
concentration gradient. Requires ATP). of sodium). Chloride
follows sodium and the osmatic pressure generated by
movement of salt and other solutes causes water to follow by
osmosis. or by paracellular transport through tight junctions
between cells
Small intestine can absorb more food than is usually ingested
(absorptive capacity)
Cells of large intestine have no digestive function. Resident
bacteria break down carbohydrates and use the released
nutrients
Bacteria synthesize vitamin B and absorb vitamin K (essential
for clotting proteins)
Colon absorbs salt and water
The Digestive System
Salivary glands
Oral cavity
Tongue
Esophagus
Stomach
Liver
Gallbladder
Bile duct
Pancreas
Pancreatic duct
Intestines
Rectum
Anus
Anatomy and Physiology relating to the
digestive system
Saliva moistens your food, makes chewing easier, and begins
chemical breakdown of carbohydrates in food so that the
stomach can convert the food into fuel for the body
3 salivary glands produce saliva: Paratoid (in front of ears),
Submandular (where jaw and chin meet), and Sublingual (under
tongue)
Food is swallowed down esophagus. Uvula stops it from
entering the throat without swallowing. If it does you gag. Gag
reflex causes epiglottis to cover larynx prevents food from
going down it
The Teeth
The Pharynx and the Esophagus
The Stomach
Incisors and cuspids help you cut your food
Biscuspids and molars are designed to grind and crush food
Swallowed food leaves oral cavity and enters the oropharynx
and the laryngopharynx. The epiglottis covers the larynx and
directs your food to your esophagus
Esophagus moves the food down the thoracic cavity and the
diaphragm and the abdominal cavity where it passes through
the cardiac sphincter before dropping into the stomach
Cardiac Sphincter-located at top of stomach. Prevents food
from backing up into the esophagus
Fundus- Holds food and digests with it HCl and pepsin. HCl
kills bacteria in the food and the pepsin turns proteins into
amino acids. Enzymes are secreted by gastric glands (rugae)
tucked in the stomach lining
Body- breaks down the food and churns it with the secreted
enzymes
Antrum- muscular grinding chamber
Pyloric Sphincter- Sends chyme (broken down food) into the
small intestine. Muscle contraction sends small amounts in at a
time
Duodenum- beginning of small intestine
The Duodenum
The Liver, Gallbladder, and Pancreas
Here an alkaline solution is secreted to neutralize the acids in
your food and prevent it from eating a hole in the small
intestines
Gets bile from gallbladder and liver and pancreatic juice from
pancreas
Liver- produces enzymes needed to aid digestion, removes
toxins and produces nutrients. Produces bile that holds
cholesterol and bilirubin (result of breakdown of hemoglobin
during the bodys destruction of red blood cells)
Releases bile through hepatic duct which leads to the cystic
duct which leads to gallbladder
Bile breaks down large globs into fat (emulsification) to give
the enzymes more to work with
Gallbladder- Sends bile out of cystic duct into common bile
duct and sends it to duodenum
Pancreas- joined to duodenum by pancreatic duct and secrets
pancreatic enzymes. Produces amylase to break down starch,
lipase to break down fat, and proteinase to break down proteins.
Produces insulin and glucagon to regulate sugar in body
The Jejunum and the Ileum
The Colon
Second and third parts of small intestine
Jejunum- absorption. Surface lined with villi which helps this
Ileum- Completes the digestion of food and is connected to the
colon by the ileocecal valve
Colon absorbs remaining fluid and gets rid of what is left
Large intestine- bacteria within the colon secretes vitamins for
your metabolism. Stores material until it can be eliminated.
Vitamins, minerals, and water absorbed into walls
Cecum-entrance to colon. Contains appendix
Colon- Ascending colon, transverse colon, descending colon,
sigmoid colon
Rectum- connected to sigmoid colon and anus which contains
anal sphincter
Changes Across the Lifespan
Infants digestive system matures after 2-3 months. Teeth come
in at 3 months and stimulate saliva and chewing. Small intestine
is longer
Children- Food moves through digestive tract less rapidly and
digestion enzyme production matures
Adolescents-Gastrointestinal system matures. All 32 teeth have
appeared
Adulthood
Late Adulthood- digestive problems begin to occur as well as
tooth decay. Decrease in digestive enzymes and decrease in
absorption of nutrients. Fluid intake and bowel
movement decline
Pathologies Relating to the Digestive System
(things that can go wrong)
Aphthous Ulcers (canker sores): Caused by faulty immune
system or nutritional defect
Cleft lip and palate- not enough tissue for upper lip and jaw
bone to fuse. Cause is unknown though it may be genetic
Herpes Labialis- Fever sores. Can be caused by too much sun
or stress
Gastroesophageal Reflux Disease: Occurs when acid flows
from the stomach to the esophagus. Many causes such as the
patient may produce a large amount of stomach acid. Antacids
can be distributed to help with this. The test for GERD is
known as esophagogastroduodenoscopy
Hital Hernia- protrusion of the stomach through the diaphragm.
GERD is a symptom
Inguinal Hernia- occurs when the small intestine pokes a hole in
a weak spot in the abdominal muscle wall
Treated by a hernioplasty
Peptic Ulcer Disease- ulcer found in the duodenum, lower
stomach, or esophagus. Caused by an excess of stomach acid or
by heliobacter pyori. Treated with an H receptor antagonist or a
proton pump inhibitor
Diagnostic Procedures Relating to the
Digestive System
Fecal Occult Blood Test and Ova and Parasite- test for blood or
parasites in fecal matter
Stool Culture Test- pathogenic bacteria
Serum Bilirubin- measures amount of bilirubin in bloodstream
to determine liver disease
Intravenous cholecystography- when doctors use dye to see the
gallbladder and bile ducts
Percutaneous Transhepatic Cholangiography- sees bile ducts
and liver
Lower Gastrointestinal Series- patient is x rayed after receiving
an enema of barium
Upper Gastrointestinal Series- patient takes barium orally
Endoscopic Procedures- tube is inserted in body. Colonoscopy,
Sigmoidoscopy (sigmoid colon), Gastroscopy (mouth and
esophagus and stomach)
Treatments Relating to the Digestive System
Nasogastric incubation- medical procedure where a tube
administers food to someone who cannot eat and digest it
properly
Gavage- tube through the nostril and into the stomach
Total parenteral nutrition- for people who cannot absorb
nutrition through their intestines
Gastric stapling- stapling or banding the stomach
Anorexiant- suppresses the appetite
Pathologies and Treatments Relating to the
Digestive System
Pathology
Definition
Treatment
Explanation of
Treatment
Cholecdocholithiasis
Presence of gallstones
Choledocholithotripsy
Diverticulitis
Inflammation of diverticula
due to food being trapped
Tubelike opening from anus to
rectum
Diverticulectomy
Hemorrhoids
Veins in the rectum
Hemorrhoidectomy
Cholecystitis
Inflamation of gallbladder
Laparoscopic
Cholecystectomy
Crushing a
gallstone in
common bile
duct
Removal of
diverticulum
Removal of
fistula
Removal of
hemorrhoid
Removal of
galbladder
Anal Fistula
Fistulectomy
Chemical Process of Digestion-the Beginning
Digestion is stimulated by brain. Thought of food stimulates secretion
of various juices and hormones (cephalic phase of digestion. Located
in medulla oblongata
Mouth breaks down food. Saliva adds water, salt, and enzymes to
break it down and protects teeth, esophagus, and stomach lining as
food moves down to the stomach
Salivary amylase breaks down starch to glucose
Food and saliva become bolus
Bolus moves to pharynx and esophagus
Goes to diaphragm
Peristalsis- circular and longitudinal muscles help propel the food
forward and break it down
Goes to stomach. Enters sphincter and prevents food from going
backwards. Stomach turns food into liquid
3 types of muscle in stomach: Inner- diagonal. Intermediate- circular.
Outer- longitudinal
Stomach adds water to the food. Becomes chyme.
Secretes gastric juices that kill bacteria
Pepsin- present in gastric juices. Breaks down chyme into peptides
Lipases digest smaller fats
Glycoprotein- bonds to Vitamin B12 and keeps it from breaking down
Goes to pyloric sphincter and small intestine
Digestion speeds up
Muscles split up and flatten chyme
Enzymes secreted by pancreas. Break down carbohydrates, fats, and
proteins (hydrolysis)
Sodium bicarbonate neutralizes chyme. Higher pH helps enzymes
break down building blocks
Digesting Carbohydrates
Digesting Fat
Digesting Proteins
Broken down into amino acids
Protein enzymes break them down into 3 or four amino acids
Broken down into 20 until the body can turn them into hydrogen,
carbon, oxygen, nitrogen, etc
Large Intestine
Absorbing Nutrients
Carbohydrate digestion begins in salivary glands with secretion of
salivary amylase
When it reaches small intestine, pancreatic amylase continues to break
it down
Water comes to break down bond with carbohydrate and enzyme,
making glucose and fructose
Enzymes are reused
Lipase- enzyme that breaks down fat. Comes from pancreas and uses
hydrolysis
Bile is secreted and helps break barrier between water and fat so that
the body can digest them better
Fats travel in 3s (trigylcerides). Made out of glycerol plus 3 fatty acids
Lipase breaks it into a monoglyceride, though a hydrolysis reaction
Good bacteria here helps break down remaining material and produce
vitamins. Helps eliminate waste
Takes place in small intestine
Has folds lined with villi that help entrap food particles to digest them
Villi digest the particles with enzymes
Microvilli on top of villi grab nutrients and help them get absorbed
through the intestine. They are then transported to parts of the body.
Water soluble components go to circulatory system. Fats go to
lymphatic system
Regulating Digestion
When food enters stomach, hormone is secreted that triggers HCl to
lower the pH t 1.5 so that the stomach can begin digesting food
In small intestine secretin is secreted with signals the pancreas to
secrete sodium bicarbonate to neutralie acidic chyme