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Body Basics
Chapter 4
Chapter 4- Body Basics (Nutrition)
1
Chapter Learning Outcomes
1. Define key basic chemistry terms, including atom,
element, ion, chemical bond, solution, solvent, solute,
acid, base, and enzyme.
2. Explain the basic function of an enzyme.
3. Define cell, tissue, organ, and organ system.
4. List the organ systems, identify major organs or tissues
in each system, and describe primary functions of each
system.
5. Discuss the overall processes of nutrient digestion,
absorption, transport, and waste elimination.
6. Identify some common gastrointestinal problems and
discuss preventive measures and treatments for these
conditions.
Chapter 4- Body Basics (Nutrition)
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Chemistry and Physiology
• Chemistry
– Study of composition and characteristics of matter
• Human physiology
– Study of how the human body functions
• Principles of chemistry and human physiology
form the foundation for the scientific study of
nutrition.
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Basic Chemistry Concepts
• Chemicals make up
food and other
aspects of the
environment.
• Humans are
complex collections
of chemicals, mostly
organized into cells.
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From Atoms to Compounds
• Matter is made of
atoms that contain:
ATOM
• Protons — Positivelycharged particles in the
nucleus
• Electrons —
• Matter is comprised of atoms
Negatively-charged
that contain particles, including
protons and electrons. The
particles that surround
nucleus of this hydrogen atom
the nucleus in a “cloud”
contains one positively-charged
proton.
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What Are Elements?
• More than 100 types of
atoms exist, and each is
an element.
• Elements:
• cannot be
separated into
simpler
substances are the
“building blocks” of
matter
• Minerals such as
calcium, iron, and zinc
are elements that are
essential nutrients.
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Molecules
• Molecule - matter that
forms when 2 or more
atoms interact and are held
together (such as H20 or
C6H12O6)
• Compound- molecule that
contains 2 or more different
elements
• Chemical bond- attraction
that holds atoms together to
form a molecule
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Types of Chemical Bonds
Some atoms form single bonds such as hydrogen.
Carbon atoms may form single, double, or triple bonds
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Solutions
• Solution – Evenly distributed
mixture of 2 or more compounds
(Kool-aid)
• The 2 compounds in a solution are:
• Solvent - the primary component
– Thing doing the dissolving (water*)
• Solute - lesser component that is dissolved in the
solvent
– Thing getting dissolved (sugar)
• Solubility- describes how easily a
substance (solute) will dissolve in a
substance (Solvent)
– Highly soluble- sugar in water
– Insoluble- oil in water
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Ions:
electrically-charged atom or group of atoms
• Electrically-charged atom or
group of atoms
• Form when the atom or group of
atoms gains or loses 1 or more
electrons
– Negative charge - gain of an electron
– Positive charge - loss of an electron
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What Are Acids and Bases?
•
•
•
•
Acids – Donate hydrogen ions in solution
Bases – Accept hydrogen ions in solution
pH – Measure of acidity or alkalinity of a solution
Your body must maintain and acid-base balance
(homeostasis) to maintain your health! 7.35-7.45
– To maintain this it must use buffers (chemicals that can pick up
excess H+ or release H+ when there isn’t enough in the blood).
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What Is a Chemical Reaction?
• Chemical Reactionprocess that changes
atomic arrangement of
molecules
• Digestion- process by
which molecules in food
are mechanically and
chemically broken down
• Metabolism- chemical
reactions occurring in living
cells
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Metabolism
• Metabolism: the sum of
all chemical reactions
occurring in living cells.
– Catabolism –
break down
molecules
– Anabolism – build
up molecules
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What Is a Salt?
A salt forms when an acid reacts with a base.
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Enzymes
Enzyme – Protein that speeds up the rate of a
chemical reaction but is not altered during the
process
Names of most enzymes end in “ase”
sucrase lactase lipase protease
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Basic Physiology Concepts
• Anatomy
– Study of cells and
other body structures
• Physiology
– Study of how cells
and body structures
function
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The Cell
• Cell – Smallest
functional structure in a
living organism
– A human has ~ 100 trillion
cells.
• Organelles – Structures
within cells that perform
specialized functions
– Organelles include:
nucleus, mitochondria,
and ribosomes
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What Are Tissues?
• Tissues – Collection of
similar cells that perform
specialized functions
1. Epithelial tissue - Cells that
form linings and coverings
(skin, inner intestine)
2. Connective tissue - Cells
that hold together, protect,
and support organs (e.g.,
bone, fat, and blood)
3. Muscle tissue- moves
4. Nervous tissue- carries
electrical signals
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From Cells to Systems
Organ: Collection of tissues that perform a
specific function
System: Collection of organs that work together
to perform a major function
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The Organ Systems of the Human Body
1.
2.
3.
4.
5.
6.
Cardiovascular System
Respiratory System
Lymphatic System
Urinary System
Muscular System
Skeletal System
7. Nervous System
8. Endocrine System
9. Integumentary System
10.Reproductive System
11.Digestive System
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Cardiovascular
System
• Organs:
– Heart
– Blood Vessels
• Functions
– Transport
– Immune Response
– Temperature regulation
21
Chapter 4- Body Basics (Nutrition)
Respiratory
System
• Organs:
– Lungs
– Respiratory Passages
• Functions:
– Oxygen & carbon dioxide
exchange
– Helps regulate the bloods
pH
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Lymphatic
System
• Organs
–
–
–
–
–
Thymus
Spleen
Tonsils
Lymph Vessels
Lymph Nodes
• Functions
– Clean Blood and Lymph
– Fight Disease
– Aids in Fat absorption
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Urinary System
• Organs
–
–
–
–
Kidney
Ureter
Bladder
Urethra
• Function
– Removes waste from blood
– Regulates pH, Water
levels, and ion levels in the
blood
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Muscular System
• Organs
– Skeletal Muscle
• Function
– Produces body movements
– Maintains posture
– Produces heat
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Skeletal System
• Organs
–
–
–
–
Bones
Cartilage
Tendons
Ligaments
• Functions
–
–
–
–
–
–
Protection
Support
Body movements
Mineral Storage
Fat Storage
Blood cell production
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Nervous System
• Organs
–
–
–
–
Brain
Spinal Cord
Nerves
Sensors
• Functions
–
–
–
–
–
Major regulatory system
Controls mental activities
Controls movement
Controls movement
Controls physiologic
processes
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Endocrine
System
• Organs
– Endocrine glands like
the thyroid, adrenal
gland, ovaries, testis,
pancreas
• Functions
– Influences metabolism,
growth and reproduction
as well as many other
processes.
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Integumentary
System
• Organs
– Skin
– Hair
– Nails
• Functions
– Protection
– Temperature
regulation
– Vitamin D Production
– Reducing water loss
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Reproductive System
• Organs
– Male
• Testis
• Tubes
• Penis
– Female
•
•
•
•
Breasts
Ovaries
Uterus
Vagina
• Function
– Male
• Organ of copulation
• Produce Sperm
• Produce male
hormones
– Female
• Organ of copulation
• Produce ova
• Produce female
hormones
• House fetus
• Feed Baby once born
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Digestive
System
• Organs
–
–
–
–
Mouth
Esophagus
Stomach
Small Intestine
• Liver
• Pancreas
• Gallbladder
– Large Intestine
– Rectum
– Anus
• Functions:
– Mechanical
digestion
– Chemical
Digestion
– Absorption
– Elimination
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Digestion
and
Absorption
GI Tract
Muscular tube that
extends from mouth
to anus
Bioavailability
Extent to which
digestive tract
absorbs nutrients
and how well the
body uses them
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Mouth
• Digestion begins in the
mouth.
• Mechanical digestion
– Biting and grinding
actions break and mash
food into smaller pieces.
• Chemical digestion
– Saliva mixes and
lubricates food.
– Salivary amylase and
lipase begin breakdown of
starch and fat,
respectively.
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Taste and Smell of Foods
Taste Buds
– Specialized sensory structures
on the tongue and in the lining of
mouth and throat
Five Tastes: Sweet, sour,
salty, bitter, and umami
Smell
– Chemicals in food become
airborne and stimulate nasal
passages, contributing to sense of
taste
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Esophagus
• Esophagus – Hallow
muscular tube
connecting pharynx
to stomach
• Epiglottis – Flap that
folds down over
trachea (windpipe)
when you swallow
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What Happens When You Swallow?
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Peristalsis
• Muscular
contractions that
move small
amounts of food
and beverages
through intestinal
tract in a milkingtype motion
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The Stomach and Duodenum
• *Gastroesophageal sphincter is the go
between from the esophagus to the
stomach and helps regulate food
passage between them.
• Stomach is lined with cells that secrete
lots of mucus so that when food does
enter and *hydrochloric acid (HCl) is
secreted (along with other enzymes)
the stomach’s lining will not be
damaged.
• Food entering the stomach stimulates
the muscular walls to begin contracting
mixing the HCl and enzymes with food
beginning both chemical and
•Depending on the meals
mechanical digestion
content the stomach can
• This mixture is called Chyme
• The pyloric sphincter is responsible for take 3 to 4 hours to empty
regulating the emptying of the stomach
into the beginning of the small intestine
(Duodenum)
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Small Intestine
• Small hollow tube
extending from the
stomach to the large
intestine (~ 9-15ft long)
• Lumen-Hole in the tube
• SI- secretes ~ 1 ½ qts of
watery fluid into the
lumen/day
– Lubricates to help chyme
move thru SI
– SI also produces mucus
•
Protect tissue as chyme
moves
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Small Intestine
• 3 sections
1. Duodenum
•
•
•
10 “ long
Entrance into the SI where
chyme mixes with basic
secretions from the
Gallbladder and Pancreas
These secretions neutralize
the acid and aid in the
function of intestinal
enzymes
2. Jejunum
•
•
3-5.5 ft long
Most digestion and
absorption occur here
3. Ileum
•
•
5-9 ft long
Digestion and absorption
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Movement thru the SI
• Peristalsis
– Milking action
• Segmentation
– Contraction and
relaxation of muscular
rings in the SI to mix
chyme with secretions.
• TIME?
– ~ 3-5 hours to go from
beginning of SI to end
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Accessory Organs of the SI
Liver, Gallbladder, & pancreas
• Liver – processes and
stores many nutrients
• Makes cholesterol
and bile
• Gallbladder – stores
bile that aids in fat
digestion
• Pancreas – produces
and secretes many
digestive enzymes and
bicarbonate ions
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Absorbing Nutrients
• Villi
– Tiny projections that line the
small intestine
• Absorptive cells
– Remove nutrients from
chyme and transfer them
into intestinal blood or lymph
• Hepatic Portal Vein*
– Next Slide
• Lacteal
– Fats do not like going to
water and have to be
surrounded by a transporter
thus they can only fit into
the lacteal and not the
capillary
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Hepatic Portal Vein
• Things that are absorbed
in the intestines can’t just
go directly into the blood
they are transferred to
the liver to be checked.
Once this is done it may
be changed, destroyed,
stored, or allowed to
have access to the blood
stream. This is to
prevent “bad” from
getting thru and having
access to the entire body
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Large Intestine
1. Colon
2 Major sections
• Rectum – lower part
of large intestine
where feces are
stored until muscular
contractions move it
into the anal canal
then out the body
thru the anus
• External Anal
Sphinctervoluntarily controlled
muscle that allows
us to decide when
we release feces
• Without villi in the
LI there is no
carbohydrates, fat,
or protein
absorption mainly it
is water and
mineral absorption
that occur
• As water is
absorbed a
semisolid material
is prod’d called
Feces.
– Made-up of large
amounts of water
and bacteria
2. Rectum
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Cystic Fibrosis and
Inflammatory Bowel Disease
Cystic fibrosis
– An inherited, incurable disease
• Thick sticky mucus blocks passageways
• Mucus blocks pancreatic ducts, interfering with
nutrient digestion, especially fat
Inflammatory bowel disease
– Group of diseases that cause inflammation
and swelling of the intestines
• Includes Crohn’s disease & ulcerative colitis
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Microbes in Your Digestive Tract
• The large intestine contains vast
numbers of various types of bacteria,
that can:
1. metabolize undigested food material
2. make vitamin K and biotin
3. produce gas
• Bacteria eventually excreted in feces.
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Your Adaptable Digestive Tract
• Humans are omnivores
– Meaning we can digest and absorb nutrients from plants,
animals, fungi and bacteria
• Human digestive tract:
• Can handle combinations of foods such as
mixtures of animal & plant foods
• Can digest foods and absorb nutrients from
wide variety of sources, including:
–
–
–
–
Plants
Animals
Fungi
Bacteria
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