Chapter Introduction
Lesson 1
Transport
and Defense
Lesson 2
Structure,
Movement,
and Control
Lesson 3
Reproduction
and Development
Chapter Wrap-Up
CMCD/Getty Images
What are the functions
of the human body
systems?
Transport and Defense
• How do nutrients enter and leave the
body?
• How do nutrients travel through the
body?
• How does the body defend itself from
harmful invaders?
Transport and Defense
• organ system
• lymphocyte
• homeostasis
• immunity
• nutrient
• Calorie
The Body’s Organization
Organ
System
Cell
Tissue
Organ
Organism
MedicalRF.com/Getty Images
The Body’s Organization
• Groups of organs
that work together
and perform a
specific task are
organ systems.
MedicalRF.com/Getty Images
• Organ systems provide movement,
transport substances, and perform many
other functions.
The Body’s Organization (cont.)
Organ systems
work together and
maintain
homeostasis, or
steady internal
conditions when
external conditions
change.
Digestion and Excretion
• The human body
breaks down food
through the
process of
digestion.
• Types
Digestion
– Mechanical (physical)
• Chew
• Tear
• Grind
• Mash
• Mix
– Chemical
• Enzymes releases or secreted to improve digestion of
– Carbohydrates
– Proteins
– Lipids
Digestion
Food enters the
digestive system
through the mouth.
Hutchings Photography/Digital Light Source
Digestion (cont.)
The esophagus
connects the
mouth to the
stomach—a
flexible baglike
organ that contains
enzymes that
break down food
into smaller parts
to be used by the
body. (chyme)
Hutchings Photography/Digital Light Source
Digestion (cont.)
• The small
intestine has
two functions—
digestion and
absorption.
• Nutrients are
absorbed by the
body through the
small intestine.
Hutchings Photography/Digital Light Source
Digestion (cont.)
The liver makes
bile and the
pancreas makes
enzymes, both of
which break down
food in the small
intestine.
(length)
Hutchings Photography/Digital Light Source
Digestion (cont.)
• The large intestine
receives solid waste
from the small
intestine.
• The large intestine
absorbs excess water
from the waste
material.
(Length)
Digestion (cont.)
• The rectum of the large intestine stores
the solid waste until the waste is expelled
from the body.
Digestion (cont.)
Some foods, like insoluble fiber, that are not
digested leave the body through the rectum.
Digestion (cont.)
• Nutrients are the parts of food used by
the body to grow and survive.
• Proteins, fats, carbohydrates, vitamins,
and minerals are all nutrients.
Digestion (cont.)
• Calories are a measure of the amount
of energy in food.
Digestion and Excretion
• Substances that are not used by the
body are removed through the digestive
system and by the excretory system.
Excretion
The excretory system removes liquid and
gas wastes from the body. This system
includes—
• Lungs
• ureter
• skin
• bladder
• liver
• urethra
• kidneys
Excretion
The excretory system removes liquid and
gas wastes from the body. This system
includes—
• Lungs (CO2)
• Skin (Sweat)
• Ureter
(connecting tube)
• Liver (Urea)
• Bladder (stores
urine)
• Kidneys
(Urine)
• Urethra (expels
urine)
Excretion (cont.)
• When the liver breaks down proteins,
urea forms. Urea is toxic if it stays in the
body.
Excretion (cont.)
• The kidneys remove urea from the body
by making urine.
Excretion (cont.)
• Urine leaves
each kidney
through the
ureter and is
stored in a
flexible sac,
called the
bladder.
• Urine is removed from the body through
the urethra.
How does food enter and
leave the body?
Respiration
The respiratory
system
exchanges
gases between
the body and
the environment.
Respiration (cont.)
• When you inhale,
air enters the nostrils
and passes through the
pharynx to the trachea.
Respiration (cont.)
• Inhaling and exhaling require the movement
of a muscle under the lungs called the
diaphragm.
Respiration (cont.)
The trachea, or
windpipe,
connects the
pharynx to the
bronchi.
Respiration (cont.)
There are two
bronchi; one enters
the left lung and
one enters the
right lung.
Respiration (cont.)
The bronchi divide into smaller tubes that
end in tiny groups of cells called alveoli.
The alveoli are surrounded by blood vessels
called capillaries.
Gas Exchange
Respiration (cont.)
vessel
Science Use a tube in the body
that carries fluids such as blood
Common Use a ship
Circulation
• Oxygen in the alveoli enters the capillaries.
• The blood inside capillaries transports
oxygen to the rest of the body.
Circulation (cont.)
The heart, blood, and
blood vessels make up
the circulatory system
which transports
nutrients, gases, wastes,
and other substances
through the body.
Image Source/Jupiterimages
Circulation (cont.)
• Blood vessels
transport blood to
all organs of the
body.
• Blood travels
through the body
in tiny tubes
called vessels.
Circulation (cont.)
• Contractions of the heart’s muscles
pump blood to the rest of the body.
Circulation (cont.)
• Arteries carry
blood away
from your
heart.
• Veins carry
blood back to
your heart.
Circulation (cont.)
Capillaries are
tiny vessels that
allow gases and
nutrients to
move between
the blood and
the entire body.
Circulation (cont.)
How do nutrients travel through
the body?
Blood
Blood
Blood
1. Formed elements
 Red Blood Cells
 White Blood Cells
 Platelets
2. Plasma
Blood
Plasma accounts for 55
% of the volume of whole
blood.
92% of plasma is water,
the rest consists of
dissolved substances.
Blood
Red blood cells are the most
common type of blood cells and its
main job is to deliver oxygen to
body cells.
They are Disk Shaped
Blood
 There are roughly 5 million RBCs in each microliter of
blood
1 microliter = 0.001 ml
 RBCs live for about 120 days (4 months)
Blood
 White blood cells
are cells involved in defending
the body.
 There are 4,500 to 10,000
WBCs in each microliter of
blood
 White Blood Cells help fight
infections, bacteria and viruses.
 WBCs live for 2 days to 2
months.
Blood
 Platelets are not cells. They are
cell fragments. Platelets help
clot blood and heal wounds.
 There are 150,000 to 450,000
platelets in each microliter of
blood
 The average lifespan of a
platelet is normally just
5 to 9 days
Blood
Blood
Blood
Blood
Lymphatic System
Tonsils, the spleen,
the thymus, bone
marrow, and lymph
nodes are parts of
the lymphatic
system.
C Squared Studios/Getty Images
Lymphatic System (cont.)
• The lymphatic
system’s three
main functions
are:
Lymphatic System (cont.)
• removing excess fluids around organs
Lymphatic System (cont.)
• producing white blood cells
Lymphatic System (cont.)
• and absorbing and transporting fats.
Lymphatic System (cont.)
• The lymphatic system helps your body
maintain fluid homeostasis.
Lymphatic System (cont.)
• Fluid that travels
through the lymph
vessels flows into
organs called
lymph nodes,
which protect the
body by removing
toxins, wastes,
and other harmful
substances.
Lymphatic System (cont.)
• The lymphatic system (Thymus) makes
white blood cells called lymphocytes to
help the body defend against infection.
Immunity
• Protection from infection or toxins is
called immunity.
Immunity
• The skeletal system produces immune
cells, which include lymphocytes and
other white blood cells, and the
circulatory system transports them
throughout the body.
Immunity
• The immune cells attack and destroy
viruses, bacteria, and other foreign
substances.
Immunity (cont.)
• Humans make billions of different types
of antibodies.
Immunity (cont.)
• Infectious diseases are caused by
pathogens, such as bacteria and viruses,
and are usually contagious.
Immunity (cont.)
• A noninfectious disease is caused by the
environment or a genetic disorder.
Immunity (cont.)
Immunity (cont.)
• The body’s first
line of defense
against viruses,
bacteria, and
harmful
substances is the
skin and mucus
which prevent
toxins and other
substances from
entering the body.
Immunity (cont.)
• The second
line of defense
is the immune
response in
which white
blood cells
attack and
destroy harmful
substances.
Immunity (cont.)
The third line
of defense is
immune cells
which make
antibodies
that destroy
harmful
substances.
• Workbook p.68 (Characterize the parts of
blood)
• + all p.69
• The kidneys remove
liquid wastes from the
body.
• The circulatory
system transports
nutrients, gases,
wastes, and other
substances through
the body.
• Immune cells detect
and destroy viruses,
bacteria, and other
foreign substances.
Which does NOT help remove
waste from the body?
A. kidneys
B. liver
C. lungs
D. white blood cells
The heart, blood, and vessels
make up what system?
A. circulatory
B. excretory
C. lymphatic
D. respiratory
Which term refers to maintaining
steady internal conditions as
external conditions change?
A. calories
B. homeostasis
C. immunity
D. nutrients