Chapter 10
•Circulation
Section 1
•The Body’s
Transport System
The Cardiovascular System
• The cardiovascular system, or circulatory
system, consists of the heart, blood vessels,
and blood.
• The system is carries needed substances to
cells and carries waste products from cells.
– The cells in blood also helps to fight disease and
infecto
The Circulatory System
• Substances in the body are carried by the
blood.
– Oxygen from your lungs
– Glucose for energy
• Waste is also eliminated by cells in the body.
– Carbon dioxide from glucose
• Certain cells in the blood also fight infection
and disease.
The
Lungs
Heart
Red is oxygen rich blood
Blue is oxygen poor
blood
The Heart
• The heart is a hollow, muscular organ that
pumps blood throughout your body
– About the size of your fist, located in the center of
your chest, right behind your sternum
• Each time your heart beats, it pushes blood
through the blood vessels of the
cardiovascular system
– Heart is made out of cardiac muscle
The
The Heart
• The right side of the heart is completely
separated form the left side by tissue called
the septum.
• Each side has 2 compartments, or chambers,
an upper and lower chamber.
• Each upper chamber is called an atrium
– The atrium is the chamber that recieves blood
that comes into the heart
The Heart
• The lower chamber is called a ventricle.
– The ventricle pumps blood out of the heart
• The atrium and ventricle are separated by
valves.
– A valve is a flap of tissue that prevents blood from
flowing backwards.
The Heart
• How the heart works
– In the first phase the heart relaxes and fills the
heart with blood.
– In the 2nd phase the heart contracts to pump
blood forward.
Two Loops
• After leaving the heart blood travels in blood
vessels through the body.
• Arteries are blood vessels that carry blood
away from the heart.
• Narrow vessels are called capillaries.
– In capillaries substances are exchanged between
blood and cells.
• Veins are what carry blood back to the heart.
Two Loops
• In the 1st loop blood travels from the heart to
the lungs and then back to the heart.
• In the 2nd loop blood is pumped from the
heart throughout the body and then back to
the heart
The Heart
Two Loops
• Blood that flows to the lungs and back, the
blood is a dark red, which is oxygen poor.
• Blood flows from the right atrium into the
right ventricle.
• The ventricle pumps the blood to the lungs
• The large vessels of blood become thinner,
into tiny capillaries
• The blood then absorbs oxygen and pumps
back to the heart.
Two Loops
• In the 2nd loop, the left atrium recieves the
blood and then moves to the left ventricle.
• The blood then moves through the aorta, the
largest vein in the body.
• The blood then pumps through the veins
throughout the body into capillaries and then
flows back to the heart to start the cycle
again.
Section 2
•A Closer Look
at Blood Vessels
Arteries
• If all the veins, arteries and capillaries in your
body were connected, they would be 100,000
kilometers long.
• When blood leaves the heart, it travels
through the arteries.
• The first branches of arteries are called
coronary arteries.
– Other branches carry blood to the brain, intestines
and other organs.
Arteries
• The walls of the arteries are thick.
• The walls consist of 3 layers
– First layer is epithelial tissue
• The smooth surface allows for the blood to flow freely
– Second layer is muscle tissue
– Outer layer is a flexible connective tissue
• This layered effect gives arteries great strength
and flexibility
Arteries
• Your pulse is caused by the alternating
expansion and relaxation of the artery wall.
• The layer of muscle tissue acts as a control
gate of blood flow
– So when you eat, your stomach and intestines
need more blood
– The arteries leading to these organs relax allowing
for greater blood flow
Capillaries
• In the capillaries, materials are exchanged
between the blood and the body’s cells.
– Materials such as glucose and oxygen pass from
the blood to the cells.
• Capillary walls are only one cell thick
• Diffusion is the process by which molecules
move from an area of higher concentration to
an area of lower concentration.
Veins
• After the blood moves through the capillaries
it enters large vessels called veins which carry
blood back to the heart.
• The walls of the veins are like the artery, the
have 3 layers, which muscle in the middle
Veins
Blood Pressure
• Blood pressure is like water flowing out of a
hose
– More water, greater pressure, less water less
pressure
• Blood exerts a force called blood pressure
against the walls of blood vessels
• Blood pressure is caused by the force with
which the ventricles contract
Section 3
•Blood and
Lymph
Blood
• Blood is a complex tissue that has several
parts.
• Blood is made up of 4 components
– Plasma
– Red blood cells
– White blood cells
– Platelets
Blood
• Most of the materials transported in the blood
is plasma
• Plasma is the liquid part of the blood
– Water makes up 90% of plasma
– Other 10% is dissolved materials
• Plasma carries glucose, fats, vitamins and
minerals
• Protein gives plasma its yellow color
Blood
• Red blood cells take up oxygen in the lungs
and deliver it to cells elsewhere in the body
• Red blood cells are made mostly of
hemoglobin, which is an iron containing
protein that binds to oxygen molecules
– When combined with oxygen its turns bright red
– Carbon dioxide is carried mostly by the plasma
• Red blood cells contain no nuclei, and live only
120 days and there are 2 million red blood cell
Blood
• White blood cells are the body’s disease
fighters
• These cells either fight disease or tell the brain
they need help
– Some fight by eating, other fight by releasing
chemicals
– White blood cells are also larger than red blood
cells
Blood
• Platelets are cell fragments that help to form
clots
• This series of reactions produce a protein
called fibrin
• Fibrin weaves a net of fibers across the cut in
the skin
Blood
Blood Types
• Sometimes when a person loose a lot of
blood, a blood transfusion is necessary.
• There are 4 blood types
– A, B, AB and O
• A means there is an A marker, B means a B
marker, AB means there is an A and B marker.
O has neither A or B
Blood Types
• The markers molecules on your red bloods
cells determine your blood type and the type
of blood you can receive for a transfusion.
Blood Types
Lymphatic System
• The lymphatic system is your body’s drainage
system.
• The lymphatic system is a network of veinlike
vessels that returns the fluid to the
bloodstream
– It acts like rain gutters carrying excess fluid away
• Once the fluid is in the lymphatic system it is
called a lymph.
– Consists of water and dissolved materials
Lymphatic System
• As the fluid flows through lymphatic system it
passes through knobs called lymph nodes.
• Lymph nodes filter lymph, trapping bacteria
and other disease causing microorganisms in
the fluid.
• When the body is fighting disease the nodes
become enlarged.
– This is called swollen glands.
Section 4
• Intergrading
Health:
Cardiovascular
Health
Cardiovascular Diseases
• Diseases of the cardiovascular system include
artherosclerosis and hypertension
• Artherosclerosis is a condition in which an artery
wall thickens as a result of fatty buildup.
– One substance is cholesterol
• A heart attack occurs when blood flow to part of
the heart is blocked
– Cells die during an attack, so there is permanent
damage
Cardiovascular Disease
• Hypertension, or high blood pressure, is the
blood pressure is higher than normal.
– This makes the heart work harder than it has to
• Hypertension and artherosclerosis are closely
related diseases.
Keeping Healthy
• To stay healthy people should:
– Exercise and diet
– Avoid smoking
– Eat a balanced diet low in saturated fats, trans
fats, cholesterol, and sodium.