Transcript The Skeletal System

The Cardiovascular
System
Warm-up:
•FREE WRITE
Why the Blood Circulates
• Your heart pumps blood to your body’s cells 24 hours
a day, even when you’re asleep.
• Your heart accomplishes the following important tasks:
• Carries oxygen from the lungs to body cells.
• Absorbs nutrients from food and delivers nutrients to
body cells.
• Carries carbon dioxide, a waste gas, from your cells back
to your lungs to be exhaled.
• Delivers other waste products to the kidneys for removal
from the body.
• Helping the white blood cells fight disease by attacking
infectious organisms.
The Cardiovascular System
• The cardiovascular system consists of the heart, blood, and
blood vessels.
• How far do you think your blood vessels would stretch, if
laid out end to end?
• 60,000 miles
• That’s enough to circle the earth two and a half times.
How Blood Circulation Works
• The Heart
• It is the muscle that makes the cardiovascular system work.
• The heart has four chambers:
• The two top chambers are called atria.
• The two lower chambers are called ventricles.
• Valves between the atria and ventricles allow blood to flow through
the chambers.
• At the top of the right atrium is an area of muscle that acts as a
pacemaker for the heart called the sinoatrial node.
• Electrical impulses stimulate the atria to contract, forcing blood into
the ventricles.
• These electrical impulses travel through the heart to an area between
the two ventricles, to stimulate them to contract, pumping blood out
of the heart.
How Blood Circulates Cont.
• Pulmonary circulation:
• Process by which blood moves between the heart and
the lungs.
• During this process:
• #1 - blood that has lost oxygen travels back from
the body picking up carbon dioxide and wastes;
• #2 – This blood then travels back through the right
side of the heart;
• #3 - The heart then pumps the blood to the lungs;
Pulmonary circulation cont.
• #4 - In the lungs the carbon dioxide is
dumped off and the blood is reloaded with
fresh oxygen.
• #5 – The freshly reloaded blood travels back
to the left side of the heart;
• #6 - The heart then pumps fresh oxygenated
blood out to the rest of the body.
• http://youtu.be/oZ1_TAwCUWw
Blood Components
• It is the fluid that
delivers oxygen,
hormones, and nutrients
to the cells and carries
away wastes.
• Blood is made up of:
• Plasma – the fluid in
which other parts of
the blood are
suspended.
• 55% of blood volume
• Mainly water, but it
also contains nutrients,
proteins, salts, and
hormones.
• Red Blood Cells
• Make up 40% of
normal blood.
• Contain hemoglobin –
the oxygen-carrying
protein in blood.
• Hemoglobin contains
iron that binds with
oxygen in the lungs
and releases the
oxygen in the tissues.
• Hemoglobin also
combines with carbon
dioxide.
Blood Components Continued
• White Blood Cells
• Protect the body against infection.
• Some white blood cells surround and ingest the
organism causing disease.
• Others form antibodies that provide immunity against a second
attack from that specific disease.
• Other types fight allergic reactions.
• Platelets
• Types of cells in the blood that cause
blood clots to form.
• When the wall of a blood vessel tears,
platelets collect at the tear.
• They release chemicals that produce small thread-like fibers
that trap nearby cells and help form a clot.
• The clot blocks the flow of blood and dries to form a scab.
Blood Vessels
• Carry blood throughout the body.
• There are three main types of blood vessels:
• Arteries – blood vessels that carry oxygenated blood
away from the heart.
• Arteries branch into progressively smaller vessels
arterioles.
• Arterioles deliver blood to the capillaries.
• Capillaries – small vessels that carry blood from
arterioles and to small vessels called venules, which
empty into veins.
• Form a vast network throughout tissues and organs in
the body.
Blood Vessels
• Veins – blood vessels that return blood to the heart.
• Walls are thinner and less elastic than the arteries.
• Many veins have valves that help prevent the back
flow of blood that is pumped back to the heart.
• When surrounding muscles contract they help exert
pressure on the vein walls, helping to move blood
against gravity to the heart.
• http://youtu.be/CjNKbL_-cwA
Maintaining Your Circulatory System
• Many cardiovascular system problems appear later in life.
However you can reduce your risk of this problems later in
life by making healthy decisions throughout your life.
• Some helpful behaviors that should become regular habits for
a healthy heart:
• Eat a well-balanced diet
• Maintain a healthy weight for your body type
• Participate in regular aerobic exercise for at least 150 minutes a
week.
• Avoid tobacco smoke and using tobacco products.
• Avoid illegal drug use
• Get regular medical check ups.
Blood Pressure
• Blood pressure – a measure of the amount of force that the
blood places on the walls of blood vessels, particularly large
arteries, as it is pumped through the body.
• A blood pressure reading includes 2 numbers.
• The 1st measures your systolic pressure – the maximum pressure
as your heart contracts to push blood into your arteries.
• The 2nd/bottom number measures your diastolic pressure – the
pressure at its lowest point when your ventricles relax.
• What is considered a healthy blood pressure?
• 120/80 or below
• What is considered to be high and places strain on the heart?
• 140/90 and above
• http://www.ehow.com/video_4398719_why-blood-pressure-important.html
Cardiovascular System Problems
• Some cardiovascular problems are inherited; others result from
illness, diet, or aging.
• Congenital heart defects
• Conditions of the heart that are present at birth.
• Septal defect – whole in septum allowing oxygenated blood to
mix with oxygen-depleted blood.
• Atherosclerosis
• Caused by the narrowing and stiffening of the arteries due to fatty
deposits accumulating in their walls. Can lead to a heart attack.
• Heart murmurs
• Unusual sounds produced by turbulent blood flow may be do to a
heart valve defect.
• Heart attack
• Also known as a myocardial infarction.
• Occurs when an area of cardiac muscle is deprived of blood, and
therefore oxygen, due to a blockage in an artery.
• The most common cause is iron deficiency.
• Thrombosis
• The partial or total blockage of an artery, vein, or even the heart
can occur when a clot (thrombus) forms due to a circulatory
problem.
• Caused by fatty build up or inflammation of the blood vessel.
• Leukemia
• Form of cancer in which white blood cells are produced
excessively and abnormally.
• Causes one to be susceptible to infection.
Heart Disease
• http://youtu.be/3cW8__wFXDA
• http://youtu.be/JtFV1EGI3B4
Assignment
•Blood Flow Diagram
DUE TOMORROW