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The Cardiovascular System

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Title: The Cardiovascular System


1
The Cardiovascular System
2
Tasks of the CV System
  • Carry oxygen from the lungs to body cells.
  • Carrying carbon dioxide, a waste gas, from your
    cells back to the lungs to be exhaled.
  • Delivering other waste products to the kidneys
    for removal from the body.

3
Tasks of the CV System
  • Absorbing nutrients from food and delivering
    nutrients to body cells.
  • Helping white blood cells fight disease by
    attacking infectious organisms (pathogens).

4
The Heart
  • The heart is the muscle that makes the
    cardiovascular system work.
  • It consists of a special type of muscle called
    myocardium.
  • It is composed of 4 chambers
  • The 2 upper chambers are the atria
  • The 2 lower chambers are the ventricles

5
The Heart
  • A wall of tissue called the septum separates the
    4 chambers of the heart.
  • One way valves at the exits of each heart chamber
    guarantee that blood can flow in only one
    direction.

6
The Heart
  • A small area of the right atrium serves as a
    natural pacemaker, controlling the rate at which
    the heart beats.
  • Electrical impulses stimulate the atria to
    contract, forcing blood into the ventricles.
  • These electrical impulses travel through the
    heart to an area between the 2 ventricles.
  • There they stimulate the muscles of the
    ventricles to contract, pumping blood out of the
    heart

7
Blood
  • Blood is the fluid that delivers oxygen,
    hormones, and nutrients to the body cells and
    carries away waste that the cells produce.
  • Blood is produced in the bone marrow of long
    bones.

8
Blood
  • Plasma
  • The fluid in which other parts of the blood are
    suspended.
  • It makes up 55 of the total blood volume.
  • Its mainly water (92), but also contains
    nutrients, proteins, salts, and hormones.

9
Blood
  • Red Blood Cells
  • The cells that transport oxygen and carbon
    dioxide molecules.
  • Makes up about 40 of normal blood
  • Each red blood cell contains hemoglobin, a
    protein in the blood which
  • Contains iron that binds with oxygen and carbon
    dioxide molecules
  • Gives the blood its red color

10
Blood
  • White Blood Cells
  • The cells that protect the body against
    infection.
  • Some white blood cells
  • Surround and ingest the organisms which cause
    disease.
  • Form antibodies that provide immunity against a
    second attack from a specific disease
  • Fight allergic reactions

11
Blood
  • Platelets
  • The cells in the blood that cause blood clots to
    form.
  • When the wall of a blood vessel tears, they
    collect at the tear and release a chemical which
    causes the blood to produce small fibers (fibrin)
    which trap the platelets along with red and white
    blood cells.
  • The mass of fibrin, platelets, and red and white
    blood cells plug the injury and forms a clot
    which dries to form a scab.

12
Blood Vessels
  • Blood is distributed throughout the body through
    a network of vessels.
  • There are more than 60,000 miles of blood vessels
    in your body.
  • The blood vessels are divided into
  • Arteries
  • Capillaries
  • Veins

13
Blood Vessels
  • Arteries
  • Blood vessels that carry oxygenated blood away
    from the heart.
  • They branch into progressively smaller vessels
    called arterioles which deliver blood to the
    capillaries.
  • The arteries thick walls enable it to withstand
    the high blood pressure it is subjected to every
    time the heart beats.

14
Blood Vessels
  • The artery walls are composed of three layers
  • A tough, fibrous outer layer
  • A thick muscular middle layer
  • An inner layer of smooth epithelial cells

15
Blood Vessels
  • The muscular wall of the artery helps the heart
    pump the blood by contracting when the heart
    relaxes.
  • Since it keeps pace with the heart, we can
    measure heart rate by counting the contractions
    of the artery (pulse)

16
Blood Vessels
  • Capillaries
  • The small blood vessels that carry blood from the
    arterioles to the venules which empty into veins.
  • Some capillaries are 50 times thinner than a
    strand of hair.

17
Blood Vessels
  • It is through the thin capillary walls that
    oxygen and nutrients pass from the blood to body
    cells, and waste products move from cells into
    the blood.

18
Blood Vessels
  • Capillaries near the skins surface dilate (open)
    or constrict (close) to help regulate the bodys
    temperature.

19
Blood Vessels
  • Veins
  • The blood vessels that return deoxygenated blood
    to the heart.
  • The walls of the veins are thinner than those of
    the arteries, so blood is visible through the
    skin on some parts of your body.
  • The blood appears blue because your skin refracts
    light.

20
Blood Vessels
  • Many veins have valves, that along with muscle
    contractions from surrounding muscles, help
    prevent the backflow of blood as its pumped back
    to the heart.

21
Circulation of Blood
  • Pulmonary Circulation
  • The movement of blood from the heart, to the
    lungs, and back to the heart again.
  • Deoxygenated blood enters the right atrium
    through the vena cava.
  • The right atrium contracts, pushing the blood
    into the right ventricle.
  • The right ventricle contracts, pushing the blood
    into the pulmonary artery.
  • The pulmonary artery takes the blood to the lung

22
Circulation of Blood
  1. In the lung, deoxygenated blood is exchanged for
    oxygenated blood
  2. The pulmonary vein takes the oxygenated blood to
    the left atrium.
  3. The left atrium contracts, pushing the blood into
    the left ventricle.
  4. The left ventricle contracts, pushing the blood
    into the aorta.

23
Circulation of Blood
  • Systemic Circulation
  • The movement of blood to and from the heart.
  • It delivers oxygen and nutrients to the tissues
    of the body and the movement of deoxygenated
    blood and waste products to the heart.

24
Circulation of Blood
  • Coronary Circulation
  • The movement of blood through the tissues of the
    heart.
  • Serious heart damage may occur if the heart
    tissue does not receive a normal supply of food
    and oxygen.

25
Blood Pressure
  • Blood pressure is a measurement 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.

26
Blood Pressure
  • Systolic Pressure the maximum pressure as your
    heart contracts to push blood into your arteries.
  • Diastolic Pressure the pressure at its lowest
    point where your heart is relaxed.

27
Blood Pressure
  • A healthy persons blood pressure will vary
    within the normal range of 120/80.
  • Blood pressure above 140/90 is considered high
    and places a strain on the heart and can lead to
    cardiovascular disease.

28
Blood Types
  • There are two distinct chemical molecules, called
    antigens, present on the surface of red blood
    cells.
  • Blood type is determined by the presence or
    absence of these antigens.
  • Type A A antigen present
  • Type B B antigen present
  • Type AB Both antigens present
  • Type O Neither antigen present

29
Blood Types
  • If two different blood types are mixed together,
    the blood cells may clump together in the blood
    vessels, causing a potentially fatal situation.
  • It is important that blood types be matched
    before blood transfusions take place.
  • In an emergency, type O blood can be given
    because it is most likely to be accepted by all
    blood types. However, there is still a risk.

30
Rh Factor
  • Most blood also contains a certain protein called
    the Rh factor.
  • If your blood contains this protein, you are
    referred to as Rh positive.
  • Blood that doesnt contain this protein is called
    Rh negative.

31
Rh Factor and Pregnancy
32
Care Problems of the CV System
  • Follow a well-balanced diet low in saturated
    fats, cholesterol, and salt
  • Maintain a healthy weight to reduce stress on the
    heart, blood vessels and lymph vessels
  • Participate in regular aerobic exercise at least
    30 minutes three or four times per day

33
Care Problems of the CV System
  • Avoid the use of tobacco products and exposure to
    secondhand smoke.
  • Avoid illegal drugs, including stimulants,
    marijuana, and ecstasy.

34
Problems of theCardiovascular System
35
Congenital Heart Defects
  • Congenital is any condition that is present at
    birth.
  • One common type is a septal defect, in which a
    hole in the septum allows oxygenated blood to mix
    with deoxygenated blood and affects the pumping
    efficiency of the heart.

36
Congenital Heart Defects
  • Other defects include valves which may not
    function properly, or the aorta may be abnormally
    narrow, reducing the amount of blood flowing to
    the body.

37
Congenital Heart Defects
  • In many cases the cause of a congenital defect is
    unknown, but the use of alcohol and other drugs,
    or certain infections during pregnancy may be
    associated with heart defects in newborns. It may
    also be hereditary.
  • Most defects require medication and possibly
    surgery to repair the affected portion of the
    heart.

38
Cardiovascular Disease
  • A group of diseases that include hypertension,
    heart disease, and stroke.
  • It is the number one killer of both men and women
    among all racial and ethnic groups in the U.S.,
    killing about 95,000 Americans each year.
  • Many of these diseases are associated with
    lifestyle behaviors.

39
Heart Murmur
  • Abnormal sounds that are made as blood flows
    through the heart.
  • It can be caused by a defective valve that is too
    narrow causing blood to be pushed through the
    restricted opening with more force than normal,
    or a valve that doesnt close properly allowing
    blood to leak back through it.
  • Most murmurs are slight and disappear without
    treatment, while others may require surgery

40
Varicose Veins
  • Varicose veins form if the valves in veins do not
    close tightly enough to prevent backflow of
    blood, causing the veins to become large and
    painful.
  • They most commonly occur in the legs.
  • Weakened valves can be the result of a congenital
    defect, or natural aging.

41
Varicose Veins
  • Physical activity helps prevent varicose veins.
  • Treatment includes
  • reducing standing time
  • Exercise
  • Elevating legs when sleeping
  • In extreme cases, surgery to remove the affected
    vein.

42
Anemia
  • A condition in which the ability of the blood to
    carry oxygen is reduced.
  • It can result from low numbers of red blood cells
    or from low concentrations of hemoglobin in the
    blood.
  • The most common cause is iron deficiency, which
    can be avoided by eating foods high in iron.
  • Taking an iron supplement may also be recommended.

43
Anemia
  • Sickle cell anemia is a special form of anemia
    where the red blood cells are sickle shaped. They
    are stiff and sticky and tend to clump and block
    blood flow in the blood vessels of the limbs and
    organs, causing pain.

44
Leukemia
  • A form of cancer in which any one of the
    different types of white blood cells is produced
    excessively and abnormally.
  • The abnormal white blood cells cannot function
    properly, making the patient very susceptible to
    infection

45
Leukemia
  • The uncontrolled production of white blood cells
    can hinder production of red blood cells and
    platelets resulting in infection, severe anemia,
    or uncontrolled bleeding.

46
Leukemia
  • Treatment options include
  • Chemotherapy
  • Radiation therapy
  • Bone marrow transplants

47
Hemophilia
  • An inherited disorder in which the blood does not
    clot properly.
  • Certain proteins, called clotting factors, are
    not present.
  • This may cause uncontrolled bleeding that can
    occur spontaneously, or as the result of injury.

48
Hemophilia
  • Bleeding may take place internally in muscles,
    tissues of the digestive or urinary tract, and
    the joints.
  • It may also occur externally as the result of
    injury or surgery.

49
Hemophilia
  • Treatment includes injections that introduce the
    missing clotting factors into the blood, which
    are extracted from blood donated by healthy
    individuals.
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