CARDIOVASCULAR SYSTEM(Circulatory System)

CARDIOVASCULAR SYSTEM(Circulatory System)• It is a system that is created to transport materials like nutrients and

even waste products throughout the body cells and organs.

According to McGraw-Hill (2009)

• It consists of the HEART, BLOOD and BLOOD VESSELS.

• It sends blood to LUNGS (for oxygen) and DIGESTIVE SYSTEM (for nutrients)

• It circulates waste products to certain organ systems for removal from blood.

Characteristics of the circulatory system

• Connects all parts of an organism• Allows individual cells to thrive as well as for organisms

to function as a unit• It is an entirely CLOSED SYSTEM

The HEART is a cardiac involuntary muscle that pumps blood throughout the blood vessels reaching body organs

Extends from the levelof the 2nd rib to about the level of the 6th rib

in the MEDIASTINUM

2009 The McGraw-Hill Companies

made of cardiac muscle

surrounded by the PERICARDIUM

The HEART is bordered laterally by the lungs, posteriorly by the vertebral column & anteriorly by the sternum

Heartbeat: 72 beats per minute (100,000 times each day)

rests on the diaphragm inferiorly

2009 The McGraw-Hill Companies

Cone-shaped organ about the size of a clenched fist; mass (250 to 350 grams)

2009 The McGraw-Hill Companies

Innermost layer; thin & smooth;Stretches as the heart pumps

Structure of the Heart(cross section)

Innermost layer; directly on the heart

Covers the heart & large blood vessels

layer on top of the visceral pericardium

Outermost layer; fat to cushion heart

Middle layer; primary cardiac muscle

2009 The McGraw-Hill Companies

The Heart consists of four (4) chambers. The atrioventricular septum separates the atria from the ventricles.

TWO VENTRICLES

• lower chambers(left & right)

• pump blood throughout the body

• larger; thick muscular wall

• Separated byVENTRICULAR SEPTUM

Two ATRIA

• upperchambers (left & right)

• pumps blood into the 2 lower

chambers• thin walls &

smaller• separated by

ATRIAL SEPTUM

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The Heart also consists of four (4) valves.

Prevents blood from flowing back into the right atrium when the right ventricle contracts

Prevents blood from flowing back into the LEFT ventricle

Prevents blood from flowing back into the LEFT atrium when the ventricle contracts

Prevents blood from flowing back into the RIGHT ventricle

The heart rate or pulse rate is the number of times your heart beats every minute.

• Consists of 2 parts: DIASTOLE & SYSTOLE

• DIASTOLE (heart muscle relaxes, allowing blood to flow into the atria and ventricles)

• SYSTOLE (ventricles contract, pumping blood to the body)

• NODES (masses of nerve & muscle cells – control center of the heart)

1) PACEMAKER or SA NODE (signals atria to contract)

2) AV NODE (relay signals to ventricles to pump blood out

of the heart)

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Blood Pressure• Force blood exerts on the inner walls of blood vessels

• Highest in arteries

• Lowest in veins

• Systolic pressure

• Ventricles contract

• Blood pressure is at its greatest in the arteries

• Diastolic pressure • Ventricles relax

• Blood pressure in arteries is at its lowest

• Reported as the systolic number over the diastolic number

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Blood Pressure • Control is based mainly on the amount of blood pumped out of the

heart

• The amount of blood entering should equal the amount pumped from the heart

• Starling's law of the heart

• Blood entering the left ventricle stretches the wall of the ventricle

• The more the wall is stretched

• The harder it will contract and thee more blood it will pump out

Heart Sounds

One cardiac cycle – two heart sounds (lubb and dubb) when valves in the heart snap shut

Lubb – First soundwhen the ventricles contract, the tricuspid and bicuspid valves snap shut

Dubb – Second sound when the atria contract and the pulmonary and aortic valves snap shut

Blood is a type of connective tissue.

It consists of the following:• Red blood cells

(erythrocytes) • White blood cells

(leukocytes) • Platelets – cell

fragments • Plasma – fluid part of

blood

Average-sized adult has 4 to 6

liters of blood

Amount depends on:

Size of person

Amount of adipose tissue

Concentrations of ions

Females have less than

males

Blood Components

•Hematocrit • The percentage of red

blood cells•Normal is about 45%

•Plasma = 55%

(White cells and

platelets = 1%)

Red Blood Cells• Erythrocytes

• Transport oxygen throughout the body

• Small biconcave-shaped cells

• The pigment in RBCs is called HEMOGLOBIN• Oxyhemoglobin carries oxygen;

bright red

• Deoxyhemoglobin DOES NOT carry oxygen; darker red • Carries carbon dioxide, so also called

carboxyhemoglobin

• Anemia – low RBC count

• Erythropoietin – regulates production of RBCs

White Blood Cells (WBC)• Granulocytes• Neutrophils (55%) –

destroy bacteria, viruses, and toxins in the bloodstream (phagocytes)

• Eosinophils (3%) – get rid of parasitic infections such as worm infections

• Basophils (1%) – control inflammation and allergic reactions

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White Blood Cells (WBC)•Agranulocytes

•Monocytes (8%) –destroy bacteria, viruses, and toxins in blood

• Lymphocytes (33%) –provide immunity for the body

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White Blood Cells (WBC)

•WBC count normally 5,000 to 10,000 cells per cubic millimeter of blood• Leukocytosis • Elevated WBC count•Usually due to infection

• Leukopenia • Low WBC count• Some viral infections and other conditions

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Platelets

• Fragments of cells found in the bloodstream

• Also called thrombocytes

• Important in the clotting process of blood

• Normal count•130,000 to 360,000

platelets per cubic millimeter of blood

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Bleeding Control

Three processes of hemostasis

• Blood vessel spasm• Platelet plug

formation• Blood coagulation

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Platelet plug

formation

27-22

Plasma• Liquid portion of blood

composed mostly of water

• Proteins• Albumins

• Smallest plasma proteins• Pull water in to help

maintain blood pressure

• – transport lipids and fat-soluble vitamins

• Fib– needed for blood clotting

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Plasma• Nutrients

• Amino acids• Glucose• Nucleotides• Lipids from the digestive

tract

• Gases – oxygen, carbon dioxide, and nitrogen

• Electrolytes

• Waste products

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Blood Types

• Types are distinguished by antigen and antibodies

• Agglutination• Clumping of red blood cells • Antigens on surface of

RBCs bind to antibodies in plasma

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Blood Types

Blood Type Antigen

Present

Antibody

Present

Blood That Can

Be Received

A A B A and O

B B A B and O

AB AB None A, B, AB, and O

O None A and B O

Apply Your KnowledgeTrue or False: Write T if the statement is TRUE. If the statement if FALSE underline the word/s that made it incorrect and write the correct answer.

__ Hematocrit is the percentage of WBCs in the blood.

__ Neutrophils destroy bacteria, viruses, and toxins in the bloodstream.

__ Platelets are important to the clotting process.

__ Albumin is a small plasma protein that pushes water out of the bloodstream.

__ Hemostasis is the control of bleeding.

__ A person with type AB blood can only receive type AB blood.

pulls water into

RBCs

can receive any type of blood

T

T

F

T

F

F

ANSWER:

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• Strongest of the blood vessels

• Carry blood AWAYfrom the heart

• Under high pressure• Vasoconstriction• Vasodilation

Blood Vessels

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• Aorta• Takes blood from the

heart to the body• MAIN ARTERY in the

human body

• Coronary arteries• Supply blood to heart

muscle

• Arterioles• Small branches of

arteries that leads to a capillary

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• Tiny, thin-walled blood vessels

• Smallest type of blood vessel

• Connect arterioles to venules

• Only about one cell layer thick

• Oxygen and nutrients can pass out of a capillary into a body cell

• Carbon dioxide and other waste products pass out of a body cell into a capillary

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• From the Latin word VENA

• Superior and inferior vena cava

• Largest veins

• Carry blood into right atrium

• Carry blood from parts of the body TOWARD the heart

• Most veins carry DEOXYGENATED blood from the TISSUES back to the heart

• Exceptions; PULMONARY & UMBILICAL VEINS (carry oxygenated blood to the heart)

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• Small vessels formed when capillaries merge

• FUNCTION: collect blood from the capillary beds (network of capillaries); allows blood to returnfrom the capillary beds todrain into the larger bloodvessels, the veins

27-32

Apply Your Knowledge

How do arteries control blood pressure?

ANSWER: The muscular walls of arteries can constrict to increase blood pressure or dilate to decrease blood pressure.

Circulation

Pulmonary circuit

right atrium right ventricle pulmonary artery trunk pulmonary arteries lungs pulmonary veins heart (left atrium)

Circulation

Systemic circuit

Left atrium left ventricle aorta arteries arterioles capillaries venules veins vena cava heart (right atrium)

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The Heart: Blood Flow

Deoxygenated blood in from body

Oxygenated blood in lungs

Atria Contract Ventricles Contract

Deoxygenated blood out to lungs

Oxygenated blood out to body

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The Heart: Blood Flow (cont.)

Right Atrium

Right Ventricle

PulmonarySemilunarValve

Left Atrium

BicuspidValve

Left Ventricle

PulmonaryValve

TricuspidValve

AorticSemilunarValve

LungsBody

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The Heart: Cardiac Cycle

• Influenced by• Exercise• Parasympathetic nerves• Sympathetic nerves• Cardiac control center• Body temperature• Potassium ions• Calcium ions

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What does having chest pain mean?• Cardiac

• Myocardial infarction

• Angina

• Pericarditis

• Coronary spasm

• Non-cardiac

• Heartburn

• Panic attacks

• Pleurisy

• Costochondritis • Pulmonary embolism

• Sore muscles

• Broken ribsTake all complaints of chest pain seriously!

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Chest Pain

• Determine cause• Electrocardiogram• Stress tests• Blood tests• Chest x-ray• Nuclear scan• Coronary catheterization• Echocardiogram • Endoscopy

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Diseases and Disorders of the Cardiovascular System

Disease

(Blood vessels)

Description

Aneurysm A ballooned, weakened arterial wall

Coronary Artery

Disease (CAD)

Atherosclerosis; narrowing of coronary arteries caused by

hardening of the fatty plaque deposits within the arteries

Varicose Veins Twisted, dilated veins

Artherosclerosis Disease of the arteries; cholesterol buildup (plaque)

Stroke Blockage & hardening of arteries in the brain or neck

vessels

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Diseases and Disorders of the Cardiovascular System

Disease

(Heart)

Description

Arrhythmias Abnormal heart rhythms

Carditis Inflammation of the heart

Endocarditis Inflammation of the innermost lining of the heart,

including valves

Murmurs Abnormal heart sounds

Myocardial

Infarction

Heart attack; damage to cardiac muscle due to a

lack of blood supply

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Diseases and Disorders of the Cardiovascular System

Disease

(Heart)

Description

Ischemic heart

disease

Inadequate oxygen supply to the heart muscles due to

impaired blood flow to the heart.

Angina A condition marked by severe pain in the chest caused by

an inadequate blood supply to the heart

Hypertension also called high blood pressure often results from

arteriosclerosis or atherosclerosis; consistent resting blood

pressure equal to or greater than 140/90 mm Hg

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Disease

(Heart)

Description

Myocarditis Inflammation of the muscular layer of the heart

Pericarditis Inflammation of the membranes that surround the heart

(pericardium)

Congestive Heart

Failure

Weakening of the heart over time; heart is unable to

pump enough blood to meet body’s needs

Diseases and Disorders of the Cardiovascular System

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Disease Description

Sickle Cell Anemia Abnormal hemoglobin causes RBCs to change to a sickle

shape; abnormal cells stick in capillaries

Thalassemia Inherited form of anemia; defective hemoglobin chain

causes, small, pale, and short-lived RBCs

Thrombophlebitis Blood clots and inflammation develops in a vein

Diseases and Disorders of the Cardiovascular System

Leukemia Bone marrow produces a large number of

abnormal WBCs

Apply Your Knowledge

ANSWER: Anemia is a condition in which a person does not have enough red blood cells or hemoglobin in the blood to carry an adequate amount of oxygen to body cells.

The doctor has told your patient she has anemia.

How would you explain this to the her?

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In Summary• Cardiovascular system

• Transport system for body• Heart, arteries, veins, and capillaries

• Blood• Transport medium• RBCs, WBCs, platelets, plasma

End of Chapter

Your work is to

discover your

world and then

with all your heart

give yourself to it. ~ Buddha

REFERENCES

• J. Ferriols-Pavico, A. Morales-Ramos, A. Bayquen, A. Silverio. Exploring Life Through Science. Phoenix Publishing House. 2014

• C. Capco & G. Yang. You and the Natural World. Biology. Phoenix Publishing House. 2010

• The McGraw-Hill Companies.2009

• B. Essenfeld, C. Gontang & R. Moore. Biology Second Edition. Addison-Wesley Publishing Company. 1996

• https://www.google.com.ph/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAYQjB1qFQoTCMDbsfnv5MYCFc8LkgodnpgAxg&url=http%3A%2F%2Fwww.imagekb.com%2F4-chamber-of-the-heart