THE CIRCULATORY SYSTEM Health Science 1 Health Science 1 Marta Valdes, Instructor Marta Valdes, Instructor

WHAT ARE THE FUNCTIONS OF THE CIRCULATORY SYSTEM ? Circulates blood through the body Transports water, oxygen and food to cells Removes wastes from the cells. Helps fight disease Helps maintain the correct body temperature

THE HEART The heart is a muscular pump. It is located in the center of chest slightly tilting to the left. It is divided into two halves by a central partition called the SEPTUM.

Each half is then, divided by valves into an ATRIUM above (A for above) and a VENTRICLE below.

We, therefore have a right and left ATRIUM and a right and left VENTRICLE.

Walls of the heart are made up of three layers of tissue: Walls of the heart are made up of three layers of tissue: –Endocardium –Myocardium –Epicardium Atria and ventricles Atria and ventricles Heart valves Heart valves Conduction system Conduction system Coronary circulation Coronary circulation Heart

BLOOD VESSELS BLOOD VESSELS 1.Arteries 2.Veins 3.Capillaries There are 3 vessel types:- The structure of ARTERIES, VEINS and CAPILLARIES is different.

ARTERIES have thick walls. Most carry oxygenated blood away from the heart. Are more elastic than VEINS and also have higher pressure. The PULMONARY ARTERIES are different, they carry de-oxygenated blood from the heart to the lungs. Pulsate as the heart beats. ARTERIES

Any vessel LEAVING the heart is called an ARTERY.

VEINS Any vessel ENTERING the heart is called a VEIN. VEINS carry de-oxygenated blood to the heart. They have much thinner walls than arteries. They contain many VALVES which keep de- oxygenated blood flowing to the heart and avoid the possibility of blood flowing backwards.

They are less elastic than arteries. They carry blood at a lower pressure. The PULMONARY VEINS, which leave the lungs on the way to the heart, are different from other veins, they carry oxygenated blood. VEINS rarely pulsate. VEINS

CAPILLARIES are vessels that link the ARTERIES with the VEINS.

TO SUM UP THE DIFFERENCES BETWEEN CAPILLARIES, VEINS AND ARTERIES

SMOKING The ARTERIES need to be clear and free from obstruction in order to carry blood and supplies to the working muscles. But these passageways can be blocked by lipids which can be caused by smoking. Nicotine, one of the main components of tobacco, affects the nervous system, which controls the HEART RATE.

HEART RATE increases raises BLOOD PRESSURE. Other conditions associated with smoking include Coronary Heart Disease (CHD) and STROKES. It is said that risk of a heart attack is decreased after the smoker has stopped smoking for one year.

WHY DO WE NEED TO TAKE OUR BLOOD PRESSURE ?

Blood pressure varies with: 1.AGE 2.GENDER 3.ALTITUDE 4.MUSCULAR DEVELOPMENT 5.STRESS 6.TIREDNESS

Guidelines The Seventh Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC VII) uses the following guidelines to define HTN in adults: (Brashers, 2006, p.1) CategorySystolicDiastolic Normal<120and<80 Pre-hypertension or85-89 Stage 1 hypertension or90-99 Stage 2 hypertension >160 or >100

What can I do to reduce the risk of high blood pressure ? 1.Check your weight 2.Limit your alcohol consumption 3.Avoid smoking 4.In some people too much salt may unbalance the body chemistry and affect blood pressure. 5.Avoid situations that cause stress, anxiety or worry. 6. Exercise regularly- this will help to control stress, keep your blood pressure normal and your whole system in good shape.

Management of Hypertension Prevention Patient education Life-style modification Medication

The Effects of Aging on the Cardiovascular System Less efficient contraction Decreased elasticity of the arteries & veins Proper diet and regular exercise can help to keep the cardiovascular system healthy

Disorders of the blood Disorders of the blood –Anemia –Leukemia –Bleeding disorders Disorders of the blood vessels Disorders of the blood vessels –Atherosclerosis –Venous disorders Disorders of the heart Disorders of the heart –Coronary artery disease –Heart failure –Conduction disorders Disorders of the Cardiovascular System

Atherosclerosis Atherosclerosis –Blocking of the arteries –Plaques build up on the inside of the arteries, restricting blood flow –Can lead to myocardial infarction (heart attack), stroke –Risk factors: high blood cholesterol, lack of exercise, smoking Disorders of the Blood Vessels

Venous disorders Venous disorders –Venous thrombosis: blood clots form in the veins; danger of embolism –Venous (stasis) ulcers: skin breakdown as a result of poor circulation Disorders of the Blood Vessels

Nonmodifiable cardiac risk factors Nonmodifiable cardiac risk factors –Age –Gender –Heredity –Body build Modifiable cardiac risk factors Modifiable cardiac risk factors –Smoking –Inactivity –Obesity –High-cholesterol diet Risk Factors for Cardiovascular Disease

Coronary artery disease Coronary artery disease –Disease of the arteries that supply the heart with oxygen and nutrients –Two closely related conditions: Angina pectoris: pain that occurs when heart muscle is deprived of oxygen Angina pectoris: pain that occurs when heart muscle is deprived of oxygen Myocardial infarction: heart attack; part of the heart muscle dies Myocardial infarction: heart attack; part of the heart muscle dies Heart failure Heart failure –Heart is unable to pump enough blood to meet the body’s needs –Types Cor pulmonale (right-sided heart failure) Cor pulmonale (right-sided heart failure) Congestive heart failure (left-sided heart failure) Congestive heart failure (left-sided heart failure) –Treated with medication; fluid intake may be restricted Conduction disorders Conduction disorders –Electrical impulses that cause the heart to contract cannot get through Heart Disease

In this test, sensors are attached to the person’s chest In this test, sensors are attached to the person’s chest Tracing of electrical activity of the heart on paper is called an electrocardiogram (EKG, ECG) Tracing of electrical activity of the heart on paper is called an electrocardiogram (EKG, ECG) Stress test: EKG obtained while a person exercises Stress test: EKG obtained while a person exercises Electrocardiography

In this test, sound waves are bounced against the body to produce an image In this test, sound waves are bounced against the body to produce an image Provides information like: Provides information like: –Size and shape of the heart –Its pumping strength –The location and extent of any damage to its tissues Echocardiography

Doppler ultrasound: sound waves are used to check the blood flow in the large arteries and veins of the arms and legs Doppler ultrasound: sound waves are used to check the blood flow in the large arteries and veins of the arms and legs Radiography: Allows the doctor to see the heart and vessels without actually entering the body Radiography: Allows the doctor to see the heart and vessels without actually entering the body Doppler Ultrasound and Radiography