Cardio System

Functions of the Cardiovascular System

• The Cardiovascular system is composed of:– The Heart– Blood vessels

• The function of it is:– To circulate blood– Maintain the internal environment so all cells

are nourished

How it works

• Heart pumps blood

• Blood vessels carry oxygen and nutrients to body cells

• Carbon dioxide and waste is carried from cells.

• Carbon dioxide is carried to lungs

• Waste carried to kidneys for removal

Structure

• The Cardio system is composed of:

–The Heart–Blood–Blood vessels–Arteries–Capillaries–Veins

The Heart

• The pump that makes the whole system work

• Most of the heart is made of muscle called myocardium, which contracts and relaxes constantly and in rhythm.

• Your heart rate will adjust depending on the activity you are doing.

Chambers of the Heart • There are 4 chambers inside the heart.

• The 2 smaller ones are called an atrium

• The 2 lower, larger chambers are called ventricles

• A wall of tissue called the septum separates the left and right atria, and also separates the left and right ventricles.

What they do• Top right of the atrium is a muscle that

acts as a natural pacemaker– Regular electrical impulses remind the

muscles of the atrium to contract, forcing blood to the ventricles.

• Valves between the atria and ventricles allow blood to flow through the chambers of the heart.

• When ventricles contract the valves close– That’s the sound when your heart beats

Circulation in the Heart

• Page 418• Blood that has been deleted of oxygen

but contains carbon dioxide and waste is carried to the heart by two large blood vessels called the vena cava.

• The deoxygenated blood enters the right atrium and is transferred to the right ventricle.

• The blood is then pumped to the lungs.

• In the lungs, blood releases carbon dioxide and picks up oxygen from air.

• Now the blood is oxygenated.

• It then returns from the lungs to the left atrium.

• The left atrium pumps the blood to the left ventricle of the heart.

• The left ventricle pumps the blood out of the heart and to the body through an artery called the aorta.

Blood• Delivers oxygen, hormones, and nutrients

to the cells.

• It carries the waste that cells produce away.

• 55% of total blood volume is composed plasma– The fluid in which other parts of the blood are

suspended

• Plasma consist of– Water, nutrients, proteins, salts and hormones

Blood• Red blood cells

– Make up about 40% of blood volume

• White blood cells and platelets – Last 5% of blood volume

• Platelets– Cells that prevent the bodies loss of blood.

– Gather at the site of an injury and release chemicals that make them stick together.

– This allows clotting to take place and slow blood loss.

Red Blood Cells

• Red Blood Cells– Transport oxygen to tissues and cells– Formed in bone marrow- red blood cells

contain hemoglobin.

• Hemoglobin– The oxygen-carrying protein in blood.

• Hemoglobin contains iron that binds with oxygen in the lungs and releases oxygen in the tissues.

White Blood Cells

• Main role is to protect the body against infection and fight infection when it does occur.

• Production increases when an infection is present.

• Some are involved in allergic reactions.

• Some form antibodies that provide immunity

HeartThings to include:•AORTA•RIGHT ATRIUM•LEFT ATRIUM•RIGHT VENTRICLE•LEFT VENTRICLE•INFERIOR VENA CAVA•SUPERIOR VENA CAVA•PULMANARY ARTERY•PULMINARY VEINS•MITRAL VALVE•AORTIC VALVE•PULMONIC VALVE•TRICUSPID VALVEAlso you need to include blood flow and where is it going, coming from!

ASSIGNMENT – 3/3

• Only 23 days till Spring Break!

• We will continue the PPT tomorrow

• Your tasks for today are:– Read chapter 16 Lesson #1

– Reading Strategy on pg. 416

– Q #1-5 & AYR on page 422

Blood Vessels

• 60,000 miles of blood vessels trasnport blood. (page 420).

• There are 3 main types

–Arteries

–Capillaries

–Veins

Arteries

• The blood vessels that carry blood away from the heart

• Arteries have thick elastic walls that contain smooth muscle fibers.

• The elastic fibers in the walls of arteries allow them to withstand the pressure exerted by the blood as the heart beats.

• Arterioles- smaller blood vessels that carry blood to capillaries

Capillaries

• Small blood vessels that carry blood between arterioles and vessels called venules.

• They form an extensive network throughout tissues and organs in the body.

• They play a role in body temperature regulation.

Veins

• Blood vessels that return blood to the heart.

• The vena cava (large veins) carry deoxygenated blood from the body to the right atrium of the heart.

• Pulmonary veins carry blood oxygenated from the lungs to the left atrium of the heart.

Lymphatic System

• Helps fight infection and plays role body’s immunity to disease.

• Helps maintain the balance of fluids in the spaces between cells.

• Helps support the cardiovascular system.

Lymph

• Lymph– Clear fluid that fills the spaces around body cells.

• Transported by lymphatic system to the heart and eventually returns to the blood.

• Similar to plasma in content– Consists of water and proteins, fats and lymphocytes

• Lymphocytes– Specialized white blood cells that provide the body

with immunity and protect against pathogens

– Two types: B cells and T cells

B & T cellsB cells• Stimulated to enlarge & multiply when they come

into contact with a pathogen.

• Some produce antibodies to attack- while others are memory cells to provide immunity again.

T cells• Stimulated to enlarge & multiply when they come

into contact with a pathogen.

• Two types: – Killer T cells stop the spread of disease– Helper T cells control the body’s immune system

Caring for the Cardio System

• Blood pressure– A measure of the amount of force that the blood

places on the walls of blood vessels, particularly large arteries, as its pumped through the body.

• Should remain in a normal range

• Prevention includes:– maintaining a healthy weight, staying

active, managing stress and avoiding drugs/alcohol.

Problems in the Cardio System

• Congenital Heart Defects– Present at birth

– Some are less serious than others, most require medical attention and sometimes surgery.

– Alcohol and Smoking during pregnancy can cause higher risk

• Sometimes its hereditary

Problems cont….

• Cardiovascular Disease– Group of diseases that include:

• Hypertension• Heart disease• Stroke

– #1 killer in men and women– 930,000 die each year from CVD

• Heart Murmur– Abnormal sounds made as blood pumps

through heart.– Some go away and some require surgery.

Probs cont….• Varicose Veins

– Form when the valves do not close tightly enough to prevent backflow of blood.

– Surgery, exercise and reducing standing time can limit and prevent these

• Anemia– Condition in which the ability of the blood to carry oxygen is

reduced.– Caused by iron deficiency

• Leukemia– Form of cancer in which any one of the different types of white

blood cells is produced excessively and abnormally.– Causes increased risk of infection– Chemo and Radiation often most common treatment.

• Hemophilia– Inherited disorder in which blood does not clot properly– Donated blood can help cure this.

Problems of the Lymphatic System

• Immune Deficiency– Can no longer protect against infection– Some are congenital, some caused by HIV.

• Hodgkin’s Lymphoma– Type of cancer that affects the lymph tissue found

in spleen.– Early detection is essential for recovery.

• Tonsillitis– Help protect against pathogens entering the body

through respiratory system.– Treated with antibiotics or removed