The Human HeartMr. Pratik TrivediMr. Pratik Trivedi

Operation Theatre ManagerOperation Theatre Manager

Learning Objectives• Define the function of the heart

• Identify the chambers of the heart

• Understand the function of the valves of the heart

• Identify the different layers of the heart and their function

• Understand blood flow

• Understand the conducting system of the heart

The Heart Muscle•The heart is the most important muscle in

the body.•You cannot live without a heart.•The heart is a hollow, cone shaped,

muscular pump or two pumps in one. The right side receives blood from the body and pumps it to the lungs. The left side does the opposite: it receives blood from the lungs and pumps it around the body.

Amazing Facts About the Human Heart

•The heart is about the same size as your fist.

•The heart beats on average 70 times per minute; 4,200 beats per hour; 100,000 beats per day; 365 million beats per year; 30 billion beats in an average life time of 80 years.

•An adult heart pumps 7,500 liters of blood daily.

More Amazing Facts About the Human Heart

•It takes about 20 seconds to pump blood to every cell in your body.

•If you lined up all the blood vessels in your body end-to-end, they would wrap around the earth twice.

Location of Human Heart•The human heart is situated in

the posterior to the middle mediastinum, between the lungs.

•The heart rest on diaphram, near the midline of the thoracic cavity.

•The heart extends from the second rib to the fifth intercostal space

•thoracic vertebrae T5-T8.

Dimentions & Weight of Human Heart•The heart is a small Organ, it is about 12

cm long (5 in.), 9 cm (3.5 in.) wide & 6 cm (2.5 in.) thick.

•Average mass of 250 gm in adult females & 300 gm in adult males

Function of the Heart•The heart pumps oxygen and nutrient rich

blood to the organs, tissues and cells of the body, and eliminates waste products

•Blood is carried from the heart to the organs through arteries, arterioles and capillaries

•Blood returns to the heart through venules and veins

Structure of Heart

Chambers of the HeartThe heart is divided into four chambers:

•RA: Right Atrium•RV: Right Ventricle

•LA: Left Atrium•LV: Left Ventricle

Arteries and VeinsSuperior Vena CavaPulmonary Veins

Inferior Vena Cava

AortaPulmonary Artery

Pulmonary Veins

Valves of the heartThe four valves are known

as:

•Tricuspid valve

•Pulmonary valve

•Mitral valve

•Aortic valve

The tricuspid valve:

• Is an atrioventricular valve, situated between the atria and the ventricle

• Controls the blood between the right atrium and the right ventricle

The mitral valve:

• Is an atrioventricular valve, situated between the atria and the ventricle

• Controls the blood between the left atrium and the left ventricle

Valves of the heart

The pulmonic or pulmonary valve:

• Is a semi lunar valve which controls the blood leaving the heart

• Situated between the right ventricle and the pulmonary artery & Controls blood flow as well

• The aortic valve:• Is a semi lunar valve which controls the

blood leaving the heart• Situated between the left ventricle and

the aorta & Controls blood flow as well

Valves of the heart

Layers of the Heart•The wall of the heart is composed of three

layers.

▫EPICARDIUM▫MYOCARDIUM▫ENDOCARDIUM

Layers of the HeartEndocardium:•Innermost/deepest layer of •the heart•Lines the heart chambers and the valves•Smooth thin lining to reduce friction of

blood flow through the chambers•Cardiac conduction system located in this

layer

Layers of the HeartMyocardium:•Middle, thickest layer

of the heart•Contains the muscle fibres which are

responsible for pumping•Contraction of this layer allows blood to

be pumped through to the blood vessels

Layers of the HeartEpicardium:•Outer layer of the heart•It is sometimes considered as a division of

the inner layer of the pericardium

Layers of the HeartPericardium:

•To limit cardiac distension and restrict excessive movement

•To protect and lubricate

Responsibilities of the Heart•The heart is responsible for two things: 1. Through the blood it pumps, the heart

provides oxygen and nutrients to our cells to keep us alive.

2. It also carries away wastes from these active cells to special organs (such as the kidneys) that rid them from our bodies.

Blood Vessels•The heart uses a network of tubes to get

blood throughout the body.•These tubes are called blood vessels.•The blood vessels that carry the fresh

blood away from the heart are called arteries.

•The ones that carry the blood that contains wastes back to the heart are call veins.

The Heart Beat• When you go to visit the doctor, the doctor

uses a stethoscope to listen to your heart. • A healthy heart makes a “lub-dub” sound,

which comes from the valves shutting inside the heart.

• The “Lub” sound happens when the blood hits valves between the atria and ventricles.

• The “Dub” sound happens when the blood hits the aortic and pulmonic valves the close up as the heart relaxes to fill the blood for the next beat.

Your Pulse•You can feel your heart beating in several

different areas of the body.•The most common place used is the wrist,

just below your thumb.•You’ll know that you’ve found your pulse

when you can feel a small beat under you skin.

•Each beat is caused by the contraction of your heart.

Keep Your Heart in Shape• Most children are born with a healthy heart.• Just like you need to exercise your leg and

arm muscles, you need to exercise your heart muscle. At least 15 to 20 minutes of exercise each day will give you heart a good workout.

• Remember to eat a variety of healthy foods, avoiding a lot of fatty foods.

• Stay away from smoking!!