The Cardiovascular System Photo Credit: © Image Shop/Phototake CrashCourse Circulatory System Video https://www.youtube.com/watch?v=9fxm85Fy4sQ

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37–1 The Circulatory System Circulatory System Introduction: The circulatory system and respiratory system work together to supply cells with the nutrients and oxygen they need to stay alive.

Functions of the Circulatory System Cardiovascular System Humans and other vertebrates have closed circulatory systems, meaning that the blood is contained within a system of vessels (tubes).

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The circulatory system as a system of tubes with a pump (heart) and valves to ensure one-way flow of blood

Describe the double circulation in terms of: a low pressure circulation to the lungs and a high pressure circulation to the body tissues High Pressure

Functions of the Circulatory System Circulatory Introduction The human circulatory system consists of: the heart blood vessels blood

Copyright Pearson Prentice Hall IB Assessment Statement Draw and Label a diagram of the heart showing the four chambers associated blood vessels, valves and the route of the blood through the heart. Know the relative thickness of the four chambers. Copyright Pearson Prentice Hall

The Heart The heart is a double pump: The right side of the heart pumps blood to the lungs The left side of the heart pumps blood to the rest of the body.

The Heart The walls of the heart are composed of cardiac muscle. Contraction of cardiac muscle is myogenic. Myogenic means that it can contract on its own it does not need to be stimulated by a nerve.

The Heart The heart is enclosed in a protective sac of tissue. In the walls of the heart, two layers of tissue form around a thick layer of muscle. Contractions of the layer of muscle pump blood.

The Heart – Coronary arteries There are many capillaries in the muscular wall of the heart. These are called the coronary arteries.

The Heart – Coronary arteries The function of the coronary arteries are listed below: Bring nutrients to heart muscle Bring oxygen for aerobic cell respiration, which provides heart tissue with energy necessary for heart contraction. Remove waste products (CO2) from heart muscle

Copyright Pearson Prentice Hall IB LEARNING OBJECTIVE State the function of the coronary arteries Copyright Pearson Prentice Hall

Coronary Heart Disease If the coronary arteries or veins become blocked, the heart muscles become: deprived of oxygen and sugar And poisonous waste products build up Resulting in a HEART ATTACK.

Coronary Heart Disease Blockage of coronary arteries is called coronary heart disease.

People at Risk for Coronary Heart Disease Smoking Cigarettes – nicotine damages the circulatory system Diet – a diet high in saturated fat, salt and cholesterol Obesity – Being overweight Stress – unmanageable or long term stress Genes – Some people inherit genes that make it more likely

A doctor can determine if you have a block coronary arteries by doing an Angiogram. It gives a picture of the coronary arteries.

If you have a blocked coronary artery or veins, you can have surgery.

Coronary Bypass Surgery In Coronary Bypass Surgery a blood vessel is removed from one part of the body and sewn in the heart muscle

Preventing Heart Disease Regular Exercise Healthy eating Maintaining weight Heart Attack Video http://www.hhmi.org/biointeractive/how-heart-attack-occurs

Copyright Pearson Prentice Hall IB LEARNING OBJECTIVE: Describe the relative thickness of the four chambers. Copyright Pearson Prentice Hall

Structures of the Heart

The Heart Superior Vena Cava: Large vein that brings oxygen-poor blood from the upper part of the body to the right atrium Right Atrium

Bring oxygen-rich blood from each of the lungs to the left atrium The Heart Left Atrium Pulmonary Veins: Pulmonary Veins: Bring oxygen-rich blood from each of the lungs to the left atrium

Pulmonary Arteries Semilunar Valves: The Heart Pulmonary Arteries Semilunar Valves: Prevents blood from flowing back into the right ventricle after it has entered the pulmonary artery. Right Atrium

Atrioventricle (Tricuspid) Valve: The Heart Right Atrium Atrioventricle (Tricuspid) Valve: Prevents blood from flowing back into the right atrium after it has entered the right ventricle

Right Atrium Inferior Vena Cava: The Heart Right Atrium Inferior Vena Cava: Vein that brings oxygen-poor blood from the lower part of the body to the right atrium.

The Heart Left Atrium Atrioventricle (Bicuspid) Valve: Prevents blood from flowing back into the left atrium after it has entered the left ventricle Left Ventricle

The Heart Aorta Left Atrium Semilunar Valve: Prevents blood from flowing back into the left ventricle after it has entered the aorta Left Ventricle

Bring oxygen-poor blood to the right or left lung The Heart Pulmonary Arteries: Bring oxygen-poor blood to the right or left lung

Brings oxygen-rich blood from the left ventricle to the body The Heart Aorta: Brings oxygen-rich blood from the left ventricle to the body

The septum divides the right side of the heart from the left. It prevents the mixing of oxygen-poor and oxygen-rich blood.

The heart has four chambers—two atria and two ventricles. There are two chambers on each side of the septum. The upper chamber, which receives the blood, is the atrium. The lower chamber, which pumps blood out of the heart, is the ventricle.

Atria vs. Ventricles Both Atria have thinner walls than the ventricles, because they only need to pump blood to the ventricles.

Left ventricle vs. right ventricle Left Ventricle wall is thicker than the right ventricle, because it pumps blood through the arteries to all the tissues in the body Right Ventricle wall is thinner and less muscular than the left ventricle because it is only pumps blood to the lungs

Left vs. Right Ventricle Venn Diagram

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Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall IB LEARNING OBJECTIVE Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing the of valves. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Flow of blood tutorial : http://www.kscience.co.uk/animations/blood_system.swf Copyright Pearson Prentice Hall

Circulation Through the Heart Blood enters the heart through the right and left atria. As the heart contracts, blood flows into the ventricles and then out from the ventricles to either the body or the lungs.

The Heart There are flaps of connective tissue called valves between the atria and the ventricles. When the ventricles contract, the valves close, which prevents blood from flowing back into the atria.

Blood leaves the left ventricle, and enters the aorta. The Heart At the exits from the right and left ventricles, valves prevent blood that flows out of the heart from flowing back in. Blood leaves the left ventricle, and enters the aorta. The aorta is one of the blood vessels that carry the blood through the body and back to the heart.

Circulation Through the Body The Heart Circulation Through the Body  The heart functions as two separate pumps.

Pulmonary Circulation The Heart Pulmonary Circulation One pathway circulates blood between the heart and the lungs. This pathway is known as pulmonary circulation. In the lungs, carbon dioxide leaves the blood and oxygen is absorbed. The oxygen-rich blood returns to the heart.

This pathway is called systemic circulation. The Heart Systemic Circulation The second pathway circulates blood between the heart and the rest of the body. This pathway is called systemic circulation. After returning from the lungs, the oxygen-rich blood is pumped to the rest of the body.

Circulation of Blood through the Body The Heart Capillaries of head and arms Circulation of Blood through the Body Superior vena cava Pulmonary artery Aorta Pulmonary vein Capillaries of right lungs Capillaries of left lung The circulatory system is divided into two pathways. Pulmonary circulation carries blood between the heart and the lungs. Systemic circulation carries blood between the heart and the rest of the body.  Inferior vena cava Capillaries of abdominal organs and legs

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Cardiac Cycle More details Step 1 Diastole The heart muscle is relaxed this is called diastole. There is no pressure in the heart chambers. Blood tries to flow back into the heart but closes the semi-lunar valves. Copyright Pearson Prentice Hall

Cardiac Cycle More details Step 2 Diastole Both atria fill with blood returning to the heart in the veins. The right atria fills with blood returning in the vena cava from the body tissues (deoxygenated). The atrio-ventricular valves are still closed and the atria fill up. When the pressure in the atria is greater than the pressure in the ventricles the atrio-ventricular valves will open. Copyright Pearson Prentice Hall

Cardiac Cycle More details Step 3 Late Diastole In this diagram the heart is still relaxed (diastole). The pressure of blood returning to the heart and filling the atria is now high enough to open the atrio-ventricular valves. The pressure in the atria is greater than the pressure in the ventricles. Atrio-ventricular valves open Ventricles begin to fill with blood.. Copyright Pearson Prentice Hall

Cardiac Cycle More details Step 4 Atrial systole Both atria contract together (see control of heart rate) The muscles of the atria contract. volume of the atria reduces. Pressure of blood increases Blood flow into the ventricle, filling this chamber and causing the ventricle wall to stretch... Copyright Pearson Prentice Hall

Cardiac Cycle More details Step 6 Ventricular Systole The ventricle contracts (systole) The pressure increases in the ventricle The atrio-ventricular valve closes The pressure rises further Pressure in the ventricle is greater than the artery, semi-lunar valve opens Blood pulses into the arteries   Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall IB LEARNING OBJECTIVE: Describe the relationship between the structure and function of blood vessels. [6] Copyright Pearson Prentice Hall

Blood Vessels Introduction As blood flows through the circulatory system, it moves through three types of blood vessels: arteries capillaries veins Blood Vessels

Blood Vessels Arteries  Large vessels that carry blood from the heart to the tissues of the body are called arteries. Except for the pulmonary arteries, all arteries carry oxygen-rich blood. Pulmonary artery carries oxygen poor blood from the right side of the heart to the left side

Arteries have thick walls. Four parts of the artery: a narrow central tube A smooth lining so no obstruction to blood flow will occur A thick layer of muscles and elastic fibers A thick outer wall.

Thick outer wall Thick muscular layer Thick outer wall Smooth lining Thick muscular layer Thick outer wall Thick outer wall Thick outer wall Thick outer wall Thick outer wall Thick outer wall In the circulatory system, there are three types of blood vessels—arteries, capillaries, and veins. The walls of these vessels contain connective tissue, smooth muscle, and endothelium. Thick muscular layer Thick muscular layer Thick muscular layer Smooth lining Smooth lining

The smallest of the blood vessels are the capillaries. Their walls are only one cell thick, and most are narrow. The capillaries bring nutrients and oxygen to the tissues and absorb carbon dioxide and other waste products from them.

Blood Vessels In the circulatory system, there are three types of blood vessels—arteries, capillaries, and veins. The walls of these vessels contain connective tissue, smooth muscle, and endothelium.

Blood vessels that carry blood back to the heart are veins. Veins have thinner walls than arteries.

Four parts to the structure of Veins: Wide central tube Thin layer of muscle Valves Thin outer wall

Thin Outer Wall Thin layer Of muscle Smooth lining Thin Outer Wall In the circulatory system, there are three types of blood vessels—arteries, capillaries, and veins. The walls of these vessels contain connective tissue, smooth muscle, and endothelium. Thin layer Of muscle Thin layer Of muscle Thin layer Of muscle Smooth lining Smooth lining Smooth lining Smooth lining

Large veins contain valves that keep blood moving toward the heart. Blood Vessels Valve open Large veins contain valves that keep blood moving toward the heart. Valve closed Valves closed Contraction of skeletal muscles helps move blood in veins toward the heart. 

Veins vs. Arteries Venn Diagram

Copyright Pearson Prentice Hall IB LEARNING OBJECTIVE Draw and Label a diagram of the heart showing the four chambers associated blood vessels, valves and the route of the blood through the heart (4 Points) Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Virtual Heart Dissection: http://www.gwc.maricopa.edu/class/bio202/cyberheart/anthrt.htm Copyright Pearson Prentice Hall