The Cardiovascular The Cardiovascular SystemSystem

OverviewOverview

► The cardiovascular The cardiovascular system includes the system includes the heart, which is the heart, which is the pump that pump that circulates blood, circulates blood, and the blood and the blood vessels, the vessels, the highways that carry highways that carry blood up and down blood up and down the body.the body.

The anatomy of the heartThe anatomy of the heart

► The heart is hollow, The heart is hollow, about the size of about the size of your fist, and divided your fist, and divided into four main parts: into four main parts: Left atrium, right Left atrium, right atrium, left ventricle, atrium, left ventricle, and right ventricle.and right ventricle.

► The heart is located The heart is located in the in the thoracicthoracic cavity.cavity.

FrictionFriction

►As any two objects rub against each As any two objects rub against each other, they cause friction. To help other, they cause friction. To help solve that problem we have the solve that problem we have the pericardium.pericardium.

►The pericardium is a serous sac that The pericardium is a serous sac that covers the heart. This sac allows the covers the heart. This sac allows the heart to pump with little resistance.heart to pump with little resistance.

The heart itselfThe heart itself

►The heart contains three different The heart contains three different layers of tissue: the endocardium, the layers of tissue: the endocardium, the myocardium, and the epicardium. myocardium, and the epicardium.

EpicardiumEpicardium

► The epicardium is The epicardium is the outermost layer the outermost layer of the heart. It is a of the heart. It is a serous membrane serous membrane that acts to reduce that acts to reduce friction. There is friction. There is adipose tissue adipose tissue found around the found around the coronary artery and coronary artery and the cardiac veins. the cardiac veins.

The myocardiumThe myocardium

► Thick middle layer Thick middle layer of the heart.of the heart.

► Rough and tough, Rough and tough, has a large supply has a large supply of capillaries that of capillaries that carry blood and carry blood and other nutrients to other nutrients to this tissue.this tissue.

endocardiumendocardium

► Consists of Consists of epithelial tissue and epithelial tissue and connective tissue. connective tissue.

► Contains blood Contains blood vessels and vessels and specialized purkinje specialized purkinje fibers (detects fibers (detects cardiac impulses in cardiac impulses in the A-V bundle).the A-V bundle).

The chambers and valves of the The chambers and valves of the heartheart

►The upper two chambers of the heart The upper two chambers of the heart are called the atria.are called the atria.

►The lower two chambers of the heart The lower two chambers of the heart are called the ventricles.are called the ventricles.

►Separating the left atrium and ventricle Separating the left atrium and ventricle from the right ones is a solid mass of from the right ones is a solid mass of tissue called the septum. It prevents tissue called the septum. It prevents blood on the left side of the heart from blood on the left side of the heart from mixing with blood from the right side.mixing with blood from the right side.

SeptumSeptum

Atrium/ventricle separationAtrium/ventricle separationThe tricuspidThe tricuspid

► On the right side of On the right side of the heart lies the the heart lies the tricuspidtricuspid, a three , a three sided valve that sided valve that prevents the blood prevents the blood that is pumped from that is pumped from the the rightright atrium to atrium to the the rightright ventricle ventricle from coming back from coming back into the right atrium.into the right atrium.

Mitral valveMitral valve

►Like the tricuspid, the mitral valve Like the tricuspid, the mitral valve prevents blood from flowing prevents blood from flowing backwards after the atrium contracts.backwards after the atrium contracts.

►The mitral valve, also called the The mitral valve, also called the bicuspid, is located between the left bicuspid, is located between the left atrium and left ventricle.atrium and left ventricle.

►The mitral valve contains two flaps The mitral valve contains two flaps instead of three.instead of three.

Pulmonary ValvePulmonary Valve

►Another tricuspid shaped valve that is Another tricuspid shaped valve that is located at the base of the pulmonary located at the base of the pulmonary artery. artery.

► Just like the other valves, it prevents Just like the other valves, it prevents the blood from “backwashing” into the the blood from “backwashing” into the heart.heart.

AORTA!AORTA!

► The aorta is the The aorta is the largest artery in the largest artery in the entire body. At around entire body. At around one inch in diameter, one inch in diameter, it can pump a massive it can pump a massive amount of blood.amount of blood.

► The first two arteries The first two arteries that branch from the that branch from the aorta are the left and aorta are the left and right coronary arteries.right coronary arteries.

Path of blood through the Path of blood through the heartheart

►1. Blood enters the right atrium 1. Blood enters the right atrium through the vena cava.through the vena cava.

►2. Right atrial wall contracts forcing 2. Right atrial wall contracts forcing blood through the tricuspid valve and blood through the tricuspid valve and into the right ventricle.into the right ventricle.

►3. As the right ventricle contracts, 3. As the right ventricle contracts, blood is forced through the pulmonary blood is forced through the pulmonary valve into the pulmonary arteries.valve into the pulmonary arteries.

►4. Blood exits pulmonary arteries and 4. Blood exits pulmonary arteries and enters the capillaries in the alveoli of enters the capillaries in the alveoli of the lungs. Gas exchange occurs, and the lungs. Gas exchange occurs, and the blood now is rich in oxygen.the blood now is rich in oxygen.

►5. Blood leaves the capillaries and 5. Blood leaves the capillaries and enters in the pulmonary veins.enters in the pulmonary veins.

►6. After passing down the pulmonary 6. After passing down the pulmonary vein, blood reaches the left atrium.vein, blood reaches the left atrium.

►7. When the left atrial wall contracts, 7. When the left atrial wall contracts, it forces blood through the mitral valve it forces blood through the mitral valve and into the left ventricle.and into the left ventricle.

►8. As the left ventricle contracts, the 8. As the left ventricle contracts, the blood is forced through the aortic blood is forced through the aortic valve into the aorta where it travels valve into the aorta where it travels throughout the body.throughout the body.

Listening to the heartListening to the heart

►When hearing the heart beat in a When hearing the heart beat in a stethoscope, the louder first noise that is stethoscope, the louder first noise that is heard is called ventricular contraction. heard is called ventricular contraction. That is when the ventricles force the That is when the ventricles force the blood inside them out through their blood inside them out through their respective arteries.respective arteries.

►The second noise is ventricular The second noise is ventricular relaxation. At this point the blood in the relaxation. At this point the blood in the atrium is forced into the relaxed ventricle atrium is forced into the relaxed ventricle during that atrium’s contraction.during that atrium’s contraction.

When to beatWhen to beat

► In the heart, there are specialized In the heart, there are specialized tissues that are designed to let certain tissues that are designed to let certain parts of the heart know when to parts of the heart know when to contract. These tissues comprise what contract. These tissues comprise what is known as the cardiac conduction is known as the cardiac conduction system.system.

►The sinoatrial node is a bundle of such The sinoatrial node is a bundle of such tissue found at the top of the right tissue found at the top of the right atrium by the superior vena cava.atrium by the superior vena cava.

► The S-A node fires The S-A node fires regularly 70 to 80 regularly 70 to 80 times per minute. times per minute.

► Another name for Another name for the S-A node is the the S-A node is the pacemaker.pacemaker.

►The impulse does not go directly The impulse does not go directly through the heart. It travels down through the heart. It travels down specialized cardiac muscle to the specialized cardiac muscle to the atrioventricular node.atrioventricular node.

►That signal that is received by the A-V That signal that is received by the A-V node and spread throughout the heart node and spread throughout the heart by the purkinje fibers.by the purkinje fibers.

Blood VesselsBlood Vessels

► The blood vessels The blood vessels act as the highway act as the highway that blood travels. that blood travels. The arteries act as The arteries act as one lane, the veins one lane, the veins as the other, and as the other, and the capillaries as the capillaries as their off ramps.their off ramps.

ArteriesArteries

► Strong and very Strong and very elastic.elastic.

► Arteries are Arteries are designed to take designed to take the force of the the force of the blood pushing blood pushing through them.through them.

► As they get smaller As they get smaller and smaller, they and smaller, they are referred to as are referred to as arterioles.arterioles.

Inside the arteryInside the artery

►The inner layer of the artery is called the The inner layer of the artery is called the tunica internatunica interna, which is composed of , which is composed of simple squamous cells. (single layer of simple squamous cells. (single layer of flat cells)flat cells)

►Surrounding the tunica interna is a layer Surrounding the tunica interna is a layer of connective tissue. On top of that is of connective tissue. On top of that is tunica mediatunica media which is the thickest part of which is the thickest part of the artery.the artery.

►On top of that is the On top of that is the tunica exteratunica extera which which is another thin layer of connective tissue.is another thin layer of connective tissue.

Vasoconstriction and Vasoconstriction and vasodilationvasodilation

►Vasoconstriction- When the muscle Vasoconstriction- When the muscle fibers in the artery contract, lessening fibers in the artery contract, lessening the blood flow. (Good when cold)the blood flow. (Good when cold)

►Vasodilation- When the muscle fibers Vasodilation- When the muscle fibers relax, increasing blood flow. (Good relax, increasing blood flow. (Good during a heart attack)during a heart attack)

VeinsVeins

► Carry blood back to the Carry blood back to the atria.atria.

► The vein is built similar The vein is built similar to the artery, however to the artery, however the tunica media is the tunica media is very under developed.very under developed.

► Less tissue means a Less tissue means a greater lumen (opening greater lumen (opening where the blood flows)where the blood flows)

► Smaller veins are called Smaller veins are called veinules.veinules.

Preventing backwashPreventing backwash

►Most veins contain these valve-like Most veins contain these valve-like flaps on them that once blood is forced flaps on them that once blood is forced through them, they collapse and through them, they collapse and prevent blood from flowing backwards.prevent blood from flowing backwards.

CapillariesCapillaries

►Smallest blood vessels of all.Smallest blood vessels of all.►Consists only of endothelium tissue.Consists only of endothelium tissue.►There are very tiny slits in the capillaries There are very tiny slits in the capillaries

that allow for gas and nutrient exchange that allow for gas and nutrient exchange between the endothelial cells.between the endothelial cells.

►Oxygen and nutrient rich blood cells will Oxygen and nutrient rich blood cells will give away their nutrients and oxygen give away their nutrients and oxygen while picking up NHwhile picking up NH33 and CO and CO22..

Blood PressureBlood Pressure

►Systolic BP- The first number in a blood Systolic BP- The first number in a blood pressure reading is the systolic blood pressure reading is the systolic blood pressure. This measures the amount of pressure. This measures the amount of force that is thrust against the arteries force that is thrust against the arteries during ventricular contraction.during ventricular contraction.

►Diastolic BP- the second number in a Diastolic BP- the second number in a blood pressure reading is the diastolic blood pressure reading is the diastolic BP. This measures the amount of BP. This measures the amount of pressure in the arteries after the pressure in the arteries after the ventricular contraction.ventricular contraction.

►Normal Systole- 110-120Normal Systole- 110-120 Normal high- 139-149Normal high- 139-149 High- 150 +High- 150 +

►Normal diastole- 70-80Normal diastole- 70-80 Normal high- 90-109Normal high- 90-109 High- 110+High- 110+

►Normal Reading = 120/80Normal Reading = 120/80►High BP= 150/120High BP= 150/120

Paths of blood circulationPaths of blood circulation

► Pulmonary circuit- Pulmonary circuit- blood circulation blood circulation from the heart to from the heart to the lungs.the lungs.

► Systemic circuit- Systemic circuit- blood circulation blood circulation from the heart to from the heart to every where else in every where else in the body.the body.

Major arteriesMajor arteries

► Coronary arteries- first arteries to branch off Coronary arteries- first arteries to branch off of the aorta.of the aorta.

► Femoral arteries- runs down inside of thighs.Femoral arteries- runs down inside of thighs.► Carotid artery- runs up the neck.Carotid artery- runs up the neck.► Renal arteries- runs to the kidneys.Renal arteries- runs to the kidneys.► Axillary arteries- runs to the arms.Axillary arteries- runs to the arms.► Illiac arteries- runs to the legs.Illiac arteries- runs to the legs.► Aorta- largest artery, takes blood from Aorta- largest artery, takes blood from

heart.heart.

Major veinsMajor veins

►Axillary veins- leads back from armsAxillary veins- leads back from arms►Femoral veins- leads back from the Femoral veins- leads back from the

legslegs►Renal veins- leads back from kidneysRenal veins- leads back from kidneys►Superior vena cava- draws blood back Superior vena cava- draws blood back

from upper half of body.from upper half of body.► Inferior vena cava- draws blood back Inferior vena cava- draws blood back

from lower half of the body.from lower half of the body.

Questions?Questions?