•The cardiovascular system includes the heart and blood vessels (arteries, veins, capillaries)

•A functional cardiovascular system is vital to survival

HEART

hollow, muscular pump found between the lungs

main function is to propel blood throughout the body

An adult heart pumps ~4,000 gal (~7,000 L) of blood daily

Structure of Heart

The pericardium is a double layered sac that encloses the heart

The pericardium consists of:

visceral pericardium - inner layer that covers the entire heart; also known as the epicardium

parietal pericardium - outer layer; tough fibrous sac

A small amount of serous fluid lies between the two layers to prevent friction

Parietal Pericardium

Visceral Pericardium

(epicardium)

Walls of the Heart

Epicardium – outermost layer

Myocardium – thick middle layer; responsible for the pumping action of the heart

Endocardium - smooth inner layer; continuous with the inner lining of blood vessels

The upper part is divided into right and left atria, which receive blood entering the heart

The bottom is divided into right and left ventricles, which pump blood out of the heart

Heart Chambers & Valves

The heart has four chambers enclosed by thick, muscular walls

•The interventricular septum acts as a wall that separates the right side of the heart from the left side

Interventricular Septum

Cardiovascular SystemNotes Page 1 Class Work

• Chapter 13 vocabulary

The left side of the heart is thicker and stronger than the right side because the left side supplies blood to all body tissues

Right side sends blood to the lungs

Valves of the heart open and close to control and ensure one way blood flow through the heart

otricuspid valve separates the right atrium and right ventricle

o(bicuspid) mitral valve separates the left atrium and left ventricle

See Your

Heart Valves

at Work

•MVP (mitral valve prolapse) – mitral valve does not close properly, which causes blood to flow backwards into left atrium•Symptoms include fatigue and chest pain

The heartbeat is produced by the closure of valves when blood is pushed through chambers of the heart

Blood Flow through the Heart

•Blue = oxygen poor blood; Red = oxygen rich blood

•Carbon dioxide is dropped off and oxygen is picked up in the lungs

•Oxygen is dropped off and carbon dioxide is picked up at the capillaries

right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle → aorta → arteries → arterioles → capillaries → venules → veins → superior and inferior vena cava→ back to right atrium

•The coronary arteries supply blood to heart muscle

•right coronary artery supplies both left and right sides of the heart

•left coronary artery supplies left side of the heart

Plaque may build-up in a coronary artery at the site of a tear in the lining of the vessel

•A heart attack or acute myocardial infarction (MI) occurs when one of the coronary arteries becomes blocked by spasm or by clot formation

•The blockage results in damaged tissue and a permanent loss of contraction of this portion of the heart muscle

Symptoms of a possible

heart attack include chest pain and pain that radiates

down the shoulder and

arm.

•Coronary artery disease is a narrowing of the small blood vessels that supply blood and oxygen to the heart

Directional Coronary Atherectomy (DCA) is a minimally invasive procedure to remove the blockage from the coronary arteries and allow more blood to flow to the heart muscle and ease the pain caused by blockages.

Percutaneous transluminal coronary angioplasty (PTCA) is a minimally invasive procedure to open up blocked coronary arteries, allowing blood to circulate unobstructed to the heart muscle.

Angina is a specific type of pain in the chest caused by inadequate blood flow through the coronary vessels of the myocardium

which can damage artery walls and block blood flow.

•These plaque deposits severely restricted blood flow in the heart muscle, resulting in chest pain.

•Atherosclerosis is another disorder of the arteries.

•Fat, cholesterol, and other substances collect in the walls of arteries,

BLOOD VESSESLS

•Arteries

•Veins

•Capillaries

Vasoconstriction is constriction or narrowing of a blood vessel.

When a blood vessel constricts, the flow of blood is restricted or slowed.

•Arteries carry blood away from the heart; thickest blood vessels

•All arteries, with the exception of the pulmonary arteries, carry oxygenated (oxygen-rich) blood.

•The pulmonary artery carries oxygen-poor blood from the right ventricle to the lungs.

•Arterioles are small arteries that connect to capillaries.

•The aorta is the largest artery

•The aorta originates in the left ventricle of the heart and carries oxygen rich blood to the rest of the body.

•The carotid arteries deliver oxygen-rich blood to the head and brain; located in the neck

•The jugular veins return oxygen-poor blood from the head and brain to the heart.

An aneurysm is a sac-like protrusion of an artery caused by a weakened area within vessel wall

•If a cerebral (brain) aneurysm ruptures, the escaping blood within the brain may cause severe neurologic complications or death.

•A person who has a ruptured cerebral aneurysm may complain of the sudden onset of "the worst headache of my life“.

Abdominal aortic aneurysm involves a widening, stretching, or ballooning of the aorta

•There are several causes of abdominal aortic aneurysm, but the most common results from atherosclerotic disease

•As the aorta gets progressively larger over time there is increased chance of rupture.

Blood Pressure is the measurement of force applied to the artery walls

The pressure is determined by:

1. Force behind blood

2. Amount of blood pumped

3. Size and flexibility of the arteries

HEART ACTIONS

Atrial Systole – atria contract

Ventricular diastole – ventricles relax

• Normal blood pressure – 120/80

• Hypertension is a disorder characterized by chronically high blood pressure (exceeding 140/90)

Hypertension is called "the silent killer" because it often causes no symptoms for many years, even decades, until it finally damages critical organs

BLOOD PRESSURE (BP)

2 Factors:

1. Cardiac output: rate of blod flow produced by the heart

2. Systemic vascular resistance (SVR): the resistance of the blood vessels to blood flow

• BP = cardiac output x SVR

• So what two factors could serve to increase blood pressure? Why would BP increase with age?

BLOOD PRESSURE CONTROL:

1. Autonomic nervous system responses

• Baroreceptors – pressure sensitive nerve endings in the carotid sinus and aortic arch

• Decreased BP causes activation of the sympathetic nervous system

2. Capillary shift mechanism – low BP makes fluid move from interstitial space into circulation

3. Hormonal responses –

• Sympathetic stimulation → adrenaline/noradrenaline

• Renin and angiotensin produced by kidney → vasoconstriction AND fluid retention

4. Kidney and fluid balance mechanisms

Hypotension

low blood pressure

symptoms include lightheadedness, dizziness, and fainting

Low blood pressure is blood pressure that is low enough that the flow of blood to the organs of the body is inadequate •Unlike high blood pressure, low blood pressure is defined primarily by signs and symptoms of low blood flow not by a specific blood pressure number •Common causes of low blood pressure include a reduced volume of blood, heart disease, and medications

•Veins are blood vessels that return blood to the heart

All veins, with the exception of the pulmonary vein, carry deoxygenated (oxygen poor) blood

Veins:

are not as strong as arteries

are thinner and less flexible than arteries

contain valves to prevent backflow of blood

Venules are small veins that connect to capillaries

1. Lumen of the vein 

2. Valve

The superior and inferior vena cava function to return oxygen poor blood to right atrium

The pulmonary vein returns oxygen-rich blood from the lungs to the left atrium

Varicose veins are enlarged, twisted, painful superficial veins resulting from poorly functioning valves; usually occur in the veins of the legs

•Jugular Vein – located in the neck; drain blood from the head, brain, face and neck; joins the subclavian vein•Brachiocephalic Vein - two veins that drain blood from the head, neck, and upper limbs; unite to form the superior vena cava

PICC Line – Peripherally Inserted Central Catheter

•In medicine, a port is a small medical appliance that is installed beneath the skin. A catheter connects the port to a vein.

•Under the skin, the port has a septum through which drugs can be injected and blood samples can be drawn many times, usually with less discomfort for the patient than a more typical "needle stick".

Hickman Catheter

The capillaries are networks of tiny, thin blood vessels that connect arterioles to venules

Gases, nutrients, and metabolic by-products (CO2) are exchanged

in capillaries

Capillaries are so small that it would take 10 to equal the thickness of a human hair

Cardiac Conduction System

•The sinoatrial node (SA node) is a group of cells that generates electrical current; these "sparks" cause the right atrium to contract

•The SA node is located in the right atrium; called the pacemaker

•The SA node sets the pulse rhythm

A pacemaker is a battery-operated electronic device which is inserted under the skin to help the heart beat regularly and at an appropriate rate

The pacemaker has leads that travel through a large vein to the heart, where the wires are anchored

The leads send the electrical impulses to the heart to tell it to beat

•The atrioventricular node (AV node), located between the right atrium and right ventricle, is the secondary pacemaker

•The AV node sets the rhythm of your heart contractions

•The AV node receives impulses from the SA node and delays the signal, giving the atrium time to contract first

•If the atrium and the ventricle contracted at the same time, the ventricles would push out their blood before they were totally full, resulting in low blood pressure

Arrhythmias problems that affect the electrical system of heart muscle; types of arrhythmias include:

Bradycardia - heart rate of less than 60 beats per minute; symptoms include fatigue, dizziness, lightheadedness, fainting due to insufficient blood flow to the brain

Tachycardia - rapid heart beating; can produce chest pain, dizziness, lightheadedness, fainting due to the heart beating too fast to circulate blood effectively

Atrial Fibrillation - type of arrhythmia, or abnormal heartbeat, that is caused by erratic electrical signals originating from the atria.

Pulmonary Circulation –heart to the lungs and back to the heart

Systemic Circulation –heart to all body tissues and back again

Cardiovascular System Disorders

Heart disease – any condition that impairs normal functioning of the heart muscle or blood vessels of heart

Specific Heart Conditions:

Congestive Heart Failure – inability of the left ventricle to pump adequate blood to the body's other organs

Congenital Heart Defects – heart problems that babies have at birth

Animation Common congenital disorders:

1. Ventricular Septal Defects (VSD)

2. Atrial Septal Defects (ASD)

abnormal openings in the interventricular septum

Review for test:

1. The outermost layer of the pericardium

2. The lining of the heart

3. Heart muscle

4. The pacemaker of the heart

5. The point in the conduction system of the heart where the impulse is temporarily delayed

6. Prevents backflow into the left atrium

7. Prevents backflow into the right atrium

8. True or False: The myocardium receives its blood supply directly from the carotid arteries.

9. True or False: A heart rate of less than 60 beats/min is called tachycardia.

10.True or False: The atria receive blood returning to the heart.

11.True or False: Congestive heart failure means that the pumping efficiency of the heart is depressed so that there is inadequate delivery of blood to body tissues.

12.True or False: Tissues damaged by myocardial infarction are replaced after a long time because myocardial cells replicate slowly.

13.True or False: The left side of the heart pumps a larger volume of blood than the right since the left side feeds the entire body except the lungs.

14.Normal heart sounds are caused by ________.

15.The left ventricular wall of the heart is thicker than the right wall in order to________.

16.Blood within the pulmonary veins returns to the ______.

17.Blood enters which of these vessels during ventricular systole?

A. Aorta C. pulmonary veins

B. pulmonary arteries D. both a and b

18.Blood is carried to capillaries in the myocardium by way of the _______ arteries.

19.Which of the following factors does not influence heart rate?

A. Skin color C. gender

B. Age D. body temperature

20.Define systole and diastole. Which heart chambers are usually referenced when these terms are used?

21.Largest artery of the body

22.Carries oxygen rich blood from the lungs

23.Which is greater: oxygen concentration in pulmonary arteries or oxygen concentration in pulmonary veins.

24.Which is greater: systolic pressure or diastolic pressure

25.True or False: The largest of the circulatory routes is the systemic route.

26.True or False: All arteries of the systemic circulation branch from the superior vena cava.

27.True or False: Hypotension is generally considered to be systolic blood pressure above 100 mm Hg.

28. True or False: Capillaries directly connect arterioles to venules.

29.True or False: Pulmonary circulation does not directly serve the metabolic needs of body tissues.

30.Which type of blood vessels contain valves and what is their function?

Measuring Blood Pressure

1. Systolic pressure (top number)

pressure inside the artery when the heart contracts and pumps blood through the body

2. Diastolic pressure (bottom number)

pressure inside the artery when the heart is at rest and is filling with blood

(Do not copy)

•You inflate the sphygmomanometer (sfĭg'mō-mə-nŏm'ĭ-

tər) to 180 mm Hg. This collapses the major arteries to the arm (that's why it is uncomfortable).(Sphygmo is Greek for pulse, and a manometer measures pressure)

•Then you slowly release air by gently turning the air valve, and watch the pressure drop. “righty tighty” “lefty lucy”

•When you first hear a sound, that will be the Systolic blood pressure. The sound you hear is the blood now flowing in the artery of the arm

•As you continue to watch the pressure drop, note when you no longer hear any sounds, that will be the Diastolic blood pressure Blood Pressure Animation