ANAPHY: U10.2 Cardiovascular System (Heart)

Heart

4-Chambered muscular organ that pumps blood through the blood vessels of the body

Pulmonary Circulation

Type of circulation done by the right side of the heart; pumps blood to lungs and back to left side of heart

lungs; left side of the heart

The right side of the heart pumps blood to ___ and back to the ___ ___ __ __ ___

Systemic Circulation

Type of circulation done by the left side of the heart; pumps blood to all other tissue of the body and back to the right side of the heart

all other tissues; right side of the heart

The left side of the heart pumps blood to __ ___ ___ and back to the ___ ___ __ __ ___

BROS

Acronym for 4 Main Functions of the Heart

1. Blood Pressure Generation

2. Routing Blood

3. Ensures One-Way Blood Flow

4. Regulating Supply of Blood

4 Main Functions of the Heart

Blood Pressure Generation

One of the four main functions of the heart; heart contractions generate blood pressure which forces blood through the blood vessels

Routing Blood

One of the four main functions of the heart; heart separates pulmonary and systemic circulation, ensuring oxygenated blood flows to tissues

Ensures One-Way Blood Flow

One of the four main functions of the heart; valves of the heart ensure one-way blood flow through heart and blood vessels

Regulating Blood Supply

One of the four main functions of the heart; changes in heart rate and force of contraction matches blood flow during rest, exercise, and change in body position

Size of a closed fist

What is the size of the heart?

In mediastinum, protected by the thoracic cage

Where is the heart located?

Pericardium

Sac consisting of fibrous and serous pericardia

Fibrous & Visceral Pericardium

2 Types of Pericardium

Fibrous Pericardium

Type of pericardium; outer layer lined by the parietal pericardium

Visceral/Epicardium

Type of pericardium; lines outer surface of heart

R & L Atria

Part of External Anatomy of the heart; 2 structures located at the base of the heart

Coronary Sulcus

Part of External Anatomy of the heart; Groove around the heart that separates the atria from ventricles

R & L Ventricles

Part of External Anatomy of the heart; 2 structures separated by interventricular sulci anteriorly and posteriorly

Superior and Inferior Vena Cava

Part of External Anatomy of the heart; enter the right atrium

Pulmonary Trunk

Part of External Anatomy of the heart; exits right ventricle

Aorta

Part of External Anatomy of the heart; exits left ventricle

R & L Atrium, R & L Ventricle

4 Chambers of the Heart

Atria

Part of the internal anatomy of the heart; separated by the interatrial septum, serves as reservoirs (receiving chamber only); contraction completes ventricular filling

Ventricles

Part of the internal anatomy of the heart; main pumping chambers that are separated by the interventricular septum

Ventricles

Part of the internal anatomy of the heart; main pumping chambers separated by interventricular septum

Pulmonary Trunk

Where does the right ventricle pump blood into?

Aorta

Where does the left ventricle pump blood into?

Valves

Part of the internal anatomy of the heart; ensures one-way blood flow

Atrioventricular & Semilunar Valves

2 Main Types of Heart Valves

Tricuspid & Bicuspid/Mitral Valve

2 Types of Atrioventricular Heart Valves

Tricuspid Valve

Type of Artrioventricular Valve; separates RA and RV

Bicuspid/Mitral Valve

Type of Atrioventricular Valve; separates LA and LV

Pulmonic & Aortic Valve

2 Types of Semilunar Valves

Pulmonic Valve

Type of Semilunar Valve; separates RV and pulmonary trunk

Aortic Valve

Type of Semilunar Valve; separates LV and aorta

Pulmonary Arteries

Only artery that doesn’t carry oxygenated blood

Right Side

Side of the heart that always has deoxygenated blood

Papillary Muscles

Attached by chorda tendineae to cusps, adjust tension on valves; prevent atrioventricular valves from stretching too much

Chorda Tendineae

What are papillary muscles attached to?

Coronary Arteries

Arteries that originate from the base of the aorta and are filled when the heart relaxes

Left Coronary Artery

Artery that supplies most of the left ventricle and anterior heart wall

3

How many branches does the left coronary artery have?

Anterior Interventricular Artery, Circumflex Artery, Left Marginal Artery

3 Major Branches of the Left Coronary Artery

Right Coronary Artery

Artery that supplies most of the right ventricle and the posterior surface of the heart

2

How many branches does the right coronary artery have?

Posterior Interventricular Artery & Right Marginal Artery

2 Major Branches of the Right Coronary Artery

(1) cardiac veins (2) coronary sinus (3) right atrium

Blood returns from the heart tissue through (1) ___ ___, (2) ___ ___, then to the (3) ___ ___

Outer Epicardium, Middle Myocardium, Inner Endocardium

3 Layers of the Heart Wall

Intercalated Disks

What component of cardiac muscle allow for action potentials to be propagated in the heart?

ATP

What does cardiac muscle depend on for energy and aerobic metabolism?

(1) Coordinated sequence of cardiac muscle is stimulated

(2) Contraction of atria

(3) Contraction of ventricles

(4) Cardiac muscle contracts then relaxes completely

4 Steps in the Movement of Blood through the Heart

Sinoatrial (SA) Node, Atrioventricular (AV) Node, Antrioventricular (AV) Bundle

3 Specialized Cardiac Muscle Cells

Sinoatrial (SA) Node

One of the specialized cardiac muscle cells; pacemaker of the heart that initiates action potential and spread to myocardium of the right atrium and left atrium, causing atrial contraction

Sinoatrial (SA) Node

What is considered the pacemaker of the heart?

(1) myocardium (2) right atrium (3) left atrium (4) atrial contraction

The Sinoatrial Node initiates action potential and spread to (1) ___ of the (2) ___ ___ and (3) ___ ___, causing (4) ___ ___.

Atrioventricular (AV) Node

One of the specialized cardiac muscle cells; spreads action potential slowly until it reaches the atrioventricular bundle that allows the atria to complete contraction before it goes to ventricles

(1) atrioventricular bundle (2) atrium (3) ventricles

The Atrioventricular (AV) Node spreads action potential slowly until it reaches the (1) ___ ___ that allows the (2) ___ to complete contraction before it goes to the (3) ____.

Atrioventricular Bundle

One of the specialized cardiac muscle cells; subdivides into the left and right bundle branches, which have inferior terminal branches, called Purkinje Fibers, which are located from the apex to the ventricular walls

Left and Right Bundle Branches

What does the atrioventricular bundle subdivide into?

Purkinje Fibers

What are the inferior terminal branches of the left and right bundle branches?

Electrocardiogram (ECG)

Record of the electrical events within the heart

P Wave, QRS Complex, T Wave

3 Components of a Normal ECG

P Wave

Component of a normal ECG; represents atrial depolarization/contraction of the atrium

QRS Complex

Component of a normal ECG; represents ventricular depolarization/contraction of the ventricles

T Wave

Component of a normal ECG: represents ventricular repolarization/relaxation of the heart

PQ Interval

Name of the part of the ECG from the start of the P-wave to the start of the QRS complex

QT Interval

Name of the part of the ECG from the start of the QRS complex to the end of the T Wave

Cardiac Cycle

(From the Book)

Term referring to the repetitive pumping process that begins with the onset of cardiac muscle contraction and ends with the beginning of the next contraction

Systole

(From the Book)

Term in the cardiac cycle; means to contract; when used alone, usually refers to that of the ventricular myocardium

Diastole

(From the Book)

Term in the cardiac cycle; means to dilate; when used alone, usually refers to that of the ventricular myocardium

Atrial Systole

(From the Book)

Term in the cardiac cycle; contraction of the atrial myocardium

Atrial Diastole

(From the Book)

Term in the cardiac cycle; relaxation of the atrial myocardium

Ventricular Systole

(From the Book)

Term in the cardiac cycle; contraction of the ventricular myocardium

Ventricular Diastole

(From the Book)

Term in the cardiac cycle; relaxation of the ventricular myocardium

1. Atrial Systole: Active ventricular filling

2. Ventricular Systole: Period of isovolumetric contraction

3. Ventricular Systole: Period of ejection

4. Ventricular Diastole: Period of isovolumetric relaxation

5. Ventricular Diastole: Passive ventricular filling

5 Steps of the Cardiac Cycle

70%

When blood returns to the heart and enters the atria with the antrioventricular valves open, what volume of the ventricles are filled?

Atrial Systole

Event in the cardiac cycle in which the atria contract and complete the filling of the ventricles; the semilunar valves remain closed

Ventricular Systole

Event in the cardiac cycle in which the atrioventricular valve closes, ventricular pressure increases, semilunar valve opens and blood flows into the aorta and pulmonary trunk

Lubb; when the atrioventricular valves close during the beginning of ventricular systole

What and when is the first heart sound?

Ventricular Diastole

Event in the cardiac cycle in which ventricular pressure decreases; the semilunar valves close (which prevents backflow to the ventricles); ventricular pressure lowered until atrial pressur increases, atrioventricular valves open and blood fills the ventrivles

Dubb; When the semilunar valves close (during ventricular diastole)

What and when is the second heart sound?

Cardiac Output

(From the Book)

The amount of blood pumped by the heart per minute

Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR)

What is the equation for Cardiac Output (CO)?

Stroke Volume (SV)

Component to calculate cardiac output; volume of blood ejected by the heart per beat

Intrinsic Regulation

Regulation mechanism contained within the heart

Venous Return

(From the book)

Amount of blood returning to the heart from the systemic circulation

Increased stretching

As venous return increases, what occurs to the heart walls?

Preload

(From the Book)

Extent to which the ventricular walls are stretched

Afterload

Pressure against which the ventricles must pump blood

(From Book) Pressure the contracting left ventricle must produce to overcome the pressure in the aorta and move blood into the aorta

Extrinsic Regulation

Regulation mechanism that refers to nervous and chemical mechanisms

Autonomic Nervous System & Baroreceptors

2 Ways of Nervous Regulation of the Heart

Autonomic Nervous System

Way of nervous regulation of the heart; sympathetic nerve fibers cause the heart rate and stroke volume to increase, while the parasympathetic nerve fibers cause them to decrease

Increases

How does the sympathetic nervous system affect heart rate and stroke volume?

Decreases

How does the asympathetic nervous system affect heart rate and stroke volume?

Baroreceptors

Way of nervous regulation of the heart; stretch receptors in carotid arteries and aorta that detect an increase in blood pressure

1. Stretch receptors/baroreceptors in carotid arteries and aorta sense a BP increase

2. Cardioregulatory center in medulla oblongata initiates a decrease in sympathetic stimulation of the heart and adrenal medulla (so decreased epinephrine and norepinephrine

3. Increase parasympathetic stimulation of the heart, causing decreased heart rate and stroke volume

4. Decreased blood pressure

How do the baroreceptors stimulate a decrease in blood pressure?

Exercise, Emotional Excitement, Stress

What 3 factors can cause the adrenal medulla to release epinephrine and some norepinephrine which cause a sympathetic response, thus an increased heart rate and stroke volume?

60-100 bpm

What is the normal heart rate range?