Heart outline pulmonary & systemic circulation location of heart in thorax pericardium external anatomy of heart internal anatomy of heart coronary circulation.

Heart outline

• pulmonary & systemic circulation• location of heart in thorax• pericardium• external anatomy of heart• internal anatomy of heart• coronary circulation• CAD, angina and heart attacks• heart valves• conduction system of heart• EKG’s

Systemiccircuit

Pulmonarycircuit

CO2 O2

O2artery

vein

vein

artery

T9

Looking at left side of heart Looking at right side of heart

Pericardial cavity

Fibrous pericardium

Myocardium

Endocardium

Parietal pericardium

Visceral pericardium

Epicardium = visceral pericardium + adipose

cardiomyopathy

Pericarditis = inflammation of the pericardium

peri = ? cardi = ? -itis = inflammation

Fibrous skeleton: collagen & elastic fibers between chambers & around valves

• structural support • prevents valves from being overly distended• anchors myocardium• electrical “insulator” between atria and ventricles

aorta

Superior vena cava

Inferior vena cava

Right atrium

Right ventricle

Pulmonary artery

Anterior View

PV

LV

LA

Left atrium

Left ventricleRV

RA

Posterior view

Chambers of the Heart

• 4 chambers – 2 upper atria (atria = entry hall) (auricle = little ear)– 2 lower ventricles (ventricles = little bellies)

Auricle

Right atrium SVC

IVC

CoronarySinus(opening)

Fossa ovalis

Pectinate muscle

Right AV orifice

Right ventricle

Pulmonary valve

Tricuspid valve

Trabeculae carneae

Papillary muscle with tendinous cords

Left ventricle

Aortic valve

Mitral (bicuspid) valve

Papillary muscleswith chordae tendineae

Trabeculae carneae

Right atrium & ventricle Left atrium & ventricle

Coronary circulation

Coronarysinus

Coronary circulation

L & R coronary artery = directly off aorta just distal to aortic valvesCoronary sinus = drains into right atrium

RCA

RCA

LCA (Under auricle)

Coronary sinusR & L coronary arteriesAortic valve

Fig. 20.12

Coronary artery disease (CAD)• narrowing of coronary arteries• leading cause of death in US

Atherosclerosis• fatty plaque on arterial walls

By-pass Graft

Myocardial infarction (MI)

• dead tissue areas in myocardium• caused by interruption of blood flow• cardiac muscles cells don’t regenerate• replaced by scar tissue• scarred or ischemic cardiac muscle can’t pump or conduct electrical impulses• arrhythmias (ventricular fibrillation)• Angina pectoris (chest pain)

Referred pain:

Organ & skin pain fibers travel to the spinal cord together

Organ pain misinterpreted as skin pain (referred pain)

Tricuspidvalve

Bicuspid or Mitralvalve

Pulmonary valve(semilunar valve)

Aortic valve(semilunar valve)

Semilunar valves• aortic & pulmonary valves• each has 3 cusps (no tendinous cords)• close when pressure in ventricles falls

Atrioventricular (AV) valves• tricuspid and bicuspid (Mitral)• tricuspid = 3 cusps, bicuspid = 2• connected to papillary muscle via tendinous cords• close when pressure in ventricles increases

Cardiac Cycle = 1 heartbeat

Diastole = relaxationSystole = contraction

Atrioventricular Valves Open

Ventricles = diastoleAtria = systole(atrial pressure > ventricle pressure)

Atrioventricular Valves Close

• Ventricles = systole• Atria = diastole

• Ventricle pressure > atrial pressure

• A-V valves close preventing backflow of blood into atria

1.What are the ventricles doing in A?

2.Is blood flowing into the coronary arteries in A or B?

Valve Function Review

A B

Murmurs – any abnormal heart sound

Stenosis – narrowing of valve orifice• Congenital, rheumatic fever• Mitral most common (aortic)

Insufficiency or regurgitation – incomplete closure of valve• Many causes (MI, RF, HF, prolapse)• Aortic and mitral most common

Prolapse: most common valve disease• CT diseases or genetic

Rheumatic fever - strepA

Cardiac Cycle = 1 heartbeat

How does the heart beat?

Conduction System of Heart

SA node – AV node – AV bundle of His (between ventricles) – Purkinje fibers

How does your heart rate change?• Nervous control (ANS)• hormones• drugs

Heart block: electrical signals blockedBundle branch block or total heart block

Ectopic focusArrhythmia: irregular heart beatFibrillations: uncoordinated contractions

• EKG = electrocardiogram– Recording electrical

currents in heart • P wave

– atrial contraction • P to Q interval

– time for impulse to travel from SA node to AV node

• QRS complex – ventricular contraction

• T wave– ventricular relaxation

Impairment of the heart to fill or pump a sufficient amount of blood through the body

• right side• peripheral edema• ascites• jugular venous distention

• left side• dyspnea (shortness of breath)• orthopnea• pulmonary edema

Heart failure