Heart pumps over 2,500 gallons per day

¼ cup per beat

70-75 beats per minute

Over 60,000 miles of blood vessels

Heart facts

1. What type of view is this?

2. Name this gland.

3. Name 2 hormones secreted by this gland.

4. Name this gland

5. What are the effects of the hormone secreted by this gland?

Heart outline

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

Systemiccircuit

Pulmonarycircuit

CO2 O2

O2artery

vein

vein

artery

T9

Looking at the left sidefrom the right

Looking at the right sidefrom the left

Pericardial cavity

Fibrous pericardium

Myocardium

Endocardium

Parietal pericardium

Visceral pericardium

Epicardium = visceral pericardium + adipose

Pericarditis = inflammation of the pericardium

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

aortaSuperior vena cava

Inferior vena cava

Right atrium Auricle of leftatrium

Right ventricle

Left ventricle

Pulmonary artery

Anterior View

Pulmonary veins

aorta Pulmonary artery

Superior vena cava

Inferior vena cava

Left atrium

Left ventricle

Right ventricle

Right atrium

Pulmonary veins

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)

Mitral & tricuspid valveAortic & pulmonary valveCoronary sinusR & L coronary arteries

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• Angina pectoris (chest pain)• scarred or ischemic cardiac muscle can’t pump or conduct electrical impulses• arrhythmias (ventricular fibrillation)

Referred pain:

Organ & skin pain fibers travel to the spinal cord together

Organ pain misinterpreted as skin pain (referred pain)

Tricuspid valve

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

Papillary muscle

Chordae tendineae(tendinous cords)

Cardiac Cycle = 1 heartbeat

Diastole = relaxationSystole = contraction

Atrioventricular Valves Open

Ventricular diastoleAtrial systole(atrial pressure > ventricle pressure)

Atrioventricular Valves Close

• Murmurs – any abnormal heart sound

• mitral valve prolapse, stenosis, insufficiency • Rheumatic fever

• Ventricle systole• Atrial diastole

• Ventricle pressure > atrial pressure

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

Aortic valve

Pulmonary valve

1.What are the ventricles doing in A?

2.What are the ventricles doing in B?

Valve Function Review

A B

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 blockedArrhythmia: 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