Heart facts Heart pumps over 2,500 gallons per day ¼ cup per beat 70-75 beats per minute Over 60,000 miles of blood vessels

1. What type of view is this? 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

Pulmonary circuit Systemic circuit artery vein artery vein Systemic circuit CO2 O2

T9

Looking at the left side from the right Looking at the right side from the left

Pericardial cavity

Visceral pericardium Myocardium Endocardium Fibrous pericardium Parietal pericardium Visceral pericardium Myocardium Endocardium 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

aorta Superior vena cava Pulmonary artery Pulmonary veins Right atrium Auricle of left atrium Right ventricle Left ventricle Inferior vena cava Anterior View

aorta Pulmonary artery Superior vena cava Pulmonary veins Left atrium Right atrium Inferior vena cava Left ventricle Right ventricle 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 Coronary Sinus (opening) Pectinate muscle Fossa ovalis IVC Right AV orifice

Right ventricle Pulmonary valve Trabeculae carneae Tricuspid valve Papillary muscle with tendinous cords

Left ventricle Aortic valve Mitral (bicuspid) valve Papillary muscles with chordae tendineae Trabeculae carneae

Right atrium & ventricle Left atrium & ventricle

Coronary circulation

Coronary circulation RCA Coronary sinus LCA (Under auricle) RCA L & R coronary artery = directly off aorta just distal to aortic valves Coronary sinus = drains into right atrium

Mitral & tricuspid valve Aortic & pulmonary valve Coronary sinus R & 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)

Aortic valve (semilunar valve) Pulmonary valve (semilunar valve) Bicuspid or Mitral valve Tricuspid valve

Atrioventricular (AV) valves 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 = relaxation Systole = contraction

Atrioventricular Valves Open Ventricular diastole Atrial systole (atrial pressure > ventricle pressure)

Atrioventricular Valves Close Ventricle systole Atrial diastole Ventricle pressure > atrial pressure A-V valves close preventing backflow of blood into atria Murmurs – any abnormal heart sound mitral valve prolapse, stenosis, insufficiency Rheumatic fever

Pulmonary valve Aortic valve

What are the ventricles doing in A? Valve Function Review A B What are the ventricles doing in A? What are the ventricles doing in B?

Cardiac Cycle = 1 heartbeat How does the heart beat? Cardiac Cycle = 1 heartbeat

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 blocked Arrhythmia: irregular heart beat Fibrillations: 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

Heart failure 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