HEART BIO 233 (1)
Page 1
Page 2: Heart and Heart Disease
Sources: Statistics Canada, Canadian Vital Statistics, Death Database and population estimates
Page 3: Heart Development
Cardiogenic precursors form the linear heart tube
Key structures:
RSCA (Right Subclavian Artery)
RCC (Right Common Carotid)
LCC (Left Common Carotid)
LSCA (Left Subclavian Artery)
AS (Aortic Sac)
IV (Interventricular)
CT (Caval Truncus)
Ao (Aorta)
DA (Ductus Arteriosus)
VI (Ventricular Inlet)
AS (Atrial Septum)
RA (Right Atrium)
V (Ventricle)
LA (Left Atrium)
PA (Pulmonary Artery)
RV (Right Ventricle)
LA (Left Atria)
RA (Right Atrium)
A (Apex)
CT (Cardiac Tissue)
AVV (Atrioventricular Valve)
RV (Right Ventricle)
LV (Left Ventricle)
Timeline: Day 15 to Day 50.
Page 4: Cardiovascular System
Overview and importance of the cardiovascular system.
Page 5: The Heart Is a Double Pump
Contraction:
Decreases chamber volume
Increases chamber pressure
Relaxation:
Increases chamber volume
Decreases chamber pressure
TWO MAJOR DIVISIONS OF CIRCULATORY SYSTEM:
Pulmonary
Systemic
Page 6: Coordination of the Beating Heart
Pumps: Pulmonary and systemic work in parallel
They are connected and highly coordinated
Both contract and relax together, pumping approximately the same volume of blood
Page 7: Anatomy and Pericardium
Location: Heart located in the thoracic cavity, protected by the pericardium
Features of the Pericardium:
Fibrous Pericardium: outer layer, dense regular connective tissue
Serous Pericardium: double-layer membrane filled with pericardial fluid
Parietal Layer: outermost layer, in contact with fibrous pericardium
Visceral Layer: surrounds the heart
Page 8: The Heart Is a Multi-layered Organ
Layers of the Heart:
Epicardium: Outermost layer, loose areolar connective and adipose tissue
Myocardium: Thickest layer, contains cardiomyocytes
Endocardium: Deepest layer, made of simple squamous endothelial tissue
Page 9: Internal Cardiac Anatomy
Chambers of the Heart:
Four chambers: Two atria (upper), two ventricles (lower)
Separated by the cardiac septum
Systemic Pump: Left atrium + left ventricle (pumps oxygenated blood)
Pulmonary Pump: Right atrium + right ventricle (pumps deoxygenated blood)
Page 10: Valves Create One-Directional Blood Flow
Valves function: Flaps anchored to cardiac skeleton, between ventricles and major blood vessels, and between atria and ventricles
Types of Valves:
Tricuspid Valve: 3 cusps
Bicuspid (Mitral) Valve: 2 cusps
Function: Anchor cusps to papillary muscles to prevent eversion
Page 11: Heart Sounds and Listening Posts
Characteristics of Heart Sounds:
Lubb (S1): Produced by turbulent flow through AV valve
Dupp (S2): Produced by closure of semilunar valves
Murmurs: Abnormal heart sounds due to incomplete closure of valves
Location: Listening posts not at anatomical positions because of overlying bone
Page 12: Blood Flow Through the Heart and Major Vessels
Deoxygenated Blood Flow:
Enters right atrium via superior and inferior vena cava
Pumps through tricuspid valve to right ventricle
Exits through pulmonary arteries into pulmonary circulation
Oxygen-rich Blood Flow:
Returns through pulmonary veins into the left atrium
Pumps through mitral valve into left ventricle
Exits through aorta into systemic circulation
Page 13: Other Names for Heart Valves
Tricuspid Valve: Right atrioventricular (AV) valve
Mitral Valve: Bicuspid valve, left atrioventricular (AV) valve
Division of the Heart.
Page 14: The Coronary Circulation
Arterial Circulation:
Left coronary artery
Circumflex artery
Right coronary artery
Venous Circulation:
Great cardiac vein
Coronary sinus
Middle cardiac vein
Anterior interventricular artery
Small cardiac vein
Right marginal artery
Posterior interventricular artery
Page 15: Blood Supply to the Myocardium
Main Components:
Aortic arch
Aortic valve
Coronary arteries (right coronary artery, left coronary artery)
Coronary veins (coronary sinus, great cardiac vein)
Heart Chambers:
Left atrium, right atrium, left ventricle, right ventricle.
Page 16: Cardiac Cycle
Cycle Steps:
Contraction of both atria
Contraction of both ventricles
Entire heart relaxes briefly (next cycle begins)
Visual Aid: Green shading indicates chamber contraction.
Page 17: The Cardiac Excitation Sequence
SA Node:
Location of pacemaker cells, generates fastest action potentials
AV Node:
Contains slower pacemaker cells, allows time for atrial contraction
Right and Left Bundle Branches:
Propagate action potential through interventricular septum to apex
Purkinje Fibers:
Spread action potentials rapidly to ventricles due to high intercalated disc content
Bundle of His:
Conducts action potential from AV node to interventricular septum
Internodal Pathways:
Conducts action potentials from SA node to atrial myocytes through gap junctions
Page 18: Extrinsic Regulation of Cardiac Output
Neural Mechanisms:
Innervated by sympathetic and parasympathetic branches of the autonomic nervous system
Sympathetic Effects:
Release of catecholamines during “fight or flight”
Parasympathetic Effects:
Release of acetylcholine during “rest and digest”
Page 19: Heart Diseases
Overview of various heart diseases.
Page 20: Risk Factors for Heart Disease
Major Factors:
Age, sex, family history
Smoking, cancer treatment
Poor diet, high blood pressure, high cholesterol
Diabetes, obesity, physical inactivity
Stress, poor hygiene
Page 21: Focus on Disease: Cardiac Arrhythmias
Definition:
Disorders characterized by abnormal electrical activity within the heart
Causes:
Breakdown in coordination of the electrical conduction system
Effects:
Changes in pumping activity, from harmless to fatal (e.g., atrial fibrillation, ventricular fibrillation)
Page 22: Electrocardiogram (ECG)
Definition:
Provides an electrical picture of heart function
Method: Obtained through skin leads
Function: Summary of electrical changes in all cells of the heart
Page 23: Impulses in Normal ECG
Conduction Sequence:
Impulses initiated at SAN, cause contractions in the atria, preparing ventricles for the next contraction.
ECG Segments: P, Q, R, S, T waves.
Page 24: Normal Patient ECG
Visual example of a normal electrocardiogram.
Page 25: Symptoms/Diseases
Inflammation:
Myocarditis (damage to heart muscle)
Pericarditis (inflammation of outer membrane)
Arrhythmias:
Abnormal rhythms, e.g., ventricular fibrillation (serious condition needing defibrillation)
Coronary Artery Disease:
Degenerative changes lead to narrowed arteries due to atherosclerosis.
Page 26: Other Heart-Related Diseases
Conditions:
Angina pectoris: moderate blood supply shortage
Myocardial infarction: blockage leading to heart attack
Heart failure: ineffective pumping due to damage
Related issues: Stroke, aneurysm
Page 27: Coronary Artery Disease Progression
Visuals of narrowing due to plaque accumulation in arteries.
Page 28: Balloon Angioplasty
Mechanism:
Catheter inserted, balloon inflated to flatten plaque, catheter removed
Visual Aid: Shows before and after procedure.
Page 29: Placing a Stent
Procedure Overview:
Involves deflated balloon for stenting, balloon inflated to open stent.
Page 30: Indicators of Cardiac Conditions
Symptoms and Indicators:
Cyanosis, dilated neck veins, low cardiac output, congestion
Related organ effects: kidneys, liver, lungs with signs of decreased flow or retention.