The Cardiovascular System

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The Cardiovascular System
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The Cardiovascular System

• Functions
• Transport nutrients, dissolved gases, and
  hormones.
• Vessels
• Veins
• Venules
• Capillaries
• Arterioles
• Arteries

• Open vs. Closed circulatory systems
• Arteries
• Characteristics
• Elastic, thick, strong, carry oxygenated blood.
• Veins
• Characteristics
• Thin, not very elastic, low pressure, carry
  deoxygenated blood, have valves to prevent
  backflow of blood.

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Blood Pressure

• Pressure in an artery.
• Usually the brachial artery or the carotid artery
  is used.
• Systolic Pressuretop number. Usually around 120
  mm of Hg.
• Pressure due to contraction of left ventricle.

• Diastolic pressurebottom numberusually around
  70 mm of Hg. Pressure when the ventricles relax.
• Vasodilation and vasoconstriction
• Effects on blood pressure

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The Anatomy of the Heart

• Mediastinum
• About the size of a fist. (250-350 grams)
• Composed of cardiac muscle tissue.
• Self-stimulating
• All cells are interconnected and beat
  simultaneously.
• Pericardium
• Visceral pericardium
• Parietal pericaridium
• Pericardial fluid

• pericarditis
• 4 chambers
• 2 atria
• 2 ventricles
• A septum separates the chambers.
• Apextoward left
• Flat posterior
• Coronary arteries nourish the heart muscle. If
  these are blocked, a heart attack will occur.

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Anatomy of the Heart

• Epicardiumvisceral pericardium.blood vessels,
  nerve fibersprotection.
• Myocardiumthick layer of cardiac muscle
• Endocardiumepithelium and connective tissues,
  Purkinje fibers

• Auricles
• Interatrial septum
• Interventricular septum
• AV valves
• Tricuspidright
• Bicuspid or mitralleft
• Chordae tendinae
• Papillary muscles
• Mitral valve prolapse6 of population.
  Stenosis, valve replacement

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Anatomy of the heart

• Semilunar valves
• Aortic valve
• Pulmonary valve

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Blood Flow

• Left ventricle
• Through aortic valve
• Aorta
• All body tissues
• Superior and Inferior Vena Cava
• Right Atrium
• Tricuspid Valve
• Right ventricle
• Pulmonary valve
• Pulmonary artery

• Lungs
• Pulmonary Vein
• Left Atrium
• Bicuspid Valve
• Left Ventricle

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Blood Flow and Heart structure Continued

• Pulmonary Circuit
• Systemic Circuit
• Mammals and Birds have 4 chambered hearts
• Reptiles have a 3 chambered heart almost divided
  into 4 chambers.
• Amphibians have a 3 chambered heart.
• Fish have a 2 chambered heart.
• What is the significance of this pattern?

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Coronary arteries

• Angina pectoris
• Myocardial infarction
• Bypass surgery
• Angioplasty
• Atherosclerosis
• Arteriosclerosis
• Arrhythmias
• Tachycardia
• Bradycardia
• Ventricular fibrillation
• Defibrillator
• Ischemia
• pH change

• Right and left coronary arteries
• First 2 branches of the aorta.
• Heart gets almost all of its energy from aerobic
  respiration.
• 1/20 of blood supply
• Collateral circulation
• Cardiac veins
• Coronary sinus
• Right atrium

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Heart Sounds

• Valves opening and closing
• Lubb-dupp
• LubbAV valves close
• DuppSemilunar valves close.
• murmurs

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Cardiac Conduction System

• Cardiac muscle
• Functional syncytium
• Self stimulating
• SA noderight atriumpacemaker
• Generates the hearts rhythmic contractions.
• From SA node to internodal atrial muscle.
• Causes atria to contract almost simultaneously.

• AV nodeinferior interatrial septum.
• Small fibers lead to AV node.
• AV bundle or Bundle of His
• Purkinje fibers
• Papillary muscles
• Cardiac muscle fibers
• Cause simultaneous contraction of the ventricles.

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Electrocardiogram

• ECG
• Electrical activity of the heart.
• Waves
• P wavedepolarization of the atria.
• QRS complexdepolarization of ventricles.
• T waverepolarization of the ventricles

• Control of then cardiac cycle.
• Parasympathetic and sympathetic innervation.
• Cardiac control center of the medulla
• baroreceptors

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ECG

• An enlarged R wave may signal enlarged
  ventricles.
• A flattened T wave may signal ischemia.
• A prolonged QT interval may signal a
  repolarization abnormality.

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