Circulatory System Heart, Blood Vessels and Blood Principles of Health Science Virginia Parker

Do you know? Where your heart is located in your chest? Where your heart is located in your chest? Centered with apex or point tipped to left. What make the lubb-dubb sound when you listen to your heart? What make the lubb-dubb sound when you listen to your heart? Sound of the valves within heart closing. How many times the heart beats per day? How many times the heart beats per day? Every day the average heart beats 100,000 times How much blood you have and how often it is circulated through the body? How much blood you have and how often it is circulated through the body? You have about 5.6 liters (6 quarts) of blood that circulates through the body three times a minute.

The pericardium is a thin double-layered sac which encloses the heart. Fluid is contained within the layers and lubricates the constantly rubbing surfaces

Myocardium- cardiac muscle

Coronary Arteries The heart supplies itself with blood before the rest of body through the coronary artery system that arises from the base of the aorta. A blockage in one of these arteries leads to a myocardial infarction – “heart attack” A blockage in one of these arteries leads to a myocardial infarction – “heart attack”

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Blood Flow Deoxygenated blood flows through right side of heart. Deoxygenated blood flows through right side of heart. Oxygenated blood flows through left side of heart. Oxygenated blood flows through left side of heart.

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Heart Sounds Lubb sound – closing of tricuspid and mitral valves Lubb sound – closing of tricuspid and mitral valves Dubb sound – closing of semilunar valves in the aorta and pulmonary arteries as blood is pumped out of heart Dubb sound – closing of semilunar valves in the aorta and pulmonary arteries as blood is pumped out of heart

Heart Valves Tricuspid Valve Tricuspid Valve Bicuspid or Mitral Valve Bicuspid or Mitral Valve Aortic Semilunar Valve Aortic Semilunar Valve Pulmonary Semilunar Valve Pulmonary Semilunar Valve

The Conduction System Though the heart does respond to stimulation from the vagus nerve, it can operate without any connection to the nervous system through its own conduction system. Though the heart does respond to stimulation from the vagus nerve, it can operate without any connection to the nervous system through its own conduction system.

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Electrocardiogram _ ECG or EKG Electrocardiogram _ ECG or EKG

Arteries Carry blood away from heart to all parts of body. High pressure system with more smooth muscle in walls of artery.

Arteries Aorta – largest artery in the body – about the size of a garden hose Aorta – largest artery in the body – about the size of a garden hose

Veins Low pressure collection vessels that return de- oxygenated, waste filled blood back to heart. Have one way valves to shunt blood flow toward heart. Need surrounding muscle action in legs to aid in venous return. Largest Vein – Vena Cava

Artery and Vein Layers

Capillaries Anatomic units that connect arterial and venous systems Anatomic units that connect arterial and venous systems Only one cell thickness, smallest vessels in body – takes 10 to be thickness of human hair Only one cell thickness, smallest vessels in body – takes 10 to be thickness of human hair Slow flow allows time for exchange of nutrients, oxygen, waste materials between tissue fluids and surrounding cells Slow flow allows time for exchange of nutrients, oxygen, waste materials between tissue fluids and surrounding cells

What is Blood Pressure? Pressure within your arteries. Measured in two ways: Pressure within your arteries. Measured in two ways: –Systolic – pressure during heart contraction –Diastolic – pressure between contractions –Expressed as fraction – average 120/80 Hypotension – low blood pressure Hypotension – low blood pressure Hypertension - Consistently elevated blood pressure Hypertension - Consistently elevated blood pressure –Systolic higher than 140 –Diastolic higher than 90

Myocardial Infarction Also known as a heart attack or MI. Due to closing off of a coronary artery and resulting in an infarction of the myocardium. Also known as a heart attack or MI. Due to closing off of a coronary artery and resulting in an infarction of the myocardium. Infarction – localized area of tissue necrosis due to lack of blood supply). Infarction – localized area of tissue necrosis due to lack of blood supply).

Atherosclerosis of Coronary Artery

Normal Heart

Opened coronary artery demonstrates thrombosis Note dark red color: (consistent with myocardial infarction) Thrombus = blood clot in vessel

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