Lesson 3: The Circulatory System

Hook: Interesting Facts Science There are 97,000km of blood vessels in every human The aorta, which is largest artery located in the body, is about the diameter of a garden hose The risk of cardiovascular disease is twice as high in women that snore regularly compared to women who do not snore The right lung of a human is larger than the left one. This is because of the space and placement of the heart The average life span of a single red blood cell is 120 days

The Circulatory System: Functions The circulatory system is the transport system of the body. Four main functions: Transport of O2 and CO2. Distribution of nutrients and transport of wastes. Maintenance of body temperature. Circulation of hormones. Explain: O2 is oxygen is CO2 is carbon dioxide

The Circulatory System: Structure There are 3 components of the circulatory system: A fluid which carries materials (blood). Spaces throughout the body where the fluid moves (blood vessels). A pump to push fluid through spaces (heart).

The Circulatory System: Vessels Arteries carry blood away from the heart, to the body. Veins carry blood from the body, to the heart.

The Circulatory System: Vessels Movement of Oxygenated Blood Through Vessels: Large Smaller Smallest Heart  Arteries  Arterioles  Capillaries  Tissues Movement of Deoxygenated Blood Through Vessels: Small Larger Largest Tissues  Capillaries  Venules  Veins  Heart

The Circulatory System: Circuits The circulatory system is actually two systems in one. The Pulmonary Circuit The right side of the heart pumps blood to the lungs. The blood picks up oxygen from the lungs and returns it to the left side of the heart.

The Circulatory System: Circuits The Systemic Circuit The left side of the heart pumps oxygenated blood to the body’s system. The blood returns to the right side of the heart without oxygen (deoxygenated).

The Circulatory System: The Heart The mammalian heart is a double pump separated by a wall of muscle called the septum. The heart consists of 4 chambers: Left atrium and right atrium (upper chambers of the heart). Left ventricle and right ventricle (lower chamber of the heart).

The Circulatory System: The Heart The atria receive blood from the body. The ventricles pump blood to the body. Recall: Pulmonary Circuit: Right ventricle pumps to the lungs; left atrium receives blood from the lungs. Systemic Circuit: Left ventricle pumps to the body; right atrium receives blood from the body.

The Circulatory System: The Heart

Blood Flow Review (Complete on work sheet) Body  Superior/Inferior Vena Cava  Right Atrium  Right Ventricle  Pulmonary Artery  Lungs  Pulmonary Vein  Left Atrium  Left Ventricle  Aorta  Body Blue: Deoxygenated blood Superior Vena Cava brings blood from the top of the body, Inferior Vena Cava brings blood from the bottom of the body – largest vein in the body; Pulmonary Artery is the only artery in the body to carry deoxygenated blood. Red: Oxygenated blood The Aorta is the largest and strongest artery in the body; Pulmonary Vein is the only vein in the body to carry oxygenated blood.

Blood Flow Summary

Review: The Human Heart

No Notes - Blood Movement in the Heart Deoxygenated blood from the body’s veins enters the right atrium of the heart. It is then passes a valve and moves into the right ventricle. From the right ventricle it is pumped to the lungs to receive oxygen and lose carbon dioxide

Blood Movement in the Heart The oxygen rich blood then flows into the left atrium. Passing another valve it moves into the left ventricle. The blood is then pumped to the rest of the body through the aorta and into the arteries. Oxygen is carried throughout the body.

Summary: Blood Flow in the Heart

Heart Attack If too much cholesterol is ingested than plaque may build up When excessive plaque builds up the artery may be clogged. If the artery is clogged then little oxygen will move to the heart = Heart attack. If lack of oxygen moves to the brain = Stroke

Method of Treatment: Angioplasty

Video on Angioplasty

Blood Pressure Blood pressure is the amount of pressure exerted by the heart on the blood. It varies between a maximum (systolic) and minimum (diastolic) pressure Systolic pressure is the pressure exerted when the heart is pumping blood Diastolic pressure is the pressure associated with the filling of the heart with blood

High and Low Blood Pressure People with high blood pressure are said to have hypertension People with low blood pressure are said to have hypotension There are three main types of hypotension: Orthostatic hypotension, including postprandial orthostatic hypotension Neurally mediated hypotension (NMH) Severe hypotension brought on by a sudden loss of blood (shock), infection, or severe allergic reaction Orthostatic hypotension is brought on by a sudden change in body position, most often when shifting from lying down to standing. This type of hypotension usually lasts only a few seconds or minutes. If this type of hypotension occurs after eating, it is called postprandial orthostatic hypotension. This form most commonly affects older adults, those with high blood pressure, and persons with Parkinson's disease. NMH most often affects young adults and children. It occurs when a person has been standing for a long time. Children usually outgrow this type of hypotension. Low blood pressure is commonly caused by drugs such as: Alcohol Anti-anxiety medications Certain antidepressants Diuretics Heart medicines, including those used to treat high blood pressure and coronary heart disease Medications used for surgery Painkillers

In Class Assignment - Homework Read pages 195-200. Page 202: #1-5. Read pages 203-206. Page 207: #1-3, 6-9. Complete the Circulatory System Review Sheet