Circulation Chapter 9 Section 2

Section 2: The Circulatory System essential in maintaining homeostasis throughout the entire body. Blood vessels carry blood to every part of your body. Blood moves oxygen and nutrients to cells, and moves carbon dioxide and other wastes away from the body.

The cardiovascular system includes your: 1.Heart 2.Blood vessels 3.Blood

Heart a muscular organ responsible for pumping blood through the blood vessels by repeated, rhythmic contractions. located behind your breastbone and between your lungs

System 4 Chambers Of the heart: 1.Right atrium 2.Left atrium 3.Right ventricle 4.Left ventricle

How the heart works: The atria and ventricles work together The atria will fill with blood, then pump it to the ventricles The ventricles then pump the blood out of the heart

3 Sections of the Circulatory System 1.Coronary circulation 2.Pulmonary circulation 3.Systemic circulation

Coronary Circulation: Blood flows via blood vessels that supply the heart with nutrients and oxygen, and remove waste. When coronary circulation is blocked, oxygen and nutrients cannot reach all the cells of the heart causing a heart attack.

Pulmonary Circulation: Flow of blood through the heart to the lungs and back to heart Blood coming to right side has wastes Blood flows to lungs, wastes are exhaled and oxygen goes into blood Blood returns to left side, through left ventricle and is pumped out aorta into the rest of your body

Systemic Circulation: circulation through the rest of the body. Oxygen rich blood flows throughout the body. oxygen poor blood returns back to the heart to start the exchange all over again.

Blood Vessels Capillaries – blood vessels that connect arteries to veins One cell thick Nutrients, oxygen, waste, and carbon dioxide diffuse across capillaries

Blood Vessels…continued Arteries – carry blood away from the heart Have thick walls made of connective tissue and smooth muscle Veins – carry blood back to the heart Have one-way valves to keep blood moving to heart

Force of the blood on the walls of the blood vessels when it is pumped throughout the circulatory system Force is the highest in the arteries, and lowest in the veins Brain sends messages to speed up or slow down heart rate to make sure that blood and nutrients reach all organs and tissues in your body Blood Pressure

What does blood pressure measure? What does blood pressure measure? The doctor will listen to your heart at a check up. That “lub dub” sound is when valves shutting the blood off inside the heart. The top number is called “systole”. This is the pressure of the blood as it is pushed out of the heart by the ventricles. The bottom number is called “diastole”. This is the pressure when the ventricles are refilling.

Checking your pulse We can see how well our heart is working by checking our pulse. You can find your pulse by pressing on the skin anywhere there is a large artery (e.g. side of your neck or inside of your wrist). You will know that you have found your pulse when you can feel the small beat underneath your skin. The average heart rate is between 60 and 90 bpm.

Cardiovascular Disease Cardiovascular Disease Atherosclerosis – fatty deposits on arterial walls can lead to heart attacks. Hypertension – high blood pressure, can be caused by a blocked artery. The walls of the arteries become stiff and hard. Heart failure – heart doesn’t pump blood efficiently. Get a buildup of fluids in the body.

Preventing Cardiovascular Disease Preventing Cardiovascular Disease Regular check-ups, eat a healthy diet, and exercise regularly Do not smoke; it makes the heart beat harder and faster. It also increases the amount of carbon monoxide in the blood.

Lymphatic System Lymphatic System Lymph is tissue fluid from cells that has entered the lymph vessels; filtered through lymph nodes Lymph contains lymphocytes that help the body defend against disease causing organisms Lymph moves throughout the body by contraction of smooth vessels in lymph vessels and skeletal muscles