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Stack #20168
7th Grade Circulatory System Study Guide
Question | Answer |
---|---|
The cardiovascular system consists of the . . . | heart, blood vessels, and blood |
What are the functions of the cardiovascular system? | It carries needed substances to cells and carries waste products away from cells. Blood also contains cells that fight disease. |
What is the heart? | A hollow, muscular organ that pumps blood throughout the body. |
During your lifetime, your heart may beat how many times? | Over 3 billion times |
How many chambers in total does the heart have? | 4 |
The two upper chambers are called the. . . | atria |
the two lower chambers are called the . . . | ventricles |
What is the function of the atria? | They receive blood that comes into the heart. |
What is the function of the ventricles? | They pump blood out of the heart. |
What is the plural of atrium? | Atria |
The atria are separated from the ventricles by. . . | valves |
What is a valve? | A flap of tissue that prevents blood from flowing backward. |
Where are valves located? | They separate the atria from the ventricles, and they are also located between the ventricles and the large blood vessels that carry blood away from the heart. |
What are the two main phases of the action of the heart? | In the first phase, the heart muscle relaxes and the heart fills with blood. In the second phase, the heart muscle contracts and pumps blood forward. |
The right side of the heart pumps blood to what part of the body? | The lungs |
The left side of the heart pumps blood to. . . | all the body except the lungs. |
What is the pacemaker? | A group of cells in the right atrium that send a signal to make the heart muscle cells contract, regulating the beating of the heart. |
What is the aorta? | The largest blood vessel in the body. It carries blood from the left ventricle to the body. |
What is the septum? | The thick muscular wall that separates the left side of the heart from the right side (hint: SEPtum / SEParate) |
What does the septum do? | It prevents oxygen-rich and oxygen-poor blood from mixing in the heart. |
What is the function of the left ventricle? | It pumps oxygen-rich blood to all parts of the body. |
What is the function of the left atrium? | It receives oxygen-rich blood from the lungs. |
What is the function of the right atrium? | It receives the spent blood from the body. It is low in oxygen and high in the waste product carbon dioxide. |
What is the function of the right ventricle? | It pumps oxygen-poor blood to the lungs when it contracts. |
What are the three types of blood vessels? | Arteries, capillaries, and veins (remember A-C-V, in alpha order) |
What are arteries? | Blood vessels that carry blood away from the heart |
From the arteries, blood flows into the. . . | capillaries |
What are capillaries? | tiny blood vessels that receive blood from the arteries |
What happens in the capillaries? | Substances are exchanged between the blood and body cells. |
Blood flows from the capillaries into the. . . | veins |
What are veins? | Blood vessels that carry blood back to the heart. |
In how many directions does blood travel? | Only one. |
When blood from the body flows into the right atrium, it contains a little what, and a lot of what? | When blood from the body flows into the right atrium, it contains a little oxygen and a lot of carbon dioxide. |
The right ventricle pumps blood into the arteries that lead to the. . . | lungs |
Where does the blood that enters the left atrium come from? | The lungs |
From the left ventricle, the blood is pumped into which artery? | The aorta |
What is a force? | A push or a pull |
When blood leaves the heart, it travels through. . . | arteries |
What are the coronary arteries? | The first vessels that branch off from the aorta. |
The coronary arteries carry blood to the . . . | heart itself. |
Are the walls of arteries generally very thick or very thin? | Very thick |
Artery walls consist of how many layers? | three |
What does the innermost layer of an artery wall consist of? | Epithelial tissue. |
The middle layer of the artery wall consists of. . . | muscle tissue. |
The outer wall of an artery is made up of. . . | flexible connective tissue |
What is a pulse? | the beat you can feel caused by the expansion and relaxation of the artery wall |
What are involuntary muscles? | Muscles that expand and contract without our thinking about it. |
How thick are the walls of capillaries? | One cell thick |
One way materials are exchanged between the blood and the body cells is by. . . | diffusion |
What is diffusion? | the process by which molecules move from an area in which they are highly concentrated to an area in which they are less concentrated. |
Blood pressure is measured with an instrument called a. . . | sphygmomanometer |
What is the function of veins? | Veins carry blood back to the heart. |
What factors help move blood through veins? | 1) The muscles inside veins contract, narrowing the opening, pushing blood along; 2) many veins are located near skeletal muscles; the contraction of the muscles pushes the blood along; 3) large veins have valves that keep the blood from going backwards |
What is blood pressure? | The pressure of the blood against the walls of blood vessels. |
What causes blood pressure? | The force with which the ventricles contract. |
As blood moves away from the heart, its pressure.... | decreases |
Blood pressure is lowest in. . . | veins |
Why does blood pressure decrease as it moves away from the heart? | Because the farther away from the heart the blood moves, the lower the force of the ventricles. |
What exerts the highest pressure? | Blood flowing through arteries. |
Blood pressure is recorded how? | By 2 numbers, written as systolic/diastolic (example: 120/80). The first number, systolic, is the measure of the maximum output pressure of the heart. The second number, the diastolic, indicates the pressure in the system when the heart is relaxed. |
What is the meaning of the first number in a blood pressure? | It is a measure of the blood pressure as the ventricles contract and pump blood into the arteries. |
Is the second number in a blood pressure measurement higher or lower than the first? | Lower |
What does the 2nd number in the blood pressure reading measure? | It measures the blood pressure while the ventricles relax between heartbeats. |
Blood is made up of how many components? | four |
What are the components of blood? | red blood cells, white blood cells, plasma, and platelets. |
About what percent of the volume of blood is made up of cells? | 45% |
About 55 percent of the volume of blood is made up of. . . | plasma |
What is the name of the liquid part of blood? | Plasma |
90 percent of plasma is. . . | water |
Dissolved materials make up what percentage of plasma? | Ten percent |
What is the function of plasma? | Carries molecules that come from the breakdown of digested food; carries vitamins, minerals, and chemical messengers, and carries away waste products |
There are how many groups of plasma proteins? | Three |
What do the three groups of plasma proteins do? | One regulates the amount of water in blood; the second group helps fight disease, and the 3rd interacts with platelets to form blood clots |
Where are red blood cells produced? | Red blood cells are produced in bone marrow. |
What is the function of a red blood cell? | Red blood cells take up oxygen in the lungs and deliver it to cells elsewhere in the body. |
A red blood cell is made up mostly of. . . | hemoglobin |
What is hemoglobin? | Hemoglobin is an iron-containing protein that binds chemically to oxygen molecules. |
Where do hemoglobin pick up oxygen? | In the lungs |
Carbon dioxide is carried away from the cells by. . . | plasma |
Do red blood cells have nuclei? | No. |
Red blood cells live for how long? | About 120 days. |
What is the shape of a red blood cell? | They look like disks with pinched-in centers. |
What are white blood cells? | White blood cells are the body's disease fighters. |
What do white cells do? | Some recognize disease-causing organisms and alert the body; others produce chemicals to fight the invaders; still others surround and kill the organisms. |
There is one white cell to how many red cells? | 500 to 1000 red blood cells. |
White cells are bigger or smaller than red blood cells? | Bigger |
Do white cells have nuclei? | Yes. |
How long do white cells live? | They can live for months or even years. |
What are platelets? | Cell fragments that help blood clots form. |
What happens when a blood vessel is cut? | Platelets collect and stick to the vessel at the site of the wound and release chemicals that start a chain reaction that produces fibrin. |
What is fibrin? | A chemical that weaves a net of tiny fibers across the wound in a blood vessel. As more platelets and blood cells become trapped in the net, a blood clot forms. |
What is a scab? | A dried blood clot on the skin surface |
What is a blood transfusion? | The transfer of blood from one person to another |
What are the four types of blood? | A, B, AB, and O |
If you have Type A blood, can you receive a Type B transfusion? | No. |
What is the lymphatic system? | A network of veinlike vessels that returns lymph fluid to the bloodstream. |
What is lymph? | The fluid inside the lymphatic system |
What happens to some of blood's fluid as it travels through the capillaries? | It leaks out of the capillaries into the surrounding tissues and carries materials that the cells in the tissues need. |
What does lymph consist of? | Lymph consists of water and dissolved materials such as glucose, as well as some white cells that have left the capillaries. |
What is glucose? | A type of sugar. |
Are lymphatic vessels part of the cardiovascular system? | Yes. |
What are lymph nodes? | Small knobs of tissue in the lymphatic system. |
What do lymph nodes do? | They filter the lymph, trapping bacteria and other microorganisms that cause disease. |
What is the leading cause of death in the United States? | Cardiovascular disease. |
What is atherosclerosis? | A condition in which an artery wall thickens as a result of the buildup of fatty materials. |
What is cholesterol? | A waxy, fat-like substance that can build up on artery walls. |
What is a heart attack? | A heart attack is an occurrence where blood flow to part of the heart muscle is blocked. Cells die in the part of the heart that does not receive blood, permanently damaging the heart. |
What is hypertension? | Another name for high blood pressure |
What, approximately, is a normal blood pressure? | Lower than 140/90. |
Why is hypertension bad? | It makes the heart work harder and can damage the walls of the blood vessels. |
Why is hypertension called the "silent killer?" | People often don't have obvious symptoms of hypertension to warn them. |