an activity that makes you breathe faster and deeper and an activity that you can sustain for 20 minutes or more.
a condition resulting in reduced oxygen transport by the blood that may be caused by a reduced number of red blood cells or not enough hemoglobin.
a bulge outward of a vessel when the vessel wall weakens.
very small arteries.
a blood vessel that carries blood away from the heart.
a build up of fatty deposits, called plaque, on the walls of arteries leading to narrowing and blockage of the arteries.
plural form of atrium.The fish heart has one atrium, but the human heart has two atria.
the top chamber of each side of the heart.The atrium receives blood from a vessel and sends blood down to the ventricle.
the fluid containing cells that circulates through the heart and blood vessels transporting nutrients, gases, chemicals, and wastes through the body.
cell fragments smaller than red blood cells that circulate with the blood and help in clotting.
a tube through which blood flows.
the spongy tissue inside bones. It is one of the places in the body where red blood cells are produced.
very tiny vessels at the ends of the smallest arteriole and leading to the smallest venules.
a system that includes the blood, the heart, and the system of blood vessels that distributes blood throughout the body.
mechanisms that control automatic body functions such as breathing and heart rate within certain limits.
the relaxation period when the heart is filling with blood.
the random movement of molecules from a region of higher concentration to a region of lower concentration.
swelling caused by the accumulation of fluids in spaces outside of blood vessels and between cells.
a system of organs and glands that releases chemicals (hormones) into the bloodstream or directly into tissue to cause some reaction.
a protein circulating in the blood that is meshed in forming blood clots.
a portion of DNA that contains the information code for a protein such as hemoglobin.
the ability to hold back. In blood vessels, resistance is the slowing of blood flow through the vessels.
the system that brings in needed oxygen and releases carbon dioxide.
specialized cells that, when stimulated, send messages to the brain.
sickle-cell anemia (uh-NEE-mee-uh)
a hereditary condition in which a gene produces an abnormal type of hemoglobin that results in a reduced amount of oxygen carried by red blood cells.The abnormal hemoglobin tends to form crystals inside the red blood cells that produce the sickle shape.
a pump that uses gravity, valves, and a squeeze bulb to move fluid from one place to another.
a condition in which too little oxygen gets to the brain due to a blockage or a leakage in a vessel.
the amount of blood pumped with each squeeze of the heart.
the muscular pump of the circulatory system.
a condition that occurs when the coronary arteries that serve the heart become clogged with plaque and/or a blood clot.
the number of times your heart beats in one minute.
a reddish protein that carries oxygen.
a hereditary condition in which the blood in people who have the gene for hemophilia takes longer than normal to clot. People with the disease are called hemophiliacs.
the condition of stability of the internal environment of the body.
chemicals that stimulate cells to respond in certain ways.
high blood pressure.
a disease in which there are more than a normal number of white blood cells produced because cell division is out of control.
oval or bean-shaped structures in the lymphatic (lim-FAT-ik) system that produce lymph.
network of vessels that carries watery fluid called lymph.
a liquid made up of water, salts, nutrients, waste products, white blood cells, proteins, and other chemicals.
a disease of the white blood cells caused by a virus.
a reaction to a change that will cause a reversal.
the brain, spinal cord, and a network of nerve cells that send and receive messages about the body's inside and outside environments.
the information and control center found in most cells.
a part of a living organism that has a specific function, such as the heart or brain.
specialized muscle cells in the right atrium. The pacemaker makes the heart beat faster or slower when it receives messages from the nervous system or from chemical “messengers” called hormones.
a type of white blood cell that can change shape and wrap around unwanted or foreign substances.
the process that occurs when a phagocyte “eats up” foreign substances such as bacteria or viruses.
the liquid part of blood.
the pressure buildup in the outlet tube of a siphon pump.
red blood cells
doughnut-shaped cells with a flat, filled center.
the contracting of the heart muscle when it squeezes and squirts out the blood.
target heart-rate zone
a specific range of heartbeats per minute considered best for an individual.
a large vessel that empties into a vein at the base of your neck returning fluids to the circulatory system.
a device that controls the flow of a liquid or gas
a blood vessel that carries blood to the heart.
the bottom chamber of each side of the heart. The ventricles receive blood from the atria and squirt it into blood vessels.
a small vein that receives blood from the capillaries.
white blood cells
blood cells that do not contain hemoglobin and attack unwanted organism such as bacteria, and unwanted materials such as a splinter.