Circulatory System

The Circulatory System Circulatory system is made up of blood, the heart, and blood vessels.

Section 37.2 Summary – pages Your Blood: Fluid Transport Your blood is a tissue composed of fluid, cells, and fragments of cells. Your blood is a tissue composed of fluid, cells, and fragments of cells. The fluid portion of blood is called plasma. The fluid portion of blood is called plasma. ComponentsCharacteristics Red blood cells Transport oxygen and some carbon dioxide; lack a nucleus; contain hemoglobin White blood cells Platelets Plasma Large; several different types; all contain nuclei; defend the body against disease Cell fragments needed for blood clotting Liquid; contains proteins; transports red and white blood cells, platelets, nutrients, enzymes, hormones, gases, and inorganic salts

Section 37.2 Summary – pages Your Blood: Fluid Transport Blood cells-both red and white-and cell fragments are suspended in plasma. Blood cells-both red and white-and cell fragments are suspended in plasma. Plasma is straw colored and makes up about 55 percent of the total volume of blood. Plasma is straw colored and makes up about 55 percent of the total volume of blood.

Section 37.2 Summary – pages Red blood cells: Oxygen carriers The round, disk- shaped cells in blood are red blood cells. The round, disk- shaped cells in blood are red blood cells. Red blood cells carry oxygen to body cells. Red blood cells carry oxygen to body cells. Side view Top view 2.0 micrometers 7.5 micrometers

Section 37.2 Summary – pages Red blood cells: Oxygen carriers They make up 44 percent of the total volume of your blood, and are produced in the red bone marrow of your ribs, humerus, femur sternum, and other long bones. They make up 44 percent of the total volume of your blood, and are produced in the red bone marrow of your ribs, humerus, femur sternum, and other long bones. Red blood cells remain active in the bloodstream for about 120 days, then they break down and are removed as waste. Red blood cells remain active in the bloodstream for about 120 days, then they break down and are removed as waste.

Section 37.2 Summary – pages Oxygen in the blood Red blood cells are equipped with an iron- containing protein molecule called hemoglobin. Red blood cells are equipped with an iron- containing protein molecule called hemoglobin.

Section 37.2 Summary – pages Oxygen in the blood Oxygen becomes loosely bound to the hemoglobin in blood cells that have entered the lungs. Oxygen becomes loosely bound to the hemoglobin in blood cells that have entered the lungs. These oxygenated blood cells carry oxygen from the lungs to the body’s cells. These oxygenated blood cells carry oxygen from the lungs to the body’s cells. As blood passes through body tissues with low oxygen concentrations, oxygen is released from the hemoglobin and diffuses into the tissues. As blood passes through body tissues with low oxygen concentrations, oxygen is released from the hemoglobin and diffuses into the tissues.

Section 37.2 Summary – pages Carbon dioxide in the blood Once biological work has been done in a cell, wastes in the form of carbon dioxide diffuse into the blood and are carried in the bloodstream to the lungs. Once biological work has been done in a cell, wastes in the form of carbon dioxide diffuse into the blood and are carried in the bloodstream to the lungs.

Section 37.2 Summary – pages White blood cells: Infection fighters White blood cells play a major role in protecting your body from foreign substances and from microscopic organisms that cause disease. White blood cells play a major role in protecting your body from foreign substances and from microscopic organisms that cause disease. They make up only one percent of the total volume of your blood. They make up only one percent of the total volume of your blood. White Blood Cells

Section 37.2 Summary – pages Blood clotting Your blood contains small cell fragments called platelets, which help blood clot after an injury. Your blood contains small cell fragments called platelets, which help blood clot after an injury. Platelets help link together a sticky network of protein fibers called fibrin, which forms a web over the wound that traps escaping blood cells. Platelets help link together a sticky network of protein fibers called fibrin, which forms a web over the wound that traps escaping blood cells.

Section 37.2 Summary – pages Rh factor Another characteristic of red blood cells involves the presence or absence of an antigen called RH, or Rhesus factor. Another characteristic of red blood cells involves the presence or absence of an antigen called RH, or Rhesus factor. Rh factor is an inherited characteristic. Rh factor is an inherited characteristic. People are Rh positive (Rh + ) if they have the Rh antigen factor on their red blood cells. People are Rh positive (Rh + ) if they have the Rh antigen factor on their red blood cells. They are Rh negative (Rh - ) if they don’t. They are Rh negative (Rh - ) if they don’t.

Section 37.2 Summary – pages Your Blood Vessels: Pathways of Circulation Arteries are large, thick-walled, muscular, elastic blood vessels that carry blood away from the heart. Arteries are large, thick-walled, muscular, elastic blood vessels that carry blood away from the heart. The blood that they carry is under great pressure. The blood that they carry is under great pressure. As the heart contracts, it pushes blood through the arteries. As the heart contracts, it pushes blood through the arteries.

Section 37.2 Summary – pages Your Blood Vessels: Pathways of Circulation Blood surges through the arteries in pulses that correspond with the rhythm of the heartbeat. Blood surges through the arteries in pulses that correspond with the rhythm of the heartbeat. After the arteries branch off from the heart, they divide into smaller arteries that in turn divide into even smaller vessels called arterioles. After the arteries branch off from the heart, they divide into smaller arteries that in turn divide into even smaller vessels called arterioles.

Section 37.2 Summary – pages Your Blood Vessels: Pathways of Circulation Capillaries are microscopic blood vessels with walls that are only one cell thick. Carries oxygenated blood. Capillaries are microscopic blood vessels with walls that are only one cell thick. Carries oxygenated blood. Blood cells travel in a single file line. Blood cells travel in a single file line. Capillaries form a dense network that reaches virtually every cell in the body. Capillaries form a dense network that reaches virtually every cell in the body.

Section 37.2 Summary – pages Your Blood Vessels: Pathways of Circulation Thin capillary walls enable nutrients and gases to diffuse easily between blood cells and surrounding tissue cells. Thin capillary walls enable nutrients and gases to diffuse easily between blood cells and surrounding tissue cells. As blood leaves the tissues, the capillaries join to form slightly larger vessels called venules. As blood leaves the tissues, the capillaries join to form slightly larger vessels called venules.

Section 37.2 Summary – pages Your Blood Vessels: Pathways of Circulation Veins are the large blood vessels that carry blood from the tissues back toward the heart. Carries deoxygenated blood. Veins are the large blood vessels that carry blood from the tissues back toward the heart. Carries deoxygenated blood. Vein Capillary

Types of Circulation Pulmonary Circulation – carries blood between the heart and lungs Pulmonary Circulation – carries blood between the heart and lungs Systemic Circulation – carries blood between the heart and body Systemic Circulation – carries blood between the heart and body Coronary Circulation– Supplies blood to the heart

Section 37.2 Summary – pages Your Heart: The Vital Pump The main function of the heart is to keep blood moving constantly throughout the body. The main function of the heart is to keep blood moving constantly throughout the body.

Section 37.2 Summary – pages Your Heart Your heart is about 12cm by 8cm-roughly the size of your fist. Your heart is about 12cm by 8cm-roughly the size of your fist. It lies in your chest cavity, just behind the breastbone and between the lungs, and is essentially a large muscle completely under involuntary control. It lies in your chest cavity, just behind the breastbone and between the lungs, and is essentially a large muscle completely under involuntary control.

Superior Vena Cava -Brings blood from the upper body & empties into the right atrium. Tricuspid Valve -Brings blood from the lower body & empties into the right atrium. Inferior Vena Cava Right Atrium To the lungs to get O 2 Right Ventricle Pulmonary Artery OXYGEN-POOR BLOOD FLOW

Bicuspid Valve Pulmonary Vein From the lungs with O 2 Left Atrium Pulmonary Vein Left Ventricle Aorta Septum From the lungs with O 2 Prevents the mixing of blood OXYGEN-RICH BLOOD FLOW

Section 37.2 Summary – pages Blood’s path through the heart Vena Cava, Right Atrium, Right Ventricle, Pulmonary Artery, (lungs), Pulmonary Vein, Left Atrium, Left Ventricle, Aorta Vena Cava, Right Atrium, Right Ventricle, Pulmonary Artery, (lungs), Pulmonary Vein, Left Atrium, Left Ventricle, Aorta Inferior vena cava Left lung Right lung Capillaries Pulmonary vein Pulmonary artery Superior vena cava Aorta RA LA LV RV

Section 37.2 Summary – pages Blood pressure Blood pressure is the force that the blood exerts on the blood vessels. Blood pressure is the force that the blood exerts on the blood vessels. Blood pressure rises and falls as the heart contracts and then relaxes. Blood pressure rises and falls as the heart contracts and then relaxes. Blood pressure rises sharply when the ventricles contract, pushing blood through the arteries. Blood pressure rises sharply when the ventricles contract, pushing blood through the arteries.

Section 37.2 Summary – pages Blood pressure The high pressure is called systolic pressure. The high pressure is called systolic pressure. Blood pressure then drops dramatically as the ventricles relax. Blood pressure then drops dramatically as the ventricles relax.

The Function of the Respiratory System. 1. Get oxygen to the cells of the body 2. Get rid of carbon dioxide

Parts of the Respiratory System: PHARYNX – muscular tube in the upper throat which serves as a passageway for air and food. PHARYNX – muscular tube in the upper throat which serves as a passageway for air and food. LARYNX – contains your vocal chords, short passageway, sometimes called the voice box LARYNX – contains your vocal chords, short passageway, sometimes called the voice box EPIGLOTTIS – flap of tissue that covers the larynx and prevents food from going down the wrong tube. EPIGLOTTIS – flap of tissue that covers the larynx and prevents food from going down the wrong tube. TRACHEA - long, straight tube in the chest cavity that leads from the throat to the lungs, also called the windpipe. TRACHEA - long, straight tube in the chest cavity that leads from the throat to the lungs, also called the windpipe.

BRONCHI – two small tubes that lead to the lungs, they divide into smaller tubes called BRONCHIOLES. BRONCHI – two small tubes that lead to the lungs, they divide into smaller tubes called BRONCHIOLES. ALVEOLI – where the bronchioles end, clusters of air sacs. Where gases are actually exchanged. CO 2 ->O 2 In healthy lungs they are elastic and can stretch, always have a small amount of air. ALVEOLI – where the bronchioles end, clusters of air sacs. Where gases are actually exchanged. CO 2 ->O 2 In healthy lungs they are elastic and can stretch, always have a small amount of air. DIAPHRAGM – powerful muscle spanning the rib cage under the lungs, aids in respiration. DIAPHRAGM – powerful muscle spanning the rib cage under the lungs, aids in respiration. Parts of the Respiratory System, cont.

The path of oxygen and carbon dioxide through the body… Oxygen from the air diffuses into the blood vessels of the alveoli where it is blood vessels of the alveoli where it is used for cellular respiration inside cells. used for cellular respiration inside cells. During this process, carbon dioxide diffuses into the blood where it is carried diffuses into the blood where it is carried back to the lungs. back to the lungs.