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Chapter 33: The Circulatory and Respiratory Systems Every breath we take brings air into the body. Oxygen in that air is needed by every cell in the body. The circulatory system brings that oxygen and other nutrients to your cells. Protozoans – single celled organisms in water absorb nutrients through the cell membrane and circulate materials by diffusion and cyclosis: streaming of the cytoplasm. Hydra – Tiny freshwater animals that absorb and circulate materials from cell to cell through cell membranes. Earthworm – some cells are NOT in direct contact with environment. Nutrients, oxygen, and wastes are transported by the fluid blood inside vessels or organs. This is called a closed circulatory system. Grasshopper –The vessels that carry the blood empty into large cavities called sinuses. The blood bathes the body tissues and is then reabsorbed into the circulatory system. This is an open circulatory system. Human Circulatory System We have a closed circulatory system with a heart, blood, and blood vessels that transport oxygen, CO2, hormones, and nutrients in the body. Function: 1. Transport dissolved and suspended materials throughout the body 2. The system also plays a role in our immunity Blood: fluid medium of transport of the circulatory system The Heart - A hollow organ near center of chest composed mostly of muscle. - The human heart is like two separate pumps sitting side by side. Each side has two chambers called atria and ventricles. ATRIUM (plural atria): upper chamber of heart that RECEIVES blood coming into the heart VENTRICLE: lower chamber of heart that PUMPS blood out of heart 4 chambers – left atrium, right atrium, left ventricle, right ventricle. Each side of the heart pumps blood to a different part of the circulatory system. The right side of heart is separated from and never mixes with the left side of the heart. They’re two separate pumps lying side by side. ARTERIES – blood vessels that take blood AWAY from the heart VEINS – blood vessels that take blood TO the heart Capillaries - small blood vessels where nutrients & wastes exchanged RIGHT SIDE OF HEART - Pulmonary Circulation – Blue blood: Only pumps deoxygenated (blue) blood from heart to the lungs. Pulmonary = lungs. Goes to lungs to pick up oxygen LEFT SIDE OF HEART - Systemic Circulation – Red blood Pumps OXYGENATED (red) blood to the rest of the body. Blood that has returned from the lungs with oxygen go through this side of heart. Valve: specialized flap of tissue that prevents backflow of blood. Blood Flow Through the Heart – Refer to page 950 in your book 1. Deoxygenated blue blood (blood lacking oxygen) enters heart through the vena cava (the great vein) dumps into Right Atrium. 2. Blood then goes from the Right Atrium through the tricuspid valve into the Right Ventricle. 3. From the Right Ventricle blood passes through a Semilunar valve into the Pulmonary Arteries which take the deoxygenated blue blood to lungs to pick up more O2 . 4. The oxygenated red blood goes into pulmonary veins that bring it to heart thru the Left Atrium. From the Left Atrium the blood goes through the bicuspid valve to the Left Ventricle. The Left Ventricle pumps this oxygenated blood another semilunar valve into the Aorta, and the aorta branches into arteries that carry the oxygen rich blood to all the body cells. After cells use up the oxygen, the deoxygenated blue blood goes back through veins to the heart to step #1 above. The heart makes a “lub-dup” sound. Lub: sound of the valves between atria & ventricles shutting Dup: sound of the semilunar valves of pulmonary arteries & aorta shutting Great website showing how the heart pumps: http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_pumping.html Label the following: Superior vena cava, heart, lungs, inferior vena cava, pulmonary artery, aorta, pulmonary vein, right ventricle, left ventricle, right atrium, left atrium, right lung, left lung, head and arms, trunk/ legs The Blood (4-6 Liters of blood in the body) - 45% of the fluid consists of red blood cells, white blood cells, and platelets. The remaining 55% of the fluid is called plasma. Plasma: fluid part of blood; 90% water, 10% sugars, salts, & proteins Red Blood Cells - Also called erythrocytes - Contain hemoglobin: an iron-containing protein that binds and carries oxygen White Blood Cells - Also called leukocytes - Fight infection, parasites, bacteria Platelets and Blood Clotting - Platelets are cell fragments in blood that aid in blood clotting Diseases of the Circulatory System 1. High blood pressure (hypertension): when blood pressure in arteries remains above normal. Causes – stress, excessive salt consumption, cigarette smoking, heredity factors 2. Atherosclerosis: arteries become narrower and inelastic because of deposits of cholesterol & other fatty materials on their inner walls. Heart disease: blockage of coronary arteries that supply the heart muscle, reduced oxygen supply to heart Blood Conditions 1. Anemia: low iron containing hemoglobin in RBCs causes less oxygen to be carried 2. Sickle-cell anemia: sickle shaped (moon/cresent) RBCs; causes blockage in capillaries causing pain, weakness, deficient oxygen carrying capacity. Also shorter life span for RBC. 3. Leukemia: disease of bone marrow where there is uncontrolled production of nonfunctional white blood cells, weakens immune system and ability to fight off disease. Type of cancer. 4. Hemophilia: sex-linked genetic disorder characterized by poor clotting ability of blood due to absence of a certain protein that clots blood. Respiratory System Respiration Cellular respiration: breaking down food in the presence of oxygen to produce energy for cells. Respiration at the organism level: exchange of oxygen and CO2 between the organism and its environment. O2 in, CO2 out Pathway of Respiratory System Nose and Mouth – Pharynx (throat) – Larynx (voice box) – Trachea (windpipe) – Bronchi – Bronchioles – alveoli (gas exchange in lung) Gas exchange Millions of alveoli in the lung provide enormous surface area for gas exchange. Oxygen breathed into the lung diffuses across the alveoli into thin capillary walls containing blood. The capillaries connect with larger arteries and veins and transport the oxygenated blood. At the same time CO2 diffuses in the opposite direction – from blood of capillaries into alveoli of lungs then up through the respiratory system & out. Role of hemoglobin Hemoglobin – a protein containing iron that is found in RBCs. Hemoglobin picks up oxygen from lung by binding to it and carries it to other cells & tissues that need the oxygen for cellular respiration. Anemia: deficient or lack of iron leads to less hemoglobin in RBC and less ability to carry the oxygen. Cilia: hair-like structures that line the respiratory track and sweep materials away from the lungs. Respiratory system also lined with a protective thin layer of mucus. Breathing: Movement of air into and out of the lungs. No muscles connected to lungs, the force that drives air into lungs is air pressure. Lungs are sealed in 2 sacs called pleural membranes, inside chest cavity. At the bottom of the chest cavity is the diaphragm muscle. Inhale: breathe in, diaphragm contracts expanding chest cavity Exhale: breath out, diaphragm relaxes, putting pressure on lungs forcing air out (Muscles around chest provide extra force) Breathing is part voluntary (controlled by you) and involuntary (controlled by Medulla) Smoking Three most dangerous substances in tobacco: Nicotine – addictive substance in tobacco Carbon Monoxide – colorless, tasteless, poisonous, odorless gas Tar – brown, sticky mixture of chemicals Chronic Bronchitis –bronchi become swollen and clogged with mucus Emphysema – loss of elasticity in the tissue of the lungs Lung Cancer – disease caused by small groups of cancer in the lungs Smoking affects other body systems: - Circulatory: increases heart rate, hypertension, atherosclerosis - Nervous System: dulls senses of smell and taste - Digestive system: stomach cancer; stomach acid issues - Reproductive system: decreases sperm, sperm motility, shape; impotence; significant decrease in fertility for women - Endocrine System: decrease levels of blood clotting hormone Respiratory System Anatomy Pharynx: throat (back of the mouth) Larynx: voice box (below pharynx) Trachea: windpipe, rings of cartilage Bronchi: trachea leads into 2 branched tubes in chest called bronchi. The bronchi further branch into smaller bronchioles of lungs Alveoli: bronchioles branch into millions of little air sacs called alveoli where gas is exchanged – oxygen moves into blood with inhaled air, CO2 moves out with exhaled air Epiglottis: Covers trachea when eating food so food does not get into respiratory tract Diaphragm: flat muscle at bottom of chest assists breathing