What is the cardiovascular system? The heart is a double pump heartarteries arterioles veinsvenules capillaries
Circulation Patterns Figure 21-18
Superiorvena cava 7 Capillaries of Head and arms Pulmonaryartery Pulmonaryartery Capillariesof right lung Capillariesof left lung Aorta 9 6 2 3 3 4 11 Pulmonaryvein Pulmonaryvein 5 LEFT ATRIUM 1 RIGHT ATRIUM LEFT VENTRICLE RIGHT VENTRICLE 10 Aorta Inferiorvena cava Capillaries ofabdominal organsand legs 8
PULMONARY CIRCULATION With blood returning FROM the Body TO the Heart…(via the Vena Cava): Right Atrium Tricuspid Valve Right Ventricle Pulmonary Semilunar Valve Pulmonary Trunk Pulmonary Arteries (2) Alveoli in the Lungs Capillaries in the Alveoli ONCE BLOOD REACHES THE CAPILLARIES – GAS & NUTRIENT EXCHANGE OCCURS! In Pulmonary Circulation, this means that Carbon Dioxide is released to the alveoli in the lungs and Oxygen is picked up by the bloodstream. Pulmonary Veins (4) Left Atrium Back to Systemic Circulation REMEMBER…the Left & Right sides of the heart pump blood SIMULTANEOSLY!
Heart’s position in thorax In mediastinum – behind sternum and pointing left, lying on the diaphragm It weighs 250-350 gm (about 1 pound) Feel your heart beat at apex 9 (this is of a person lying down)
CXR(chest x ray) Normal male 11
Chest x rays Lateral (male) Normal female 12
Pericardium(see next slide) Starting from the outside… 13 Without most of pericardial layers
Circulatory System Functions • Carry O2 to cells and CO2 away from cells • Deliver nutrients through body (after absorption in small intestine) • Carry liquid wastes away from cells (H2O, salt, urea) • Help in fighting infections • Temperature regulation
The Pulmonary Circuit Figure 21-19
The Pulmonary Circuit (1 of 3) • Deoxygenated blood arrives at heart from systemic circuit: • passes through right atrium and ventricle • enters pulmonary trunk
The Pulmonary Circuit (2 of 3) • At the lungs: • CO2 is removed • O2 is added
The Pulmonary Circuit (3 of 3) • Oxygenated blood: • returns to the heart • is distributed to systemic circuit
Three circuits • Pulmonary • Blood goes from heart to lungs to pick up oxygen and release carbon dioxide • Systemic • Blood pumped out of heart to the rest of the body • Sound of heart (lub/dub) made by valves closing • Coronary • Heart muscle itself supplied with oxygen, nutrients, etc.
Requirements of gas exchange • Moist environment • O2 and CO2 must be dissolved to diffuse • Lungs, gills, moist surface (slime) help • Surface area--large area allows for more diffusion • Cleaned and filtered • Warmed
Movement of air into body • Nose--external opening to allow entry • Air is filtered, cleaned, warmed, moistened • Enters a series of tubes • Protected by cartilage to keep tubes firm/open • Mucus--traps foreign particles • Cilia-- “sweep” foreign material away from lungs to be swallowed (or spit/coughed)
Diffusion of gases • O2 concentration is higher in alveoli than blood: oxygen diffuses into blood • Remember High Conc. -> Low Conc. • At body cells O2 concentration is higher in blood: oxygen diffuses out of blood
Oxygen Transport • O2 diffuses from alveoli to the pulmonary capillaries. • O2-rich blood travels to heart and pumped to the body • O2 diffuses into cells. In tissues O2 levels are lower triggers Hb to release O2 • In tissues, CO2 makes blood more acidic and causes Hb to change shape. • CO2 diffuses from cells to blood. Travels to heart in form of Bicarbonate ions (HCO3-) • Heart pumps blood to lungs where CO2 is released in in gaseous form and then expelled.
Health of Respiratory System • Colds • Caused by virus, Attacks nasal mucous membranes • Causes cells to produce histamine--eyes to tear, more mucus, labored breathing • Pneumonia • Caused by virus or bacteria, Inflammation of alveoli • Weak and tired due to less oxygen exchange • Bronchitis • Caused by bacteria or virus (cold or flu), Inflammation of bronchi • Cough to clear excess mucus
Health of Respiratory system • Asthma • May be allergic, or response to stress, exercise, etc. • Narrowed breathing passages (bronchi) • Treated with drugs that relax air passages
Cigarette smoke contains Cyanide Cancer-causing tar Carbon monoxide Radioactive materials Nicotine Addictive Increased heart rate and narrowed blood vessels Cancer and smoking Lung cancer from smoking Mouth and throat cancers from chewing tobacco Other problems: Chronic coughing--due to paralyzed/destroyed cilia Emphysema--Labored breathing due to inelasticity of alveoli Smoking