Presentation on theme: "Chapter 47-1, 2 Circulatory System"— Presentation transcript:
1Chapter 47-1, 2 Circulatory System Blood: the "chemical highway" that connects the many cells of an organismCarries nutrients, oxygen to each cellCarries wastes away from cells (CO2, urea) to kidneys, lungs, skinCarries enzymes, hormones, water, antibodies around body for distribution
2Components of Blood Men, on average, have about 10-12 pints Women, on average, have about 8-10 pintseach cc (cubic mL) of blood contains about 4 million RBCs and 7,000 WBCs
3Plasma Plasma = 60% of blood; straw-colored fluid about 90% of the plasma is watercarries most CO2, nutrients, plasma proteins, hormones, etc.plasma proteins:albumin (to maintain high osmotic potential)fibrinogen (clotting)globulins (immunity, antibodies)
4Red Blood Cells Called “erythrocytes” Transport oxygen; about 30 trillion in bloodstreamcontain HEMOGLOBIN (red pigment protein) which acts like an "oxygen magnet"; ironnon-nucleated (cannot repair themselves)short lifespan ( days)Replaced from bone marrow stem cells
5White Blood Cells called “leukocytes” 1 or 2 WBC for every 1,000 RBC larger than RBC, have nucleus, no hemoglobin, colorlessCan migrate outside of vessels (RBC’s cannot) to directly cleanse tissues (lymph)Some act by: phagocytosis of bacteria/viruses/etc.Others make antibodies (proteins) that attack microorganisms"Pus"-dead WBC; new WBC form in spleen, bone marrow
6Platelets colorless, oval/irregular shaped smaller than RBCs "little bags of chemicals" that function in clotting and plugging up breaks in vesselsBlood Clotting- a complex series of chemical reactions, involving platelets and plasma "clotting factors". Often referred to as the "clotting cascade". Thromboplastin(produced in liver)Prothrombin >ThrombinFibrinogen > Fibrin15 CF’s involved in this conversation (Hemophiliacs usually genetically lack Factor VIII)clotting animation
9Arteries thick, muscular walls, elastic, to allow for high pressure made of layers of endothelium/muscle/connective tissuesNarrow down into smaller arterioles
10Veins carry blood back toward the heart thinner walls (than arteries) less elastic (less pressure to withstand)have valves to prevent backflowendothelium, muscle, connective tissue layersnarrow down into smaller diameter venules
12Capillaries Diffusion the site of all exchange with cells in very close contact with all cellsLined with a single layer of epitheliumsmallest diameter of all vessels -only about 5 micrometers in diameter- (RBCs pass in single file)
13Atherosclerosis …is a disease affecting arterial blood vessels. Main cause: cholesterol buildup in arteries (plaques)It is commonly referred to as "hardening" of the arteries.It is caused by the formation of multiple plaques within the arteriesThis often leads not only to clogs, but also hypertension (high blood pressure), which both may result in heart attacks.
15Evolution of the Heartsimplest (in earthworms) are enlarged, muscular portions of a blood vessel = "aortic arches"Mollusks= tube shaped heart with open circulationVertebrates= multi-chambered heart with closed circulationmultiple chambers serve to separate oxygenated/ deoxygenated bloodAtrium (receiving chamber)Ventricle (pumping chamber)
16The Human Heart is made of epithelial, nerve, connective tissues and cardiac muscle (infatiguable) Four chambers (2 atria, 2 ventricles)septum- dividing wall between right and left side of heartvalves at strategic locations prevent backflowseparation into chambers prevents mixing oxygenated, deoxygenated bloodDo right and left seem backward? That's because you're looking at an illustration of somebody else's heart. To think about how your own heart works, imagine wearing this illustration on your chest. Did you know that your heart beats over 100,000 times a day? Get "heart smart" by checking out these amazing heart facts.
17The Human HeartSuperior and Inferior Vena Cava lead into heart (right atrium)Pulmonary artery brings blood to lungs; pulmonary vein returns oxygenated blood to the heartAorta leads out to systemic circulationsemilunar valves: prevent backflow between vessels/chambersatrioventricular valves: (mitral and tricuspid) between atria & ventricles; allow one-way flow between atria and ventricle
18Trace the Path of Blood Through the Heart “How Stuff Works” narrated animation of cardiac parts & cycleHow your heart works (animation)
19Initiation and Regulation of Heartbeat Cardiac muscle is able to initiate its own impulseSinoatrial Node (SA)- "pacemaker" in Right Atrium; initiates beat through both Atria; stimulates another area near center of heart called AV NodeAtrioventicular Node (AV)...then impulse is carried to the ventricles by the BHBundle of His (BH) = like the transfer of an electrical current along a circuitHeart Rate (bpm) is modified by the Autonomic Nervous System (vagus nerve)Parasympathetic Nerves- slow down HRSympathetic Nerves- increase HR
20Oxygen-poor blood (shown in blue) flows from the body into the right atrium. Blood flows through the right atrium into the right ventricle.The right ventricle pumps the blood to the lungs, where the blood releases waste gases and picks up oxygen.The newly oxygen-rich blood (shown in red) returns to the heart and enters the left atrium.Blood flows through the left atrium into the left ventricle.The left ventricle pumps the oxygen-rich blood to all parts of the body.To assess heart rate (BPM), take your arterial pulse!@ rest?After exercise?
21How much blood does the heart pump? The heart pumps the equivalent of 5,000 to 6,000 quarts (about 6800 L) of blood each day!Total volume of blood pumped by heart per minute = “cardiac output”Cardiac Output = Heart Rate x Stroke volume(L/min) = (BPM) x (L/beat)[ex: 72 BPM x 0.07 L/beat = 5 L/min.]
22Blood Pressure Regulation arterial BP >>> venous BP120 = systole; ventricles contract (empty);arteriole diameter enlarged80 =diastole; ventricles relax (fill)Cardiovascular Regulating Center (in medulla)controls activity of the nerves regulating the smooth (circular) muscle contraction of the blood vesselalso controls strength of heartbeat, HRreceives and interprets and responds to sensors through the cardiovascular system (esp. in the walls of the vessels) baroreceptors, CO2 receptors
23The Lymphatic SystemUnder arterial pressure, the BP exceeds the osmotic potential, thus forcing some plasma and WBC out into tissues.This “lymphatic fluid” is collected by Lymph vessels which clean the tissue/ cellular debris (such as bacteria) out of the body cells.Lymph flows thru Lymph Nodes to be cleanedThese also make Lymphocytes (WBC’s)Lymph re-enters the circulatory vessels via the Subclavian Veins in the neck (back into bloodstream)