Circulatory System Chapter 10

Components & Main Function Made up of blood, blood vessels, and heart Also ties into lymph vessels and nodes contained within the lymphatic system. Main function is to transport nutrients to, and take wastes away from, the cells.

Blood Vessel Types 3 main types – arteries, veins, capillaries Arteries transport blood away from heart, veins transport blood back to the heart and capillaries connect arteries and veins. Arterioles and venules are same as arteries and veins but smaller Arterioles have sphincter muscles at junction to organ or capillary bed Sphincters contract (constrict) or relax (dilate) to  or  blood flow to that region and therefore helps regulate blood pressure

Arteriole Sphincters Diagram

Blood Volume Locations At any one time the veins contain about 75% of the body's blood. About 20% of the body's blood is in the arteries and only about 5% is in the capillaries. You have close to 100,000 km of blood vessels!

Blood Vessel Types Diagram

Major Blood Vessels Subclavian – shoulders and arms Carotid arteries/jugular veins – head and neck Mesenteric arteries – intestines  goes to villi Pulmonary – lungs Renal – kidneys Iliac – legs  branches off to femoral Coronary – heart

Major Blood Vessels cont... Aorta – main artery out of heart Vena Cava – superior (anterior)/inferior (posterior) – main vein into heart Hepatic Vein – from liver Hepatic Portal Vein – from intestines to liver A portal system begins and ends in capillaries

Major Blood Vessels Diagram

Systemic vs. Pulmonary Circulation Systemic – blood vessels from heart (arteries) carry oxygenated blood to body cells and veins carry deoxygenated blood back to heart Pulmonary – carries blood to and from lungs ***only artery to carry deoxygenated blood and only vein to carry oxygenated blood

Blood Circuit Diagram

The Heart A muscular organ about the size of a fist. The major portion is called the myocardium, and is mostly composed of cardiac muscle. Epithelial and fibrous tissue called pericardium covers the heart. This tissue forms the pericardial sac, in which the heart is located. The sac contains lubricating liquid. The heart is divided into a left and right side by a structure called the septum.

The Heart cont... On each side are two chambers. The smaller one, located on the top, is called the atrium (plural = “atria”). The larger one, on the bottom, is called the ventricle. The left ventricle is considerably larger than the right ventricle because while the right ventricle only pumps blood to the lungs, the left ventricle must pump to the rest of the body.

The Heart cont... There are valves between the atria and ventricles, collectively referred to as atrioventricular (AV) valves. These valves control the flow of blood between the chambers, and prevent "backflow." The AV valve on the right is called the tricuspid valve (has 3 flaps or "cusps"), while the AV valve on the left is called the bicuspid (mitral) valve (has 2 cusps). Very strong, fibrous strings called the chordae tendinae support the valves and prevent them from inverting.

Heart Diagram

Path of Blood Blood low in O2 (“deoxygenated”) enters the right atrium through the superior (top) and inferior (bottom) vena cava, the body's largest veins. The right atrium contracts, forcing blood through the tricuspid valve and into the right ventricle. The right ventricle contracts, sending blood through the pulmonary semilunar valve and into the pulmonary trunk.

Path of Blood cont... The pulmonary trunk divides into pulmonary arteries, which take the deoxygenated blood to the capillaries of the lungs. At the lungs, carbon dioxide diffuses out of the blood, and, oxygen diffuses into it. The blood is now oxygenated. The oxygenated blood feeds into the pulmonary veins, which take it from the lungs to the left atrium.

Path of Blood cont... The left atrium contracts, forcing blood through the bicuspid valve into the left ventricle. The left ventricle contracts, forcing blood through the aortic semilunar valve into the aorta, the body's largest artery. The aorta divides into smaller arteries, which carry oxygenated blood to all body tissues.

Heart Contraction Videos Blood Flow Theory (2:43) http://videos.howstuffworks.com/science- channel/29103-100-greatest-discoveries- blood-flow-theory-video.htm The Heart (2:56) http://videos.howstuffworks.com/visible- productions/14626-visible-productions-the- heart-video.htm

Fetal vs Adult Circulation The fetus receives O2 from the mother (through the placenta) and therefore does not use its lungs. 4 features present in fetus but absent in adults: Foramen Ovale (Oval Opening) Opening between left and right atria Covered by a flap which acts as a valve Blood bypasses lungs and goes into left side of heart directly

Fetal vs Adult Circulation cont… Ductus Arteriosus (Arteriole Duct) Connection between pulmonary artery and aorta Reroutes blood away from lungs to aorta Umbilical Arteries/Vein To and from placenta (1 vein from mother/2 arteries to mother) Receives nutrients O2, carries out wastes Ductus Venosus (Venous Duct) Connection between umbilical vein and vena cava Umbilical vein carries O2-blood which mixes with deO2-blood in vena cava

After Birth When baby is born, blood enters lungs for 1st time and into the left atrium which causes the foramen ovale to close and seal over the course of a few days. If foramen ovale does NOT close, result is a “blue baby”. Must be fixed with open heart surgery.

Fetal Circulation Diagram

Blood 2 major parts: 55% plasma, 45% blood cells Plasma (the liquid portion of blood) consists of 91% water, 7% proteins, 2% ions and gases Water – from intestines – maintains blood volume and transports materials plasma proteins – all maintain blood osmotic pressure and pH albumin  transport, fibrinogen  blood clotting, globulins  fight infection Gases – O2 and CO2 from lungs and tissues Nutrients – e.g. Glucose, amino acids, fats, nucleotides – from digestion

Blood cont... Salts – e.g. Na+, K+, Cl-, HCO3- - maintain blood osmotic pressure, pH, aid metabolism Wastes – product of metabolism in tissues Hormones & Vitamins – aid metabolism Formed Elements (the solid portion of blood) consists of 3 parts all produced in bone marrow. Erythrocytes (Red blood cells) Small, biconcave in shape, and lack a nucleus Transport O2, CO2 and H bound to Hemoglobin Production can be  by erythopoietin which stimulates bone marrow. Called Acclimatization and usually happens over a 2-3 week period when people move to higher elevation

Blood cont... Leukocytes (White blood cells) Platelets (Thromobocytes) Each RBC has about 280 million hemoglobin molecules RBC’s live for 120 days and then are destroyed in liver and spleen  iron reused, globin turned into bile pigments Leukocytes (White blood cells) Larger than RBC, have nucleus, fewer in number (600 RBC: 1 WBC), fight infection Several kinds  differentiate as they mature Platelets (Thromobocytes) Small fragments of bone marrow Involved in blood clotting Release thromoboplastin (prothrombin activator) which causes conversion of prothrombin  thrombin which then convert fibrinogen  fibrin and results in a clot.

RBC vs WBC Diagram

Blood Cells Diagram

Blood Cell Formation Diagram

Blood Videos Blood Products (3:01) http://videos.howstuffworks.com/science- channel/36383-how-its-made-blood-products- video.htm Blood Transfusions (2:03) http://videos.howstuffworks.com/science- channel/29280-100-greatest-discoveries-blood- transfusion-video.htm

Antigens & Antibodies Proteins found on the outer surface of cell membranes (glycoproteins) are called antigens Antibodies are proteins which bind to antigens considered foreign to the body binding leads to agglutination (clumping of cells) agglutinated cells are then engulfed by WBC

Application to Blood Typing RBC’s have 2 types of antigens: A and B Can be present alone, in combination with the other, or not present at all If antigen A  type A blood, B  type B blood, A and B  type AB, neither  type O If type A person receives blood with antigen B  agglutination which can lead to death therefore, person must receive blood that will not agglutinate (* antibodies from donors blood are removed)

ABO Blood System Diagram

Rh Factor Another antigen also present on RBC’s called rhesus factor (Rh factor)  Rh+ or Rh- Important in childbirth If Rh- mom has Rh+ child then during birth, child’s blood MAY come into contact with mother’s  antibodies form (not a problem right now) If a 2nd baby is Rh+, then antibodies from mom’s blood may cross the placenta and destroy childs RBC’s (Fetal Erythroblastosis)

Current Treatment give Rh- women an Rh immune globulin injection (like an injection of antibodies) called RhoGAM just after the birth of any Rh+ child. This injection will destroy any red cells left over from the baby, before the mother has a chance to start producing her own antibodies. The injection won't work if the woman has already started producing antibodies.

Blood Type Distribution Diagram

Tissue-Capillary Fluid Exchange O2 in lungs/alveoli diffuse through capillaries and into RBC  attach to hemoglobin (Hb) - 4 O2/Hb Oxygenated Hb (HbO2) is taken to body tissues At tissues, O2 diffuses from RBC  tissues through capillaries and CO2 diffuses from tissues  RBC At capillaries, BP has  to ~35 mm Hg (compared to 100 mm Hg in arteries)  largely due to  area for blood flow.

Fluid Exchange cont... This pressure forces H2O out of plasma into surrounding tissue along with smaller molecules Proteins, RBC’s and WBC’s stay in capillary causing blood to become hypertonic This now causes fluid containing wastes, etc… to diffuse back into blood By the time blood enters venules, BP has dropped to ~15 mm Hg Any excess fluid is picked up by lymphatic system and returned to circulatory system

Fluid Exchange Diagram

Lymphatic System Consists of lymphatic vessels and lymphoid organs Vessels/capillaries are similar in structure to blood veins/capillaries Has 3 main functions: take up excess fluid and return it to bloodstream extensive network of lymphatic capillaries collects the fluid and carries it into the lymphatic vessels lymph = fluid inside lymphatic vessels lymphatic vessels merge to form the thoracic and the right lymphatic ducts these ducts in turn empty the lymph into the bloodstream at the subclavian veins

Lymphatic System cont... absorb fats at the intestinal villi and transport them into the bloodstream help defend the body against diseases done mostly by the lymphoid organs which are: lymph nodes – small structures located along lymphatic vessels contain WBC’s which purify the lymph of infectious organisms and produce antibodies tonsils –lymphatic tissue located in the pharynx same function as lymph nodes but are more prone to infection since they are the first to come into contact with infections

Lymphatic System cont... Spleen – located in upper left region of abdominal cavity purifies blood (instead of lymph) by removing pathogens and worn out/damaged RBC’s thymus gland – located along trachea behind sternum larger in children and gets smaller as we age site of maturation of T-lymphocytes and production of some hormones (e.g. thymosin) Red Bone Marrow – located at the ends of all bones in children but only some bones of adults site of maturation of all types of blood cells

Lymphatic System Diagram

EKG Diagram

Lub-Dup Diagram

Cardiac Cycle Diagram

Blood Pressure Diagram

Pressure, Velocity and SA

Heart Beat Video Heart Beat (1:57) http://videos.howstuffworks.com/science- channel/29732-exploring-time-heart-beat- video.htm