The Circulatory System Human Biology 11 Ms. Bowie

Learning Outcomes Describe the structure of the heart and the function of each part. Trace the flow of blood through the heart. List the most common heart sounds and what events produce them. List the different types of blood vessels and describe the functions of each. Trace the flow of blood through the pulmonary and systemic circulation.

Learning Outcomes (cont.) List and describe the components of blood. Give the functions of red blood cells, the white blood cells, and platelets. List the substances normally found in plasma. Explain how bleeding is controlled. Explain the differences among blood types A, B, AB, and O. Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the cardiovascular system.

Part 1 Heart Structures

Introduction The circulatory system consists of heart (a pump) and blood vessels (tubes) Blood is sent to: Lungs for oxygen Digestive system for nutrients Every cell of the body to deliver “products” It also circulates waste products to certain organ systems for removal from the blood

The Heart: Structures The heart is an organ about the size of a loose fist Located slightly left of the midline

The Heart: Structures (cont.) Two ventricles Lower chambers Left and right Separated by a septum The Heart has 4 chambers Two atria Upper chambers Left and right Separated by a septum

The Heart Valves: Structures (cont.) Tricuspid valve – prevents blood from flowing back into the right atrium when the right ventricle contracts Mitral valve – prevents blood from flowing back into the left atrium when the left ventricle contracts Pulmonary valve – prevents blood from flowing back into the right ventricle Aortic valve – prevents blood from flowing back into the left ventricle

The Heart Labeled

Pulmonary System of Circulation Part 2 Pulmonary System of Circulation

The Heart: Blood Flow Oxygenated blood out to body Deoxygenated blood in from body Oxygenated blood in lungs Deoxygenated blood out to lungs Atria Contract Ventricles Contract

The Heart: Blood Flow (cont.) The pulmonary system explains the flow of blood through the heart & lungs. It does not include the rest of the body.

Systemic Circulation of the blood Part 3 Systemic Circulation of the blood

Blood Vessels: Arteries and Arterioles Carry blood away from the heart Strongest of the blood vessels Under high pressure Arterioles Small branches of arteries Aorta Takes blood from the heart to the body Gives an extra “push” Coronary arteries Supply blood to heart muscle

Blood Vessels: Veins and Venules Blood under no pressure in veins Moves blood BACK to the heart Low pressure means that the blood needs help to get back to the heart Muscle contractions in the body help move blood Valves in the veins prevent backflow Venules Small vessels formed when capillaries merge Superior and inferior vena cava Largest veins Carry blood into right atrium

Blood Vessels: Capillaries Tiniest branches of arterioles Smallest type of blood vessel Connect arterioles to venules Only about one cell layer thick Oxygen and nutrients can pass out of a capillary into a body cell Carbon dioxide and other waste products pass out of a body cell into a capillary

The Heart: Cardiac Cycle The systemic circulation describes the flow of blood through the vessels that supply the body. It does not include the lungs.

Heart Beat Cardiac Rhythm Part 4 Heart Beat Cardiac Rhythm

The Heart: Heart Sounds One cardiac cycle – two heart sounds (lubb and dubb) when valves in the heart snap shut Lubb – First sound When the ventricles contract, the tricuspid and mitral valves snap shut Dubb – Second sound When the atria contract and the pulmonary and aortic valves snap shut

Composition of the Blood Part 5 Composition of the Blood

Blood Composition

Blood A tissue made up of: Red blood cells (erythrocytes) White blood cells (leukocytes) Platelets – cell fragments Plasma – fluid part of blood Average-sized adult has 4 to 6 liters of blood Amount depends on: Size of person Amount of fat tissue Gender - females have less than males

Blood Components: Red Blood Cells Erythrocytes Another name for red blood cells Transports oxygen throughout the body Hemoglobin is a pigment in RBCs Oxyhemoglobin carries oxygen; bright red Deoxyhemoglobin does not carry oxygen; darker red Carries carbon dioxide Blood is NEVER actually blue! Anemia Is a condition where a person has a low red blood cell count

Blood Components: Platelets Platelets form sticky nets that are important in the blood clotting process.  

Blood Components: Plasma Liquid portion of blood composed mostly of water Proteins Albumins Pull water in to the blood help maintain blood pressure Globulins – transport fats and vitamins Fibrinogen – the “glue” that holds platelets together and are needed for blood clotting Nutrients Amino acids Glucose Nucleotides Lipids from the digestive tract Gases – oxygen, carbon dioxide, and nitrogen Electrolytes Waste products

Part 6 Blood Types

Blood Types Types are distinguished by antigen (“think – gang colours”) and antibodies There are 4 main types: Antigen A (Type A blood) Antigen B (Type B blood) Combination A + B (AB) (Type AB blood) No Antigens at all (called O Type)

People with this blood type can receive: Blood Types (cont.) Blood Type Antigen Present (Gang colours) Antibody Present (attackers) People with this blood type can receive: A B Types A and O Types B and O AB None ALL Blood Types A, B, AB, and O O A and B Only Type O

Heart Disease Signs & Symptoms Part 7 Heart Disease Signs & Symptoms

Diseases and Disorders of the Cardiovascular System Description Anemia The blood does not have enough red blood cells or hemoglobin to carry an adequate amount of oxygen to the body’s cells Aneurysm A ballooned, weakened arterial wall Arrhythmias Abnormal heart rhythms Carditis Inflammation of the heart Endocarditis Inflammation of the innermost lining of the heart, including valves

Diseases and Disorders of the Cardiovascular System (cont.) Description Myocarditis Inflammation of the muscular layer of the heart Pericarditis Inflammation of the membranes that surround the heart (pericardium) Congestive Heart Failure Weakening of the heart over time; heart is unable to pump enough blood to meet body’s needs Coronary Artery Disease (CAD) Atherosclerosis; narrowing of coronary arteries caused by hardening of the fatty plaque deposits within the arteries

Diseases and Disorders of the Cardiovascular System (cont.) Description Hypertension High blood pressure; consistent resting blood pressure equal to or greater than 140/90 mm Hg Leukemia Bone marrow produces a large number of abnormal WBCs Murmurs Abnormal heart sounds Myocardial Infarction Heart attack; damage to cardiac muscle due to a lack of blood supply

Diseases and Disorders of the Cardiovascular System (cont.) Description Sickle Cell Anemia Abnormal hemoglobin causes RBCs to change to a sickle shape; abnormal cells stick in capillaries Thalassemia Inherited form of anemia; defective hemoglobin chain causes, small, pale, and short-lived RBCs Thrombophlebitis Blood clots and inflammation develops in a vein Varicose Veins Twisted, dilated veins

Bravo! Apply Your Knowledge The doctor has told your patient she has anemia. How would you explain this to the her? ANSWER: Anemia is a condition in which a person does not have enough red blood cells or hemoglobin in the blood to carry an adequate amount of oxygen to body cells. Bravo!

In Summary Circulatory system Blood Transport system for body Heart, arteries, veins, and capillaries Blood Transport medium RBCs, WBCs, platelets, plasma