The Circulatory System Ms. Martinez Biology
The Circulatory System The circulatory system transports : Nutrients Metabolites Excretory/Waste Products Gases Hormones Cells Heat To and from different places in the body
The Closed Circulatory System
lungs head & arms liver digestive system kidneys legs pulmonary artery aorta pulmonary vein main vein LeftRight How does this system work? Circulatory System
Three Major Elements Heart Blood Vessels Blood
The Heart The heart pumps blood into large vessels that branch into smaller ones leading into the organs.
The Heart Has 4 Chambers Right atrium Right ventricle Left atrium Left ventricle
what ’ s in red blood cells white blood cells platelets plasma carbon dioxide digested food waste (urea) hormones oxygen
Flow and Resistance Blood flow occurs due to hydraulic pressure differences. The high pressures are created by the pumping of the heart (specifically ventricular contraction) Flow resistance Blood velocity is dependent on cross sectional area, not pressure Any change in the radius of the small arteries or arterioles has a large effect on the resistance and therefore the pressure necessary to pump blood
More cellsconstriction of blood vessel walls
Cardiac Cycle Heart is two pumps that work together, right and left half Repetitive contraction (systole) and relaxation (diastole) of heart chambers Blood moves through circulatory system from areas of higher to lower pressure. Contraction of heart produces the pressure
Blood Pressure Blood against the blood vessel’s walls The SYSTOLIC pressure refers to The pressure recorded while the ventricles pump the blood The DIASTOLIC pressure refers to The pressure recorded as the ventricles fill with blood
Hypertension High blood pressure Heart works harder than necessary Increases risk of heart attack orstroke
Viscosity Having relatively high resistance to flow Example: Think about pouring these items…how do they flow? Syrup Oil Yogurt milkshake
Artheroclerosis Fatty Deposits called plaque Builds up in walls of arteries Obstructs flow Also a risk is clot breaks free and blocks flow elsewhere
SUMMARY Complete the following; Arteries take blood ______ from the heart. The walls of an artery are made up of thick _________ walls and elastic fibres. Veins carry blood ________ the heart and also have valves. The _________ link arteries and veins, and have a one cell thick wall. Blood is made up of four main things ______, the liquid part of the blood; Red Blood Cells to carry ______; White Blood cells to protect the body from disease and _________ to help blood clot.
SUMMARY Complete the following; Arteries take blood ______ from the heart. The walls of an artery are made up of thick _________ walls and elastic fibres. Veins carry blood ________ the heart and also have valves. The _________ link arteries and veins, and have a one cell thick wall. Blood is made up of four main things ______, the liquid part of the blood; Red Blood Cells to carry ______; White Blood cells to protect the body from disease and _________ to help blood clot. away platelets towards capillaries plasma oxygen muscular