CARDIOVASCULAR SYSTEM Blood Vessels

BLOOD VESSELS Arteries function to carry blood away from heart Arteries function to carry blood away from heart The largest artery is the aorta The largest artery is the aorta Smaller arteries are called arterioles which flow into capillaries Smaller arteries are called arterioles which flow into capillaries

ARTERIES Consist of 3 thick walled layers Consist of 3 thick walled layers Pulsate to regulate blood flow in the body Pulsate to regulate blood flow in the body * Arteries are the most muscular of all blood vessels * Arteries are the most muscular of all blood vessels

ARTERIOLES Branches of arteries Branches of arteries Regulate blood flow to capillaries via vasoconstriction & vasodilation Regulate blood flow to capillaries via vasoconstriction & vasodilation

3 LAYERS OF ARTERIES & VEINS Tunica interna Tunica interna Tunica media Tunica media Tunica externa Tunica externa

BLOOD VESSELS Veins return blood back to heart Veins return blood back to heart The smallest veins are called venules which receive blood from the capillaries The smallest veins are called venules which receive blood from the capillaries The superior and inferior vena cava are the largest veins The superior and inferior vena cava are the largest veins

VENULES Capillaries unite to form venules Capillaries unite to form venules Venules deliver blood to veins Venules deliver blood to veins

VEINS Consist of 3 layers Consist of 3 layers Thin tunica interna & tunica media Thin tunica interna & tunica media Contain valves to prevent backflow of blood Contain valves to prevent backflow of blood

BLOOD VESSELS Aorta  arteries  arterioles Aorta  arteries  arterioles Capillaries (gas & Capillaries (gas & nutrient exchange) Venules  Veins  vena cava Venules  Veins  vena cava

CAPILLARIES Connect arterioles to venules Connect arterioles to venules Function in exchange of gas & nutrients btwn. blood & tissues Function in exchange of gas & nutrients btwn. blood & tissues

How oxygen, carbon dioxide, glucose and water move across capillary walls Oxygen, carbon dioxide and glucose move across the capillary wall by diffusion Oxygen, carbon dioxide and glucose move across the capillary wall by diffusion Osmotic pressure and hydrostatic pressure determines movement of fluid through capillaries Osmotic pressure and hydrostatic pressure determines movement of fluid through capillaries Fluid moves out of the capillary at the venule end and returns at the arteriole end Fluid moves out of the capillary at the venule end and returns at the arteriole end

Blood Flow through arteries Pressure Pressure Velocity of blood flow Velocity of blood flow Resistance Resistance

3 Actions the provide pressure gradients in veins Skeletal muscle action Skeletal muscle action Respiratory movements Respiratory movements Contraction of smooth muscle in venous walls Contraction of smooth muscle in venous walls

6 pulse points Radial artery Radial artery Common carotid Common carotid Axillary artery Axillary artery Brachial artery Brachial artery Temporal artery Temporal artery Popliteal artery (behind the knee) Popliteal artery (behind the knee) Dorsalispedis artery Dorsalispedis artery

Systolic vs. Diastolic Pressure Systolic pressure- pressure in the arteries during ventricular contraction (Normal is about 120 mm Hg) Systolic pressure- pressure in the arteries during ventricular contraction (Normal is about 120 mm Hg) Diastolic pressure- pressure in the arteries during ventricular relaxation (Normal is about 80 mm Hg) Diastolic pressure- pressure in the arteries during ventricular relaxation (Normal is about 80 mm Hg) Pulse pressure- difference between systolic and diastolic pressure (Normal is about 40 mm Hg) Pulse pressure- difference between systolic and diastolic pressure (Normal is about 40 mm Hg) Use a sphygomomanometer to measure blood pressure Use a sphygomomanometer to measure blood pressure

Factors that affect blood pressure Cardiac output Cardiac output Blood pressure in blood vessels Blood pressure in blood vessels Peripheral resistance Peripheral resistance Viscosity of the blood Viscosity of the blood

CIRCULATORY ROUTES Systemic circulation- transport of blood between heart and rest of the body Systemic circulation- transport of blood between heart and rest of the body Pulmonary circulation- transport of blood between heart and lungs Pulmonary circulation- transport of blood between heart and lungs Coronary circulation- transport of blood through the heart Coronary circulation- transport of blood through the heart Fetal circulation- placenta and umbilical artery and vein Fetal circulation- placenta and umbilical artery and vein

Common Heart Diseases Anemia- low blood iron due to insufficient amounts of hemoglobin Anemia- low blood iron due to insufficient amounts of hemoglobin Artheroscerosis- plaque formation from lipids in arteries Artheroscerosis- plaque formation from lipids in arteries Arteriosclerosis- calcification of plaque on the inner walls of the arteries Arteriosclerosis- calcification of plaque on the inner walls of the arteries Hypertension- high blood pressure Hypertension- high blood pressure Mitral valve prolapse- defect in the valves of the heart Mitral valve prolapse- defect in the valves of the heart