The Circulatory and Respiratory Systems

Name ______Period ______Accelerated Biology The Circulatory and Respiratory Systems The Circulatory System Notes

Functions of the Circulatory System  Transport system o ______from digested food  all body cells o oxygen from the lungs  all body cells o metabolic ______(CO2)  organs to be excreted o ______ target tissues

 Regulates body temperature o in a ______environment blood vessels ______, allowing more heat to leave the body o in a ______environment blood vessels ______, preventing heat from escaping from the body

Blood Vessels  Arteries – carry ______blood ______from the heart o arterioles – small arteries o thick ______walls to withstand the ______action of the heart o ______blood pressure

 Capillaries – connect ______to ______o Walls are only ______cell thick so molecules can easily ______across o Nutrients diffuse from capillaries  body cells o Wastes diffuse from body cells  capillaries o Capillaries are vey narrow; thickness of a single RBC

 Veins – carry ______blood ______to the heart o thin walls due to ______blood pressure o have ______to help prevent ______of blood The Heart  A muscular pump that propels blood through the blood vessels o Atria – two ______chambers that ______blood returning to the heart o Ventricles – two ______thick–walled chambers that ______blood away from the heart o Pericardium – ______sac around the heart

The Vessels  Vena cava – ______veins o Superior – drains blood from the ______body into right atrium o Inferior – drains blood from the ______body into right atrium  Aorta – largest artery o comes from ______ventricle and branches to deliver blood to the ______body  Pulmonary arteries – carry blood ______the ______to the lungs  Pulmonary veins – carry blood ______the ______back to the heart  Coronary arteries – delivers blood to ______muscle o When the ______arteries become ______a heart attack occurs o Stroke – when blood supply is cut off to the ______and an area of the brain dies.

The Valves  Valves – prevent the ______of blood as it is being pumped through the heart  Named according to where they ______or how they ______o Atrioventricular Valves – between the atria and ventricles . tRicuspid – on the ______side . bicuspid – on the ______side (a.k.a. as the ______v.) o Semilunar Valves – between the ventricles and arteries . pulmonary – right ______ pulmonary artery . aortic – left ventricle  ______

Pathway of Blood through the Heart Vena cava  right atrium tricuspid valve  right ventricle  pulmonary valve pulmonary artery  lungs pulmonary veins left atrium  bicuspid valve  left ventricle aortic valve  aorta Systemic Circulation  The ______side of the heart pumps ______blood out to the body through a network of arteries  ______blood is returned to the ______side of the heart through veins.

Pulmonary Circulation  The right side of the heart pumps ______blood through the pulmonary arteries to the lungs.

 ______exchange (release of C02 and and pick up of O2) occurs in the ______.  The ______blood then returns to the left side of the heart through pulmonary veins

 In the pulmonary circuit the oxygen content of the vessels is ______! o The pulmonary ______carries ______blood away from the heart to the lungs o The pulmonary ______carries ______blood from the lungs back to the heart

What Regulates Heartbeat?  Sinoatrial (SA) node o acts as the ______for the heart o cluster of cells located in the upper wall of the ______atrium o sends a rhythmic ______stimulus causing both ______to ______pushing blood into the ventricles  Atrioventricular (AV) node o in ______the atria o causes ______of the ______just after the atria contract pushing blood out of the heart