Physio notes: Cardiovascular SystemLecture 1: three main points: overall design of circulation, blood question, blood flow question- Purpose of the circulatory system is a transport system- it takes substances and things from external environment that we bring into body through the lungs or GI system and then circulation system transports this to organs and tissues. Circulation: moves things from one cell to another, whether we have metabolism there are waste produced- so we need to transport heat produced in all cells, get rid of at skin. - **critical transport: oxygen** oxygen is delivered to tissues.- Blood pumped out of heart= cardio output or CO- We don’t use all the oxygen in blood, only about a quarter of it.- a-vO2 difference : arterial venous O2 difference- 2 major factors: CO and blood flow to tissues- Table 14-2 shows major components of circulation; heart has four chambers: right and left atrium and ventricles- Right atrium get blood from the venae cava-( major vein) sends blood to right ventricle (gets blood from right atrium) pumps blood to lungs ( this is called pulmonary circulation). Blood back from lungs comes through pulmonary veins to the left atrium pumps blood to the left ventricle pumps blood all over the body- Venae cava receives blood flow from systemic veins which are all over the body. - Arteries: carries blood away from the heart (typically oxygenated blood, exception is the pulmonary artery..)- Veins: carry blood to the heart (typically deoxygenated blood, exception to this is the Pulmonary vein..) - Blood has two major components- water and red blood cells (RBCs), water is there to generate pressure and the blood cells are what carries O2. RBCs are diluted in this solution in the body in a very mixed way. - Blood flow is proportionate to pressure so we can surmise that the pressure in the pulmonary circulation is lower than pressure in the arterial circulation: right heart needs to generate less pressure than left heart. Flow through the lungs is the same as the rest of the tissues together but the pressure and resistance in lungs is much lower.- Resistance in systemic is relatively high, and the resistance in the lung is relatively low.- System arteries are high in resistance but low in pressure. - High to low pressure flows- high pressure in the heart, low pressure in arteries.. heart needs to generate pressure, valves determine direction of the flow.- Valves between atrium and ventricle on both sides as well as in pulmonary and aorta, these make sure blood flows the correct direction, the pressure differences are responsiblefor this. Pressure from the heart is transmitted to aorta and the pressure in the aorta is greater than the trunk. - Pressure in right atrium approaches 0, so we say veins have low resistance- veins are verylarge-flaccid, moveable. Veins are compliant-low resistance, low pressure.- About 40% of blood is in the systemic arteries, where about 60% is in the systemic veins-b/c they are very compliant. - Blood high in O2= red - Blood low in O2= blue- Volume of blood coming back to the heart is called the Venous return (VR) this is equal to the blood pumping out of the heart – Cardiac output (CO) VR=CO- Hydrostatic pressure: when heart contracts it compresses blood in the heart, blood needs to have a fluid that can be compressed to generate pressure, so a major component of blood is water or saline (blood) - CO2 is carried in water, dissolved- O2 carried in RBCs bound to RBCs- White blood cells fight infection (WBCs make up 1% of blood)- Blood volume is proportionate to the size or body mass of the person, usually ranges from 5-6L. Women have about 5L, men about 6L. RBCs are the heaviest-sink to bottom when put in a centrifuge, RBCs make up about 42% of blood volume. WBCs make up less than 1%, 58% of blood volume is made up of plasma volume- RBCs are usually dispersed in the plasma- RBCs are made of hemoglobin, hemoglobin bind O2 to carry oxygen, males generally have more hemoglobin then women.- Packed RBC volume is called Hematocrit b/c there are more hemoglobin in males, this will also be a little bigger than in females.- REMEMBER: % of blood made up of plasma- 58%, % that is packed RBCs or hematocrit- 42%, % WBCs –less than 1%, hemoglobin concentrations and gender differences- males have 14-17 females: 12-16 along with total blood volume. - RBCs turn over every 2-3 weeks b/c they lose their ability to carry O2. MAKING OF RBCs IS HIGHLY DEPENDENT ON IRON. KNOW: iron is important, combines with hemoglobin to make RBCthey’re destroyed, their end products are excreted (in urine) (most RBCs happen in bone marrow) - RBCs are very compressible, elastic b/c diameter is larger than the final vesicle in the circulation capillary- so it has to be squeezed through capillary.. Important b/c it helps dislodge oxygen.- Each RBC has four attachment proteins that oxygen binds to- each RBC can carry four O2 molecules, the more RBCs the more O2- Platelets: just know they plug up holes in circulation- Radius is the main factor that determines resistance and therefore blood flow.Lecture 2Three main points: anatomy of the heart, blood flow through the heart, autonomic regulation of the heart.- Ribcage protects the heart from mechanical blunt force trauma.- Heart hangs from blood vessels- obliquely oriented, size of fist. - Heart is in between 2 lungs- obliquely oriented important b/c right lung is full sized, left lung has a spot for the heart to sit..also diaphragm moving up and down changes the pressure on the heart. - Pressure on the heart increases during expiration, decreases during inspiration.- Heart has four valves: between right atrium and right ventricle, right ventricle to pulmonary artery, between left atrium and left ventricle, and between left ventricle and aorta. - Doctors listen to heart at the four valves. - Blood flow comes out of top of the heart, so the heart actually squeezes blood from the base of the heart to toward the top of the heart-where there is a large arch called the aortic arch. Out of the aortic arch going straight to the brain are the carotid arteries-makes sure blood flow to brain is protected since it comes from the upper part of the heart.- Heart incased within a membranous fluid-filled sac called the pericardium- Pericardium: protective layer, connective tissue sac surrounding heart- like a balloon, protects from outside chemicals. Disease: if there is infection of the pericardium