Human Physiology BIOL 2213Topic List for Chapter 12 – Cardiovascular Physiology12A.1 – Know the design of the circulatory system. - Pulmonary loopo Carries oxygen poor blood to the lungs and back to the heart- Systemic loopo Carries blood from the heart to the rest of the body- Closed system leaks are badWhat are the three main components of the circulatory system? - Heart, blood, and blood vesselsWhat are the components of blood (Fig. 12-1)? - Plasma- 55%- Formed elements- 45%o Buffy coat- leukocytes and plateletso Erythrocytes/hematocrit is basically all of the 45%Know the layout of the systemic and pulmonary circulation and the names of the major blood vessels feeding into and out of the heart and the names of chambers and important structures in the heart (Fig. 12-2). You will not be asked questions on these things specifically during the exam but you will need to know them to describe blood flow through the heart and factors affecting cardiac output etc. 12A.2 Know the factors that affect blood flow through vessels and the relationships between flow, pressure differences and resistance. What factors affect resistance?- Pressure- force exerted- Flow- volume moved- Resistance- how difficult it is for blood to flow between two points at any given pressure difference; measure of friction that impedes flowo 3 things that contribute to resistance Blood viscosity- affected by volume and # of RBC) Total blood vessel length- how much tubing is needed; longer means more friction Blood vessel diameter- relaxed vessels decrease and constricted vessels increaseresistance; biggest contributor to minute-to-minute control of resistance - Flow=change in pressure/resistanceo If you increase resistance you decrease flow if the pressure stays the same12A.3 – Know the anatomy of the heart as shown in Fig. 12-6. Know how the blood flows through the heart. FIGURE 12-8 HELPFULKnow the different layers of tissue in the heart and what cell types comprise the heart. - Epicardium- most superficial layer; visceral layer of the serous pericardium- Myocardium- middle layer; composed of cardiac muscle; layer that contracts- Endocardium- inner layer; continuous with the lining of the blood vessels entering and leaving the heart- Cells- endothelial cells; located in endocardiumKnow how the autonomic nervous system innervates the heart and what the effects are of sympathetic and parasympathetic stimulation.- Sympathetic nervous system- innervates whole heart and releases norepinephrine; speeds up heart rateo Epinephrine does the same thing because norepinephrine has beta adrenergic receptorsthat allow epinephrine to bind too and have the same function- Parasympathetic nervous system- innervates the node cells and releases acetylcholine; slows down heart rate; come from vagus nerveso Has muscarinic receptor for Acho Only innervates the atria and not the ventricles. Know how blood is supplied to the tissues that comprises the heart. - Coronary arteries supply the myocardium with blood; if clogged results in a heart attack- Cardiac veins drain into the coronary sinus and empty into the right atrium12B.2 – Know the structures of the conducting system of the heart and how they function. - Sinoatrial node- pacemaker of the heart. Starts the excitation with a signalo Normal rate is about 75 signals- From SA node there is a wave of depolarization through the intermodal pathway by gap junctions to the AV mode. o There is a .1 second delay here so the atria can fully contract and and totally fill the ventricles before they have to contract- Then wave of depolarization goes through AV bundle towards Purkinji fibers that go to the apex and then turn upwardsKnow the sequence of events in the conducting system of the heart during a typical heartbeat. How does the action potential of a ventricular muscle cell (Fig. 12-12) differ from that of a Sinoatrial Node cell?o Ventricular muscle cell- Resting potential is -90 which is closer to K+ because the membrane is more permeable to K+ than Na+o Spikes up because of Na+ entry and then slightly repolarizes but then plateaus because of Ca2+ entry. Once K+ exits there is a major repolarization until the cell is at resting againo SA node cell- does not have a steady resting potential, but undergoes a slow depolarization called pacemaker potentialo Brings membrane to potential; Na+ and Ca2+ enter before threshold is reachedo There is less of an increase than ventricular and repolarization occurs when K+ exitso Pacemaker currents bring cell to threshold more quickly than AV cello Capable of automaticity- the capacity for spontaneous, rhythmic self-excitation(Fig. 12-13)? How do the differences relate to the function of those two cells? Why is a refractory period present in ventricular muscle cells and why is that important? o Refractory period present so that the atria can fully contract and fill the ventricles before they contractKnow what an electrocardiogram is and what the different parts of the graph mean (P QRS and T waves).Be able to detect irregularities in and ECG (Fig. 12-14, 12-15, and 12-16).o Electrocardiogram- machine that measures electrical events in the hearto P- atrial depolarizationo QRS- ventricular depolarizationo T- ventricular repolarizationo Atrial repolarization is not shown because its occurs at the same time as the QRS complexo Irregularitieso Partial block- only every other atrial impulse is transmitted to the ventricles so there are too many P waves; every second P wave is not followed by a QRS and T waveo Complete block- the ventricles are being controlled by a node in the bundle of His that isvery slow and the atria and ventricles are not synchronized at all. Random waves.12B.3 – Know the mechanical events that occur in the cardiac cycle and the names of the different events in the cycle (Figs. 12-18 and 12-19). o Cardiac cycle has 2 major phases; systole and diastoleo Systole- time when the ventricles contracting and blood being ejectedo Diastole- ventricular relaxation and blood filling How does the pressure change in the different chambers and blood vessels as the cycle proceeds? READ PAGE 367-370o Aortic pressure- start much higher than the other pressure and pressure is highest during ventricular contraction (systole) o Left ventricular pressure- starts at same level as atrial pressure, but drastically increases systoleo Left atrial pressure- starts low and stays relatively lowHow does the volume change? o Left