BSCI 202 Exam 2 Study guide Cardio Vascular System function o to deliver oxygen and nutrients and to remove carbon dioxide and other waste products transport of substances o such as oxygen and nutrients to cells wastes from cells to liver and kidneys hormones immune cells clotting proteins to specific target cells use blood that is pumped through the heart which circulates through all parts of the body used for delivery heart located in thoracic cavity o o pulse monitered at poiint of the body that are easily felt through the skin is the pressure wave of blood palpated closer to heart or larger arteries are stronger averages 70 76 bpm at rest o blood pressure check the arterial blood pressure vein blood pressure flucuates all the time to measure blood pressure use pressure to stop flow of blood systolic pressure is pressure when blood begins flowing again diastolic pressure is when last sounds of resistance are heard artierial blood pressure varies with cardiac cycle and is measured with a sphygmomanometer arm blood pressure monitering thing difference of systolic and diastolic pressure systolic pressure maximum pressure due to ejection of blood into aorta contraction diastolic pressure minimum pressure ventricle relaxation pressure gradient in systemic circuit pressure gradient pressure in aorta minus pressure in vena cava just before it empties in the right atrium pressur ein aorta mean arterial pressure 90mmHg pressure in vena cava central venous pressure 0 mmHG MAP CVP 90 mmHg pulmonary edema extra fluid gets pushed into pulmonary circuit effects of blood pressure cardiac output CO amount of blood being pumped out of left ventricle per minute Peripheral resistance PR amount of friction blood encounters as it flows through vessels narrowing blood vessels and increased blood volume increases PR contsriction state of blood vessels also effect resistance lots of water will elevate blood pressure to make room for more liquid hypertension is when blood vessels have friction BP PR x CO localized vasodilation contriction to skin only changes amount of blood to skin systemic vasodilation contriction changes overall blood pressure the pericardium double walled membraneous sac that surrounds the heart and allows it to beat in a basically frictionless environment prevents heat build up serous fluid fills the space between the layers of pericardium pericarditis inflammation of the pericardium cardiac muscle o gap junctions allow impulse to travel throughout the heart rapidly to allow the heart to contract as a whole desmosomes resist stress to allow heart to beat constantly intercalated discs distinct key that your looking at cardiac muscle aerobic muscle growth only by hypertrophy no cell division 99 contractile cells sympathetic nervous system speeds up heart rate parasympathetic nervous system slows down heart rate 1 autorhythmic cells allow the atria to contract as a unit and the ventricles to contract as a unit autorhythmicity is the ability to generate own rhythm autorhythmic cells that provide pathway to spread excitation through the heart sinoatrial node is the pacemaker of the heart not able to regenerate function rhythmic contraction and relaxation generates heart pumping action contraction pushes blood out of the heart into vasoculature relaxation allows the heart to fill with blood again conduction system sinoatrial node SA node in right atrium pacemaker cells spontaneous depolarizing membrane potentials to generate action potentials closing of potassium channels and opening of cation channels o o coordinate and provide rhythym to heartbeat electrical activity in pacemaker cells depolarize to threshold with funny Na channels and T type Ca2 channels sodium channels can open without a stimulus open fast L type Ca2 channels action potential repolarization is an opening of sodium channels to allow for repol Atrioventricular node AV node at the junction of the atria and ventricles atrioventricular bundle AV bundle in the interventricular septum bundle branches are also in the interventricular septum purkinje fibers are spread within the ventricle wall muscles rapidely conduct action potentials initiated by pacemaker cells to myocardium conduction velocity CV 4 meters second ordinary fibers are only 4 meters second resting membrane potential caused by the membranes ability to maintain a positive surface charge on its outer surface opposing a negative charge on its inner surface o diaphragm seperates abdominal cavoity from thoracic cavity size of fist o o weighs approx 250 350 grams o valves present for unidirectional blood flow valves open passively based on pressure gradient pressure within chambers of heart vary with heartbeat cycle pressure difference drives blood flow blood flows from areas of high pressure to areas of low pressure four valves valves operate opposite of one another to force a one way path of blood through the heart open passively based on the pressure gradient atrioventricular valves between atria and ventricles anchored in place by chordae tendineae heart strings open during heart relaxation closed during heart contraction bicuspid mitral valve left side of heart tricuspid valve 3 flaps to close or open valve semilunar valves between ventricle and artery closed during heart relaxation but open during ventricular contraction pulmonary semilunar valves aortic semilunar valve o four chambers 2 atria 2 ventricles right and left as seperate pumps left ventricles are much more muscular because need to send blood throughout the whole body septa generic seperates right and left chambers intraventricular septum seperates the two ventricles interatrial septum seperates the two atria coronary circulation o intrinsic conduction system nodal system heart muscles cells contract without nerve impulses in a regular continuoues way blood in heart chambers does not nourish myocardium coronary arterial system how the heart myocardium is nourished cardiac arteries branch from aorta to supply the heart muscle with oxygenated blood cardiac veins drain the myocardium of blood coronary sinus is a large vein on the posterior of the heart and receives blood from the cardiac veins dexygenated blood from myocardium empties into right atrium via the coronary sinus o heart contractions slow heart rate less than 60 beats per minute Bradycardia tachycardia rapid heart rate over 100 beats per minutes o cardiac cycle events associated with the flow of blood through the heart during a single
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