The Cardiovascular System – Physiology Chapter 12Physiology 12.1 NotesVocab:- Atrium: holds blood until ventricles can pump them- Ventricle: pushes blood out of heart (to lungs or to body)- Septum: separates the heart into two- Pulmonary/Aortic Valves: regulates blood flow one way out of heart- Diastole: relaxation of the heart- Systole: contraction of the heart- SA Node: the pacemaker of the heart in the right atrium. - AV Node: controls the beating impulse of ventricles.- Electrocardiogram (ECG): graphic representation of electrical impulses during a heartbeatNotes:- Heart is a four layer, three chambered, two cycle organ, responsible for transporting blood (oxygen/nutrients) to tissues and taking away wastes.- Heart walls have 3 layers: epicardium, myocardium (muscle), endocardium. - Ventricular walls are much thicker (esp in left) than the atria. - Septum divides the heart into 2 sides- Valves between atria and ventricles are atrio-ventricular valveso Tricuspid in right ventricleo Bicuspid in left ventricleo Held closed in place by chordae tendinae (heart strings)o Heart problems can cause fluttering or murmuring of valves sounds,- Arteries leave the heart: pulmonary + aorta. - Normal heart beats sound like lubb-dupp. o Lubb = resonating sound caused by blood pressure against atrio-ventricular valves. Closes the bicuspid/tricuspid valves. o Dupp = ventricles relax and blood in artery/aorta flows back to ventricles. Valves catch backflow and snap into each other.- Blood flows twice through heart for one circuit- Cycle of Blood in heart.o Deoxygenated blood enters superior/inferior vena cava and sits in right atriumo Through tricuspid valve into right ventricleo Through Pulmonary valve into pulmonary artery to lungso Blood is oxygenated in gas exchangeo Oxygenated blood enters pulmonary vein into left atriumo Goes through bicuspid (mitrial) valve into right ventricleo Goes through aortic valve into aorta to body- Volume of blood doesn’t change but blood pressure does- Pressure comes from force of ventricular muscles squeezing blood to rest of the body.o Systolic Pressure = force of left ventricle contractiono Diastolic Pressure = force exerted on blood vessel walls by the blood when heart is relaxed. o Normal systolic/diastolic reading = 120/80- Rate of heartbeat can be controlled intrinsically (automated) or extrinsically (changed by outside stimulus). o Intrinsic Controls occur in the natural pacemaker SA Node. AV Node delays the contraction impulse so that the atria can complete its contraction before ventricles can pump blood out.o Extrinsic Controls are in the medulla, can override intrinsic heartbeat if body has increased needs (sympathetic NS)- Cardiac muscle cells always generate a pattern of electrical signals given off in cardiac cycle, picked up by ECG.- Cardiac Cycle = diastole (relaxed), atrial systole (filling), ventricular systole (contraction)- Cells depolarizie before contraction and repolarize in relaxation.o P Wave = SA node firing; atrial cells depolarize and pumpo QRS Complex = depolarization of ventricles, pumpo T Wave = return to diastole. Physiology 12.2 NotesVocab:- Systematic Circuit: blood going from heart to tissues- Pulmonary Circuit: blood going from heart to lungs- Arteries: take blood away from heart.- Veins: bring blood back to heart.- Capillaries: smallest blood vessels, one layer thick and allows for exchange of gases, nutrients, wastes across vessel walls.- Lumen: hollow center of the blood vessel- Capillary Beds: interwoven mat of capillaries in tissues- Venules: small veins that drain blood from capillaries and mergeNotes:- All arteries + veins have 3 layers: endothelium (inner), smooth muscle (middle), and connective tissue (outer)- Arteries have thicker layers and veins are thinner, diameters of blood vessels decrease as it is farther away from the heart.- Arteries become smaller into arterioles then into capillaries.- Capillaries are thin enough (one cell thick) that gases, nutrients, wastes can diffuse across vessel wall. o Thinness also slows down blood traveling through it, allowing for more diffusion.- Venules merge capillaries into veins going back to heart.o Barely any heart/blood pressure to push blood back to heart.o Fluid/physics dynamics pushes blood one way.Physiology 12.4 Notes- Cardiovascular diseases are the leading cause of death in western countrieso Males suffer more from CVD than femaleso African Americans more affected than Caucasian whiteso Genetic history can affect level of individual’s risk- Hypertension (High Blood Pressure): almost no symptoms, when systolic blood pressure is above 140 or diastolic pressure is above 90. (140/90)o Blood vessels are less elastic and key risk is stroke.- Artery Damage (Atherosclerosis) = when plaques/fats block up the lumen and reduce blood flow. Clots can form and embolism (tissue death) can occur.- Aneurysm: when vessel walls balloon under pressure and burst from heart beat pressure. Usually fatal but can be prevented.- Strokes: embolism or aneurysm in the brain. Starves tissues of nutrients and can cause permanent brain/nerve damage.- Heart Attack: death of a part of the heart due to lack of oxygen/nutrients or when blood flow is continuously blockedo Dead cardiac tissue stops conducting electricity so contraction impulses are impeded, therefore heart may stop beating.o Angina = less severe heart attack, a heart cramp.o Can be helped with a balloon treatment (crushing of plaques), bypass surgery (more tubes in heart) or stents. Artificial hearts in testing- Congestive Heart Failure: aging weakens the left ventricle, fails to move blood into lungs. A gradual disease that can also cause lung infections and a liquid back up effect.- Vericose Veins: when blood moves into veins and pools up due to lack of movement. Vessels expand and veins pop out of muscles.Physiology 12.5 NotesVocab:- Hormones: compounds secreted in one area that affect another via bloodflow- Plasma: Liquid portion of the blood- Formed Elements: bits of cells in blood that originate from bone marrow- Electrolytes: compounds that can conduct electricity- Red Blood Cells: transports most of oxygen and carbon dioxide- Hemoglobin: protein that contains iron and helps carry oxygen- White Blood Cells (leukocytes): combat pathogens that enter bodyNotes:- Blood is composed of a liquid (plasma) and solid (formed