EXPH 386 Leary Notes Pages 1-2 PDF

EXPH 386 Miriam Leary Notes Key functions of the CV system ○ Delivers oxygen and nutrients to active tissues ○ Returns deoxygenated blood to the lungs ○ Transports heat (byproduct of cellular metabolism) and hormones Circulatory System ○ Circulatory/Cardiovascular ○ Th...

EXPH 386 Miriam Leary Notes Key functions of the CV system ○ Delivers oxygen and nutrients to active tissues ○ Returns deoxygenated blood to the lungs ○ Transports heat (byproduct of cellular metabolism) and hormones Circulatory System ○ Circulatory/Cardiovascular ○ The heart is dual pump ○ 2 blood flow circuits Systemic circulation- heart and system Everywhere else in the body besides the lungs Pulmonary circulation- heart and lungs A few differences between the circuit The blood flow to the pulmonary circuit doesn’t have to go very far so the blood doesn’t have to travel as far as the blood in systemic circulation System circulation has higher pressure Arteries carry blood away from the heart but it may not always be oxygenated ○ Systemic circulation: carries oxygenated blood away from the heart to the body and returns deoxygenated blood back to the heart The heart has 2 cell types ○ Electrical: electrical pathway ○ Contracticle: mechanical cell Heart Structure and Function ○ Skeletal muscle main features Fibers: striated tubular and multi nucleated Voluntary Usually attached to skeleton ○ Cardiac muscle main features Fibers: striated branched and uninucleated Involuntary Only covering the walls of the heart Anatomy of the Heart ○ 4 chambers Right atrium Right ventricle Left atrium  Left ventricle ○ 4 valves Atrioventricular valves Tricuspid (right) Bicuspid/mitral (left) Semilunar valves Pulmonary Aortic Terms and Definitions for Heart Contraction ○ Diastole: rest End Diastolic Volume: volume in the heart during rest ○ Systole: contraction End Systolic Volume: volume in the heart during contraction ○ EDV-ESV= Stroke Volume (how much blood is ejected/heart beat) ○ Isovolumetric: same volume Isovolumetric contraction: brief period of time (0.02-0.06 seconds) when all heart valves remain shut, ventricular pressure rises but volume remains unchanged Isovolumetric relaxation: brief period of time (0.02-0.06 seconds) when all heart valves remain shut, ventricular pressure drops but volume remains unchanged Venous Return ○ One way valves: helps prevent backflow and keeps blood moving toward the heart ○ Smooth muscle layer ○ Skeletal muscle pump Alternate compression and relaxation to return back to the heart Distribution of Blood at Rest ○ Venous pooling May induce fainting from insufficient cerebral blood supply So much blood stored at the bottom of the body so blood flow cannot get to the brain quick enough Varicose Veins ○ Veins fail to maintain their one way blood flow ○ Blood gathers- veins are distended and painful ○ Phlebitis- venous wall is inflamed and progressively deteriorates Vessel removal is necessary ○ Exercise cannot prevent varicose veins but minimizes complications Blood Pressure Follows a Gradient ○ The mean BP decreases from the aorta to the venae cavae