Chapter 20 The Heart

Transcription

1 Chapter 20 The Heart ANATOMY OF THE HEART The adult heart is apprximately the size f. The heart is lcated in the cavity, between. Base is directed, and the apex is directed. The membrane surrunding and prtecting the heart is called. Pericardium cnsists f tw parts; uter is the and the inner is the. Serus pericardium is duble layered; uter is and inner is called. Visceral pericardium is als called the. Space between the parietal and the visceral pericardium is called the cavity filled with the fluid. Inflammatin f the pericardium leads t. The utermst layer f the heart wall is called the. The middle layer f the heart wall is called the. The innermst layer f the heart wall is called the. Chambers f the Heart Hw many chambers des the heart have?. The superir chambers are called and the inferir chambers are called. Each atria has a flap like extensin called, which functins t. An external grve separating the atria frm the ventricles is called.

2 Right atrium receives bld frm, and. is an pening in the fetal heart in the inter-atrial septum, it clses after birth and becmes. Bld mves frm the right atrium t the right ventricle by passing thrugh the valve. Inner wall f Ventricles have irregular ridges and flds, which are called. Left and right ventricles are separated frm each ther by septum. Bld passes frm the right ventricle t the, thrugh a valve called the. Left atrium receives bld frm the via veins. Bld passes frm the left atrium t the left ventricle thrugh a valve called the, als knwn as the. Bld passes frm the t the arta thrugh a valve called the. During fetal life, a temprary bld vessel called, cnnects pulmnary trunk t the arta, this bld vessels clses shrtly after birth, leaving a remnant called. What is the functin f ductus arterisus?. Between the atria and ventricles which ne has a thicker mycardial wall? Why? Wall f the ventricle is 2-4 times thicker than the wall f ventricle, since it has t pump bld lng distance t all bdy parts. HEART VALVES AND CIRCULATION OF BLOOD Heart Valves pen and clse in respnse t changes in the heart chambers. The valve is made up f 2-3 r. Valves prevent the. Where are the papillary muscles lcated?.

3 Papillary muscles are cnnected t the cusps by. Cntractin f the right ventricle causes the valves t clse and the valves t pen, causing the bld t flw in t. Where is the bicuspid valve?. Why is it called the bicuspid valve?. Bicuspid valve is als called the valve. With each beat f the heart, the bld is pumped int tw clsed circuits called and circulatin. The side f the heart is fr circulatin. it receives xygenated bld frm the and distributes it t the. The side f the heart is fr circulatin. it receives de-xygenated bld frm the and sends it t the fr xygenatin. Bld frm the systemic circulatin enters the f the heart and then passes thrugh the tricuspid valve t the f the heart. Cntractin f the right ventricle frces the bld t flw int the and finally t the where gas exchange takes place. Oxygenated bld returns t the by fur veins. Bld then passes thrugh the mitral valve t the. Cntractin f the left ventricle frces the bld t flw int the and finally distributed t the. The tw majr arteries supplying bld t the mycardium are called: and. Bld is drained frm the atria and ventricles by which empties int the right atrium. CARDIAC MUSCLE TISSUE AND THE CARDIAC CONDUCTION SYSTEM

4 Cardiac muscles fibers are cnnected t each ther by. Intercalated discs are rich in which allw cell-cell cmmunicatin. Cardiac muscle cells are rich in which prduce fr muscle cntractin. Specialized cardiac muscle cells capable f generating spntaneus actin ptentials are called. Sinatrial nde is lcated in the wall f. Sinatrial nde is als called the. Why? Atriventricular nde is lcated in the. At the AV nde the actin ptential is delayed by, which allws fr. AV nde passes the actin ptential t the, which divides t frm and The Bundle branches are lcated in the and they transfer the actin ptential finally t the. On its wn, SA nde is capable f generating an actin ptential every sec, which results in cntractin at the rate f beats/min. Signal frm the nervus system and (hrmne) can mdify the rate f heartbeat. Actin Ptential and Cntractin f Cntractile Fibers Deplarizatin begins by the pening f channels, causing an influx f causing rapid deplarizatin. What is the plateau phase?. Plateau phase is characterized by the pening f channels, increasing the influx f which triggers muscle cntractin. Replarizatin is due the clsure f channels and pening f channels. Define refractry perid?.

5 The lnger refractry perid in the cardiac muscle fibers allws. What is ECG r EKG?. The instruments used t recrd ECG is called. P wave is the result f and signals the nset f. QRS cmplex results frm and signals the nset f. T wave results frm and signals the nset f. What des the PQ interval represent? An abnrmal ECG can indicate. CARDIAC CYCLE Cardiac cycle refers t. The average duratin f cardiac cycle in an adult is sec. The term means t cntract. The term means t relax. The majr phases f the caridac cycle are:. Atrial systle lasts sec and invlves the cntractin f. Cntractin f the atria pens the valve, causing the bld t flw int the ventricles. The ttal vlume f bld in the ventricles at the end f this phase is called the. As ventricular systle begins, the pressure in the ventricle, causing the clsure f valves.

6 All fur valves clse at this time and this brief perid is called. When the ventricular pressure becmes grater than the pressure in the pulmnary trunk and the arta the valves are pushed pen and bld begins t flw ut f the ventricles. At the end f all ejectin the vlume f bld still left behind in the ventricles is called. As the ventricular diastle begins, the pressure in the ventricles, causing the bld t flw back int the which clses the valves. HEART SOUNDS: Heart sunds are caused by. The act f listening t the heart sunds with the help f stethscpe is called. Each cardiac cycle prduces sunds, nly the first are lud enugh t be heard thrugh the stethscpe. The first heart sund is called, and is caused by. The secnd heart sund is called, and is caused by. An abnrmal heart sund is called. CARDIAC OUTPUT (CO) Define cardiac utput?. Cardiac utput is equal t times. Define heart rate?. Define strke vlume?.

7 Three factrs that regulate strke vlume are, and. Define Frank-Starling law f the heart. Substance that increase cntractility are called agents, e.g.. Substance that decrease cntractility are called agents, e.g.. What is cardiac reserve?. Hw is cardiac reserve affected by exercising?. Regulatin f Heart Rate: Cardivascular center in the is the main cntrl center fr cntrlling heart rate. Receptrs sending infrmatin t medulla blngata include. Sympathetic impulses tend t heart rate, whereas parasympathetic impulses tend t heart rate. DISORDERS is a cnditin in which the heart muscle des nt receives the required amunt f bld. is the depsitin f fatty substances, especially chlesterl and triglycerides (neutral fats) in the walls f the arteries. is a defect that exists at birth. A cngenital birth defect in which a segment f the arta is t narrw, thereby reducing the flw f bld t the bdy.

8 A cnditin characterized by the failure f ductus arterisus t clse after birth. An pening in the septum that allws xygenated bld t mix with dexygenated bld. is an irregularity in heart rhythm resulting frm a defect in the cnductin system f the heart. A cnditin characterized by slwer than nrmal heart rate is called. A cnditin characterized by an abnrmally high heart rate is called. A cnditin characterized by rapid, uncrdinated heart beats. is a chrnic r acute state that results when the heart is nt capable f supplying the xygen demands f the bdy.