Pericardium and Heart Anatomy PDF

Pericardium and Heart - Pericardium is a fibrous membrane that covers the heart and its vessels - Pericardium has various layers - Outermost is fibrous: inelastic, attached anteriorly and inferiorly to sternum and diaphragm. - Blends with the adventitia (outer mos...

Pericardium and Heart - Pericardium is a fibrous membrane that covers the heart and its vessels - Pericardium has various layers - Outermost is fibrous: inelastic, attached anteriorly and inferiorly to sternum and diaphragm. - Blends with the adventitia (outer most blood vessel layer) of the great vessels as they enter of leave sac - Holds heart in the middle mediastinal position and limits heart expansion - Inner layer of pericardium: SEROUS pericardium - Inner serous layer is glistening and lubricated to allow heart free movement required for its motions during contraction - Inner divides into: - Parietal layer: lines inside of cavity - Visceral: covers over heart - Pericardial cavity: between these 2 layers with pericardial fluid - Arterial supply and venous drainage and nerve supply of pericardium - Arteries, blood flow away from heart - Pericardium artery is primarily from the pericardiophrenic artery, this is branch of internal thoracic arteries - Vein: pericardiophrenic veins: tributaries of the brachiocephalic vein - Nerve supply: primarily from phrenic nerves (C3-C5), referred pain sensations conveyed by these nerves are felt on top of the shoulder of same side  - PERICARDIOCENTESIS: procedure to remove excess fluid from pericardium - Cardiac tamponade: excess fluid or bleeding inside pericardium and it compromises pumping - To remove fluid: insert need near left 5^th^ or 6^th^ intercostal space via bare area of pericardium - Could also do from xiphocondral angle but could puncture the internal thoracic arteries - HEART - Double, self adjusting suction and pressure pump - Parts of pump work in unison to receive blood from veins and pump it to arteries - RIGHT SIDE OF HEART= right heart - Right side of heart receives poorly oxygenated blood from body through the SVC and IVC and pumps it through pulmonary trunk and arteries to lungs for oxygenation in pulmonary circulation - LEFT SIDE OF HEART= LEFT HEART - Receives well oxygenated blood from the lungs through pulmonary veins and pumps in into aorta for distribution into systemic circulation to the body  Looking at deoxygenated right side, blood comes into RA via the SVC (upper body) and IVC (lower body) and goes into right atrium, then deoxygenated blood goes through TRICUSPID VALVE into right ventricle Blood passes PULMONARY VALVE to go to lungs After oxygenated in lungs, blood comes in from lungs via pulmonary vein Blood passes to left atrium and then MITRAL valve to go to left ventricle Then oxygenated blood passes through aorta to go to rest of body to upper head and limbs or through descending aorta to lower limbs and trunk - Diastole begins with closure of aortic and pulmonary valves - Then open the atrio-ventricular valves early - Atrial contraction in last moment of diastole - Close the atrioventricular valves (mitral and tricuspid) right after systole begins - Open aortic and pulmonary valves during systole SYSTOLE: SQUEEZE- CONTRACTION -ventricular constriction, aortic and pulmonary valves open, AV valves of mitral and tricuspid closed DYSTOLE= relaxation -aortic and pulmonary valves closed, AV valves (mitral and tricuspid open) - Heart - Heart chambers wall are 3 layers from deep to superficial: - Endocardium: thin internal layer of endothelium and subendothelial connective tissue lining inside of heart chambers and covers valves - Endothelium and areolar tissue - Myocardium: thick helical layer in middle made of cardiac muscle - Cardiac muscle is myocardium and connective tissue - Epicardium: thin external layer (mesothelium) made by visceral layer of serous pericardium - Visceral pericardium - Mesothelium - Areolar tissue - Parietal pericardium: dense fibrous layer, areolar tissue and mesothelium - Heart has 4 chambers - 2 Atria: L and R - Superior chambers and receive blood from major veins - 2 ventricles (R and L) - Inferior discharging chambers that pumps blood into major arteries - Right and left sides are separated by interventricular and interatrial septum - INTERIOR OF RIGHT ATRIUM - Sinus venarum is smooth, thin walled posterior part of wright atrium - POSTERIOR= sinus venarum - Anterior wall= pectinate muscle - Rough, muscular wall anterior for right atrium - Smooth and rough parts of atrial wall are separated externally by SULCUS TERMINALIS or terminal groove - Internally, smooth and rough parts are separated by VERTICAL RIDGE CALLED CRISTA TERMINALIS - Sinus is posterior, pect is anterior - External divider is sulcus, internal is crista - Interatrial septum is a thin wall of tissue and seperates R and L atria of heart - OVAL FOSSA= L. fossa ovalis= small oval depression on right atrium, between L and R atrium - INTERIOR OF LEFT ATRIUM - Larger smooth walled part - Smaller muscular auricle containing pectinate muscles - 4 pulmonary veins = 2 superior and 2 inferior, entering its smooth posterior wall - Slightly thicker wall than R atrium - Interatrial septum slopes posteriorly and to right Right ventricle - Received blood from right atrium - Pumps blood into pulmonary trunk - Internal walls of right ventricle: - Trabeculae carneae: muscular ridges - Papillary muscles: finger like projections - Chordoe tendiane: fine strings attach to papillary muscles to leaflets of tricuspid valves LEFT VENTRICLE - Forms ape of heart - 3 times thicker than right ventricle as it exerts more pumping force - Internal walls: - Trabeculae carneae - Papillary muscles - Chordae tendineae - Pumps blood into aorta HEART VALVES - 2 pairs of one way valves prevent backflow during contraction - Atrioventricular valves: - RIGHT AV valve= tricuspid, between right atrium and right ventricle - Left AC= mitral or bicuspid, between left atrium and lef ventricle - Semilunar valves: with 3 cusps support like tripod prevent backflow from pulmonary trunk and aorta into ventricles - Right semilunar= pulmonary valve, between right ventricle and pulmonary trunk - Left semilunar= AORTIC valve, between left ventricle and aorta Fibrous skeleton of heart - Isolate fibrous skeleton is made of 4 fibrous rings= 2 rings and 2 coronets each encircling a valve, 2 trigones between valves and the membranes portions o fthe interatrial, interventricular and atrioventricular septa - Keeps orifices of the AV and semilunar valves patent - Provides attachments for the leaflets and cusps of the valves - Provides attachment for the myocardium - Forms electrical insulator by separating myenterically conducted impulses of the atria and ventricles so they contract indepdently - Heart sounds= lub dup - Sounds of valves closing - First is lub and this is AV valves closing - Second sound is dup which is semilunar valves closing - Faulty valve function is abnormal heart sound= murmur VASCULATURE OF HEART and ORIGIN - Right coronary RCA= right aortic sinus - SA nodal: RCA near its origin - Right marginal= RCA - Posterior interventricular: RCA - AV nodal: RNA near origin of posterior IV artery - Left coronary artery= RCA, origin is left aortic sinus - SA nodal: circumflex branch of LCA - Anterior interventricular: LCA - Circumflex: LCA - Left marginal: circumflex branch of LCA - Posterior interventricular: LCA Venous Drainage of Heart - Cardiac veins collect blood from capillary beds - Great cardiac vein runs in anterior interventricular sulcus - Middle cardiac vein in posterior interventricular sulcus - Small cardiac vein from inferior margin - Coronary sinus formed by merging cardiac veins and empties into right atrium - Lost posterior ventricular vein and left marginal vein open into coronary sinus Coronary artery disease= CAD - \#1 cause of death in developed countries - Atherosclerosis= fatty deposits - Ischemia= low blood supply leads to hypoxia (low oxygen) - Angina pectoris= chest pain from ehart - Myocardial infarction= MI= heart atttacl, tissue death is necrosis because clocked coronary artery by a blodd clot - Conducting system - A series of specialized cardia muscle cells generate and conduct electic impulse= depolarization for myocardial contraction - Aafter eavh depolarization comes repolarization that causes relaxation of heart muscles - Heart is indepdent from brain for heartbeats - Sinoatrial SA node is pacemaker and it generates impulse - Impulse pauses at AV node - AV bundle connects atria to ventricles - Bundle branches conduct impeulces throughout interventriucalr septum - Subendocardial conducting network stimualr contractile cells of centricles - Punkinje fibers are subendocardial ECG= electrocardio graph - waves and intervals and segments - P wave= depolarization of aorta - QRS complex: ventricular depolarization - T wave= ventricular repolarization Cardia nerves and plexus - Heart rate altered by brain controls - Parasympathetic fibers: decrease heart rate - Symapthetic= increase heart rate and strength of contraction - Cntroleld by cardiac centers of medulla  Microscopic anatomy of cardiac muscles - Cardiac muscles cells are striated - Branching - Have one or 2 nuclei - Cells join at intercalated disc - Involuntary function A diagram of a heart and an x-ray Description automatically generated Dextrocardia refers to a condition where the heart is positioned on the right side of the chest, while an ASD (atrial septal defect) is a hole in the wall separating the upper chambers of the heart (atria), and a VSD (ventricular septal defect) is a hole in the wall separating the lower chambers of the heart (ventricles); essentially, dextrocardia describes the heart\'s position, while ASD and VSD are structural defects within the heart itself.