Heart Flashcards
Position of heart
. Middle mediastinum post. And slightly left of sternum, ant. To esophagus
. Apex: med. to midclavicular line
. Base: faces post., directly ant. To esophagus at T6-9 vertebral levels
Pericardium
. 3 layered membranous sac surrounding heart
. Pericardiacophrenic a. And pericardiacophrenic vv.
Fibrous pericardium
. Thought, outer layer
. Attaches to central tendon of diaphragm
Serous pericardium
. Thin membranous lining prevents friction during heart movement
. Parietal layer: lines internal wall of fibrous pericardium
. Visceral layer: directly adheres to surface of heart, contains coronary vessels
Transverse and oblique pericardial sinuses
. Where visceral and parietal layers becomes continuous where great vessels enter/exit the heart
Pericardial cavity
. Btw visceral and parietal serous pericardia
. Contains small amt serous fluid
. Heart is NOT in cavity
Pericardiacophrenic a.
. Branch of internal thoracic a.
Pericardium innervation
. Pericardial branches of phrenic nn. (C3-5) contain sensory fibers
. Vagus nerve
. Branches from sympathetic trunk (vasomotor)
Where is pericardial pain referred to?
Ipsilateral shoulder region (C3-5 dermatome)
Acute pericardial effusion
. Rapid accumulation fo excess fluid in pericardial cavity
. Heart becomes compressed and circulation fails (tamponade)
Pericarditis
. Inflammation of pericardium
. Causes chest pain
. Rough surfaces of smooth serous pericardium produce rub sound
. Can lead to cardiac tamponade
Epicardium
. Outermost layer, visceral layer of serous pericardium plus subepicardial fat
Myocardium
Middle layer, consists of cardiac muscle
Endocardium
. Inner layer, endothelial lining and subendothelial CT of heart chambers
Fibrous skeleton of heart
. 4 fibrous rings surrounding orifices of cardiac valves
. Provides attachment and suppler for myocardium and leaflets/cusps of valves
. Electrical insulator allowing independent contractions of the atria and ventricles
Apex of heart
. Formed by tip of L ventricle
Surfaces of heart
. Anterior (sternocostal): mainly R ventricle
. Diaphragmatic: mainly L ventricle w/ some R ventricle
. Left pulmonary: faces L lung, primarily L ventricle
. Right pulmonary: faces R lung, primarily R atrium
. Base: formed by L atrium, small contribution from R atrium
Borders of the heart in radiographic examination
. Right border: mostly R atrium
. Inf. Border: mostly R ventricle, some L ventricle
. Left border: mostly L ventricle
. Sup. Border: R and L atria and auricle, sup. Vena cava, ascending aorta, and pulmonary trunk
External sulci (grooves) of the heart
. Coronary (AV) sulcus: surface groove encircling heart, delineates the separation of atria from ventricles
. Ant. And post. Interventricular sulci: surface grooves delineating interventricular septum
Pulmonary trunk
. Pulmonary trunk: exits R ventricle carrying deoxygenated blood to lungs and divides into R and L pulmonary aa.
Pulmonary veins
. Carry oxygenated blood from lungs to L atrium
. Sup. And inf right pulmonary veins
. Sup. And inf. Left pulmonary veins
Ascending aorta
Exits L ventricle carrying oxygenated blood from heart to the rest of the body
Interatrial septum
Separates 2 atria
Interventricular septum
. Separates ventricles
. Thin membranous part, continuous w/ skeleton of heart
. Thick muscular part
right atrium
. Forms right border of heart
. R auricle overlaps the ascending aorta
. Receives blood from the SVC, IVC, and coronary sinus
Coronary sinus
Opens btw IVS and tricuspid valve orifices
Right atrium. Interior walls
. Rough ant. Wall contains bundles of cardiac muscle fibers (pectinate mm.)
. Pectinate mm. Merge together forming crista terminalis that extends btw openings of SVC and IVC
. Sulcus terminalis: groove on surface that marks location for crista terminalis
. Post. Atrial wall smooth where orifices of SVC, IVC, and coronet sinus located
Interatrial septum
. Has fossa oval is (oval-shaped depression) that is remnant of foraman ovale
Right atrioventricular (tricuspid) valve
. Deoxygenated blood flows from R atrium into R ventricle through this
Right ventricle
. Forms largest part of sternocostal and small part of diaphragmatic aspects of heart
. Defines almost entire inf. Border of heart
. Middle myocardial layer thinner than L ventricle
. Interior lined by trabeculae carneae (muscle bundles)
. Papillary muscles (ant., post., septal) project from wall and connect to R AV valve via chordae tendineae
Septomarginal trabecula (moderator band)
. Muscular band that connects interventricular septum to base of ant. Papillary muscle
Tricuspid valve
. 3 leaflets attached to atrioventricular orifice
. During ventricular contraction the papillary muscles contact to prevent version of valve leaflets and blood reflux into R atrium
Pulmonary (pulmonic) valve
Brings deoxygenated blood exits R ventricle to pulmonary trunk
Left atrium
. Forms most of base of heart
. Left auricle forms sup. Part of left border of heart and overlaps pulmonary trunk
. Interior walls smooth, rough surface only found in auricle from pectinate muscles there
. Pulmonary vv. Open into L atrium carrying oxygenated blood from lungs
. Fossa ovalis visible on interatrial septum
. Blood flows to L ventricle via mitral valve
Left ventricle
. Forms left margin, apex, and most of diaphragmatic surface of the heart
. Middle myocardial layer thicker than R ventricle as L ventricle must pump blood into systemic circulation
. Interior lined by trabeculae carneae
. 2 (ant. And post.) papillary muscles connect mitral valve leaflets via chordae tendineae
. Aortic orifice marks beginning of aorta from L ventricle (aortic valve here)
. La dn R coronary aa. Branch from aorta just sup. To aortic valve
Left atrial appendages closure
. Surgery to reduce risk of stroke in patients w/ atrial fibrillation
. Erratic heat eat causes blood collection and clot formation in left auricle so it is closed to reduce risk
AV valves
. Separate atria and ventricles
. Valves consist of cusps that are attached to fibrous cardiac skeleton
. Chordae tendineae in each ventricle attach papillary muscles to free edges of leaflets
. Closure of valves prevents regurgitation
Semilunar valves
. Prevents blackflow of expelled blood into ventricles
. 3 pocket-like cusps
. Pulmonary and aortic valve
Cardiac cycle
. Ventricular diastole, atria fill, AV valves open, blood flows into ventricles, semilunar valves closed
. SA node initiates contraction of aria completing passage of blood to ventricle
. Inc. bp causes AV valves close
. AV node stimulation starts ventricular contraction (systole)
. Semilunar valves open and blood flows from R ventricle to pulmonary trunk and from L ventricle into aorta
. Relaxation of ventricles causes backflow of blood in pulmonary trunk and aorta closing semilunar valves
When is coronary aa. Blood flow greatest?
Diastole because they are compressed during systole
Auscultation sites of cardiac valves
. Aortic valve: right 2nd intercostal space at sternal margin
. Pulmonary valve: left 2nd intercostal space at sternal margin
. Tricuspid valve: near left sternal border
. Bicuspid: left 5th intercostal space at midclavicular line, cardiac apex
HEart valve disease
. Narrowing of orifice (stenosis) from failure of valve to open properly
. Valvular incompetence caused by failure of the valve to close completely
. Defective valves surgically replaced
Coronary aa. And cardiac vv.
. Supply tissue of heart
. On outer surface of heart w/in epicardium and fatty CT
Right coronary a.
. Gives of SA nodal branch to SA node
. Courses to right w/in coronary sulcus
. Right marginal a. Branches off and courses along inf. Border of heart
. R coronary continues post. Along post. Portion of coronary sulcus
. Gives off AV nodal branch to AV node and post. Interventricular a. That goes in post. Interventricular sulcus
Regions supplied by R coronary a.
. R atrium . SA node (in 60% cases) . AV node (80% cases) . Most R ventricle . Diaphragmatic surface of L ventricle . Post. Third of interventricular septum
L coronary a.
. Divides into ant. Interventricular a. That goes in ant. Interventricular sulcus and circumflex a. That goes to the left in coronary sulcus
Circumflex a.
Gives off L marginal branch and sometimes a diagonal branch
. Courses post. In coronary sulcus where it terminates
Acute MI
. Sudden bloackage of blood flow in coronary circulation that causes ischemia and necrosis of cardiac muscle
. Most common area of occlusion is ant. Interventricular a. Followed by R coronary a. Then circumflex a.
Coronary atherosclerosis
. Most common cause of ischemic heart disease
. Causes angina pectoris
. Coronary angioplasty and/or bypass surgery performed to inc. blood supply to myocardial tissue
Leading cause of death worldwide
Ischemic heart disease
Regions supplied by L coronary a.
. L atrium . Most of L ventricle . Part of R ventricle . Most of interventricular septum including AV bundles . SA node (40% cases)
Right dominant pattern of arterial branches
. R coronary a. Has prominent transverse branch that extends across base of heart in coronary groove at expense of circumflex a.
Co-dominant pattern of coronary branches
. Both R and L coronary aa. Give off branches that course in post. Interventricular sulcus
Left dominant pattern of coronary branches
. L coronary a. Has large circumflex branch that gives off post. Interventricular a.
. R coronary a. Will not have transverse branch
Cardiac vv.
. Empty into coronary sinus on post. Part of coronary sulcus
. Coronary sulcus drains into R. Atrium adjacent to IVC
Great cardiac v.
. Drains areas supplied by L coronary a.
. Main tributary of coronary sinus
. Beings in ant. Interventricular sulcus and courses sup. To coronary sulcus
Middle cardiac v.
. Accompanies post. Interventricular a.
. Drains areas supplied by R coronary a.
Small cardiac v.
. Parallels R marginal a. And joins coronary sinus as it enters R atrium
. Drains areas supplied by R coronary a.
Ant. Cardiac vv.
Drains into R atrium
Venae cordis minimae
Smallest veins, open directly into each heart chamber
Lymphatic drainage of heart
. Cardiac lymph vessels follow coronary aa. And drain into tracheobronchial lymph nodes
T/F autonomic innervates regulates HR and force fo contractions but DOES NOT generate HR
T
Sup. And deep cardiac plexuses
. Carry Autonomic fibers and visceral afferent fibers
Preganglionic cardiac sympathetic fibers
. T1-5/6 levels of sympathetic trunks
. Synapse in cervical and sup. Thoracic sympathetic trunk ganglia
Postganglionic cardiac sympathetic fibers
. Known as cardiopulmonary splanchnic nn.
. Pass to heart to terminal in SA and AV nodes and along coronary aa.
. Innervation inc. HR and inc. contraction strength
Preganglionic cardiac parasympathetic fibers
. From cervical and upper thoracic branches of vagus nn.
. Synapse w/ intrinsic ganglia located near SA and AV nodes an along coronary aa.
. Dec. HE and contraction force
Afferent visceral pain fibers in heart
. Accompany sympathetic fibers retrogradely and enter spinal cord at T1-4
. Pain from heart perceived as pain originated from superficial body regions w/ T1-4 sensory input
. Referred pain in upper chest, upper back, and ant. Surfaces of upper limb
sinoatrial node
. Initiates and coordinate heartbeat (pacemaker)
. Located just deep to epicardium at junction of SVC and R atrium
Atrioventricular node
. Receives electrical signal from SA node
. Carries signals to AV bundle for distribution to ventricles
AV bundle of His
. Conducts electrical signals btw atrial and ventricular myocardial
. Passes from AV node through membranous part of interventricular septum
. Divides into R and L bundle branches at junction of membranous and muscular parts of interventricular septum
. R bundle branches to moderator band and other branches that extend to IV septum and wall of R ventricle
. L bundle branches extend to IV septum, ant. And post. Papillary muscles, and wall of L ventricle
Purkinje fibers
. Arise as bundles continue on each side of septum deep to endocardium
. Extend to walls of ventricles
Septomarginal trabecula (moderator band)
. Allow branches of right AV bundle to reach ant. Papillary muscle
Atrial fibrillation
. Common arrhythmia
. Cardiac electrical signals in SA node are overwhelmed by signals starting in other parts of the heart, usually roots of pulmonary veins
. Leads to disorganized, irregular impulses propagating through heart
. Causes poor blood flow in body
