Heart Flashcards
Pericardium layers?
- Visceral Serous Pericardium
- Parietal Serous Pericardium
- Fibrous Pericardium
Fibrous Pericardium?
- entirely parietal
- outside layer of heart, no contact with heart
- fused with parietal serous
- fused with central tendon
- fused with great vessels
- attaches to sternum by sternal pericardial ligaments
- bare area (not covered): inferior vena cava
Serous Pericardium?
- Parietal
- fused with Fibrous layer - Visceral
- adherent to cardiac muscle
- epicardium
Clinical application of pericardium?
- Pericarditis
- closed sac where fluid can accumulate between two serous layers (pericardial effusion)
- substernal chest pain
- can occur due to viral infections, kidney failure, CHF, cancer
- Fibrous can dilate with fluid
Innervation to pericardium?
- Phrenic nerve passes over and supplies Fibrous and Parietal serous pericardium
- visceral serous has no sensory, pain fibers
Blood supply to pericardium?
Internal thoracic:
- pericardiophrenic
- coronary
Acute vs chronic pericarditis?
Acute:
- outer fibrous layer does not dilate
- fluid accumulates and pushes on heart and will have decreased blood volume pushed out
Chronic:
-fibrous layer will distend gradually and become larger
Location of heart?
middle mediastinum
Layers of heart?
- Endocardium
- simple squamous endothelium inside of heart - Myocardium
- middle cardiac muscle tissue layer - Epicardium
- visceral serous pericardium
- outer most layer of heart
Apex of heart?
- part of left ventricle
- inferior portion of heart
Sternocostal surface of heart?
- posterior to sternum
- near right ventricle
Diaphragmatic surface of heart?
-inferior two ventricles
Base of heart?
both atria
coronary groove of heart?
- external indication of separation between atria and ventricles
- coronary arteries run here
Interventricular groove of heart?
divides left and right ventricles
Blood flow through heart?
- deoxygenated blood from systemic circulation enters right atrium through superior and inferior vena cava
- deoxygenated blood from heart enters from Coronary sinus - blood goes through Atrioventricular tricuspid valve to right ventricle
- blood pumped through pulmonary valve (semilunar) through pulmonary trunk and artery to lungs
- blood is oxygenated and sent back through pulmonary veins
- oxygenated blood enters left atrium
- blood goes through mitral or bicuspid valve to left ventricle
- pumped through Aortic valve (semilunar)
- through Aorta and to systemic circulation
- first branches off Aorta are left and right coronary arteries
why is the right ventricle muscle wall smaller than left?
- lungs are low pressure system
- located next to heart
- left has to pump to whole body
Left atrium hypertrophy clinical significance?
- Mitral valve disease
- could be caused by Rheumatic fever
- left atrium pushes on esophagus
- give patient radio liquid to see heart chambers
- see if left atrium dents esophagus
Where does right atrium receive blood?
- superior and inferior vena cava from systemic circulation
- coronary sinus from heart circulation
Pectinate muscles?
- rough muscles in anterior part of right atrium
- smooth in posterior right atrium
- separated by Crista terminalis
Right auricle function?
- collects deoxygenated blood
- extra space for blood to flow if atrium fills
Fossa ovalis? clinical significance?
- thin fibrous band closes over at birth
- Foramen ovale in embryo connects right and left atrium
clinical:
- periosteal embolism
- foramen ovale remains open after birth
- if blood clot travels to lower extremities, it can now travel to brain or kidneys
Location of SA and AV node?
- right atrium
- SA: pacemaker
- AV: receives electrical impulse
what drains into the left atrium?
-pulmonary veins carrying oxygenated blood
left atrium
- few pectinate muscles
- very smooth
- most posterior chamber
Conus Arteriosus?
- smooth
- contains spiral valve in development
- external structure around where pulmonary trunk arises
Papillary muscles?
- muscles inside the ventricles
- attached to Chordae Tendinae
- attach to AV valves to hold them shut
- prevent inversion during systole (prolapse) or backward flow
Sepromarginal trabecula (moderator band)?
- muscle band elevated off internal surface of right ventricle
- from inter ventricular septum to papillary muscle
- carries branch of cardiac conduction system
- allows coordinated contraction of anterior papillary muscle
- happens before rest of ventricle to keep valve shut
Septum is functionally part of what ventricle?
- left
- wall 2x thicker than right
Semilunar valves?
- pulmonary
- aortic
- function in outflow
Atrioventricular valves (AV)?
- tricuspid
- mitral (bicuspid)
- function in inflow
Cardiac skeleton? Function?
- consists of fibrous and fibrocartilaginous tissue that surrounds the AV and semilunar openings
- gives attachments to valves, muscle, membranous inter ventricular septum
- all muscles except papillary muscles insert on cardiac skeleton
- electrical insulator
What is the most important function of cardiac skeleton?
- electrical insulator
- muscles of atrial conductance are separated from that of the ventricles
- atria contract before the ventricles
- without cardiac skeleton, they would squeeze at the same time
SA node (sinoatrial)?
- found in epicardium of right atrium
- supplied by right coronary artery
- rich in autonomic fibers
- sets the beat for the heart (60-100 bpm)
- rate of depolarization depends on sympathetic nerve impulses
- parasympathetic (vagus) inhibits SA to slow it down
What could cause disruption in SA node conduction?
- block of right coronary artery
- flow interrupted to SA
- heart rate slows down
AV node (atrioventricular)?
- in right atrium close to interventricular septum
- slows down impulse so blood can fill the ventricles
- supplied by right coronary artery
- sends impulse to AV bundle
AV bundle (common bundle)?
- only connection between atria and ventricles
- enters septum for ventricles to contract
Path of conduction?
- SA node
- AV node
- AV bundle (His)
- Bundle branches left and right in inter ventricular septum
- Purkinje fibers in walls of ventricles
3 kinds of surface projections?
- ridges
- bridges (moderator band)
- papillary muscles
Right Coronary artery supply?
Supply:
- SA and AV node
- right atrium
- posterior IVS
- travels through coronary groove between atria and ventricles
- if blocked, beat slows down
Left coronary artery supply?
Supply:
- left atrium and ventricle
- IVS
- AV bundles
-travels in aortic sinus and gives off anterior interventricular artery (LAD) and circumflex branch
First branch of Aorta?
left and right coronary arteries
Great cardiac vein?
drains areas supplied by left coronary arteries
-travels through coronary sulcus and dilates to form coronary sinus
Coronary sinus?
- runs from left to right on the posterior side of the heart in the coronary sulcus
- drains into right atrium
Venae cordis minimae?
- veins empty into all chambers of the heart
- small veins- chambers receive venous blood
How do the semilunar valves work?
- when ventricles contract blood pushes leaflets against walls of aorta
- blood flows out of aorta
- Aorta is elastic and expands to push some blood backward toward the valve
- valve is forced shut preventing blood from regurgitation
- no chordae tendinae
Systole?
- ventricles squeeze
- blood exits through Aortic valve and pulmonary valve
- Aorta expands
- AV valves held shut by papillary muscles
Diastole?
- ventricles relax
- Aorta squeezes shooting blood back
- semilunar valves shut
- coronary arteries are filled (aortic sinus)
- AV valves open
Cardiac cycle?
- Atria contract to push blood into ventricles
- AV valves open
- Impulse from AV node
- ventricles contract
- AV valves shut, semilunar valves open
- blood exits
Clinical significance of ruptured papillary muscles?
- chordae tendinae in place
- mitral regurgitation
- blood flows back into atria
- atria then pump more blood than it should
- mitral valve prolapse
T/F
Cardiac muscle squeezes and twists when it pumps.
True
Tumor on apex of lung? problems?
- erode through membrane and put pressure on brachial plexus
- pain radiates somewhere else
- could also affect sympathetic ganglion (horner’s)
- autonomic fibers up to face affected (toss-drooping eyes, myosis-constricted pupil, anhidrosis- no sweat)
Path of azygous vein?
- hemiazygous on left crosses over to right to drain into azygous vein
- anastomoses with intercostals
- enters superior vena cava
Superior vena cava syndrome?
- lymph nodes grow due to Non-Hodgkins Lymphoma or lung cancer and compress SVC
- cannot drain arms and face
- pressure in brain increases
- treat with chemo and steroids
Why need a pacemaker?
- conduction system of heart is diseased
- electrode threaded down into ventricle to contract
Why not place pacemaker in atrium at SA node?
-you would still need to rely on the AV node and the rest of the conduction system
Ventricular heart failure?
- water gets into alveoli
- diffusion cannot take place
- pulmonary congestion
What can mitral valve disease cause?
- dilation of right ventricle
- results in right side heart failure
Aneurysm?
- weakness of interior wall of artery
- caused by atherosclerosis
what can syphilis do to the aorta? symptoms?
- large dilated aorta
- hoarse voice because left recurrent laryngeal is stretched
Problems of acute MI?
- abnormal EKG
- scar tissue forms
- ventricle cannot contract effectively
- clot can break loose from wall of ventricle and travel to brain
Aortic valve stenosis?
- narrowing of opening where blood leaves left ventricle
- rheumatic fever
- makes it harder to pump blood out
- left ventricular hypertrophy
Which layer causes cardiac tamponade?
Fibrous pericardium
Right vs left heart failure?
Right: venous pooling in systemic circulation, edema in legs
Left: pulmonary congestion, dyspnea
