Heart and Great Vessels Flashcards
What are the function of the cardiovascular system?
Maintain homeostasis
Transport of metabolites and waste, hormones and signal molecules, dissolved gases, cells involved in immune and inflammatory responses
Regulation of body temperature
What are the 4 components of the cardiovascular system?
Pump (the heart)
Conducting vessels (arteries and veins)
Sites for exchange with the tissues (capillaries)
Drainage system fir excess tissue fluids (lymphatic vessels)
What are the two circuits of the circulatory system?
DO they work together?
Pulmonary circuit to the lungs
Systemic circuit to the rest of the body
They pump in parallel
What is the name of the cavity that the heart lies in?
Mediastinum, heart is the only thing in the middle mediastinum
What is the location of the heart?
Resides in the mediastinum
Mediastinum is the region of the thorax between the lungs
It contains the heart, esophagus, trachea, thymus gland, large blood vessels
What is the top and bottom of the heart called? Is the heart on the right or left side?
Base of the heart is the top (superior)
Apex of the heart is the bottom left of the heart , more anterior and points out, this is where contraction of the heart muscle occurs, enlarges and expands when full of blood and hits thoracic wall
What is the pericardium?
Heart contained in the pericardial cavity, which is formed by the pericardial sac which site beside the heart during growth and heart invades it and grows
When the heart beats it torques and the pericardial sac moves
Serous membrane: secrete fluid that reduces friction when heart beats
What are the three tissue layers of the pericardium?
Visceral pericardium (epicardium) outside the heart
Parietal pericardium
Fibrous pericardium (outer surface of parietal pericardium, protects it)
What are the characteristics of the pericardial layers?
Fibrous pericardium: fibers anchor diaphragm to heart and pericardial sac
Parietal pericardium: outside space
Visceral pericardium (epicardium): imitate contact with the heart, has serous membrane
What makes up the wall of the heart?
Myocardium (interlocking muscle fiber), parietal pericardium, visceral pericardium, endocardium (innermost layer of heart, simple squamous (delicate)
What are the features of the cardiac muscle?
Intercalated discs: separate cells via gap junctions, send signals to next cell while contracting therefore directional contraction
Gap junctions allow directional contraction therefore blood moves in one direction out of heart
What are the 6 parts of the aorta or things coming off the aorta?
Ascending aorta
Brachiocephalic trunk
Left common carotid artery
Left subclavian artery
Aortic arch
Descending aorta
What are the vessels that dump blood into the right atrium? Where is this blood coming from?
Superior and inferior vena cava (inferior from the structures below the diaphragm) that bring blood into the right ventricle from the body (deoxygenated blood) and then into right ventricle and out into the pulmonary arteries (right and left, pulmonary trunk)
What are the two sulci on the anterior surface of the heart?
Coronary sulcus: separate atria and ventricles on anterior/posterior
Anterior interventricular sulcus (separates right and left ventricle)
What vessels dump into the left ventricle?
Left and right pulmonary veins dump into the left ventricle (with oxygenated blood from the lungs), which then pumps into left ventricle which is very muscular and pumps blood to the rest of the body through the aorta
What are the two structures like sulci on the posterior side of the heart?
Coronary sinus (separates the atria and ventricles) and posterior interventricular sulcus (separates ventricles)
Does the right or left ventricle have more muscle?
LT is more muscular (more trabeculae) because it pumps to entire body, RT only pumps to the lungs
What is the function of the aorta and its 3 parts?
Arch, ascending, descending
From RT to LT side of the heart, and anterior to posterior, need to look at oblique angle to see everything
Pumps blood from left ventricle to the body
What is the first branch off the aortic arch and what does it bifurcate into?
Brachiocephalic trunk
Branches into RT subclavian artery (feeds upper extremities) and the RT common carotid artery
What is the second branch off the aortic arch?
LT common carotid artery and bifurcates into the internal/ external carotid
What is the third branch off the aortic arch?
LT subclavian artery which feeds left upper extremities
What is the flow of blood through the heart (LUNG PATH)?
Superior and inferior vena cava bring blood back from the body into the RT atrium, contracts and blood goes through tricuspid valve into the RT ventricle, then through the pulmonary valve into the pulmonary arteries (RT/LT) to the lungs
What is the flow of blood through the heart coming back from lungs?
RT/LT pulmonary veins bring back oxygenates blood from the lungs into LT atrium, contracts and goes through the mitral valve (bicuspid) into the LT ventricle , then contracts and goes through the aortic valve into the aorta
What is the cardiac cycle? What are the relaxation and contraction phases?
All the events associated with one heartbeat
Two atria contract (in unison) while ventricles relax
Two ventricles contract (in unison) while atria relax
Diastole: relaxation phase (ventricles relax, atria contract)
Systole: contraction phase (ventricles contract, atria relax)
These refer to the ventricles usually because they are stronger, but both atria and ventricles have diastole and systole associated with them
What are the heart valves (where do they occur between, what do they do)?
Valves occur between: atria/ ventricles, ventricles/ outflow vessels (pulmonary artery, aorta)
Valves ensure one-way flow of blood: open to allow blood flow through and close to prevent backflow
What are the four different valves in the heart?
Tricuspid valve: between RT atria and RT ventricle
Mitral valve (bicuspid): between LT atria and LT ventricle
Pulmonary valve (semilunar): between RT ventricle and pulmonary artery
Aortic semilunar valve: between LT ventricle to aorta
What is the structure and function of tricuspid valve?
Between is RT atria and RT ventricle
3 leaflets, capillary muscles in ventricles attach to leaflets with chord-like tendons (chordae tendineae)
3 cusps: anterior, posterior, and septal each sending chordae tendineae to 2 separate cusps to improve strengths
What is the bicuspid valve (mitral) function and structure?
2 leaflets, anterior and posterior
Between the LT atria and LT ventricle
What is the structure of the semilunar valves?
3 cups (not leaflets), semilunar valves, blood sent from V. middle cup moves towards wall of vessel therefore blood can move out
What is the structure of the aortic valve?
3 cusps (RT, LT, post), RT/LT have openings therefore when blood fills the opening allows blood the spill into coronary arteries (passive) and can feed the heart tissue
What do the valves do during ventricular diastole (relaxation)?
Atria are contracting, the tricuspid and mitral valve to open and the pulmonary/aortic valve are closed
Chordae tendinae are relaxed (when atria are contracting), atria are pushing blood down which is passive (do not need muscle)
Papillary muscle is relaxed
What do they valves do during ventricular systole (contraction)?
Ventricles are contracting, tricuspid and mitral valve are closed, and the aortic/pulmonary valves are open to allow blood to be pumped to the body or to the lungs
CUSPS open and fill with blood when this happens therefore no retrograde flow
Chordae tendinae are tense to prevent backflow, leaflets come together therefore do not open backwards
Papillary muscles are tense and pull valves shut
What makes the heart sounds?
“Lub dub” : valve leaflets slamming together
Lub: valve leaflets (tri/bi) closing
Dub: aortic and pulmonary valves closing
Sound is carried by direction/ movement of blood–> hear them away from actual valve in direction blood goes
What is the location of each valve?
Aortic valve: RT 2nd intercostal space
Pulmonary valve: LT 2nd intercostal space
Mitral valve: LT 5th intercostal space
Tricuspid valve: LT side by the 5th rib
What do the RT and LT coronary arteries do and where are they? (ANTERIOR)
RT: located between the RT atria and RT ventricle, lies in coronary sulcus (marginal artery branches off the goes along bottom of RT ventricle)), atrial arteries branch off of this
LT: between LT atria and ventricle, bifurcates into Circumflex artery (coronary sulcus around heart), and anterior interventricular artery (descends into the sulcus)
What branches off the LT coronary artery? (ANTERIOR)
Circumflex, anterior interventricular artery
Great cardiac vein: parallels AIVA to coronary sulcus and parallel to circumflex artery, gets larger as it goes, becomes coronary sinus and gives this blood to RT atrium
What branches off the RT coronary artery? (ANTERIOR)
Atrial arteries, small cardiac vein, anterior cardiac veins, marginal artery
What branches off the RT coronary artery? (POSTERIOR)
Marginal artery, posterior interventricular artery
What vein runs parallel to the RT coronary artery? (POSTERIOR)
SMall cardiac vein, great cardiac vein, coronary sinus (takes all deO2 blood back to the RT atrium to go to lungs)
Posterior cardiac vein
What is the conduction system of the heart (electrical activity)?
- Sinoatrial node: high in RT atrium, starts electrical activity, group of cells that move Na+ across walls, therefore charge disbalance across membrane (contract)
- Atrioventricular node: atrial muscle tissue on RT and LT side and comes back to this in RT atria sends signal into ventricles, at opening of RT atria and ventricle)
- AV bundle (of His): single outflow tract until septal wall
- RT and LT bundle branches: continuous down septal wall to apex
- Purkinje fibers: spreads depolarization back up and therefore all muscle tissue contracts up to base
What is the electrical conduction pathway?
- Atrial systole begins (SA NODE)
- Atrial systole ends and atrial diastole begins
- Ventricular systole first phase
- Ventricular systole second phase
- Ventricular diastole early
- Ventricular diastole late
What does the P, Q, R, S, T mean in the wave?
P: movement of electricity through atrial muscle (SA node)
Flat spot: electricity has returned to AV node which dekays b/c electricity flows faster than muscle can contract
Q/R: AV node sends signals to bundle branch along septal wall to apex
R-S: once apex goes up to base via purkinje fibers
Flat line: ventricle working/contracting
T-wave: shift ions back and electrical charge moves back (repolarization)
