Cardiopulm A&P Flashcards
what is the mediastinum?
space where the heart is located within the thoracic cavity
what is the heart’s position?
apex located at 5th intercostal space under the sternum
What is the innermost cardiac layer?
endocardium
what is the “meat of the heart?”
myocardium, this muscle does all the work
what is the outer layer of the heart?
visceral pericardium or epicardium - houses nerves here as well
why are there two layers to the pericardium, and what are they?
Parietal pericardium and Fibrous pericardium – contains 10-20ml of serous fluid between to reduce fruction
which layer is connected to the diaphragm?
fibrous pericardium
when does perfusion of the heart occur?
during diastole as the valve closes and blood returns to coronary arteries
What are the 5 main coronary arteries?
Left Main, Left Anterior Descending, Left Circumflex, Right Coronary Artery, Posterior Descending
what does the left main artery supply?
left ventricle / atrium
what does the left anterior descending artery supply?
front region of the left side of the heart // anterior 2/3 of septum and anterior portion of left ventricle // **provides 1/2 of aterial supply
what does the left circumflex artery supply?
back and outer side of the heart’s left pumping chambers, including the left atrium and the posterior-lateral aspect of the left ventricle
what does the right coronary artery supply?
right atrium, right ventricle, and the SA and AV nodes
what does the posterior descending artery supply?
the posterior one-third of the interventricular septum
what is the blood flow through the heart?
right atrium –> tricuspid valve –> right ventricle –> pulmonary semilunar valve –> pulmonary trunk –> pulmonary veins –> left atrium –> mitral valve –> left ventricle –> aortic semilunar valve –> aorta –> thru body –> sup/inf vena cava –> right atrium
what is the atrial kick?
blood flows passively to the ventricle, when atria contacts it squeezes last 25% of blood from atria to ventricles
does the atria or ventricles contract first?
atria by milliseconds
what does the radial pulse measure?
left ventricular output to the body
what is the pathway of electrical signals in the heart?
SA node generates signal –> signal spreads throughout atria –> signal gathers in AV node –> signal travels to Bundle of His –> signal passes through ventricles (continuations of Bundle of His) –> singal spreads to Perkinje fibers
What is the P wave on an EKG?
Depolarization of atria - contraction
What is the QRS complex on an EKG?
Perkinje depolarization of ventricles - contraction
What is the T wave on an EKG?
system resets – repolarization
what does the cardiac plexus contain?
both sympathetic and parasympathetic systems
What role does the sympathetic nervous system play in the cardiac plexus?
increases HR and contractility, increases BP, reduced AV conduction time
What role does the parasympathetic nervous system play in the cardiac plexus?
lowers sympathetic influence, vagus nerve acts to slow HR and decreases contractility
what is the stroke volume?
volume/amount of blood ejected from ventricles with each contraction
what is the cardiac output?
amount of blood ejected into aorta each minute // stroke volume x HR = CO (usually 5 L/min)
what is the Ejection Fraction?
proportion of blood pumped from left ventricle at end of diastole // EF = SV/EDV (end diastolic volume) ((whatever filled ventricle at end of diastole)) // usually 55-75%
What three factors influence stroke volume?
Preload, Afterload, and Contractility
What is Preload?
amount of tension on the muscle before it contracts
What is afterload?
load against which the muscle exerts its contraction
what is contractility?
muscular performance
what is Frank Starling’s Law?
indicates that the increased filling pressure of the right heart results in increased cardiac output
what is blood flow determined by?
pressure gradient & vasular resistance (vasodilation / constriction)
What is laminar blood flow?
streamlined flow
What is turbulent blood flow?
disorderly flow created by obstruction or bifurcation
how do you measure arterial pressure?
CO x Total Peripheral Resistance
What does a high arterial pressure indicate?
increased workload on the heart
what is venous return?
return of blood to right atrium via superior and inferior vena cava
Where is venous pressure the highest?
distally, lowest at junction of vena cava w/ atrium
how does blood flow back to the heart from the feet?
muscles contract / helps push the blood up and valves stop it from going back down
what are normal levels of sodium?
134-145 mmdl/L
what are normal levels of potassium?
3.5 - 5.0 mmdl/L
what is the major muscle of inspiration?
diaphragm
what are the accessory INspiratory muscles?
SCM, scalenes, upper traps, pec major/minor, serratus anterior, rhomboids, lats
what does the diaphragm look like at rest?
jellyfish, visceral organs help maintain its position
how far down does the diaphragm descend at rest and during exercise?
descends down to an inch at rest, with exercise diaphragm drops 4”
when a patient is bent over and stabilizing their arms on knees or a surface, what muscle is aiding in breathing out?
pec major, serratus
when coaches instruct athletes to raise their arms above their head after exercising, what type of breathing are they encouraging: diaphragmatic or accessory?
diaphragmatic // not a good option and wouldn’t use for cardiopulm patients
when the diaphragm flattens/contracts, which direction does it go?
anterior/posterior + head/toe, all directions, circumferential expansion of thoracic cage
what layer surrounds the lungs?
pleural layer - parietal and visceral and also contains fluid to allow sliding during expansion
how far down does the pleural layer extend past the lung tissue and why?
2 ribs lower than the lungs to allow protected room for expansion
at rest, where do the lungs sit? how far down do they go when you inhale?
at rib 5-6, expand to about rib 8
what is the hilus of the lungs?
point where nerves, vessels, and primary bronchi enter parenchyma of lungs
what is the root of the lungs?
primary bronchus, pulmonary artery/veins, bronchial arteries and veins, pulmonary nerve plexus, lymph vessels
how many lobes does the R/L lobe have?
R - 3, L - 2. L is smaller because of the heart
what is the purpose of the upper respiratory tract?
filtration and warms/adds moisture to the air
what is the purpose of the lower respiratory tract?
some pathways are for just for air to travel through, some are for gas exchange
what are the 3 lobar branches of the right lung?
upper, middle, lower
what are the 2 lobar branches of the left lung?
upper/lingula, lower
what are the 3 segments of the right upper lobe?
apical, anterior, posterior
what are the 2 segments of the right middle lobe?
medial, lateral
what are the 5 segments of the right lower lobe?
superior, medial, anterior, lateral, and posterior
what are the 4 segments of the left upper lobe?
Anterior, apicoposterior, inferior, and superior lingular
what are the 4 segments of the left lower lobe?
Lateral, anteromedial, superior, and posterior
what is involved in the removal of inhaled particulare matter?
mucociliary escalator
what is the functional unit of the lungs?
respiratory bronchioles, alveolar ducts, alveoli // sit for exchange of O2 and CO2
how thick are the alveoli?
1 cell layer thick , surrounded by capillary beds to allow blood/gas exchange
what do the alveoli produce?
surfactant - decreases affinity to collapse // decreases surface tension
what is the parenchyma?
“meat of the lung,” does the work and this is what you hear during lung sounds. alveoli, alveolar ducts, small pulm. blood vessels
what is the interstitium?
space of thin layer of connective tissue between alveoli and alveolar capillaries to keep them next to each other
what input does the parasympathetic system do to the lungs?
vagus nerve –> bronchial constriction, dilation of pulmonary artery smooth muscle, increased mucous secretion
what input does the sympathetic system do to the lungs?
bronchial relaxation, constriction of arterial smooth muscle, decreased mucous secretion
what is ventilation?
movement of gases
what is respiration?
diffusion of gases
what are the mechanics of ventilation?
change in pressure gradient to allow for airflow –> we create a negative pressure in relation to atmospheric air pressure when we breathe in so air can come in
what is happening during quiet breathing / how is air moved? (expiration)
expiration results from passive recoil of the lungs
what muscles are actively working during expiration?
abdominal muscles, rectus abdominis, ext. obliques, int. obliques, transversus abdominis
what is normal atmospheric pressure?
760 mmHg
what is tidal volume?
the amount of air that moves in/out in one breath cycle
what is compliance?
ability to expand
what is elasticity?
tendency of structure to recoil // passive (think: quiet breathing during expiration)
what is surface tension?
resistance to expansion – surfactant decreases this
