In order from most superficial to deep, what is the order of the following heart layers: myocardium, epicardium, endocardium
Epicardium, myocardium, endocardium
Inflammation of the pericardium:
Pericarditis
The pulmonary arteries deliver ______ blood to the lungs.
deoxygenated (this is unique! In the body, arteries normally pump oxygenated blood to the periphery)
The natural pacemaker of the heart that initiates the electrical impulse is the ____.
sinoatrial (SA) node
What's the tough, outer membranous structure surrounding the heart called? Bonus: what's it (partially) made of?
Fibrous pericardium (collagen)
A stenotic valve is hard and inflexible, so blood flows through it with difficulty, forcing the heart to work harder to push blood forward. What causes this?
Calcium deposits
After blood goes through the inferior/superior vena cava, right atrium, tricuspid valve, and right ventricle, where does it go next?
After passing through the right ventricle, blood goes next into the pulmonary valve.
Gas exchange, where the body allows oxygen (O2) IN, and diffuses OUT carbon dioxide (CO2), happens in the _____.
alveoli
Unlike skeletal muscle, which requires a nerve signal from the brain to contract, cardiac muscle can generate its own electrical impulses to keep the heart beating independently. What is this unique property called?
A
This is why a heart can continue to beat even if it is completely removed from the body during surgery, as long as it has oxygen! Also, in movies, doctors always use a defibrillator to "shock" a flatline (asystole) back to life. In reality, you cannot shock a flatline. A defibrillator does not jump-start a stopped heart like a car battery. Instead, it acts like a "reset button" that temporarily stuns a heart experiencing a chaotic, erratic rhythm (like ventricular fibrillation) so its natural pacemaker can take over again. If there is no electrical activity at all (a flatline), doctors use CPR and medications like epinephrine, not shocks!
Which side are the tricuspid vs bicuspid (mitral) valves on?
Tricuspid: right
Bicuspid (mitral): left
In the order of blood through the heart, what's the correct order of the following: lungs, pulmonary artery, pulmonary veins
pulmonary artery (deoxy), then the lungs, and finally the pulmonary veins (oxygenated)
Canterbury: "After depolarization _____ follows!"
_________ ____ with desmosomes hold cardiac muscle cells together and gap junctions allow ions to flow from one cell to another.
Intercalated discs
When the pericardial cavity becomes filled with excess fluid ______ may result
Cardiac tamponade:
Fibrous pericardium is strong but not very flexible, excess fluid in pericardial cavity squeezes heart; reduces capacity of ventricles to fill with blood, compromising amount of blood pumped with each beat.
Treatment may include a procedure in which excess fluid is removed via a needle inserted into the pericardial cavity (Pericardiocentesis).
Which of the 4 heart chambers is the largest and why?
Left ventricle (3x thicker walls than the right ventricle), it must pump blood through the entire body against high systemic resistance, which requires much greater force and pressure.
What's the order of artery/vessel size in the body from smallest to largest (venule, vein, arteriole, artery, capillary)
capillary, venule, arteriole, vein, and artery
What pathway does the electrical impulse in the heart follow?
SA node → AV node → Bundle of His → Bundle Branches → Purkinje fibers
What are the names of the 3 major veins in the body (hint, two are the same, just upper and lower)
Superior vena cava (deoxy), inferior vena cava (deoxy), pulmonary veins (oxygenated)
What do the semilunar values do?
What hormone does the heart release as it's endocrine function AND what's its main function?
Atrial natriuretic peptide (ANP), which lowers blood pressure (by releasing sodium, and therefore, increasing water in urine)
If the heart's primary pacemaker (the SA node) fails or stops firing, which secondary structure typically takes over to pace the heart, and approximately what heart rate does it generate?
The AV node (Atrioventricular node), firing at 40 to 60 beats per minute.