Quiz 1 Flashcards
What two factors principally determine the cardiac output?
Heart Rate
Stroke Volume
What are LVEDV and LVESV?
LVEDV- Left ventricular end diastolic volume
LVESV- Left ventricular end systolic volume
What is the formula for stroke volume?
SV = LVEDV - LVESV
What is the formula for Ejection fraction (EF)?
EF = SV / LVEDV
What is the range for a normal ejection fraction?
55-70%
What is the general definition of preload?
What is the definition of preload as it pertains to the heart? What factor primarily determines preload?
What is the definition of afterload as it pertains to the heart? What is it often approximated by?
What is contractility in the heart? What nervous system regulates contractility? What effect does it have on ESV (LVSEV)?
What is venous return?
What are the three main factors that affect venous return?
1) Right atrial pressure
- decreased RAP increases VR
2) Mean systemic filling pressure
- Increased MSFP increases venous return
3) Total peripheral resistance
-Decreased TPR increases venous return
What is right atrial pressure? What is the normal range? What can cause it to decrease/increase?
What is MSFP? What causes it to increase/decrease?
What proportion of resistance to venous return is determined by arteriolar/small artery resistance? What proportion by venous resistance?
What is the resting membrane potential for a contractile cardiac mucle cell?
-80 mV
What occurs during phase 4 of a ventricular myocyte action potential?
What occurs during phase 0 of a ventricular myocyte action potential?
What occurs during phase 1 of a ventricular myocyte action potential?
What occurs during phase 2 of a ventricular myocyte action potential?
What occurs during phase 3 of a ventricular myocyte action potential?
What occuring during phase 4 of a ventricular myocyte action potential?
What event during a cardiac myocyte action potential induces muscle contraction?
In a healthy heart, the only viable pathway for electrical signaling between the atria and the ventricles is what structure?
The bundle of His
Myocytes specializing in conduction have notably smaller levels of what two contractile proteins?
Myosin and Actin
What occurs during phase 4 of a cardiac pacemaker cell action potential?
What occurs during phase 0 of a cardiac pacemaker cell action potential?
What occurs during phase 3 of a cardiac pacemaker cell action potential?
What is the sarcolemma as found in cardiac myocytes?
What are T-tubules as found in cardiac myocytes (also present in other muscle types)?
What are L-type Ca2+ channels as found in cardiac myocytes?
What is the Ryanodine receptor? What is its function?
What elements does a couplon consist of?
What is the role of the sarcoplasmic reticulum?
What is the first step of excitation contraction coupling?
What is the second step of excitation contraction coupling?
What is the third step of excitation contraction coupling?
What is the fourth step of excitation contraction coupling?
What is the role of SERCA in step 5 of excitation contraction coupling?
What is the role of NaCaX in step 5 of excitation contraction coupling?
What is the role of the Ca2+ pump in step 5 of excitation contraction coupling?
Descrie which leads should be observed in the “quick and dirty” axis determination method:
What are three potential causes of a left axis deviation?
What are three potential causes of a right axis deviation?
STEMI localized to the LCX or diagonal branch of LAD arteries will involve which EKG leads?
STEMI localized to the RCA or LCX arteries will involve which EKG leads?
STEMI localized to the LAD will involve which EKG leads?
What is true about the relationship between ST elevations and ST depressions?
What is a hallmark on an EKG denoting a prior MI?
What is Ohm’s law?
I = V/R
V= IR
How can Ohm’s law (picture attached) be related to blood flow?
What is the formula for MAP derived from Ohm’s law?
What are two formulas for MAP using SBP and DBP?
What is the formula for calculating resistance to blood flow in a vessel?
What is the signifance of Poiseuille’s law in terms of blood flow?
Why is Poiseulle’s law referred to as a fourth power law?
The relationship between radius and flow (or resistance in medical applications) is massive due to r being raised to the 4th power
What is the most important factor determing blood flow in the CV system?
Vessel radius
How is resistance totaled when the resistors are arranged in a series?
How is resistance totaled when the resistors are arranged in parallel?
What is the formula for compliance? How is compliance different from elastance? Of arteries and veins, which are more compliant? Which are more elastance?
What are three notable causes of blood viscosity? What is a notable cause of low viscosity?
How is pulse pressure calculated? What is its relation to stroke volume and to arterial compliance?
What is the law of Laplace in context of ventricular myocardium?
*where h is the thickness of the ventricular myocardium
At what structure does an AP orginating from the SA node slow before entering the ventricles?
The AV node
Which two catecholamines are the most responsible for binding adrenergic receptors?
Epinephrine and Norepinephrine
What G protein is preferred by a-1 adrenergic receptors?
What G protein is preferred by a-2 adrenergic receptors?
What G protein is preferred by b-1 adrenergic receptors?
What G protein is preferred by b-2 adrenergic receptors?
Which alpha adrenergic receptor acts pre-synaptically, inhibiting the release of NE?
alpha-2 receptors
Which alpha receptor acts post-synaptically, stimulating phospholipase C to cause vasoconstriction and pupil dilation?
alpha-1 receptors
What effect does alpha-1 receptor activation have on associated muscle?
What three tissues are associated with alpha-1 receptors? What are the associated responses at each tissue?
Where are alpha-2 receptors found? What response is associated with receptor activation?
What two tissues are beta-1 receptors associated with?
The heart and kidneys
Which parts of the heart and kidney are beta-1 receptors associated with? What responses are associated with receptor activation?
In which five tissues are beta-2 receptors principally found? What responses are associated with activation of these receptors?
Which catecholamine has a preference for alpha receptors over beta receptors?
NE
Does EPI have a preference for alpha or beta receptors?
Neither; EPI stimulates alpha and beta receptors equally
If a tissue has only beta receptors, will EPI or NE be the effective stimulant?
EPI
T/F: NE has an 100 fold greater affinity for the beta-2 receptor than EPI
False; EPI has an 100 fold greater affinity for the B2 receptor relative to NE
What signaling molecule binds to cholinergic receptors?
Acetylcholine (ACh)
What are the two types of cholinergic receptors?
Nicotinic
Muscarinic
What are the two synapse types where muscarinic receptors are found?
What tissues are M1 receptors found in? What response is associated with receptor activation?
Which four parts of the heart are M2 receptors associated with? What are the responses to receptor activation?
The fourth is to decrease contractility in the ventricles
What six tissues/organ systems are M3 receptors associated with?
What occurs in response to M3 receptor activation in secretory glands and in sweat glands?
What three divisions of the respiratory system are associated with M3 receptors? What response is associated with receptor activation?
What 5 elements of the GI tract are associated with M3 receptors? What responses occur as a result of receptor activation?
What two elements of the urinary bladder are associated with M3 receptors? What responses are associated with receptor activation?
What three elements of the eye are associated with M3 receptors? What responses are associated with receptor activation?