heart Flashcards
what is the location and function of the pericardium
it is the very outside layer of the heart that protects and anchors the heart to surrounding structures
what is the location and function of the epicardium
it is the layer under the pericardium that wraps around the heart and is surrounded by pericardial fluid which acts as a lubrication
what is the location and function of the myocardium
it is the layer under the epicardium and has contractile muscle cells that are responsible for beating and pulsing
what is the difference between the systemic and pulmonary circuits
systemic transports blood to all organs using systemic vessels and pulmonary transports blood to the lungs using pulmonary vessels
what is the function of coronary circulation and how does it relate to angina and myocardial infraction
the circuit provides a blood supply to the heart when it is relaxed
-angina relates because it is due to chest pain from the coronary arteries narrowing and not giving the heart enough blood when it needs it (ex: exercise)
-myocardial infraction relates because it is due to the coronary artery is narrow or closing bc of plaque build up
what are the differences between cardiac and skeletal muscle
cardiac: striated, short, has nucleus, has gap junctions, functions as one, and relies only on aerobic respiration (oxygen used for energy) LONG refractory periods
skeletal: striated, long, no nucleus, no gap junctions, functions individually, relies on both aerobic and anaerobic respiration
what are the functions for gap junctions and intercalated discs in cardiac muscle
gap junctions allow the cells to function as a unit and intercalated discs allow synchronized contraction
how does stroke volume and heart rate contribute to cardiac output
SV and HR can increase or decrease cardiac output this is dependent on how much oxygen you need from your blood in different activities
-at rest CO is 5.25 L
-max CO is 25 L in regular people and 35 L in athletes
how does preload, contractility, and afterload affect stroke volume
SV can increase by increasing contractility/preload or decreasing after load and vice versa
-preload is the degree of the heart stretching before contraction
-contractility is the forcefullness of the contraction
-afterload is the amount of pressure required for ventricular ejection of blood
how does ANS, hormones, and other factors affect heart rate
-ANS affects the degree of stretching before contraction
-hormones affect the forcefulness of the contraction
-personal factors such as sex, age, fitness level, and body temp can affect heart rate
how does the vagus nerve, sa node, and av node affect heart rate
the vagus nerve can slow and increase heart rate
the sa node regulates heart rate
the av node can act as a back up regulator for heart rate and can decrease heart rate if its working alone
what becomes congested in the left and right sides of the heart in congestive heart failure
left side: blood backs up in lungs (pulmonary congestion)
right side: blood fills up in organs and tissues (peripheral congestion)
does level of fitness in a person increase heart rate
no, the more fit you are the lower your heart rate is
how does body temp affect heart rate
lower body temp means low heart rate and high body temp means high heart rate
is high or low cardiac out put more prone to congestive heart failure
low cardiac output
