Biol 320 Exam 2 QUESTIONS AND CORRECT
ANSWERS
What causes a heart murmur? - CORRECT ANSWER-reflex back
through valves by not sealing correctly due to inflammation, calcium
crystals, scarring
What does the heart skeleton do? - CORRECT ANSWER-provides site
for muscles attachment, electrical insulation between atria and
ventricles, plate of fibrous connective tissue between atria
What are desmosomes? - CORRECT ANSWER-velcro that holds cells
together
What are gap junctions? - CORRECT ANSWER-allows ions to pass
What are intercalated disks? - CORRECT ANSWER-specialized cell to
cell contact
What is the functional syncytium? - CORRECT ANSWER-all cardiac
muscle acts as a single unit electrically
,What causes the plateau phase in a heart's action potential? -
CORRECT ANSWER-calcium
What is the rate of the SA node? - CORRECT ANSWER-70-75 bpm
What is the delay of the AV node and why? - CORRECT ANSWER-
1/10 a second allows for both atria to contract
What is the neurotransmitter for the sympathetic ANS? - CORRECT
ANSWER-norepinephrine
What is the neurotransmitter for the parasympathetic ANS? -
CORRECT ANSWER-acetylcholine
What is the Bainbridge reflex? (atrial reflex) - CORRECT ANSWER-
Heart rate increases when blood volume increases
How does thyroxin affect heart rate? - CORRECT ANSWER-longer,
slower HR
What can cause an arrhythmia? - CORRECT ANSWER-nicotine,
caffeine
, What is fibrillation? - CORRECT ANSWER-rapid irregular
uncoordinated contraction (no blood movement)
What is arrhythmia? - CORRECT ANSWER-irregular, uncoordinated
heartbeat
What is ectopic focus? - CORRECT ANSWER-abnormal pacemaker
forms, non-nodal variable effects
What causes bradycardia? - CORRECT ANSWER-drugs, overactive
PS-ANS, athlete, high stroke volume, warning sign of brain edema
What is the formula for stroke volume? - CORRECT ANSWER-EDV-
ESV
What is the formula for cardiac output? - CORRECT ANSWER-heart
rate x stroke volume
What are the 3 factors affecting stroke volume? - CORRECT
ANSWER-preload, contractility, afterload
What is preload? - CORRECT ANSWER-degree of stretch of the
cardiac muscle
ANSWERS
What causes a heart murmur? - CORRECT ANSWER-reflex back
through valves by not sealing correctly due to inflammation, calcium
crystals, scarring
What does the heart skeleton do? - CORRECT ANSWER-provides site
for muscles attachment, electrical insulation between atria and
ventricles, plate of fibrous connective tissue between atria
What are desmosomes? - CORRECT ANSWER-velcro that holds cells
together
What are gap junctions? - CORRECT ANSWER-allows ions to pass
What are intercalated disks? - CORRECT ANSWER-specialized cell to
cell contact
What is the functional syncytium? - CORRECT ANSWER-all cardiac
muscle acts as a single unit electrically
,What causes the plateau phase in a heart's action potential? -
CORRECT ANSWER-calcium
What is the rate of the SA node? - CORRECT ANSWER-70-75 bpm
What is the delay of the AV node and why? - CORRECT ANSWER-
1/10 a second allows for both atria to contract
What is the neurotransmitter for the sympathetic ANS? - CORRECT
ANSWER-norepinephrine
What is the neurotransmitter for the parasympathetic ANS? -
CORRECT ANSWER-acetylcholine
What is the Bainbridge reflex? (atrial reflex) - CORRECT ANSWER-
Heart rate increases when blood volume increases
How does thyroxin affect heart rate? - CORRECT ANSWER-longer,
slower HR
What can cause an arrhythmia? - CORRECT ANSWER-nicotine,
caffeine
, What is fibrillation? - CORRECT ANSWER-rapid irregular
uncoordinated contraction (no blood movement)
What is arrhythmia? - CORRECT ANSWER-irregular, uncoordinated
heartbeat
What is ectopic focus? - CORRECT ANSWER-abnormal pacemaker
forms, non-nodal variable effects
What causes bradycardia? - CORRECT ANSWER-drugs, overactive
PS-ANS, athlete, high stroke volume, warning sign of brain edema
What is the formula for stroke volume? - CORRECT ANSWER-EDV-
ESV
What is the formula for cardiac output? - CORRECT ANSWER-heart
rate x stroke volume
What are the 3 factors affecting stroke volume? - CORRECT
ANSWER-preload, contractility, afterload
What is preload? - CORRECT ANSWER-degree of stretch of the
cardiac muscle
