Biol 320 Exam 2 QUESTIONS AND CORRECT ANSWERS 2025/2026 /ACCURATE ACTUAL EXAM
WITH FREQUENTLY TESTED QUESTIONS AND STUDY GUIDE
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
What is contractility? - correct answer intrinsic ability of tissue to contract
What is afterload? - correct answer weight of leftover blood on semilunar valve
What can blood loss and rapid heartbeat lead to? - correct answer lower stroke volume
What effect does CO2 have on blood pH? - correct answer lowers blood pH
By how many weeks is the heart fully formed during pregnancy? - correct answer 5 weeks (35
days)
What is the purpose of the foramen oval in fetus hearts? - correct answer bypass pulmonary
circuit
What is the purpose of the ductus arteriosus in fetus hearts? - correct answer backup
pulmonary circuit
What is a ventricular septal defect? - correct answer more blood is shunted from left to right
because of lack of interventricular septum
What is a coarctation of the aorta? - correct answer part of aorta is narrowed, increasing
workload of left ventricle
What is the tetralogy of Fallot? - correct answer pulmonary trunk too narrow and pulmonary
valve stenosed, hypertrophied right ventricle, ventricular septal defect, aorta opens from both
ventricles
What does it mean that all cardiac cells are amitotic? - correct answer dead cells are replaced
with scar tissue
What is the result of sclerosis and thickening of valve flaps? - correct answer heart murmur
What is the result of cardiac reserve decline? - correct answer heart less able to respond to
sudden and prolonged stresses that increase CO2
What is fibrosis of cardiac muscle? - correct answer cardiac cells die, stroke volume is reduced
What is atherosclerosis? - correct answer hardening of the arteries
What can cause atherosclerosis? - correct answer inactivity, smoking, stress, high cholesterol
diet
What are the risks of atherosclerosis? - correct answer heart attack, stroke
What is the purpose of elastic arteries? - correct answer allows large pulse, smooth flow
WITH FREQUENTLY TESTED QUESTIONS AND STUDY GUIDE
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
What is contractility? - correct answer intrinsic ability of tissue to contract
What is afterload? - correct answer weight of leftover blood on semilunar valve
What can blood loss and rapid heartbeat lead to? - correct answer lower stroke volume
What effect does CO2 have on blood pH? - correct answer lowers blood pH
By how many weeks is the heart fully formed during pregnancy? - correct answer 5 weeks (35
days)
What is the purpose of the foramen oval in fetus hearts? - correct answer bypass pulmonary
circuit
What is the purpose of the ductus arteriosus in fetus hearts? - correct answer backup
pulmonary circuit
What is a ventricular septal defect? - correct answer more blood is shunted from left to right
because of lack of interventricular septum
What is a coarctation of the aorta? - correct answer part of aorta is narrowed, increasing
workload of left ventricle
What is the tetralogy of Fallot? - correct answer pulmonary trunk too narrow and pulmonary
valve stenosed, hypertrophied right ventricle, ventricular septal defect, aorta opens from both
ventricles
What does it mean that all cardiac cells are amitotic? - correct answer dead cells are replaced
with scar tissue
What is the result of sclerosis and thickening of valve flaps? - correct answer heart murmur
What is the result of cardiac reserve decline? - correct answer heart less able to respond to
sudden and prolonged stresses that increase CO2
What is fibrosis of cardiac muscle? - correct answer cardiac cells die, stroke volume is reduced
What is atherosclerosis? - correct answer hardening of the arteries
What can cause atherosclerosis? - correct answer inactivity, smoking, stress, high cholesterol
diet
What are the risks of atherosclerosis? - correct answer heart attack, stroke
What is the purpose of elastic arteries? - correct answer allows large pulse, smooth flow
