BME 235 Exam 2 Guide With
Complete Solution
The Heart
atrium - ANSWER weaker primer pump for the ventricle, moving blood into
the ventricle
ventricle - ANSWER main pumping force propelling blood out of the heart
right heart - ANSWER side of heart that pumps blood through lungs
superior vena cava - ANSWER brings in deoxygenated blood from head and
upper extremities
inferior vena cava - ANSWER brings in deoxygenated blood from trunk and
lower extremities
pulmonary artery - ANSWER sends deoxygenated blood to the lungs
left heart - ANSWER pumps blood through systemic circulation that provides
blood flow to rest of body
pulmonary veins - ANSWER bring in oxygenated blood from the lungs
aorta - ANSWER largest artery in the body, connects to left heart
cardiac rhythmicity - ANSWER transmitting action potentials throughout the
muscle to cause the heart's rhythmic beat
atrial/ventricular muscle - ANSWER contracts like skeletal muscle but
duration of contraction is longer
,excitatory/conductive muscle - ANSWER provide an excitatory system that
controls the rhythmic beating of the heart
syncytium - ANSWER arrangement of cardiac muscle cells in an
interconnected way so that when one cell becomes excited, the action
potential spreads rapidly to all of them (2 types: atrial and ventricular)
AV bundle - ANSWER bundle of fibers that conduct signal from atria to
ventricles
atria - ANSWER Which contracts first: atria or ventricles?
1. spike (depolarization): caused by fast Na+ channels
2. initial repolarization: fast Na+ channels close, K+ ions leave cell through
channels
3. Plateau: L-type channels open, decrease in K+ ion permeability
4. Rapid repolarization: K+ ions bring membrane potential back to resting
5. return to resting membrane potential: -90 mV - ANSWER What are the 5
steps of action potential for a ventricular muscle cell?
excitation-contraction coupling - ANSWER action potentials follow the
transverse T tubules and act on the longitudinal sarcoplasmic reticulum,
which in turn cause contraction
cardiac cycle - ANSWER events that occur from the beginning of one
heartbeat to the beginning of the next
1. sinus node
2. diastole
,3. systole - ANSWER What are the three steps of the cardiac cycle?
sinus node - ANSWER first step of cardiac cycle; spontaneous generation of
an action potential
diastole - ANSWER period of relaxation during which the heart fills with
blood
systole - ANSWER step in the cardiac cycle; period of contraction; blood is
pushed out
1. P wave
2. QRS waves
3. T waves - ANSWER Steps of an electrocardiogram reading?
P wave - ANSWER caused by the spread of depolarization of atria and atrial
contraction
QRS waves - ANSWER caused by the spread of depolarization of the
ventricles, and initiates ventricle constriction
T wave - ANSWER repolarization of the ventricles
1. A-wave: caused by atrial contraction
2. C-wave: when ventricles begin to contract
3. V-wave: toward end of ventricular contraction when blood begins to flow
into the atria from the veins, while A-V valves are closed - ANSWER Order of
atrial pressure waves?
1. Isovolumic or isometric contraction period
2. Ejection period
, 3. Isovolumic relaxation - ANSWER What is the order of the A-V valve
process during a cardiac cycle?
Isovolumic/Isometric contraction period - ANSWER ventricular pressure rises
abruptly until pressure builds to the point just before where aortic and
pulmonary semilunar valves open
Ejection period - ANSWER when the aortic and pulmonary semilunar valves
open
Isovolumic relaxation - ANSWER end of systole ventricular relaxation occurs
suddenly and pressure in the ventricle drops, and pressure in pulmonary
artery and aorta snap the aortic and pulmonary valves closed
heart valves - ANSWER prevent backflow of blood during systole
Atrioventricular valves - ANSWER open and close passively, they open when
a forward pressure gradient is present and close with a backward pressure
gradient
Tricuspid and mitral valves - ANSWER prevent backflow from the ventricles
to the atria during systole
semilunar valves - ANSWER prevent backflow from the aorta and pulmonary
arteries into the ventricles during diastole
papillary muscles - ANSWER hold the vanes of A-V valves in shape
aortic and pulmonary artery semilunar valves - ANSWER high pressure of the
arteries at the end of systole cause the semilunar valves to close
Frank-Starling mechanism of the heart - ANSWER amount of blood pumped
by the heart is determined almost entirely by the rate of blood flow into the
Complete Solution
The Heart
atrium - ANSWER weaker primer pump for the ventricle, moving blood into
the ventricle
ventricle - ANSWER main pumping force propelling blood out of the heart
right heart - ANSWER side of heart that pumps blood through lungs
superior vena cava - ANSWER brings in deoxygenated blood from head and
upper extremities
inferior vena cava - ANSWER brings in deoxygenated blood from trunk and
lower extremities
pulmonary artery - ANSWER sends deoxygenated blood to the lungs
left heart - ANSWER pumps blood through systemic circulation that provides
blood flow to rest of body
pulmonary veins - ANSWER bring in oxygenated blood from the lungs
aorta - ANSWER largest artery in the body, connects to left heart
cardiac rhythmicity - ANSWER transmitting action potentials throughout the
muscle to cause the heart's rhythmic beat
atrial/ventricular muscle - ANSWER contracts like skeletal muscle but
duration of contraction is longer
,excitatory/conductive muscle - ANSWER provide an excitatory system that
controls the rhythmic beating of the heart
syncytium - ANSWER arrangement of cardiac muscle cells in an
interconnected way so that when one cell becomes excited, the action
potential spreads rapidly to all of them (2 types: atrial and ventricular)
AV bundle - ANSWER bundle of fibers that conduct signal from atria to
ventricles
atria - ANSWER Which contracts first: atria or ventricles?
1. spike (depolarization): caused by fast Na+ channels
2. initial repolarization: fast Na+ channels close, K+ ions leave cell through
channels
3. Plateau: L-type channels open, decrease in K+ ion permeability
4. Rapid repolarization: K+ ions bring membrane potential back to resting
5. return to resting membrane potential: -90 mV - ANSWER What are the 5
steps of action potential for a ventricular muscle cell?
excitation-contraction coupling - ANSWER action potentials follow the
transverse T tubules and act on the longitudinal sarcoplasmic reticulum,
which in turn cause contraction
cardiac cycle - ANSWER events that occur from the beginning of one
heartbeat to the beginning of the next
1. sinus node
2. diastole
,3. systole - ANSWER What are the three steps of the cardiac cycle?
sinus node - ANSWER first step of cardiac cycle; spontaneous generation of
an action potential
diastole - ANSWER period of relaxation during which the heart fills with
blood
systole - ANSWER step in the cardiac cycle; period of contraction; blood is
pushed out
1. P wave
2. QRS waves
3. T waves - ANSWER Steps of an electrocardiogram reading?
P wave - ANSWER caused by the spread of depolarization of atria and atrial
contraction
QRS waves - ANSWER caused by the spread of depolarization of the
ventricles, and initiates ventricle constriction
T wave - ANSWER repolarization of the ventricles
1. A-wave: caused by atrial contraction
2. C-wave: when ventricles begin to contract
3. V-wave: toward end of ventricular contraction when blood begins to flow
into the atria from the veins, while A-V valves are closed - ANSWER Order of
atrial pressure waves?
1. Isovolumic or isometric contraction period
2. Ejection period
, 3. Isovolumic relaxation - ANSWER What is the order of the A-V valve
process during a cardiac cycle?
Isovolumic/Isometric contraction period - ANSWER ventricular pressure rises
abruptly until pressure builds to the point just before where aortic and
pulmonary semilunar valves open
Ejection period - ANSWER when the aortic and pulmonary semilunar valves
open
Isovolumic relaxation - ANSWER end of systole ventricular relaxation occurs
suddenly and pressure in the ventricle drops, and pressure in pulmonary
artery and aorta snap the aortic and pulmonary valves closed
heart valves - ANSWER prevent backflow of blood during systole
Atrioventricular valves - ANSWER open and close passively, they open when
a forward pressure gradient is present and close with a backward pressure
gradient
Tricuspid and mitral valves - ANSWER prevent backflow from the ventricles
to the atria during systole
semilunar valves - ANSWER prevent backflow from the aorta and pulmonary
arteries into the ventricles during diastole
papillary muscles - ANSWER hold the vanes of A-V valves in shape
aortic and pulmonary artery semilunar valves - ANSWER high pressure of the
arteries at the end of systole cause the semilunar valves to close
Frank-Starling mechanism of the heart - ANSWER amount of blood pumped
by the heart is determined almost entirely by the rate of blood flow into the
