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WorksheetsIB biology option D4 the heart
Total questions: 15
Worksheet time: 8mins
What type of muscle is found in the heart?
skeletal
smooth
voluntary
cardiac
In the section of cardiac muscle shown, structures A and B respectively are
mitochondrion, intercalated disc
mitochondrion, myosin/actin filaments
nucleus, intercalated disc
nucleus, myosin/actin filaments
What is a similarity between cardiac and skeletal muscle?
both are striated
both fatigue
both multinucleate
both under voluntary control
Which is correct about the SA node?
located in left atrium
a collection of cardiac cells initiating action potentials
referred to as the artificial pacemaker
it is the equivalent of the AV node in birds
In general, what is systole?
contraction
the same as diastole
relaxation
the system of blood vessels in the heart
Where is the AV node?
in the left atrium wall
junction between the atria and ventricles
in the right atrium wall
in the ventricles
What is the correct sequence of electrical signals spreading throughout the heart?
SA node→bundle of His→AV node→Purkinje fibres
SA node→AV node→Purkinje fibres→bundle of His
SA node→AV node→bundle of His→Purkinje fibres
AV node→SA node→bundle of His→Purkinje fibres
What causes the "lub" sound?
AV valves closing
AV valves opening
semilunar valves closing
semilunar valves opening
An artificial pacemaker would be beneficial for which one of the following conditions?
obesity
inability of brain to send rhythmic signals to the hear
malfunctioning SA node
narrowing of coronary arteries
During diastole which one of the following is not occurring?
semilunar valves are closed
both atria and ventricles are relaxed
"dub" sound is made
only ventricles are relaxed, atria are contracting
Why is there a delay in the conduction of a signal from the AV node?
So that right atrium contracts before the left atrium
So that right ventricle contracts before the left ventricle
So the both atria have contracted and emptied all the blood into the ventricles
So that the AV valves are closed before the ventricles contract
What chamber of the heart has the thickest walls?
right atrium
left atrium
right ventricle
left ventricle
The human heart is referred to as myogenic because
nerve impulses stimulate the heart muscle tissue to contract
an individual has an SA node that is not functioning
a signal originates within the heart muscle tissue to contract
the size of the heart is genetically determined based on the myocyte gene
Read the following statements.
1.cells are self-excitatory
2.cells have a long linear shape for better contraction
3.cells contain many lysosomes
4.cell joined end to end by intercalated discs
5.cells have a large central nucleus
6.cells contain many mitochondria
7.arteries supply the cells with oxygenated blood
8.a branched structure allows for coordinated contraction throughout the heart
Which set of statements will get you the most marks if you were asked to describe the unique properties of cardiac muscle cells on an IB Biology exam?
1, 4, 6
1, 2, 4, 7
2, 3, 5, 6, 8
2, 4, 5, 8
The two causes of normal heart sounds are
AV valves closing and semilunar valves opening
AV valves opening and semilunar valves closing
AV valves closing and semilunar valves closing
AV valves opening and semilunar valves opening
