SCN1111 Heart Exam Latest Update
Define sinoatrial node - Answer A cluster of cells in the right atrial wall that generates
impulses at approx 75bpm. It sets the sinus rhythm and is called the pacemaker
Describe the regulation of the cardiac stroke volume and heart rate - Answer Stroke
volume is the volume of blood pumped by one ventricle in one beat.
*Stroke volume* is affected by end systolic volume (ESV), end diastolic volume (EDV).
These in turn are *regulated by preload* and *afterload* and *contractility*.
*Heart rate* is regulated extrinsically by the *sympathetic and parasympathetic nervous
system* in response to exercise, stress or decrease in blood pressure.; AND regulated
by Hormones - Ep, Thyroid AND Ions
Name the parts of an ECG - Answer P = Atrial depolarisation
QRS= Ventricular depolarisation and atrial repolarisation
T= Ventricular repolarisation
P-Q interval - Beginning of atrial excitation to the beginning of ventricular excitation.
Q-T interval - Ventricular depolarisation through to repolarisation.
S-T interval - the entire ventricular myocardium is depolarised
Describe the cardiac cycle - Answer Describes the mechanical events associated with
blood flow through the heart. It involves:
1. atrial systole and diastole
2. ventricular systole and diastole
this is a very basic explanation! more to add
Describe how the coordinated contraction of the heart is achieved - Answer An
electrical signal is generated at the SA node, travels to the AV node where pauses
before travelling down the AV bundle (connects atria to ventricles), bundle branches
and the purkinje fibres.
Describe the structure and function of cardiac muscle cells - Answer Cardiac muscle
cells have 1 or 2 nuclei, striated, short, fat and branched fibres. Plasma membranes
interlock by intercalated discs (containing desmosomes and gap junctions). Fibres have
a large number of mitochondria.
The structure of the heart enables forceful contraction (but not sustained (tetanic)),
achieved through aerobic respiration as a single unit.
Why do heart sounds occur? Why do abnormal sounds occur? - Answer Represent
Define sinoatrial node - Answer A cluster of cells in the right atrial wall that generates
impulses at approx 75bpm. It sets the sinus rhythm and is called the pacemaker
Describe the regulation of the cardiac stroke volume and heart rate - Answer Stroke
volume is the volume of blood pumped by one ventricle in one beat.
*Stroke volume* is affected by end systolic volume (ESV), end diastolic volume (EDV).
These in turn are *regulated by preload* and *afterload* and *contractility*.
*Heart rate* is regulated extrinsically by the *sympathetic and parasympathetic nervous
system* in response to exercise, stress or decrease in blood pressure.; AND regulated
by Hormones - Ep, Thyroid AND Ions
Name the parts of an ECG - Answer P = Atrial depolarisation
QRS= Ventricular depolarisation and atrial repolarisation
T= Ventricular repolarisation
P-Q interval - Beginning of atrial excitation to the beginning of ventricular excitation.
Q-T interval - Ventricular depolarisation through to repolarisation.
S-T interval - the entire ventricular myocardium is depolarised
Describe the cardiac cycle - Answer Describes the mechanical events associated with
blood flow through the heart. It involves:
1. atrial systole and diastole
2. ventricular systole and diastole
this is a very basic explanation! more to add
Describe how the coordinated contraction of the heart is achieved - Answer An
electrical signal is generated at the SA node, travels to the AV node where pauses
before travelling down the AV bundle (connects atria to ventricles), bundle branches
and the purkinje fibres.
Describe the structure and function of cardiac muscle cells - Answer Cardiac muscle
cells have 1 or 2 nuclei, striated, short, fat and branched fibres. Plasma membranes
interlock by intercalated discs (containing desmosomes and gap junctions). Fibres have
a large number of mitochondria.
The structure of the heart enables forceful contraction (but not sustained (tetanic)),
achieved through aerobic respiration as a single unit.
Why do heart sounds occur? Why do abnormal sounds occur? - Answer Represent
