Lectures 3-6 Cardiac Physiology

Which of the following statements are TRUE regarding cardiac myocytes?

The Na+/K+ ATPase helps maintain the resting membrane potential of roughly -85mV in cardiac myocytes. For each unit of ATP expended [blank_start]3[blank_end] [blank_start]Na+[blank_end] Ions are pumped out and [blank_start]2[blank_end] [blank_start]K+[blank_end] ions pumped in

During Diastole which of the following movement of ions are occurring in cardiac myocytes.

Which of the following statements are correct?

Which of the following statements is FALSE regarding the refractory period of a cardiac myocyte Action Potential?

Fast response action potentials occur in the SA Node

Order the following from those most permeable to sodium and calcium, to those least permeable to sodium and calcium. 1. [blank_start]SA Node[blank_end] 2. [blank_start]AV Node[blank_end] 3. [blank_start]Bundle of His[blank_end] 4. [blank_start]Purkinje Fibres[blank_end] Options: Bundle of His SA Node Purkinje Fibres AV Node

Which of the following are true of pacemaker cells in the AV Node

Parasympathetic/Vagal Innervation of the SA Node will result in

Which of the following are TRUE regarding conduction velocity

Which of the following are functions of the cardiac skeleton

Pacemaker Tissue is located in the

Adipose tissue can be found in the

Order the following events correctly [blank_start]HBLIADECJFMKG[blank_end] Your answer should be of the form ABCDE Options: A Activation of Ryanodine receptor channels in the Sarcoplasmic reticulum B Opening of Voltage Gated Sodium Channels C Tropomyosin shifts out of the actin cleft D Influx of Calcium from the Sarcoplasmic Reticulum E Calcium Binds to Troponin F Crossbridge Cycle Occurs and Tension of Myocyte Increases G Membrane Potential restored by the Na+/K+ ATPase and the Na+/Ca2+ Exchanger H Depolarisation of Myocyte Above Threshold, Action Potential Initiated I Influx of Calcium from the ECF J Actin may now bind to Myosin K Voltage Gated Calcium Channels Close L Opening of Voltage Gated Calcium Channels M Ca2+ ATPase activated, Calcium pumped back into the Sarcoplasmic Reticulum

Which of the following statements regarding an Isotonic Contraction are true?

Which of the following are likely to increase Afterload for the Left Ventricle

Preload is synonymous with

On Trace 1 Person A has leads attached to the upper arms and thighs. On Trace 2 Person A has leads attached to the forearms and lower legs. If all other variables are constant, following Einthoven's Hypothesis, the ECG for Trace 1 and 2 would be identical.

The Magnitude of the Dipole on a ECG is determined by

A Dog has the positive lead on his left arm, and the negative lead on his right arm, and the ground lead attached to the right leg. This arrangement is described as:

Which lead is considered most useful

Atrial depolarisation occurs during the

The T Wave is highly variable in domestic animals, it could be positive or negative deflection, or sometimes not even noticeable.

A Patient presents with a prolonged P-R Interval on their ECG. All other intervals are within normal range. This could suggest

Exercise, Anxiety and Fever would most likely cause

A Patient presents with an absence of P waves on their ECG. The QRS and T Waves are normal. The Patient most likely has a

A Patient has a 3rd Degree AV Block. Which of the following features would you expect to be present on their ECG.

A Patient's ECG shows QRS Complexes that are not always preceded by a clear P Wave. Which of the following are possible

Atrial Contraction contributes what percentage to ventricular filling?

With an Increase in Heart Rate, Atrial Contribution to Ventricular filling also increases

During the 1st Phase of Ventricular Systole which of the following statements are true?

Which of the statements regarding the Dichrotic Notch are incorrect

Which of the following are incorrect

The 4th Heart Sound is caused by the vibration of ventricular wall due to deceleration of blood leaving the ventricles