Lecture 4 - Cardiac Electrical Activity

Question 1

Cells with fast electrical response?

Answer 1

atria, ventricles, fast parts of specialised conduction system

Question 2

Cardiac non-neurogenicity?

Answer 2

electrical impulse originating at heart, spreading through electrical coupling to neighboring cells

Question 3

Locations of Automaticity (pacemaker activity)?

Answer 3

SA nodes, some cells of AV node, His-Purkinje network

Question 4

Mechanisms for alternating intrinsic pacemaker discharge?

Answer 4

alter rate of depolarisation (slope), alter threshold value, alter maximum diastolic pressure

Question 5

Job of AV node?

Answer 5

slow down electrical conduction, allowing A’s to fill V’s before they contract

Question 6

Normal activation sequence?

Answer 6

Sinoatrial node, internodal tracts, atria, AV node, bundle of His, bundle branches, purkinje fibres, ventricular myocardium