lecture_notes_19_(ta)

lecture_notes_19_(ta) - Lecture 19: Cardiovascular System -...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 19: Cardiovascular System - Cardiac Physiology Reading: chapter 9, section: electrical activity of the heart, pgs 308-315 (pgs 312-320, if using 5 th edition) Nodes - specialized cardiac muscle cells capable of pacemaker activity are grouped together to form nodes (Figure 9-8,9-10) . Sinoatrial (SA) Node - bundle of specialized cardiac pacemaker cells located in the wall of the right atrium near the opening of the superior vena cava. This node exhibits an autorhythmicity of 70-80 action potentials per minute and leads the activity of the other pacemaker structures in the heart (Figure 9-8,9-10) . ( THIS IS THE PRIMARY NODE , ENTRAINING THE OTHER NODES . IT IS ALSO SUBJECT TO MODULATION BY THE NERVOUS SYSTEM ) Atrioventricular (AV) Node - bundle of specialized, cardiac pacemaker cells located at the base of the right atrium. This node exhibits an autorhythmicity of 50 action potentials per minute. Under normal conditions, this node follows the faster SA node at 70 A.P./min. ( THIS CAN BE THOUGHT OF AS A PRIMARY BACKUP NODE , INCASE THE SA NODE MISSES A PULSE ) Bundle of His ( HISS ’ ) - a tract of specialized, cardiac pacemaker cells that originates at the AV node and divides and projects into the left
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

lecture_notes_19_(ta) - Lecture 19: Cardiovascular System -...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online