HUBS1404 Lecture Notes - Lecture 3: Interventricular Septum, Depolarization, Purkinje Fibers

29 views2 pages

Document Summary

Pa(cid:272)e(cid:373)aker (cid:272)ells dri(cid:448)e the a(cid:272)ti(cid:448)it(cid:455) of the heart, (cid:271)ut (cid:449)e do(cid:374)"t (cid:449)a(cid:374)t the (cid:272)o(cid:374)tra(cid:272)tio(cid:374) to (cid:271)e fro(cid:373) the top down, so there needs to be a way for the excitation to travel down to the bottom quite quickly. So: the pacemaker depolarises and contracts, the impulse stops at the av node, the impulse travels down the interventricular septum without depolarising and contracting, the purkinje fibres then depolarise to contract the ventricles. These are all modified muscle cells not nerves, they have different membrane properties to alter how they perceive action potentials. The delay at the av node is there so the atria have time to contract. The e(cid:454)(cid:272)itatio(cid:374) of the atria does(cid:374)"t gi(cid:448)e a lot of pumping into the ventricles, this is a reasonably passive movement. The extracellular currents travelling around the heart and through the skin is what can be measured.

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers

Related Documents

Related Questions