cardiac muscles excitation contraction coupling

excitation

involves AP conduction

contraction

involves presence of ca+

AP’s are conducted along where

the sarcolemma

sarcolemma → T tubules

@ T Tubules they activate & open DHP receptors

what are DHP receptors at the skeletal muscle called

L-type Ca++ channels

open DHP Receptor

allows external ca+ intro cardiac cell

external ca+ in cardiac cell

activates ryanodine receptors type 2

DHP receptors and ryanodine receptors

not directly connected

(not coupled)

ryanodine receptors activated from external Ca+ is described as what

calcium-induced calcium release

Ca++ from SR

binds to troponin which stimulates cardiac muscle contraction

difference of R receptor activation in skeletal muscle and cardiac muscle

skeletal muscle: DHP directly opens R receptor

cardiac muscle: external Ca++ from DHP directly opens the R receptor