Week 2 Flashcards
Describe the role of intercalated discs and gap junctions in cardiac excitation
*2 things
anchor cardiac cells together and allow free passage of ions via gap junctions
allow heart muscle to behave as functional syncytium
Differentiate between the primary roles of contractile and conductile myocytes
Contractile:
contraction
Conductile:
initiation and conduction of AP signals thr the heart.
Discuss the events associated with a wave of excitation spreading thr the conduction system
k
Explain why there is a delay in th AV node
l
Describe automaticity and evaluate the underlying ionic currents
l
Describe the 4 phases of the cardiac action potential
k
Compare and contrast action potentials in myocytes from different parts of the heart
j
Compare and contrast activation, inactivation recovery from inactivation and closing the ion channels (deactivation)
k
Explain absolute and relative refractory periods
o
Explain how parasympathetic and sympathetic nervous systems modulate heart rate, conduction velocity thr the AV node, and contractility
k
Describe what stimulates cardiac muscle
nerves and automaticity (self excitable
Where could you find autorhythmic cells and what do they initiate?
SA node
action potentials
Thr which pathways do action potentials move the to other heart regions?
via intrinsic conduction
Contactile/Conductile:
- Which has a stable RMP and needs to be activated?
- Which has greatly reduced contractile proteins?
- Which can also conduct via gap junctions
- Which has an unstable RMP and what is this also kown as?
- The action potential generation is an intrinsic property of the cell?
- Contractile
- Conductile
- Contractile
- Conductile, pacemaker potentials
- Conductile
Identifiy the conduction system
*5
j
