CV system: The Heart Session 2 Flashcards
What is the role of the pericardium and how many layers does it have?
Protects the heart. 1 fibrous and 2 serous layers that form the pericardial sac
Inflammation of the pericardium is called…
Pericarditis
What part of the heart has the thickest muscle?
Left ventricle
Describe the internal anatomy of the heart
The atria are separated from the ventricles via valves
Angioplasty
A catheter is passed through the femoral artery, a stent is placed at site of blockage in coronary artery; removes the blockage causing angina
Which of these are oxygenated? A. Pulmonary arteries B. Pulmonary veins C. Aorta and branches D. Vena cava
B. Pulmonary veins
C. Aorta and branches
What is the significance of intercalated discs
They allow electrical impulses to jump across cells quickly for synchronous contractions
What element is the strength of contraction dependent on?
Ca++. Ca++ leaking out of t-tubule is very important.
Describe the 3 steps of Ventricular AP Plateau
Step 1. Fast Na channels open, causing the potential to be more positive and depolarize
Step 2. Slow Na and Ca channels
Step 3. K channels open so sodium can go back out, repolarization
Components of intrinsic conduction system:
SA node Internal pathway AV node AV bundle Left and right bundle
Do the SA node fibers contract?
No
What is special about the SA node cell membranes?
They are leaky to Na and Ca ions, giving it a less negative resting membrane than other cardiac mm cells. Allows for easier self-contraction
