Exam 4 Lecture 1 Flashcards
Lower part of the heart, per lecture
Ventricles
What is Phase 2 of Cardiac AP
Plateau Phase: Ca++ influx via L-Type Ca++ channels; K+ channels still closed/closing [decreased permeability]
What is the Subendocardium
*What could happen here and why
Super deep muscle layers where a MI would probably happen [increased wall/chamber pressures]
What is the Epicardium
*What sit on these and go deeper into the heart
Outside wall of the heart; most superficial
*Vessels sit here and go deeper into the heart
How do Myocytes communicate with each other?
Gap Junctions
How many nuclei/nucleus do each myocyte have?
1 nucleus
What is the Parietal Pericardium
Inner, stretchy layer
Ionic Current is dependent on? 2 things
CG/ electrochemical gradient and Amount of Ion channels
How long is a Cardiac AP
around 200 ms
What is the Myocardium
Bulk of Muscle Wall
What are the Parts of the Pericardium
Epicardium, Pericardial Space, Parietal, Fibrous
What is the Pericardium
The connective tissue sac that covers the heart
Are ACE and ARBS safe in pregnant women?
No, mess w RAAS system and are teratogenic
What are Cardiac Stem cells?
*Fast or slow process
Patching areas of dying cells; slow process
What are cardiac fibroblasts?
*When are they activated?
*What disease process is a result of increase fibroblasts?
*Tx for this disease process
Lay down scar tissue
*Activated when stem cells are overwhelmed; can also lay down unnecessary scar tissue
*CHF from increased scar tissue = decreased conductance
*Tx: ACE and ARBS [Teratogenic]
What is a way to cause a AV HB in a pt?
*What type of surgery
*What CN are involved
*Pathophys of this
Eye muscle reflex due to eye surgery
*V [trigeminal] + X [vagus]
*Sensory perception in eye socket, sends input to brain, vagus nerve then signals massive vagal output, which prevents AP in AV node [wait 30 sec to get HR back]
Purkinje Fibers
*VRM
*Threshold Potential
*What does it rely on to fire an AP
-90 mV; Threshold is -70 mV
*Can SLOWLY fire own AP, but mostly relies on upstream AP to help fire AP