Heart stuffs Flashcards
Pulmonary circuit
Pumps deoxygenated blood from heart to lungs and returns O2 rich blood from lungs
systemic circuit
pumps O2 rich blood around body and returns O2 poor blood to heart
fibrous pericardium
outer layer of heart that provides strength and resistance
serous pericardium
contains two laters visceral (epicardium) and parietal layer outer layer
pericardial cavity
between the two layers of serous pericardium (visceral and parietal) layer of fluid
Heart layers
-epicardium (visceral)
-myocardium
-Endocardium
Heart muscle tissue
They are interconnected (intercalated discs)
-very high in mitochondria and myoglobin
-also very vascularized
Functional syncytium
Group of heart muscle cells that function together as result of their gap junctions
Conduction fibers
Very rapidly project APs through the myocardium
Sinoatrial node
SA node is superior in the right ventricle and is the “pacemaker”
Atrioventricular node
AV node passes on signal but adds delay for atrial contraction
Conduction pathway
1.SA node
2.Internodal pathway to AV
3.AV delay
4.Atrioventricaular bundle (bundle of His)
5.Splits right and left
6.Purkinje fibres reach far sections of ventricle
Phase 0
Increased Na+
Phase 1
Na+ permeability stops
Phase 2
Ca+ fast channels open
K+ close
Phase 3
K+ channels open for fast repolarization
Ca+ channels close
Phase 4
Resting potential
Heart efficiency variability
ANS effects SA, AV node to effect rate and cardiac cells and muscle to effect force